AECL-5959/2

ATOMIC ENERGY W É F & L'ÉNERGIE ATOMIQUEOF CANADA UMITED E f i j F DU CANADA LIMITÉE

REPORT BY THECOMMinEE ASSESSING FUEL STORAGE

PART 2: APPENDICES

| Edited by W. W. Morgan

Whiteshell Nuclear Research Establishment

Pinawa, Manitoba, ROE 1LO

November, 1977

(work completed 1972-1974 )

ATOMIC ENERGY OF CANADA LIMITED

REPORT BY THECOMMITTEE ASSESSING FUEL STORAGE

PART 2: APPENDICES

Edited by W.W. Morgan

Whiteshsll Nuclear Research Establishment

Pinawa, Manitoba, ROE 1LO

November, 1977 AECL-5959/2

(Work completed 1972-1974)

Rapport du Comité d'évaluation du stockage du combustible

2ieme P a r t i e : Appendices

édité par W.W. Morgan

Résumé

On a envisagé divers concepts de stockage intérimaire pour

le combustible nucléaire irradié. Des études préliminaires ont été faites

et des devis estimatifs ont été préparés pour les concepts suivants: deux

à refroidissement par eau - stockage prolongé en bassin près d'une centrale

nucléaire et stockage en bassin dans un établissement central; trois à

refroidissement par air dans un établissement central - "cartouche en béton",

"cavité à convection" et "cavité à conduction" - et un projet de stockage

souterrain dans du sel gemme. Les coûts estimés en dollars de 1972 compren-

nent les frais de transport et un fonds destiné à l'entretien perpétuel et

au renouvellement périodique des installations de stockage. La 1 Partie

de ce rapport est le sommaire des résultats obtenus. La Partie 2 donne des

précisions au sujet des concepts et des méthodes employés pour évaluer les

coûts. Les coûts de tous les concepts étudiés se sont révélés modestes

puisqu'ils ne s'élèvent qu'à environ 0.1 m$/kWh dans le coût unitaire de

l'énergie. Les avantages et les inconvénients des différents concepts sont

comparés entre eux.

L'Energie Atomique du Canada, Limitée

Etablissement de Recherches Nucléaires de Whiteshell

Pinawa, Manitoba, ROE 1L0

Novembre 1977

AECL-5959/2(Travaux effectués de 1972 à 1974)

REPORT BY THE COMMITTEE ASSESSING

FUEL STORAGE. PART 2: APPENDICES

Edited by W.W. Morgan

ABSTRACT

Various concepts for interim storage of spent nuclear fuel have

been considered. Preliminary design studies and cost estimates have been

prepared for the following concepts: two with water cooling - prolonged

pool storage at a generating station and pool storage at a central site - ,

three with air cooling at a central site - "canister", "convection vault",

and "conduction vault" - and one underground storage scheme in rock salt.

Costs (1972 dollars) were estimated including transportation and a perpetual

care fund for maintenance and periodical renewal of the storage facility.

Part 1 of this report summarises the findings. Part 2 provides details of

the concepts and costing methods. All concepts gave moderate costs providing

a contribution of about 0.1 m$/kWh to the total unit energy cost. Advantages

and disadvantages of the respective schemes are compared.

Atomic Energy of Canada Limited

Whiteshell Nuclear Research Establishment

Pinawa, Manitoba ROE 1L0

November, 1977 AECL-5959/2

(Work completed 1972-1974)

FOREWORD

by

M. Tomlinson

This report covers certain aspects of an early phase in the

formulation of the program for long-term management of nuclear waste.

Since the material was of an exploratory and preliminary character, the

report was prepared with a view to internal use only and was initially

issued as an internal report. Since then, we have reported our findings

in various publications. Because of recent widespread interest in interim

fuel storage, the entire report is being published so that the full details

of the work may be generally available. It should be noted that consider-

able further evolution has occurred in concepts and strategies of spent

fuel management so that those depicted here do not necessarily correspond

with those of the present. The hereditary influence is nevertheless

powerful.

Individual authors are indicated in those sections which were

primarily the work of the one or two individuals named. Other sections

were the work of many people or of the committee as a whole.

MEMBERSHIP OF CAFS

S.R. Hatcher

W.W. Morgan

J.A. Morrison

W.R. Taylor

J.C. Tremblay

A. Duchesne

R.W. Barnes

I. Lauchlan

ff.M. Campbell

D. Radojkovic

D.R. McLean

J.R. Coady

M.M. Ohta

R.V. Baker

WNRE, Chairman (-1)

WNRE, Chairman

CRNL

CRNL

Hydro Quebec

Hydro Quebec

Ontario Hydro

Ontario Hydro

PPSP

PPSP

WNRE

WNRE

WNRE

WNRE, Secretary

Many others made significant technical contributions. The

work of E.W. Fee, PPSP, R. MacFarlane, WNRE, C. Purdy, CRNL, S.C. Bhatia,

a CIDA fellow from the Bhabha Laboratories, and R. Wilson, Ontario Hydro,

was particularly helpful.

01) S.R. Hatcher was the original chairman of CAFS, but resigned in June

1973 to carry out a special assignment at Bruce Heavy Water Plant.

CONTENTS

Page

APPENDIX A GROUND RULES AND DATA REQUIRED FOR THE A-lCAFS STUDY

1 GROUND RULES A-l1.1 General Conditions for the

Storage of Spent Fuel A-l1.2 Scope of the Present Investigation A-21.3 The Fuel A-21.4 Financial Aspects A-21.5 Siting A-3

APPENDIX B TECHNIQUES USED IN ESTIMATING STORAGE COSTS B-l

1 ESTIMATION OF STORAGE CHARGES, $/kg U B"l1.1 Derivation.of Storage Cost Equation B-l1.2 Comments on the Use of the Storage B-5

Cost Equation2 ESTIMATION OF INVESTMENT REQUIRED IN B-6

PERPETUAL CARE FUNDS2.1 Derivation of Sinking Fund Equation B-62.2 Form of Equation for Future B-7

Operating Costs2.3 Form of Equation for Withdrawals at B-8

50 Year Intervals2.4 "F" Values for 100 Year Care and B-9

Perpetual Care2.5 General Comments on the Use of B-9

Perpetual Care Funds

APPENDIX C THE TOXIC LIFE OF SPENT CANDU FUEL C-l

APPENDIX D STORAGE OF SPENT FUEL IN WATER-FILLED BASINS D- 1AT A CENTRAL SITE

1 GENERAL DESCRIPTION D- 12 COST SUMMARY D-3

2.1 Summary of Capital Costs D- 32.2 Storage Baskets D-42.3 Summary of General Operating Costs D" 42.4 Perpetual Care Costs D" 52.5 Levelized Costs, $/*kg U for Capital, D~ 6

Operating and Perpetual Care2.6 Shipping D- 6

2.7 Public Relations and Site Selection D-62.8 Total Costs for Management of Spent D-6

Fuel in Basins3 GENERAL COMMENTS ON POOL STORAGE D-6

APPENDIX E STORAGE OF SPENT FUEL IN WATER POOLS AT E-lREACTOR SITES

SUMMARY OF STUDY1.1 Introduction1.2 Design Basis1.3 Long-Term Facility1.4 Short-Term Facility1.5 Possible Design Improvements

SUMMARY OF COST2.1 Cost Estimate for Long-Term

Facility2.2 Cost Estimate for Short-Term

FacilitySAFETY ASSESSMENT3.1 Activity in Spent Fuel3.2 Containment of Activity3,3 Activity Release Paths

CONCLUSIONS AND RECOMMENDATIONS4.1 Conclusions4.2 Recommendations

SUPPLEMENTARY DATA5.1 Special Ground Rules for this

Project5.2 Design Criteria for Short-Term

Facilities

E-lE-lE-3E-6E-8E-9E^IOE-10

E-13

E-13E-13E-14E-14E-15E-15E-15E-16E-16

E-18

APPENDIX F STORAGE OF SPENT CANDU FUEL IN CONCRETE F-lCANISTERS

12

INTRODUCTIONGENERAL DESCRIPTION2.12.22.3

2.42.5

CanistersFuel Handling at the Reactor SiteFlask and Canister Handling at theCentral Storage SitePersonnel RequirementsOverall Schedule

COST SUMMARY3.13.23.33.4

3.5

Capital CostsAnnual Operating CostsPerpetual Care CostsLevelized Storage Price at CentralSite - $/kg UPenalty for Storage for Four ExtraYears

F-lF-lF-1F-2F-3

F-5F-5F-6F-6F-7F-7F-8

F-8

3.6 Shipping3.7 Development Costs3.8 Total Cost for Management of Spent

Fuel in Concrete CanistersGENERAL COMMENTS ON CANISTER STORAGE

F-9F-9F-9

F-9

APPENDIX G STORAGE OF SPENT FUEL IN LARGE AIR-COOLED VAULTS G-l

1 INTRODUCTION G-l2 REACTOR SITE OPERATIONS G-23 CENTRAL STORAGE FACILITIES G-34 CONVECTION SCHEME VAULT G-45 CONDUCTION SCHEME VAULT G-46 GENERAL STORAGE CONSIDERATIONS G-57 DEVELOPMENT REQUIRED G-68 ESTIMATED COSTS G-79 CONCLUSIONS G-8

APPENDIX H THE STORAGE OF SPENT CANDU FUELS IN SALT MINES

INTRODUCTIONGENERAL CONCEPTS2.1 Mine Layout

Mining OperationsWaste HandlingPersonnel RequirementsOverall Schedule

2.22.32.42.5

COSTS3.13.23.33.43.5

Initial InvestmentSalt Mining and Salt Disposal CostsSpent Fuel Handling CostsPerpetual Care CostsLevelized Costs, $/kg U for Capital,Operating and Perpetual Care

3.6 Penalty for Four Extra Years ofStorage

3.7 Shipping3.8 Development Costs3.9 Total Cost for Mangement of Spent

Fuel in Salt MinesGENERAL COMMENTS ON SALT STORAGEREFERENCES

H-l

H-1H-2H-2H-3H-3H-4H-5H-5H-6H-6H-6H-711-7

H-8

H-8H-8H-8

H-9H-12

APPENDIX I TRANSPORTATION1 INTRODUCTION2 DISTRIBUTION OF CANADIAN SPENT FUEL

ARXSINGS IN THE YEAR 20003 SHIPPING SYSTEM

3.1 General Assumptions3.2 Flask and Unit Train Requirements

1-11-11-1

1-11-21-2

COSTS1.4.1 Capital Costs1.4.2 Unit Shipping Costs1.4.3 Weighted Average Shipping Costs

for More Than One SiteSUMMARYRECOMMENDATIONS

1-21-21-21-3

1-41-4

APPENDIX J RETRIEVABILITY J-1

1 INTRODUCTION J-12 PROJECTED ARISINGS OF SPENT CANDU FUEL J- 23 STORAGE REQUIREMENTS J-34 CONSEQUENCES OF REHANDLING J- 45 EMERGENCY RETRIEVAL J-4

J.5.1 Standby Storage J-5J.5.2 Relocation Time J- 5

6 OBSERVATIONS J-6

A-l

APPENDIX A

GROUND RULES AMD DATA REQUIRED FOR THE CAFS STUDY

1. GROUND RULES

A great deal of attention was given to arriving at an

acceptable set of ground rules for the project.

The main aim was to tie all the separate studies together,

giving them a common set of guidelines. Some of these were derived

directly from the report of the Radioactive Waste Management Committee

while others were arrived at during the meetings.

The ground rules are summarized below:

It was recognized that special sub-sets of rules might have to be

introduced for specific design studies, for example, a stipulation with

regard to water table could not be made that would satisfy engineered

storage both on the surface and in a salt bed.

1.1 GENERAL CONDITIONS FOR THE STORAGE OF SPENT FUEL

1. In all studies, safety will be the prime concern.À full safety analysis is not required for the initialstudies but obvious accident occurrences should be bornein mind. These should be documented in order to assistthe later safety analyses.

2. The fuel will not be reprocessed.

3. The stored fuel must be retrievable.

4. Release of active solids, liquids, and gases to theenvironment must be as small as possible.

A-2

5. Ownership and operation of the storage facility will beassumed to be under control of the Federal Government.

6. Ownership of the fuel will be transferred from the utilityto the government at the reactor site.

1.2 SCOPE OF THE PRESENT INVESTIGATION

1. Only fuel discharged up to the year 2000 will be consi-dered.

2. All the fuel will be stored at one central site.

3. All known defected bundles will be canned before storage.

4. It must be possible to locate and can bundles which defectduring storage.

5. Adequate and sufficient supervision of the facility willbe provided at all times.

1.3 THE FUEL

X. Standard Pickering type fuel will be used.

2. Burnup will be taken as 9000 MW.d/Mg U.

3. All fuel will be cooled for one year at the reactor site.The cost of any extra cooling required by a particularmethod will be included in the price of that method.

4. The quantities of fuel involved will be as shown in Table 1.

5. The heat characteristics of the fuel will be as shown inFigure 1.

1.4 FINANCIAL ASPECTS

1. A perpetual fund must be set up to allow for maintenancesurveillance and replacement of the facility as necessaryin perpetuity.

See the note on perpetual care funds in Appendix B.

2. The cost will be expressed as a levelized price so as tobe independent of the date of storage.

A-3

3. All money used for capital will be borrowed at 7%.

4. Money invested up to the year 2000 will be at a 7% return.

5. Escalation during construction will be 4% per annum.

6. Interest on the perpetual fund beyond 2000 will be 7% perannum.

7. Escalation beyond 2000 will be at 4% per annum.

8. All values will be expressed in 1972 Canadian dollars.

1.5 SITING

1. The location of the central storage site will be definedby taking a fixed shipping charge FOB the storage site.

2. Access by road and rail and availability of power can beassumed.

3. Optimistic conditions can be assumed for items such aswater table, excavation, and foundations.

REFERENCE

CO H.B. Merlin, Energy Consumption its Growth and Pattern, Atomic Energy

of Canada Limited Report, AECL-3293, March 1969.

A-4

TABLE 1

ACCUMULATION OF SPENT CANDU FUEL TO THE YEAR 2 0 0 0 ^

Date

1971

1972197319741975

197619771978(ii)19791980

19811982198319841985

19861987198819891990

19911992199319941995

19961997199819992000

Quantity of 1-Year-Cooled

Fuel to be Stored at Central Site (Mg)

Annual

23

5496

154239

324401471556648

741895

104912341466

16981975226925772917

32413627401243214706

50155324563259416327

Cumulative

23

77173327566

8901291176223182966

37074602565168858351

1004912024142931687019787

2302826655306673498839694

4470950033556656160667933

Note: (i) Based on nuclear power forecasts by Merlin in 1969 .

(ii) The first shipments of spent fuel are to be received at thecentral site in 1978. Spent fuel produced prior to that datewill be stored temporarily at reactor sites. The backlog willbe shipped to the central site over a 5 year period beginningin 1978.

DECAY HEAT (watts/ Mg U)

omo

S70(A

m §_ o

c

nCm

toooo

c

B-l

APPENDIX B

TECHNIQUES USED IN ESTIMATING STORAGE COSTS

1. ESTIMATION OF STORAGE CHARGES, $/kg U

1.1 DERIVATION OF STORAGE COST EQUATION

1.1.1. PRESENT WORTH CONCEPT

The present worth concept was used to calculate the storage

charges for spent fuel from basic capital, operating and perpetual care

cost data. It is a concept frequently used in economic evaluations and

provides the basis for a simple algebraic relation between income and

cost. The basis is the time value of money.

Consider for example, a $1 million expenditure to be made 10

years hence. Assume an investment is to be made at time zero, earning

interest at 7% compounded annually, to cover this cost. The size of the

investment required is:

$1 million x = $0.5 million

C1.O7)10

The $0,5 million is the net cost expressed at time zero or the "present

worth" of the future expenditure.

If expenditures are to be made at different dates in the

future, the present worth of each one can be determined in a similar

manner. The results may then be summed to get the combined present

value of these future expenditures.

B-2

In a similar way, the present value of future incomes may be

calculated. If these incomes are to be used to pay future costs, the sum

of their present worths should equal the present worth of the future

expenditures. This may be expressed algebraically as:

EPWIncomes= ZPWCosts ^

This is the basic relationship used to calculate storage charges for spent

fuel.

1.1.2 PRESENT WORTH OF INCOME FROM FUEL ARISINGS

At a fuel storage site, the income in any year "n" taay be

expressed as follows:

I = S x F 1.2n z n

where I = income in year "n", S = storage price, $/kg U, in time zeron zdollars and F = fuel arisings, kg U, in year n.

The present worth of all the future incomes then becomes:

ZPWT = PW(S F ) + PW (S F ) + (S F ) + PW (S F ) 1.3Incomes z o z i z z z t

where t = year in which the site is filled with fuel and hence is the

final year in which there is income from fuel arisings.

Equation 1.3 can be rearranged:

EPWIncomes = Sz[PW(Fo) + P W ( V + PW(F2>+---+ P W < V ] 1.4

= Sz(£PWF) 1.5

1.1.3 PRESENT WORTH OF STORAGE SITE COSTS

The basic costs incurred at the storage site are capital,

operating and perpetual care. Capital and operating expenditures occur

B-3

over the site filling period. Perpetual care costs are treated as a lump

sum expenditure required in the final year of the filling period to set

up a sinking fund to take care of all future costs. The method used in

calculating the size of fund required is described in Section 2 of this

appendix. The equation for the present worth of the costs is:

PW = ZPW + ZPW + PW n ,

costs c o p 1.6

where the subscripts c, o and p refer to capital, operating and perpetual

care respectively.

Substituting equations 1.7 and 1.6 in equation 1.1 and solving

for S yields

ZPW + ZPW + PWS =z F

The denominator is the sum of the present worth of the fuel arisings

which has no meaning in an economic sense but is valid in an algebraic sense.

1.1.4 ALLOWANCE FOR ESCALATION IN PRESENT WORTH ANALYSES

Normally in present worth analyses, escalation of costs is

ignored because of the difficulty in forecasting escalation trends. It is

assumed that all costs and incomes will escalate at the same rate, and

therefore the effects of escalation cancel out. This assumption however

is not always valid.

If, in the example of the $1 million expenditure discussed

earlier, costs escalate at the rate of 4% per year, the investment required

at time zero to cover the escalated cost would be

(1 04^10

$1 million x KX'W ' = $0.74 million

(1.07)ao

Thus, an additional $0.24 million is required in the initial investment.

It should be noted in this calculation that the escalation and

interest factors appear as a ratio, 1.04/1.07. The value of this ratio is

primarily dependent on the net difference between the two rates rather than

on absolute values. This is illustrated in Table 1.

Thus in spite of substantial variations in i and e, for a fixed

net difference, the value of the ratio (TZT)11 i s essentially a constant.

This is further illustrated in Table 2 when the net difference is fixed

at 2%.

This observation eases one of the difficulties in making economic

evaluations, which is choosing suitable escalation and interest rates. The

task becomes one of estimating a reasonable value for the net difference,

or determining the sensitivity to different values of the net difference.

The change in the value of the ratio (TTT) 1 0 is illustrated in

Table 3 for a difference of 2%, 3% and 4%. Even here the effect is not large.

1.1.5 FINAL FORM OF STORAGE COST EQUATION

After analyzing the cost data for one of the storage schemes,

it became evident that an allowance should be included for escalation.

Including escalation effects, the final detailed form of equation 1.8 for

calculating the storage price is:

n=t .. n n=t£ C (4rf) + S Czn 1+i

s _ n=o n^o 1.8z

where S = storage price, $/ kg U, in time-zero dollars that will escalateat the same rate as costs,

Z • indicates time-zero dollars,

n = number of years from time zero. Time zero is the date used forestimating costs in fixed-time dollars. It may or may not bethe same date that the first shipments of spent fuel are shippedto the site. (For CAFS studies it was assumed that the firstfuel is shipped in ,1978, six years beyond time-zero).

B-5

t = number of years elapsed from time zero until all the storagefacilities at the site are filled (i.e., 28 years from 1972 toyear 2000 or from 1982 to 2004 for CAFS studies).

C = capital costs in time-zero dollars spent in year n.

0 = operating costs in time-zero dollars spent in year n.

P = size of perpetual care fund expressed in time-zero dollars thatz will be required in year t (year 2000 or 2004 for CAFS studies)

to cover all future costs including future escalation. Themethod used for estimating F is described in Section 2 ofthis appendix. z

F = fuel, kg U, placed in storage in year n.

e = annual escalation rate, % (used in equation as a decimal fraction).

1 = annual interest rate, %, for both borrowed and invested money(used in equation as a decimal fraction).

1.2 COMMENTS ON THE USE OF THE STORAGE COST EQUATION

( 1. To utilize equation 1.8, a schedule of spending expressed in! time-zero dollars is required. The use of time-zero dollars: in the schedule provides an indication or measure at any time. of the quantity of goods and services being purchased. However,: for borrowing or investment purposes, it is necessary to usej real dollars since interest charges or earnings in actualI practice are based on the flow of the actual number of real' dollars. Time-zero dollars are automatically converted to real

dollars in the equation assuming escalation at e% per year.

2. Capital expenditures for any phase of site development must beshown on an annual basis and not as a Jump sum at the end ofeach construction period. The costs must be expressed in time-zero dollars without any allowance for escalation or interestcharges during construction. These charges are automaticallyincluded in the equation.

3. The expenditure required for perpetual care is shown as a singleitem, P , in year t (i.e., the year in which all the storagefacilities are completely filled). The equation is based onthe premise that surplus funds (i.e., excess of income overexpenses) are invested each year at interest rate i and thatthe total surplus funds plus interest earnings will equal therequired amount of real dollars in year t for perpetual care.

B-6

4. The net difference between interest and escalation rates chosenfor CAFS was 3%. This was arrived at from a comparison of thecorporate borrowing rates and inflation rates in the CanadianGross National Product over a period extending from 1926 to 1969.The average net difference over this 43 year period was 3%.The absolute values of interest and escalation rates used inCAFS as specified in the ground rules is 7% and 4% respectively.These values are low compared with current rates, but we assumedthey would be more realistic for the long term than the currenthigh rates. In any case it is the net difference between theinterest and escalation rates that really matters. Our mainconcern was to adopt a standard approach for estimating thestorage price for all the storage schemes for comparisonpurposes.

5. A breakdown of the storage price, S , to determine the relativecharges for capital, operating and perpetual care can be obtainedby dividing the present worth of each of these main cost itemsby the total present worth of all the costs.

6. A computer program was prepared by the Systems Analysis Branchat WRNE utilizing this type of equation for the calculation oftotal unit energy costs for power produced by nuclear reactors.This program can also be used to calculate tne storage price forspent fuel by adjusting the inputs.

2. ESTIMATION OF INVESTMENT REQUIRED IN PERPETUAL CARE FUNDS

The present worth technique discussed in Section 1 of this

appendix is also utilized here. A general equation is derived for a

sinking fund from which withdrawals may be made at regular intervals.

2.1 DERIVATION OF SINKING FUND EQUATION

Once a storage site hafc beefc filled with spent fuel, there is

no longer any new income. One way of paying for future costs of surveillance,

maintenance and other costs is through the establishment of sinking funds

which will generate sufficient interest earnings to cover these costs as

they escalate with time. Assuming that future costs can be estimated in

fixed-time dollars and occur at regular intervals, the sum of the present

worth of these costs is the size of investment required to meet them.

B-7

Let P = present worth of future costs = principal to be invested initially,

C = cost, in fixed-time dollars,, to be paid out in intervals,

H = interval in years between payments,

n = number of payments to be made,

e = annual escalation rate - % (use in equation as decimal fraction),

i = annual interest - % earned by fund (use in equation as a decimal

fraction),

R = ratio of escalation and interest = TTT, e.g. y Tyr»

F = ratio of P to C i.e. F = P/C.

Then

or P = C(RA + Rz£ + R3* +...-Rnl) 2.1

The R terms in this equation form a geometric progression with

an initial term of R and a multiplier of R for which the sum is

1-R*

Thusi-r-

This is the general form of the equation and it may be observed

tnat the size of the fund P, is a function of the ratio of ~T+t' A s shown

in section 1, the value of this ratio is primarily dependent on the net

difference between the interest and escalation rates and not on the absolute

values. Thus the size of the initial investment is essentially a function

of the net Interest rate (i-e).

2.2 FORM OF EQUATION FOR FUTURE OPERATING COSTS

Assuming annual withdrawals are made from a sinking fund, P ,

to cover annual operating costs, C , then

B-8

and P = C U\~l } 2.3o o 1-R

or P = P F (Note P and C are expressed in time-zero dollars).o o o o

The sensitivity of F and hence P to the length of time in the

future over which operating costs must be paid and their sensitivity to

different values of i-e are shown in Table 4.

For a given value of n as i-e increases, F and therefore P

decrease. This effect is expected. Larger values of i-e mean larger net

interest rates and as a result the size of the initial investment required

is reduced. For conservative estimating purposes it is better to pick a

value of i-e that is on the low side to ensure that sufficient funds are

invested initially.

For a given value of i-e, the F value increases as n, the life

of the fund, increases up to 200 years. Leyond that time F is essentially

constant. Thus the size of sinking fund required for perpetual care is

nearly the same as that required for 200 years of care.

reduces to

For the case of perpetual care(n=»), R — K ) , and equation 2.3

C R o .

„ = _g . 2.4o 1-1R

2.3 FORM OF EQUATION FOR WITHDRAWALS AT 50 YEAR INTERVALS

In the surface storage schemes studied by CAFS, a vault service

life of 50 years was assumed. Therefore a sinking fund is required that

will pay the cost of replacing site facilities at 50 year intervals. For

this case, £«50 and equation 2.2 becomes

B-9

or P r = C r x F 5 0

where C = replacement cost in time-zero dollars for replacingr facilities at each 50 year interval.

For use of a particular scheme in perpetuity, n*°° and R K),

and equation 2.5 becomes

R 5 0

P = C -S-^TT 2.6r r 1-R50

2.4 "F" VALUES FOR 100 YEAR CARE AND PERPETUAL CARE

In the CAFS study, sinking funds for all future costs were

calculated assuming a 3% net difference between escalation and interest.

The corresponding F values for funds set up to care for wastes for a

period of 100 years, and for perpetual care are shown in Table 5.

2.5 GENERAL COMMENTS ON THE USE OF PERPETUAL CARE FUNDS

1. It is important to recognize that perpetual care costs derivedin the manner described above are theoretical costs based on aset of assumptions about future costs, interest rates andescalation rates. They provide one means of determining thecost of managing wastes for their hazardous life. This techniquealso provides a basis for comparing the future costs of differentstorage schemes.

2. Establishment of perpetual care funds provides a method wherebycharges for waste management could be placed against the cost ofproducing electrical power at the time it is produced.

3. The use of sinking funds to pay for future costs is not withoutprecedent. Two common examples are life insurance and pensionfunds. However, the time scales involved are drastically different.It is not credible to assume that perpetual care funds could bemanaged successfully over the hazardous life of spent fuel. Inview of this factor, geologic storage schemes are very attractivesince it appears that operating and surveillance costs may benegligible once mines have been backfilled and sealed.

B-10

TABLE 1

3% NET DIFFERENCE BETWEEN ESCALATION AND INTEREST

e %

i %

Comparison:

0.

0.

2

5

7484

995

0.

1.

4

7

7525

00

0.

1.

6

9

7565

005

0.

1.

8

11

7603

01

TABLE 2

2% NET DIFFERENCE BETWEEN ESCALATION AND INTEREST

e %

i %

1+e 1 0

Comparison:

0

0

2

4

.8235

.996

0

1

4

6

.8265

.00

0.

1.

6

8

8295

003

0

1

8

10

.8323

.007

TABLE 3

COMPARISON

e %

i %

(~\"

Comparison

OF

0.

1.

2%, 3%

4

6

8265

1

AND

0

1

4% NET

4

7

.7525

.0

DIFFERENCE

4

8

0.6856

.91

B-ll

TABLE 4

"F" VALUES FOR ANNUAL OPERATING COST FUND

Life of FundCYears)

n

50100200

Values of "F"

i-e=0.02

32.67 '"45.3952.2753.49

i-e=0.03

27.0633.5935.5435.66

i-e-0.04

22.7626.1626.7326.74

TABLE 5

"F" VALUES FOR 3% NET DIFFERENCE BETWEEN INTEREST AND ESCALATION

Time Interval BetweenWithdrawals from Fund

Of ears)

125102050

100

F Factor

100 YearCare

32.715.96.142.871.230.300.058

PerpetualCare

35.716.96.523.051.310.3180.062

C-l

APPENDIX C

THE TOXIC LIFE OF SPENT CANDU FUEL

The activity of spent fuel diminishes with time and therefore,

in general, so does the toxicity. This raises the possibility that at

some time in the future the fuel may no longer be considered a potential

hazard.

The period of time for which spent fuel is considered a potential

hazard has been defined as the "toxic life" of the fuel. It is necessary to

have an appreciation of how long this might be in order to determine the kind

of precautions that must be taken to ensure its containment.

One method of assessing the toxic life is to compare the toxicity

of spent fuel, at various times to the toxicity of other similar materials

such as natural uranium and uranium mill tailings. Such comparisons take no

account of the consequences of a release of spent fuel to the biosphere nor

do they consider the pathways by which a release might take place. They can,

however, provide a useful perspective for assessing, on a weight for weight

basis, the toxicity of spent fuel in relation to materials which are more

familiar and for which the need for special precautions is well recognized.

The toxicity of radioactive materials is usually measured in

terms of the volume of water or air that would be required to dilute a given

amount of the material to the maximum concentration allowed for the general

public. Graphs of this toxicity index versus time for CANDU fuel are shown

in Figures 1 and 2. Both graphs show that fission product decay is

essentially complete In less than 1000 years. This is because the principal

components, strontium-90 and cesium-137, have half-Jives of t>30 years.

Actinide activity, however, is of much longer duration;, due to the plutonium

and americium present, and reaches a minimum in about 250,000 years. This

\

C-2

level is then maintained for many millions of years; in the case of air

toxicity, for over a thousand million years.

As indicated in Figures 1 and 2, and Table 1, the toxicity of

irradiated fuel eventually reaches the same level as that attained by un-

irradiated fuel. This occurs after approximately a quarter of a million

years when the toxicity of both materials is essentially that of uranium-238

in equilibrium vith its daughter products. At this level they are as much

as 100 times more toxic than freshly separated uranium and up to 2000

times higher in toxicity than uranium ore. Perhaps the most significant

comparison that can be made, however, is with respect to the tailings produced

from uranium mining operations. The lowest level of toxicity ever reached

by Irradiated fuel is still as high as 2000 times the toxicity of the tailings

pile created at the mine when the uranium was first produced. The problems

associated with the containment of these piles are well known.

The materials used in these comparisons are all potentially

dangerous in their own right and there are regulations covering their handling

and storage. The significance of the comparisons, therefore, is that at no

time is the toxicity of spent fuel lower than the toxicity of the other materials.

It is also significant that the lowest toxicity of spent fuel occurs only

after approximately a quarter of a million years.

There are other substances having chronic toxicity to which

spent fuel can also be compared. Examples of these, as shown in Figures

3 and 4, are the heavy metal poisons, lead and mercury. Both are well

known and both are widely distributed in the environment as pollutants.

These graphs should not be used to draw firm conclusions as to the relative

hazards of radioactive and non-radioactive materials. They do demonstrate,

however, that when these different materials are compared, using the same

units, they appear to be similar in potential hazard. This is in contrast

to the popularly held belief that radioactivity demands far greater attention

than any other form of toxicity.

^Average values obtained from the ratios given in Table 1.

C-3

The graphs also clearly show that while some amelioration of

the total potential hazard present in radioactive materials can be expected

with the passing of time, no such change occurs with elemental poisons.

Their toxicity, with which society seems to have come to terms, remains

the same forever.

Although spent fuel undergoes a significant reduction in

toxicity, eventually reaching a level which in the case of water is well

below that of both mercury and lead, it is obvious that it never really

reaches a level that could be considered non-hazardous. As shown in Figure

1, even when the long lived uranium has all decayed, stable lead isotopes

produced from the uranium still represent a significant potential hazard.

It is clear, however, that after about 250,000 years there is no longer

any decrease in toxicity. Therefore, with these considerations in mind,

the toxic life of spent CANDU fuel can be said to be at least a quarter

of a million years.

C-4

TABLE 1

COMPARISON OF TOXICITIES*

SPENT FUEL; UNIRRADIATED FUEL; ORE; TAILINGS

a)

b)

c)

d)

e)

F u e l ( 2 1 6 M W h / k g )( 0 2 5 0 , 0 0 0 a )

S e p a r a t e d U r a n i u m( @ t i m e z e r o )

S e p a r a t e d U r a n i u m( < 3 2 5 0 , 0 0 0 a )

U r a n i u m O r e( @ 2 5 0 , 0 0 0 a )

T a i l i n g s ( 9 5 % E x t r a c -t i o n ( @ t i m e z e r o ) )

R A T I O S

a/b

a/c

a/d

a/e

W A T E R

SOLUBLE(mVkg)

3.2

6.4

3.4

4.4

4.3

50

0.9

730

740

x 1 0 "

x 1 0 z

x 1 0 1 *

x 1 0 1

x 101

T O X I C I T Y I N D E X

INSOLUBLE(mVkg)

1.2

2.0

8.0

6.0

6.0

6.0

1.5

20

20

x 1 0 2

x 1 0 2

x 1 0 1

S O L U B L E(mVkg)

1 . 2 . x 1 0 1 0

1 . 3 x I f , 8

4 . 8 x 1 0 9

5 . 6 x 1 0 6

5 . 4 x 1 0 6

96

2»6

2 1 0 0

2 2 0 0

AIR

I N S O L U B L E( m 3 / k g )

1 . 6 x 1 0 9

1 . 5 x 1 0 8

1 . 3 x 1 0 9

1 . 7 x 1 0 6

1 . 5 x 1 0 6

11

1.3

940

1 1 0 0

* C A N I G E N , J u n e 1 9 7 4

** D i l u t i o n r e q u i r e d t o r e d u c e 1 k g o f m a t e r i a l t o m a x i m u m p e r m i s s i b l ec o n c e n t r a t i o n i n w a t e r o r a i r a s r e c o m m e n d e d b y t h e I n t e r n a t i o n a lC o m m i s s i o n o n R a d i o l o g i c a l P r o t e c t i o n ( I C R P ) f o r t h e g e n e r a l p u b l i c .

*** " T y p i c a l " u r a n i u m o r e i s a s s u m e d t o c o n t a i n 0 . 1 % u r a n i u m a n d 0 . 0 3 % l e a d .

103 - r

102 - r

101

10"2

T| I"mTTTT| ' ' ' Mill)

•TOTAL (ACTINIDES + FISSION PRODUCTS)

i ii in>| r-rr f Mill I I I TTTTa

SPENT FUEL - ACTINIDES

SPENT FUEL - FISSION PRODUCTS

FRESHLY SEPARATEDNATURAL URANIUM

r URANIUM ORE

103

TIME (years)

FIGURE 1. RELATIVE TOXICITY OF SPENT CANDU FUEL IN WATER

<o

1011 - r

1e9

) J nui) 1 ) i i)iii| i i r IIIIT] r i i riinj 1—i i iinrj 1—i mm) 1 i 11 ini[

TOTAL (ACTINIDES + FISSION PRODUCTS)

SPENT FUEL - ACTINIDES

SPENT FUEL - FISSIONPRODUCTS

: FRESHLY SEPARATEDNATURAL URANIUM

: URANIUM ORE

i i i j t u i l i ' ' ' i i f i f * ' l i t 1 1 1 ! * 1 1 i f i n lj — *»% •*• •103

11lira

108

TIME (years)FIGURE 2. RELATIVE TOXICITY OF SPENT CANDU FUEL IN AIR

IB3

«

BHU

I

i I I i 1 1 * 1 1 l \ IITTÏT —miTïïj 1 i ) rrrrrj f—i t u HTJ—i—rmrnrj 1—rnrmj—

,,TOTAL (ACTINIDES + FISSION PRODUCTS)

1 G T 1

10-2

SPENT FUEL - FISSION PRODUCTS

1J Ji.1 U 1 t 1 I M U.

MERCURY

LEAD

PENT FUEL - ACTINIDES

' i i i nul 1—I.IIHI,1 I L-LJJ

o

TIME (years)

FIGURE 3. RELATIVE TOXICITY OF SPENT CANDU FUEL IN WATER

>11 T T iTrriTj ;—rnrm—r~rrrrr.Ti—TT-rr T~T l~ !i l!j--

10 1 J -v-,TOTAL (ACTINIDES + FISSION PRODUCTS)

.SPENT FUEL - ACTINIDES

10,10

10s - j

10 s

SPENT FUEL - FISSION PRODUCTS

105

TIME ( y e a r s )

FIGURE 4 . RELATIVE TOXICITY OF SPENT CANDU FUEL IN AIR

D-l

APPENDIX D

STORAGE OF SPENT FUEL IN WATER-FILLED BASINS AT A CENTRAL SITE

by

D.R. McLEAN

1. GENERAL DESCRIPTION

The purpose of this study was to look at the application of

storage pools, as they are currently used at reactor sites, for use at a

central site. One variation adopted was the use of cooling towers rather

than lake or river water since it was believed this would give more

flexibility in the choice of a central site.

Since pool storage is generally a very familiar concept, only

a brief description of site facilities is provided. Costs are dealt with

at length since storage costs at a location apart from reactors are not

widely known.

An overall site plan and a detailed site plan for the storage

basin area are shown in Figure 1. The entire site, including a buffer zone

around the site proper and waste disposal grounds, covers an area 1.6

kilometres (1 mile) square. Eight storage basins are required. They are

arranged in two banks each of which contains one flask handling center with

two basins on each side. A water-filled transfer canal links each basin in

the bank with the others and with, the flask-handling center. Each basin

will hold 8,500 Mg of spent fuel and is designed to handle fuel that has

been cooled for one year at reactor sites.

D-2

It is assumed that the spent fuel is shipped by rail in 50 Mg

flasks containing a total of 3,840 kg U stacked in six Pickering-type

baskets C32 Pickering-type bundles per basket). A schematic drawing of

this basket is shown in Figure 2. The rail cars are moved into the flask

handling center where the flasks are monitored and then moved by crane into

a dry hot cell for unloading. The baskets are removed with a light crane

and placed on a trolley car which carries them underwater along the transfer

canal to the storage basin. At the storage basin the baskets are removed

by crane from the trolley car and placed in storage. The stacked baskets

are stored under a minimum of 4.3 m 0 3 ft.) of water to provide radiation

shielding for workmen handling the spent fuel. A flask-handling center

and a storage basin are shown in Figures 3,4, and 5.

Each basin is equipped with a primary cooling system to remove

radioactive decay heat from the spent fuel and a purification system to

remove activity from the water and to keep it clear for viewing purposes.

The flowsheets are shown in Figures 6 and 7.

The superstructure above each basin is continually purged with

ventilation air for humidity control and to remove hydrogen generated from

radiolytic degradation of the basin water. The ventilation air is heated

in winter to prevent condensation and/or frost buildup on the walls of the

superstructure and to maintain suitable temperatures in the area for workmen.

Normally, the exhausted air is not filtered but the basins are equipped

to filter all the air if necessary.

The main auxiliary systems at the site include:

1. A bank of cooling towers to supply secondary cooling water tothe primary basin cooling systems. The towers will handle amaximum flow rate of 190 m3/min, (50,000 gpm*) cooling it from29.4°C to 23.9°C. A flowsheet Is shown in Figure 8.

2. An oil-fired steam heating plant for heating the basin ventilationair and the other buildings on the site. Total steam raisingcapacity is 77 Mg/h at a gauge pressure of 590 kPa.

3. A water supply and treatment system to provide démineraiizedwater for the basins, to provide make-up to the cooling towers,and water for general usage. The flowsheet is shown on Figure 9.

*Gallons in this report refer to U.S. gallons

D-3

Emergency reservoirs located on the site will supply water forregular site operation for about two weeks or emergency coolingwater on a recirculation basis if the cooling towers fail.Total capacity of the water treatment plant is about 5.5 m3/min(approximately 1,500 gpm) .

4. An electrical distribution system and emergency dieselgenerators to ensure continued operation of the basin coolingand ventilation systems in the event of a power failure. Thetransformers at the main station on the site are sized tohandle a maximum load of 21,000 kVA. The total emergencypower generating capacity is 12,000 kVA.

5. Waste management facilities for domestic wastes, storm runoff,non-active chemical wastes, active liquid waste treatment, andactive solid and liquid waste disposal. When all basins arefilled, for example, approximately 700 m3 of active solidwaste will be generated per year.

Other site facilities include a maintenance shop, a warehouse,

a garage, a firehall, a gatehouse, fuel oil storage tanks, roads, railroads,

and mobile equipment (trucks, cranes, tractors, rail car puller, etc.).

The number of personnel required for regular site operation

ranges from 34 when the first basin is being filled to 70 when the last

two basins are being filled. A breakdown for the latter period is shown

in Table 1. These totals do not include manpower for major maintenance

work since this work is assumed to be handled by outside contractors. ji

A schedule for development of the site is shown in Figure 10.

The systems installed in each of the five phases are listed in the capital

cost summary.

2. COST SUMMARY

2.1 SUMMARY OF CAPITAL COSTS

These costs are summarized in Table 2. The construction costs

for all five phases of site development total $76 million and include

equipment, materials, labour for installation of equipment and materials,

and all contractor overheads and indirect costs including contractors'

D-4

profit. Costs for design and engineering, startup, owner costs, and the

contingency allowance raised the total fixed investment required to $100

million.

The capital expenditure for each phase of site development

averages about $20 - 25 million with the exception of phase II where the

total cost is about $11 million.

2.2 STORAGE BASKETS

The Pickering-type storage baskets cost about $200 each, or

$0.31/kg U. The total expenditure for baskets amounts to $21 million.

2.3 SUMMARY OF GENERAL OPERATING COSTS

Total annual general operating costs for the final year of

Phases I, III, and V are shown in Table 3. They include the costs for

manpower, utilities (electrical power, fuel oil, water treatment), fresh

resin (for basin purification systems), waste storage (for spent resin,

filter cake, etc.), maintenance labour and material, operating supplies,

taxes, insurance and storage fees. Costs were estimated at the end of

each phase and the general operating costs in the intervening years were

determined by interpolation. Manpower costs were determined from the

estimate of the personnel requirements at the end of Phase I and at the

end of Phase V. Utility and fresh resin costs were based on estimated

consumptions for each phase. Waste storage costs were based on the

estimated volumes of spent resin and filter cake discharged annually in

each phase. The material and labour costs for major maintenance were

estimated at 1% of the total fixed investment for each phase of the site

development period. Operating supplies were estimated at 15% of the

maintenance cost. Taxes and insurance were estimated at 1.5% of the fixed

investment for each phase and storage contract fees at $10 per Mg. These

fees are for contractual agreements for placing spent fuel in storage and

D-5

transferring the title for ownership of the fuel to the owner of the

storage site. The total general operating costs amount to $1.4 million

in 1985 and to $6.2 million in the year 2000.

A percentage breakdown of the total annual operating costs is

also shown in Table 3 to indicate the relative influence of each of the

operating cost items.

Total annual operating costs during the site filling period

amount to $68 million.

2.4 PERPETUAL CARE COSTS

The costs beyond the year 2000 must be paid for from accrued

interest in perpetual care sinking funds. These costs Include annual

general operating costs, costs for equipment replacement every 25 years,

cost for site replacement and new buildings and facilities every 50 years,

and costs for transferring spent fuel from the eld site to the new site

and decommissioning the old site. These costs, along with the size of the

investments required in the various sinking funds in the year 2000, are

found in Table 4.

The investment required in the sinking funds at the end of the

year 2000 totals $247 million, of which nearly $200 million is required

to cover the annual general operating expense. The manner in which the

size of perpetual funds is calculated is described in Appendix 8. It was

assumed that future costs would escalate at the rate of 4% per year and

that interest would accumulate at the rate of 7% per year. The sinking

funds are to be established by placing a charge against the spent fuel as

it is received year by year and investing the resultant income at an

interest rate of 7% per year until the year 2000.

û-6

2.5 LEVELIZED COSTS, $/kg U FOR CAPITAL, OPERATING AND PERPETUAL CARE

A breakdown of the levelized costs for capital operating and

perpetual care is given in Table 5.

2.6 SHIPPING

The cost for shipping fuel from the reactor site to a central

storage site has been calculated in Appendix I. It amounts to $2.20/kg U.

2.7 PUBLIC INFORMATION AND SITE SELECTION

Costs for development of pool storage should be small. An

expenditure of $1.0 x 106 for public relations and $1.0 x 106 for site

selection have been allowed. This amounts to a levelized cost of = $0.05/kg U.

2.8 TOTAL COSTS FOR MANAGEMENT OF SPENT FUEL IN BASINS

A breakdown of the total levelized costs for the management

of spent fuel in basins is given in Table 6.

3. GENERAL COMMENTS ON POOL STORAGE

1. Since water is used as a shielding material and as a coolant,a basin design providing high integrity containment of thewater is required. This requirement will probably restrictthe service life of the basin to about 50 years.

2. The free space in the basin superstructure above the basinwater must be ventilated continuously for the following reasons:

a) To ensure habitable working conditions.

b) For humidity control to avoid frost buildup on the super-structure walls in the winter and to prevent condensation

D-7

of moisture on equipment such as storage basin cranes.

c) To purge the radiolytic hydrogen released from the basinwater.

The ventilation requirements for humidity control are substantial.The intake air must be filtered to remove dust that mightsettle on the basin water and require removal in the basinpurification system. In winter, this air must be heated.The design heat transfer load for heating the ventilationair in basin No.l is 25% of the design heat transfer required forcooling the spent fuel in that basin immediately after it isfilled with spent fuel. Provision is also required forfiltration of the exhaust air if it becomes contaminated withradioactive particulates.

3. Since continuous purification of the basin water is required,active wastes in the form of spent ion-exchange resin andfilter cake are continually being produced and must be stored.

4. The use of forced convection cooling requires extensive use ofmechanical equipment. Strict surveillance is required and aheavy maintenance program is essential to keep the equipmentin operation.

5. A distinct advantage of the pool storage is ready retrievabilityof the spent fuel.

6. Because of the high operating costs, perpetual care costs forpool storage are high. However, a large perpetual care fundhas the advantage of allowing more flexibility in switchingto other storage schemes in the future. In this case thefunds with cunmulative interest earnings reach their maximumvalue in the 50 year cycle just prior to the expenditure forreplacement of site facilities. This is equivalent to $5.45/kg U.

D-8

TABLE 1

MANPOWER REQUIREMENTS

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

Site Superintendent

Manager of Operations

Fuel HandlingDriver - Rail Car PullerFlask UnloadersBasket Stacker in BasinTotal

I/shift2/shiftI/shift ,..4/shift x 5 shifts W

Utility and Basin Operators (powerhouse, watertreatment plant, cooling tower, basin cooling,purification and ventilation systems) ,...

3 men/shift x 4 shifts111'

Laboratory StaffChemistTechnicianTotal

Traffic and Records ClerkOne man per day shift onlyby health surveyors)

1 (day shift only)I (day shift only)

'he is to be assisted

Health and SafetyHealth and Safety Head 1 (day shift)Technician ' 1 (day shift)Shift Surveyors (fuel handling)

1/shift x 4/shifts 4Total

Changing Spent Resins - day shift

Minor Maintenance - day shift

Other ServicesJanitorial ServiceGrounds KeepersMiscellaneous DutyGuard Duty

I/shift x 4/shiftsTotal

Engineering Services

Business AdministrationAccountantPayroll ClerkEmployee ServicesStenograhersTotal

TOTAL for Phase V Operations

3 (day shift)2 (day shift)3 (day shift)

4.

1 (day shift)1 (day shift)1 (day shift)3 (day shift)

Number of PeopleRequired

during Phase V

1

1

20

12

2

1

6

4

4

12

1

_6

70

(i) Actually require 4.7 nen to provide full coverage for 3 shifts perday including weekends, holidays, vacation and sick leave. Duringslack periods, men are to be used for minor maintenance.

(11) To ensure full coverage of all shifts, minor maintenance staff willbe used as operators when required.

D-9

TABLE 2

SUMMARY OF CAPITAL EXPENDITURES

Construction Costs

LandYard DevelopmentFlask Handling CentresStorage BasinsStorage BasinsCooling Towers and C.W. Distribution

Steam Supply andDistribution

Power HouseFuel Oil Storage TanksWater Supply Systems

& Emergency CoolingWater

Waste ManagementSystems

Ph.I

0.031.941.686.52

1.17

0.230.190.08

1.64

0.97Miscellaneous Buildings

& Equipment(Maintenance Shop etc.]Plant and Instrument

Air Supply

0.63

0.10Electrical Supply - main

& sec. transformer stationsprimary distributionemergency generators

Rolling StockSpare PartsEngineering, Design,

Inspection, Adminis-tration, SafetyAnalyses

StartupOwner CostsContingency

Total Fixed

and0.690.110.08

2.760.080.752.94

Investment 22.59

Ph

6

0

000

0

1.0.01.

11.

Costs,

.11

.75

.81

.08

.14

.04

58

02032445

14

Ph

0166

0

0

0

1

0

0

00.0.

2.0.0.3.

25.

Million

.III

.12

.68

.81

.86

.84

15

09

49

03

07

911308

33085133

51

Ph

66

0

000

0

1002

20

$ (1972)

.IV

_

--.91.97

.83

.15

.22

.07

.80

28083565

31

Ph.V

_

--

7.007.06

0.86

0.15

-0.07

-

-

-

-

0.97

--

1.290.080.352.67

20.50

Total

0.032.063.36

QA OOJt. OO

4.51

0.760.550.35

3.13

1.00

0.63

0.17

3.950.240.16

8.68(i)0.352.20(11)

13.04(iii)

100.05(iv)

(i) This cost varied as a percentage of the construction costs,depending on the phase of the building program. The overallcost amounts to 11% of the total construction costs or 8.7%of the total fixed investment.

(ii) Includes site selection, property taxes and insurance, generaland administrative expense and public relations.

(ill) Estimated to be 15% of each of the main cost items.

(Iv) No allowance is included here for cost escalation or Interestcharges during construction. These items are included, however,in the determination of the price to be charged for storing the

D-10

TABLE 3

BREAKDOWN OF ANNUAL OPERATING COSTS

IN THE FINAL YEAR OF PHASES I, III, AND V

Total Annual Cost $106

Manpower, %

Utilities, Resin, WasteStorage, %

Maintenance (M & C) andOperating Supplies, %

Taxes and Insurance, %

Storage Contract Fees, %

1985

1.42

24

27

21

27

1

100

1994

3.61

14

36

21

28

1

100

2000

6.21

11

41

21

26

1

100

D-ll

TABLE 4

SUMMARY OF FUTURE COSTS AND INITIAL INVESTMENT REQUIRED IN

THE PERPETUAL CARE FUNDS

(All costs are given in 1972 dollars)

General Operating Costs

Costs for Replacement ofEquipment Every 25 Years

Net Cost For Site ReplacementEvery 50 Years

Costs For Transferring Fuel ToNew Site & Decommissioning OldSite

Future CostsAfter

Year 2000

Investment RequiredIn Sinking Fund atEnd of Year 2000

CIO6 dollars)

5.7Ci>

15

67

til)

(ill)

,Civ)

(106 dollars)

198

14

21

14

Total Initial Investment RequiredIn The Sinking Funds 247

Ci) Estimate of operating costs per year for the first 50 years ofsite operation after the year 2000. This cost is not expectedto decrease significantly beyond that time.

(ii) Total installed cost for replacement of equipment, piping,instrumentation, etc. in the basins, flask handling centresand auxiliary systems.

Ciii) Net Cost • total cost for site replacement every 50 years(estimated to be $82 million) less the allowance for equipmentreplacement spent every 25 years. Site replacement includes thecost of a new site, yard development costs, and all new buildingsand equipment.

(iv) Estimate includes decanning defective bundles, loading andunloading flasks, transport costs, an allowance for operatingcosts while both sites are being operated and the cost ofdecommissioning old basins.

D-12

TABLE 5

LEVELIZED COSTS FOR CAPITAL, OPERATING

AND PERPETUAL CARE

Cost,

CAPITALGeneral Capital Expenditures

Interest Charges for BorrowedMoney

Basket Costs

GENERAL OPERATING

TOTAL FOR CAPITAL AND GENERAL OPERATING

PERPETUAL CARETotal Value of Sinking Fund inYear 2000

Interest Earned to Year 2000

Deposits to Sinking FundDuring Filling

TOTAL COSTS FOR CAPITAL, OPERATING AND

PERPETUAL CARE

106

100.

13.

21.

68.

247.

-47.

Dollars

1

6

1

0

202.8

0

8

199.2

402.0

Levelized

Costs,

1.

0.

0.

1.

$/kg U

47

20

31

00

2.98

2.93

5.91

D-13

TABLE 6

TOTAL COSTS FOR MANAGEMENT OF SPENT FUEL IN BASINS

1.

2.

3.

4.

5.

Site Selection and Public Relations

Capital and Operating Costs DuringSite Filling Period

Petpetual Care

Shipping

Total

Levelized Costs$/kg U

0.05

2.98

2.93

2.20

8.16

POOLS

7C2 m

< Î > STORAGE I A 9 N «RE*

<§> WASTE STORAGEAREA FOR STORAGEVAULTS • TANKS

WRIAL omuNos AREA

SITE SUFFER ZONE

— OVERALL SITE PLAN —

{ I , STORAGE BASINS

{Zj FLASK HANDLING CENTRES

(lj COOLING TOWERS

.4; COOLING WATER PIPEWAY

(5 POWER HOUSE

^6 ACTIVE WASTE TREATMENT PLANT

* \7. WATER TREATMENT PLANT0»

3 l'a GARAGE a Fl REHALL

(9 MAINTENANCE SHOP

'!§> WAREHOUSE

fît) GATEHOUSE

( ^ STORM SEWER DELAY PONOS

@ EMERGENCY WATER SUPPLY RESERVOIRS

'Ï4 FUEL OIL STORAGE TANKS

f5 MAIN ELECTRICAL TRANSFORMER STATION

(j PARKING LOT

@ SEPTIC TANKS

FIGURE 1.

SITE PLAN FOR STORAGE BASIN AkEA

PLAN

1.02 m

.17

NOTES

1. BASKETS ARE FABRICATED FROMSTAINLESS STEEL.

2. BASKETS HOLDS A TOTAL OF 3 2PICKERING FUEL BUNDLES (640 kg U)

. 55 mm

2 FUEL BUNDLES aPER ROW I

FRONT ELEVATION SIDE ELEVATION

FIGURE 2.

SCHEMATIC DRAWING OF PICKERING STORAGE

BASKET

TGRADE

(DL5-1 !l EL - iOS I

.5 Mi

EL = 108.8 m

GRADE EL -100.0 m

f * M ^ REINFORCED CONCRETE

• • • • • » : CRANE RAIL SUPPORTS

0 CELL FDR MONITORING, OPENING AND DECONTAMINATING FLASKS(2) FLASK UNLOADING CELLiS) CELL FOR CANNING DEFECTIVE BUNDLES4) FLASK ON TROLLEY CAR WITH COVER REMOVED® FLASK COVER(6) CABLE DRIVEN UNDERWATER TROLLEY CARf) RAILWAY FLAT CAR

,6)

EL • 92.4 m

ELEVATION

FIGURE 3

LAYOUT OF FLASK HANDLING CENTRE

D-I7

STORAGE BASKETS

6 PER STACK-^

4 ROWS OFSTACKS PERSECTION, 8 ROWSPER STORAGECANAL.

7 ROWS CONTAIN4 6 STACKS ANDI ROW CONTAINS

4 7 STACKS

L

51.2 m

EQUIPMENT BAY

h- 159 m -Ih- 15.9 m.92 m

15.9 m -H

LOCATIONOF CANALDOORWHILEC/>NAL IFBe NGTILLED

EQUIPMENT BAY

( LAYOUT OF OTHEREQUIPMENT BAYIS SIMILAR EXCEPTFOR GANTRYMAINTENAMCE AREAWHICH IS USEDINSTEAD FORTRANSFER CANALPURIFICATIONEQUIPMENT )

_£_:

STORAGE CANALS

STORAGE CANALS

STAINLESSSTEELSTORAGECANALDIVIDER

d

MAINTENANCEAREA FORSTORAGECANALGANTRY

{COOLING EQUIP FOR 3 IPURIF" EQUIPI ADJACENT STORAGEI CANALS

FOR 3ADJACENTSTORAGECANALS

1E

in

t-

o

•JFIGURE 4.

STORAGE BASINPLAN VIEW

EL» 108.8 m

BASIN FLOOR E L - 9 2 . 4 m

.92 m

SECTION A-A

SEE FIGURE A. 2.1.1

I

00

EQUIPMENTBAY

EL • 105.1 mEQUIPMENT

BAY

GRADE

(VENT •»EQUIP)

(COOLING 8|PURF"BQUIPj

PIT FOR CANALWATER PURF"EQUIPMENT

WATER LEVELS

E L - 108.8 m

EL- 104.4 m

GRADE EL- 100.0 m

\»-.e\ m EL- 96 . 3 m

- 9 2 mFLOOR EL • 92.4 m

SECTION B-BSEE FIGURE A . 2 . I . I

STORAGE BASIN ELEVATIONS

FIGURE 5

LEGEND

£Y PRIMARY CIRCUIT PUMP

_?£.PRIMARY CIRCUIT HEAT EXCHANGER

—— PRIMARY CIRCUIT COOLING WATER (CANAL WATER)

SECONDARY CIRCUIT COOLING WATER(FROM COOLING TOWERS)

SECONDARY COOLING, WATER RETURN

29.4 °C

t»

SECONDARY COOLINGWATER SUPPLY7S°F (23.9°OMAX. FLOW BO m 3 /min. (25 ,000 qpm)- FOR BASINFILLED IN 13 ytora.

FIGURE 6

BASIN PRIMARY COOLING SYSTEM

TRANSFER CANAL PURIFICATION EQUIPMENTPUMP

FILTER ( WIRE WOUND PERFORATED TUBE TYPE)

MIXED BED ION EXCHANGE COLUMN

.379 m3/m

379

.379 m3/m

STORAGE CANAL PURIFICATION EQUIPMENT STORAGE CANALS . I . STORAGE CANALS STORAGE CANAL PURIFICATION EQUIP.

• 379 m 3 / m

f STANDBY EQUIPMENT

STORAGE _CANALHMVJDER

£M i t 1

.379 m 3 / m

O

STANDBY EQUIPMENT

NOTE

1. EACH ION EXCHANGE COLUMN CONTAINS ABOUT I m 3 OF MIXEDRESIN THE COLUMNS FOR THE STORAGE CANALS CAN BE RUN FORABOUT I MONTH BEFORE REPLACEMENT OF THE RESIN IS REQUIRED

2. THE STORAGE CANAL FILTERS ARE EXPECTED TO PICK UP ABOUT O . I 5 m 3

OF CAKE PER MONTH AND WILL REQUIRE BACKWASH ING ONCEEVERY 6 MONTHS.

FIGURE 7.

BASIN PURIFICATION SYSTEM

EMERGENCY COOLING WATER

RETURNED TO EMERGENCY SUPPLYRESEVOIR

AMBIENT DESIGN CONDITION

0. B. 294 °C ( 8 5 ° F )

W.B. 21.1 °C ( 70°F)

MAKE-UP WATER

LOSSES

(EVAPORATION, ENTRAINMENT)

•LOWDOWN(TO STORM SEWER)

STORAGE BASINS

29,4

(85 °F)RETURN

233 °CH EADER

INDUCED DRAFTCOOLING TOWER

) {75°F ) SUPPLY£ HEADER

EMERGENCY COOLING WATER

—

FROM EMERGENCY WATER SUPPLYRESEVOIR

NOTES

1. IT IS ASSUMED THAT CONNECTIONS FROM EACH BASIN TO EACH SET OF MAIN HEADERS IS REQUIRED TO ENSURE

ADEQUATE FLEXIBILITY IN DISTRIBUTING COOLING WATER.

FIGURE 8.

SECONDARY COOLING WATER SUPPLY SYSTEM

(Typical of installation required for one phase )

EFFLUENT FROM FILTER. .9m3/iT

. 4 m3 / m i n .

BACKWASH TO STORM SEWER

SEEPAGE AND

EVAPORATION LOSSES*4nVmin.

D 3.1 m3/min. ..

* ,44,000 m 3

Q 3. a n>3/min. - ,

SEEPAGE ANDEVAPORATION LOSSES . I n

RAW WATER INTAKE

SYSTEMS

EMERGENCY

WATER SUPPLY

RESERVOIRS

LEGEND

INSTALLED IN PHASE I FOR PHASES I a H

« _ ^ _ » INSTALLED IN PHASE n FOR PHASES HI , IZ ;

— - - ^ F O R EMERGENCY

- — 4 U S E ONLY

3. 79 m 3 / m i n .

.3 m 3 /m in .

FILTER .4m3/mW

BACKWASH

TO FIRE LOOP ( FROM SPECIAL

"RESEVOIR OF FILTERED WATER)

. LAWN WATERING

.01 m^/nin.->-MAKE-UP TO STEAM SYSTEM

I.9m3/min.

2.9 m3/min.• MAKE-UP TO COOLING TOWERS

• I m3/mjg.1

FILTER 5n?/

BACKWASH

WATER

TREATMENT

PLANT

• 3 m ymm.

DEMINERALIZED MAKE-UP4 m ./minwftTER TO STORAGE CANALS

FOR EVAPORATION LOSSES

OEMINERALIZER PLANT O

. 4 ff|3/mln. SUPPLY TO STORAGE CANAL £*"DEMINERAUZERS TO INCREASE

SUPPLY OF DEMINERALIZED WATERDURING INITIAL FILLING OF

BASINS

.2 m 3 / m i n .

.2 m 3 / in in .

.GENERAL USAGE

47 m V m i n .1 94 m/min.

47 n> / min.

EMERGENCY COOLING WATER

»• TO SECONDARY COOLING

WATER DISTRIBUTION SYSTEM

FIGURE 9.

WATER SUPPLY SYSTEMS

DATE_

PHASE III1 D 1

K N O . 3/iSNo It

PHASE IVIn 1 „ .

lNo5WIobl

LEGENDD

C

Design

Construction

Filling Basin with

1Spent

Start-up

Fuel

FIGURE 10.

SCHEDULE FOR SITE DEVELOPEMENT

E-l

APPENDIX E

STORAGE OF SPENT FUEL IN WATER POOLS AT REACTOR SITES

by

R.W. Barnes

Ontario Hydro

1. SUMMARY OF STUDY

1.1 INTRODUCTION

This section is a summary of work carried out by Ontario

Hydro as a member of CAFS. It contains a summary design description and

an assessment of cost to store spent fuel for long periods of time in

pools at a reactor site.

The accumulated production of spent fuel from the Ontario

Hydro nuclear power stations planned up to and including the station

designated E20 (see Figure 1) has been plotted against time in Figure 2.

By 1989 about 1 million bundles will have been discharged from

the reactors at these stations. The present storage capacity of the spent

fuel bay at Pickering G.S. A is just over 80,000 bundles while the bay

capacity at Bruce G.S. A is about 32,000. It is planned to build auxiliary

bays for Pickering G.S. A and Bruce G.S. A. The auxiliary spent fuel bay

at Pickering G.S. A will be capable of holding approximately 9 station

years of spent fuel and the one at Bruce G.S. A at least 10 station years

and probably more.

E-2

Ontario Hydro regards spent fuel as a resource because of its

fissile plutonium content and until recently, it was the policy of Ontario

Hydro that the spent fuel would be sold for plutonium recovery. The

market for spent fuel however is not likely to materialize in significant

quantities until towards the end of this century at the earliest. Therefore,

spent fuel will have to be stored for an interim period of at least 30 years.

The auxiliary bays provide temporary storage and allow time for a carefully

planned approach to interim storage. The CAFS study will provide a basis

for Ontario Hydro to act in the future.

As a member of the CAFS study group, Ontario Hydro agreed to

provide the following:

1. A conceptual design and cost information for perpetual (approx.106 years) storage of the total spent fuel produced at areactor site. The spent fuel would be stored in water pools.Since the pools would deteriorate, it was assumed that newpools would be built and the spent fuel stored in them. Thiscycle of events would continue until the hazardous radiationlevel from the spent fuel was very small.

2. The incremental capital and operating cost, for extendingspent fuel storage in the reactor station spent fuel bayfrom one year up to three years and from one year up to fiveyears.

This report refers to the perpetual storage scheme as the long-

term facility and refers to the spent fuel bay which is part of the

generating station, as the short-term facility.

The design of the long-term facility is considered in enough

detail to demonstrate the feasibility of the concept. The cost analysis

is sufficiently detailed to identify major cost areas. No provision has

been made for costs resulting from requirements of international commitments

for safeguarding the spent fuel.

For the short-term facility, although only incremental costs

were required, a review was made of existing bay designs and fuel handling

systems. The review was carried out in the conceptual design stage and

some of the recommendations became part of the ground rules. A modified

E-3

Bruce G.S. A spent fuel bay was used as a basis for the study. Cost

assessments were made for the incremental storage times.

1.2 DESIGN BASIS

1.2.1 GROUND RULES FOR STORAGE OF SPENT FUEL IN POOLS AT REACTOR SITES

A set of ground rules for all the studies was prepared by the

CAFS group at the start. However, for this study additional ground rules

were required. The CAFS ground rules are set out in Appendix A. The

additional ground rules are given in Section 5 of this Appendix.

1.2.2 SITE

For the purposes of the study, Bruce Nuclear Power Development

(Bruce NPD) was used as the reactor site because basic costs of engineering,

construction and supplies are well known. A location for the facility on

the Bruce NPD site is shown in Figure 3 to give some idea of how distance

affects the transfer of spent fuel between the station spent fuel bays

and the long-term spent fuel storage facility located on-site.

1.2.3 SPENT FUEL BUNDLE PRODUCTION

The average bundle production rate for the existing and proposed

stations at Bruce NPD is given in Table 1. The figures in this table

assume an 80% capacity factor and the bundle production rate is averaged

over the year. For the purposes of this study it is assumed that an

additional 6000 MWe will be built and that this additional 6000 MWe

would be in-service in 1984. This was assumed since that is the largest

quantity of electric generation (12,000 MWe, see Appendix A, Al.l) likely

at any one energy centre and therefore is a maximum design condition. The

total number of spent fuel bundles discharged assuming each unit has a

lifetime of 30 years is 2.3 x 106 bundles.

E-4

1.2.4 DECAY HEAT GENERATION

The decay heat generation rate used for the design is shown

in Figure 4. This curve was produced using a modified version of the

program ISOGEN. The program was originally written at Hanford and has

been modified to fit the decay properties of spent CANDU fuel. The

modifications that have been made to the program are:

1. extensions to the nuclide library,2. addition of new isotope properties,3. incorporation of new options into the program,4. variations in the manipulation of basic output data.

Although the nuclide library has been expanded, the total

number of isotopes in the library has been reduced. This reduction in

fission products was achieved by dropping all the short-lived species,

which in the context of the study means those products having negligible

activity after one year's cooling. The addition of stable fission products

and their significant capture products has yet to be completed.

1.2.5 MAN-REM

One of the basic design objectives adhered to was that

occupational.doses should not dictate labour costs. A man-rem audit

was carried out and this indicated that this objective had been met.

1.2.6 RADIOACTIVE RELEASE TO THE ENVIRONMENT

1.2.6.1 General Activity Control

It is postulated that a certain percentage of the fuel will

fail in storage, even though the storage environment is less severe on

the bundles than in the reactor. Normally, there will be no attempt to

retrieve and can these defective bundles. This means that the cooling

«rater circulating through the vaults will be contaminated. The volume

of water in the vault is very large and it is expected that the dilution

factor alone will be adequate to keep radiation levels to very low values.

E-5

If there was a massive failure of bundles, an attempt would be made to

retrieve and process these bundles.

Flow through the chemical control circuit is dictated by

chemical needs and net purification requirements. The chemical control

circuit will be used basically for pH control and not for purification,

although purification of the water will result from its passage through

the ion-exchange columns. It is possible to put the whole cooling flow

through the ion-exchange columns for purification of the water if that

ever becomes necessary.

An attempt to keep the cooling water very clean would almost

certainly result in very large quantities of low-level contaminated

resin. The resin would then have to be disposed of in some storage

system. There appears to be no gain from transferring the low-level

activity in the water to the resin except that on the resin it is fixed.

Spent fuel bundles that are known to be defective in the short-term

facility will not be stored in the long-term facility.

1.2.6.2 Radioactive Liquid Release

The design was carried out with the objective of keeping to a

minimum the risk of a radioactive liquid release to the environment. Any

loss of radioactive fluid will be directed to a leakage collection tank

by way of the leakage collection system.

1.2.6.3 Radioactive Gas Release

The Health Physics Department suggests limits on releases of85Kr, 3H and 1 2 9I to the environment. It is expected that these isotopes

would be the main contributors of radiation dose in any radioactive gas

release. They would be the major gaseous isotopes remaining because of

their long half-lives. It may be necessary to limit releases of these

nuclides on a world-wide dose commitment basis rather than a local dose

basis. Any gaseous release would be by way of the ventilation system.

This system is required to prevent the collection of explosive quantities

E-6

of hydrogen and oxygen caused by the radiolytic decomposition of water,

through the gamma ray activity from the fuel. The system is kept under

negative air pressure thus preventing uncontrolled leakage to the

environment. A once-through ventilation system was chosen for this

design. If the release of airborne activity proves to be a problem, a

filtering system could be connected into the exhaust.

There is a monitoring system for control and an extraction

system through which the ventilation exhaust air can be diverted in the

event of a large, sustained release of radioactive gas. It is not

expected that the release of radioactive gas will be a problem. Should

it prove to be one, the system could be converted to a closed system and

an extraction system placed on the exhaust. The exhaust would be required

to keep the system at a negative pressure. A catalytic recombiner would

be used to control the concentrations of hydrogen and oxygen.

1.3 LONG-TERM FACILITY

1.3.1 GENERAL DESCRIPTION

The storage facility consists of four concrete vaults partially

above ground, with each vault consisting of a row of eight bays separated

by expansion joints (Figure 5). A bay is an integral, reinforced concrete

structure partially subdivided into six sections by cover support beams

(Figure 6). The capacity of each storage bay with baskets stacked six

high is 82,150 (approximately) fuel bundles. In addition, floor space

is allocated for flask setdown during unloading. When filled, each bay

is covered by stainless steel plate and reinforced concrete covers are

then placed over each bay section for protection of the stainless steel

covers (Figure 7).

During and after filling, each bay is connected to process

equipment to provide air space ventilation (Figure 8), water cooling,

water chemistry control and purification (Figure 9). Most of the process

and monitoring equipment is located in the Service and Control Centre

Building at the southeast corner of the site.

E-7

Fuel handling is performed within a single loading cell

facility (Figure 10) which is moved from vault to vault on a transfer

vehicle and along each vault to any bay on its own wheels. The cell is

designed to reside over and be sealed around a single bay section where

it will remain until the bay is filled. Connection points are provided

at regular intervals to the pipe chase alongside each vault. These

connections provide the loading cell with electric power, domestic water,

sewage and liquid radioactive waste return lines directed through the

Service and Control Centre.

1.3.2 CONSTRUCTION OF THE SPENT FUEL STORAGE FACILITY

1.3.2.1 Method of Construction

As the first step in construction, the chosen area is fenced

off and the site cleared for the whole project. Excavation for the first

concrete vault consisting of eight water bays is carried out and the

concrete poured. The stainless steel liner for the first bay in that

vault is then installed. The preliminary cost estimate indicated that

the stainless steel liner was a major cost factor and that the liners

should be installed only when needed, allowing suitable cushion time

(approximately one full year before filling is due to start) for labour

and supply problems.

The Loading Cell, the Service and Control Centre and part of

the retaining walls for the Loading Cell transfer vehicle track will be

constructed during this first stage. The transfer vehicle track is

extended as new vaults are built. The main headers and leakage collection

system for the first vault are also installed at this stage. The

connecting piping to each bay is not installed until the stainless steel

liner for that particular bay is in place.

Figure 11 shows the project life cycle for the spent fuel

storage facility including the main milestones leading up to the operation

of the first bay. The time requirements for regulatory licensing and for

E-8

public approval have not been included at this stage. These may add an

additional twelve months from start of project to commencement of filling.

1.3.2.2 Construction Schedules

Figure 12 gives the construction schedule for this facility.

The schedule shows the relative timing of the engineering, construction,

liner installation and filling of the bays with spent fuel. Note that

only seven of the eight bays are used in any one vault. The eighth bay

is kept as a standby to be used if a major leak develops in a liner of

one of the filled bays requiring the fuel in that bay to be transferred

to a new bay. The construction order used on the first vault is repeated

for each of the other three vaults.

1.4 SHORT-TERM FACILITY

1.4.1 DESIGN CRITERIA

The basic intent of this study was to determine the incremental

cost for holding spent fuel at the generating station for an extra two

Cl-3) years and an extra four (1-5) years assuming the normal holding

time to be one year. This study was done because some of the proposed

long-term schemes were unable to remove the decay heat produced by spent

fuel that had only been one year out of the reactor. The extra cost to

hold the spent fuel at the reactor station for the longer period is added

to the overall cost of the scheme.

To do a realistic cost study, a certain amount of redesign

was required. It was decided to use this opportunity to collect information

on the operation of present systems as well as any suggestions for

improvement. Much of this work was done during the conceptual stage of

the study. Discussions were held with:

1. operations personnel on spent fuel bay operation,

2. members of the Spent Fuel Bay Working Parties about theirfindings, and

3. designers about problems encountered.

E-9

The basic findings are discussed in Section 5 of this Appendix.

1.4.2 SUMMARY OF DESIGN CHANGES

The review of the existing spent fuel handling and storage

systems showed that the systems at Bruce G.S. A complied with some of the

suggested improvements. It was decided to use the spent fuel bay at Bruce

G.S. A as the basic design, incorporating most of the accepted suggestions.

Since the costs for Bruce G.S. A are well established, reasonable reliance

can be placed on the incremental cost estimates.

The hypothetical modifications were carried out by Generation

Mechanical Department. Figure 13 is a layout of the existing spent fuel

bay at Bruce G.S. A and acts- as a base to compare the overall changes.

The modifications (Figures 14, 15 and 16) do not affect the station

arrangement and foundations. Two major changes included in the design

were the relocation of the spent fuel ports above water, necessitating

additional shielding, and an increase in the water depth to suit the fuel

handling system employed. This would rais the building roof line in the

central fuelling area.

The reference basket for holding fuel in the storage bay is

based on the Pickering G.S. A version which holds four rows of four end-

to-end fuel bundle pairs (32 bundles per basket). This design of basket

was used to benefit from simplified loading while maintaining good

support of the fuel bundle. The major drawback of the design is poor

storage density which has been improved to some degree for this study.

Further improvement is possible. The general pool construction is

similar to that at Bruce G.S. A.

The water and air space is partitioned into a receiving bay area

(Figure 17) and a holding bay area. The spent fuel passes from the

fuelling machine into the receiving bay. The bundles are placed in baskets

and stacked. It is here that any defective fuel bundles are canned. From

here the stacked baskets move to the holding bay. Each area is served by

E-1Q

a two-ton manbridge/gantry with a basket-handling mechanism. Transfer of

baskets between bays is accomplished by a short conveyor.

The receiving bay has the potential of being highly contaminated

with fission products. It is provided with a high blow purification

circuit for the water. The turn-over of the ventilation air can also be

increased to assist in the removal of airborne activity and fission gases.

The bay floor space utilization is very similar to Bruce G.S.

A. In each case the main basket storage area is in the large holding

area adjacent to the receiving bay. Five metres (16 feet) at the north

end of the holding bay is largely reserved for booster fuel storage and

flask operation. The latter area is served by a 100-ton overhead crane.

1.5 POSSIBLE DESIGN IMPROVEMENTS

1.5.1 STAINLESS STEEL USAGE

The stainless steel liner is a large factor in the capital

cost. Optimization of the design with respect to stainless steel would

lead to a lower cost. The following actions can be taken:

1. Use a 4.76 mm thick stainless steel liner instead of theproposed 6.35 mm thick liner. At Douglas Point G.S. 3.18 mmthick stainless steel plate was used for the liner.Difficulty was experienced in construction with the thinplate so it was decided to use 4.76 mm thick stainless steelplate for the Bruce G.S. A spent fuel bay liner. For thisstudy the 4.76 mm could be considered as proven from aconstruetability point of view.

The corrosion of the liner is expected to be very smallalthough with thinner liners the chances of getting a leakare probably increased. However, with the provision of oneemergency bay for each vault, sufficient flexibility has beenprovided for the situation where a liner develops a severe leak.

2. Replace the stainless steel bay cover with a less expensivematerial. The cover acts as a barrier to dust and forms anenvelope for the ventilation system which operates at anegative pressure.

The reinforced concrete beams that span each bay are wrapped

E-ll

in stainless steel plate. The beams are used by the Loading Cell to seal

off an area of the bay whi}.e it is loaded with spent fuel and for

supporting the concrete covers. Redesign of these functions would eliminate

a substantial quantity of stainless steel plate.

1.5.2 BAY FLOOR SPACE

It was intended in the original design that there would be

no empty space on the bay floor except for the setdown area for the flask.

However, the space under each of the beams spanning the bay was not

utilized and this space is capable of stacking an extra row of baskets.

1.5.3 FUEL BUNDLE STACKING DENSITY

Recent work has indicated that the fuel bundles can be stacked

mechnically about 60% closer than with the Pickering style baskets.

2. SUMMARY OF COST

2.1 COST ESTIMATE FOR LONG-TERM FACILITY

2.1.1 GENERAL

One of the ground rules of this study was that all cost

estimates would be expressed in 1972 dollars. However, the basic cost

estimate was prepared in the fall of 1973. Therefore, 1973 dollars were

used and the capital and operating costs have been expressed in 1973

dollars in the tables. For the unit storage cost the figures were

converted into 1972 dollars assuming an overall escalation rate of 5%.

The cost estimate was prepared using the present worth method

of analysis as outlined in Appendix B. The calculation assumed an annual

interest rate of 8% on borrowed or invested money and an escalation rate

E-12

of 5%. The cost estimates are based on the schedule for construction

(Figure 12).

2.1.2 CAPITAL COST ESTIMATE

The cash flows for capital and operating expenditure together

with the annual fuel arisings at the spent fuel storage facility are

given in Table 2. A summary of the estimate showing a breakdown of

expenditure into the areas where the money is spent is given in Table 3.

The largest capital expenditure occurs in the building and structures

area. The stainless steel liner accounts for approximately 75% of the

69 x 106 M$ (1973$).

2.1.3 OPERATING COST ESTIMATE

The summary of operating cost is given in Table 3. In this

table, building maintenance and major equipment maintenance have been I

separated. An annual cost of 0.1% of building capital costs has been '

allowed for major equipment maintenance. It is assumed that from the

year 2014 onwards the operating costs will be constant. The last bay

is filled in the year 2013. The estimate for taxes and insurance has

been allowed at 1-1/2% of capital costs. The storage contract costs have

also been added into the total overall operating costs although not

included in Table 4. The cost assumed was the same as for the other

schemes i.e., $10/ Mg U.

2.1.4. PERPETUAL CARE COST ESTIMATE

The vault will be filled by the year 2013. From the year 2014

onwards the annual operating costs, retrieval of spent fuel from a leaking

bay and the storing of it in an emergency bay <Cevery 25 years), equipment

replacement (every 33-1/3 years), facility replacement (every 100 years)

transfer of the fuel to a new facility and de-commissioning of the old

facility (every 100 years) must be paid for from the sinking fund. The

total investment required by the year 2013 is 99M$ Q.973 $). Table 5

shows the breakdown of the total investment.

E-13

2.1.5 COST OF SPENT FUEL MANAGEMENT IN POOLS

Combining the costs (Capital, Operating and Perpetual Care)

on a present worth basis Csee Table 6) expresses the total unit cost of

management of spent fuel (1972 $/fcg TJ). The storage basket cost included

in the operating cost has been taken at $0.31/kg U (.1972 $), a figure

given at the start of the study. The total unit cost of spent fuel

management at a reactor site in pools is $5.33/kg U (1972 $).

2.1.6 COST SAVINGS THROOGH DESIGN IMPROVEMENTS

In this section it is assumed that the design has been optimized

as described in Sections 1.5.1 and 1.5.2 and the new capital cost evaluated.

The assumptions are:

1. The thickness of the stainless steel liner has been reducedto 4.76 mm C3/16 inch).

2. The stainless steel covers have been replaced by a lessexpensive material such as fibre-glass.

3. Spent fuel is stacked in the space under the beams. Thisresults in a reduction of the number of bays required (4 less).

The new costs are expressed in Table 7. There is a significant

reduction in the capital cost ($0.58/kg U) and a slight change in the

perpetual storage cost.

2.1.7 COST SAVINGS THROUGH HIGHER BUNDLE STACKING DENSITY

In this section the cost of management is calculated assuming

that the fuel has been stacked closer as proposed in Section 1.5.3 and

include the design improvements suggested in Sections 1.5.1 and 1.5.2.

The fuel stacking density will be increased by about 60%. This results

in substantially fewer bays (12 less than the 28 originally required),

and thus lower capital cost. The results are set out in Table 8. The

storage basket cost is increased (from $0.31/kg U to $0.43/kg U 1972 $)

causing an increase in the operating costs but an overall decrease in

total cost. Once again there is a slight decrease in the perpetual care cost.

E-14

2.2 COST ESTIMATE FOR SHORT-TERM FACILITY

The incremental cost for the short-term facility was calculated

using the present worth, analysis (Appendix B).

The breakdown of incremental capital expenditure is given in

Table 9. The capital expenditure estimates are based on Bruce G.S. A costs.

The breakdown of the incremental operation and maintenance

cost is given in Table 10. There is probably no increase in the labour

cost due to the extension. The main increase in cost results from the

extra power, equipment, materials (e.g. resin), and storage baskets

required and management of the extra radioactive wastes produced.

Combining the costs, the estimate for storing spent fuel for

an extra two (1-3) years is $0.27/kg U and for an extra four (1-5) years

is $0.47/kg U. These figures are expressed in 1972 dollars (Table 11).

3. SAFETY ASSESSMENT

3.1 ACTIVITY IN SPENT FUEL

The radioactivity associated with spent fuel can be categorized

into two groups, fission products and actinides. While gamma radiation

is the main hazard earlier in the life of the spent fuel, this decays

relatively quickly and beta and alpha radiation become the main hazards.

Broadly stated,the beta activity is associated with the fission products

and the alpha activity with the actinides. The fission products and the

actinides emit gamma radiation but mostly of low energy, so that the hazard

is relatively low.

Beta and alpha radiation are not very dangerous from an external

radiation dose aspect because of their low penetrability. They are

dangerous if located in body tissues because of their high rate of damage

E-15

per unit distance. The fission products and the actinides have to be

isolated from the biosphere to prevent their being ingested by man

through the food chains and/or through inhalation.

3.2 CONTAINMENT OF ACTIVITY

Since the primary safety objective is to keep the spent fuel

isolated from the biosphere, any safety assessment must evaluate the

possibility of release to the biosphere. This involves an examination

of the possible barriers and what accidents could occur that would lead

to their failure. The primary containment barrier for the spent fuel is

the fuel sheath. To maintain its integrity, the fuel sheath requires

the support of auxiliary systems, for example, a cooling system to

remove the decay heat produced. Part of the safety assessment is to

evaluate the reliability of such supporting systems.

.1i

For water pools, the cooling system is a circulating water '

system with water as a transport agent. The water takes the heat from

the fuel and passes it to the heat sink through heat exchangers. The

water system itself has to be contained and this containment acts as a

secondary barrier against escape of activity to the environment. The

gaseous products of the activity pass through the ventilation exhaust

system to the atmosphere while the solid active material circulates with

the water. A tertiary containment is provided by the leakage collection

system. This however provides only partial containment since it can

handle only small to moderate water leaks.

3.3 ACTIVITY RELEASE PATHS

The possible escape paths of activity from the spent fuel

bundles have been charted in Figure 18. Identified on the chart are the

boundary failures and possible causes together with activity collection

points. An accident analysis would be the next step to determine the

extent of the activity release as well as the probability of the release

occurring along this path.

E-16

4. CONCLUSIONS AND RECOMMENDATIONS

4.1 CONCLUSIONS

1. Previous experience has shown that spent fuel can be storedsafely in pools. This experience is of the order of tens ofyears. Development work would be required to project thisconclusion into the 100 years and longer time range.

2. This study demonstrated that water pools can be engineeredon a large scale.

3. The technology is simple, reliable, well developed and tested.

4. Previous design, construction and operational experiencedemonstrates that a high quality storage facility could bebuilt and operated.

5. The cost estimates are based on actual experience and showthat this method of storage is competitive with other lessproven schemes.

4.2 RECOMMENDATIONS

The following development work should be undertaken if it is

decided to store spent fuel in water pools for a long period of time.

1. Determine the extent of the electrochemical action that takesplace between zircaloy and stainless steel in view of thelong periods of time that these metals will be together.

2. Determine the effects, if any, of the contact of stainlesssteel with concrete over long periods of time.

3. Determine the best methods for controlling the corrosion thatwill take place between the stainless steel liners and thewater in the bays.

4. Determine the corrosion rate of zircaloy in the bay water overthe long term.

5. Evaluate the effects of extended irradiation on the propertiesof zircaloy Ceg. strength, corrosion resistance etc).

E-17

5. SUPPLEMENTARY DATA

5.1 SPECIAL GROUND RULES FOR THIS PROJECT

5.1.1 GENERAL

1. The study used the nuclear power development at Bruce. Atpresent there are 4 x 750 MWe units under construction (1974)and a second station consisting of 4 x 750 MWe units will beadded. In long-term planning, it has been assumed that12,000 MWe would be a limit to work to for electricalgeneration at one location. For the study it was assumedthat another 6000 MWe will be added to complete the nuclearcomplex.

2. It is assumed that a nuclear power plant will operate for30 years.

3. The storage of spent fuel is divided into two areas.

(a) Short-term storage at the reactor site, i.e., up to oneyear of storage although the study will consider storageat the plant up to three and five years.

(b) Long -term storage at the nuclear complex, i.e., fromone year up.

4. Release of gaseous radionuclides to the environment from thelong-term storage facility will be kept to an absolute minimum.The intent of the design is to achieve an essentially zerorelease of radioactive gases. This also applies to the releaseof radioactive liquids.

5. Handling and movement of fuel is to be kept to a minimum.

6. The general ground rules of the study are set down inAppendix &. (Some exceptions have been made especially inthe financial area and the actual values used are noted inthe text.)

E-18

5.1.2 SHORT-TERM STORAGE FACILITY

1. This facility is divided into two bays.

(a) A receiving bay, where fuel bundles received from thefuel transfer mechanism are loaded into baskets priorto being moved to the holding bay. Any canning of fuelin the short-term storage is done in the receiving bay.

(b) A holding bay, which is used to store the spent fuelfrom the reactor up to one year (or three or five years)including the full inventory of one reactor should thatbe necessary.

2. Separate storage and shipping baskets are to be used forcanned fuel and uncanned fuel.

3. The design intention is to keep the spread of contaminationbetween the receiving bay and holding bay to a minimum. Theventilation system in the receiving bay is to be capable ofkeeping the level of gaseous fission products in the atmosphereto a minimum. The release of gaseous and liquid radionuclidesfrom the short-term facility is to be included in the allowablerelease for the station.

IJ. 1.3 LONG-TERM STORAGE FACILITY

1. This facility is to be capable of safe storage from one yearupwards.

2. The storage facility is to be designed to store fuel for 100years after filling.

3. The storage facility is to be designed so as to requireminimum upkeep and operation.

4. The stored fuel, after 100 years, must be capable of beingretrieved and stored in a similar or another facility to bechosen.

5.1.4 FUEL

1. All fuel bundles must be retrievable.

2. Fuel bundles will be stored in baskets capable of being placedin a flask, and used in the long-term storage facility.Pickering fuel storage baskets will be assumed since theWhiteshell Study has used Pickering storage baskets.

E-19

5.2 DESIGN CRITERIA FOR SHORT-TERM FACILITIES

5.2.1 CONCLUSIONS

It was concluded that the major problem In spent fuel bay

operation would be defected fuel. The escaping fission products would

contaminate both the bay atmosphere and the bay water. From there they

would spread throughout the station causing low level contamination - a

constant source of man-rem consumption. When the spent fuel bay water is

contaminated, flasks and other equipment lowered into it have to be

decontaminated causing further expenditure of man-rem.

Experience has demonstrated that on certain occasions the

concentration of fission products (mainly gaseous) in the bay water reaches

the point where the bay itself is a significant source. The fuel handling

equipment often lacks simplicity and accessibility. Thus maintenance on

this equipment usually results in a sizable expenditure of man-rem.

5.2.2 RECOMMENDATIONS

The basic recoimnendations resulting from the study are:

1. Divide the spent fuel bay into two basic areas, a receivingbay and a holding bay.

2. Separate the atmospheres and water of the two basic areas.

3. Design simple and accessible fuel handling equipment.

5.2.3 RECEIVING BAY AND HOLDING BAY

The first bay, the receiving bay, would receive the fuel directly

from the fuelling machine. This bay would be designed to handle high

levels of fission products both in the bay water and the bay atmosphere.

Since the bay would be effectively isolated from the rest of the station,

the spread of contamination would be minimal. Defected fuel would be

canned in this bay and then transported to the holding bay. Any inspection

E-20

or experimentation would be done here as well.

To handle large releases of fission products effectively, the

bay would be kept as small as possible and the ventilation and bay water

purification system would be capable of high clean-up rates. The receiving

bay should be located as close to the reactor as possible. This will

ensure that the defected fuel will be quickly transferred to the receiving

bay for canning, reducing the time available for fission product release.

The second bay, a holding bay, should be separated from the

receiving bay by a water lock, and an atmospheric partition. Pressure

differences between the two bays should be sufficient to ensure that the

air flow between bays would result in flow from the holding bay to the

receiving bay. It is expected that there will be an occasional fuel

defect in the holding bay. The frequency of this occurrence is expected

to be small. The concentration of fission products in the bay should be s,

at a low level and the purification and ventilation systems would be |

designed accordingly. \

E-21

TABLE 1

AVERAGE PRODUCTION RATE OF SPENT FUEL

PLANT

Douglas Pt. G.S.220 MWe

Bruce G.S. A4 x 750 MWe

Bruce G.S. B4 x 750 MWe

Bruce6000 MWe

TOTALBUlwJLÎSS/DAY

1973-1975

6

0

0

0

6

1976

6

13

0

0

19

1977

6

26

0

0

32

1978

6

39

0

0

45

1979

6

52

0

0

58

1980

6

52

0

0

58

1981

6

52

13

0

71

1982

6

52

26

0

84

1983

6

52

52

0

110

1984

6

52

52

100

210

Average bundle discharge rate assumes a capacity factor of 80%.

Each reactor assumed to have 30 years life.

Assumed that 6000 MWe In-service at the beginning of 1984 and finishservice at the end of 2013.

TABLE 2

CAPITAL, OPERATION AN0 MAINTENANCE CASH FLOWS AND FUELARISINGS AT THE SPENT FUEL STORAGE FACILITY

DESCRIPTION

Capital Cash Flow

(less Interest)

1973 MS

Operation and Mtce.

Cash Flow

1973 H$

Fiid ArUings *kgU x 10»

DESCRIPTION

Capital Cash Flow

(less Interest

1973 M$

Operation and Mtce.

Cash Flow

1973 M$

Fuel Arisings

kgU x 10'

1975

0.971

-

0.305

1995

1.975

1.701

1.525

1976

0.886

-

0.138

1996

1.975

1.897

1.525

1977

22.347

-

0.232

1997

-

2.093

1.525

1978

-

0.961

0.327

1998

1.975

2.093

1.52S

1979

1.975

0.955

0.421

1999

1.975

2.092

1.482

1980

-

0.955

0.421

2000

1.975

2.092

1.482

1981

1.003

0.956

0.516

2001

2.078

2.092

1.482

1982

1.004

0.956

0.610

2002

10.920

2.092

1.482

1983

1.975

0.959

0.799

2003

1.975

2.092

1.482

1984

1.975

0.967

1.525

2004

1.975

2.386

1.482

1985

1.975

0.967

1.S25

2005

1.975

2.386

1.482

1986

2.078

0.967

1.525

2006

-

2.385

1.387

1987

11.325

0.967

1.525

2007

1.975

2.384

1.293

1988

1.975

0.968

1.525

2008

1.975

2.383

1.198

1989

1.975

1.701

1.525

2009

-

2.382

1.104

1990

1.975

1.701

1.525

2010

1.975

2.382

1.104

1991

1.975

1.701

1.525

2011

-

2.381

1.010

1992

1.975

1.701

1.525

2012

-

2.380

0.915

1993

2.078

1.701

1.525

2013

-

2.378

0.726

1994

10.641

1.701

1.525

2014

-

2.256

-

to

Fuel arising* In 1975 Is the sum of all Douglas Fc. G.S. spent fuel from in-service date to end of 1975.

E-23

TABLE 3

SUMMARY OF CAPITAL COST

COST SOURCE

DIRECTSCommissioningSite Improvements and WorkBuilding and StructuresElectricsInstrumentation and ControlCommon Processes and Services

TOTAL DIRECTSConstruction IndirectsEngineering

TOTAL CONSTRUCTION COSTAdministration OverheadsInterest During Construction

TOTAL ALLOCATED COSTContingencies

TOTAL PROJECT COST

1973 k$

2,260.0879.0

69,193.0388.0220.0

9,868.0

82,808.0

14,264.01,300.0

98,372.0

2,215.04,136.0

104,723.0

4,250.0

108,973.0

Ï

TABLE 4

SUMMARY OF OPERATING COST

SOURCE

Labour

Transport andWork Equipment

Resin Replacement

Demineralized Water

Power

Radiation Waste

Building Maintenance(0.1% of Bldg Capital)

Major Equip Mtce(1% of Equip Capital)

Taxes and Insurance(1 1/22 of Capital Inv)

TOTAL (1973 k$)

1978-1988

295

30

32

1

27

15

100

65

386

951

1989-1996

402

66

32

2

31

15

100

80

957

1685

1996-2003

402

66

32

2

35

16

100

95

1329

2077

2004-2013

402

66

32

2

46

16

100

105

1602

2371

2014 +

287

5

16

-

41

11

100

105

1691

2256

E-24

TABLE 5

INVESTMENT IN THE PERPETUAL CARE FUND AT THE YEAR 2014

COST SOURCE

General Operating Costs(Annual)

Leaking Bay Recoveryand Restorage(Every 25 years)

Equipment Replacement(Every 33 1/3 years)

Facility Replacement(Every 100 years)

Fuel Transfer AndDecommission(Every 100 years)

AMOUNT1973 M$

2.256

3.2

15.0

84

31

F

34.7

0.98

0.66

0.062

0.062

TOTAL INVESTMENT IN FUNDAT START OF YEAR 2014

INVESTMENT INFUND AT 2014

1973 M$

78.3

3.1

9.9

5.2

1.9

98.4

(Investment at 2014 = Amount x F)

TABLE 6

PRESENT WORTH ESTIMATE OF COSTFOR MANAGEMENT OF SPENT FUEL

COST SOURCE

A. STORAGE COSTCapital CostOperating Cost(includes storage basket)

B. PERPETUAL CARE COSTTOTAL UNIT COST OF

MANAGEMENT OF SPENT FUEL

1972 $/kgU

2.57

1.53

1.23

5.33

E-25

TABLE 7

PRESENT WORTH ESTIMATE OF COST FORMANAGEMENT OF SPENT FUEL WITH DESIGN IMPROVEMENTS

COST SOURCEA. STORAGE COST

Capital CostOperating Cost(includes storage basket)

B. PERPETUAL CARE COSTTOTAL UNIT COST OF

MANAGEMENT OF SPENT FUEL

1972 $/kgU

2.02

1.53

1.22

4.77

TABLE 8

PRESENT WORTH ESTIMATE OF COST FOR MANAGEMENT OF SPENT FUELWITH DESIGN IMPROVEMENTS AND INCREASED STACKING DENSITY

COST SOURCEA. STORAGE COST

Capital CostOperating Cost(includes storage baskets

B. PERPETUAL CARE COSTTOTAL UNIT COST OF

MANAGEMENT OF SPENT FUEL

1972 $/kgU

1.69

1.65

1.21

4.55

E-26

TABLE 9

PRESENT WORTH ESTIMATE OF INCREMENTAL CAPITAL COST

COST SOURCEDIRECTSCivil and StructuralElectricalInstrumentation and ControlCommon Services

TOTAL DIRECTSConstruction IndirectsEngineering

SUBTOTALAdministration OverheadsC2 1/4% of Subtotal)Interest During ConstructionC8% per annum)

TOTAL ALLOCATED COSTContingencies

TOTAL ADDITIONAL COST

1-3 Years1972 $

610,00057,000

230,000

897,000

243,000

1,-140,000

26,000

48,000

1,214,000

127,000

1,341,000

1-5 Years1972 $

1,026,000113,000

418,000

1,557,000

448,000

2,005,000

46,000

83,000

2,134,000

214,000

2,348,000

TABLE 70

PRESENT WORTH ESTIMATE OF INCREMENTALOPERATION AND MAINTENANCE COST

COST SOURCELabour (approx)

Power, Materialsand Waste Storage

Extra Storage Baskets

TOTAL

1-3 Years1972 $

405,000

281,000

686,000

1-5 Years1972 $

688,000

550,000

1,238,000

E-27

TABLE 11

PRESENT WORTH ESTIMATE Of TOTALINCREMENTAL COST FOR A SHORT-TERM FACILITY

No. of BundlesProcessed ThroughSpent Fuel Bay

Weight of Spent FuelProcessed

569,400

11.4x106kgU

COST SOURCEIncremental CapitalExpenditure

Incremental Operation

TOTALUnit Cost

1-3 Years1972 $1,341,000

686,000

2,027,000

$0.27/kgU

1-5 Years1972 $

2,348,000

1,238,000

3,586,000

$0.47/kgU

PROJECTS

BRUCE 1—4

E12 PICKERING 5—6

El 3 BRUCE 5—8

El4 BOMMANVILLE

El5 FOSSIL OR NUCLEAR

4—750 MW

El 6 NUCLEAR 4—750 MW

El 7 NUCLEAR 4—1200 MW

El 9 NUCLEAR 4—1200 MW

E20 NUCLEAR 4—1200 MW

1976

•

1977

•

1978

•

1979

•

1980

•

1981

• «

•

1982

» •

1983 1984

. . . |

• + '• <

(

1985

> •

1986

•

1987

1 (

1988

}

•

•

1989

•

•

^

FIGURE 1

FUTURE PROGRAM

IN SERVICE DATE

E-29

20x106

J5JOD6

„_ 10M06

o

0.5 x106

BGS B - BRUCE GS B

PGS B - PICKERING GS B

BGS A - BRUCE GS A

PGS A - PICKERING GS A

1970 1975 1980 1990 1395 2000

YEAR

FIGURE 2: ACCUMULATED SPENT FUEL

E-30

BAIK DU DORE

STUDY LOCATION OF , - -.SPfHITFUEl \ S"^ \

PROPOSED BRUCE STORAGE FACILITYHEAVY WATER PLANT

MCTftI*

FIGURE 3: STUDY LOCATION OF SPENT FUEL STORAGE FACILITY

E-31

S

I

5o

10'

10 -

IOC 10 '

FISSION PRODUCTS

J L J L

I 0 3 10' 10s 10 '

TIME (YEARS)

10' 10 ' 10!

FIGURE 4: DECAY HEAT PRODUCTION FROM SPENT CANDU FUEL(9000 MWd/Mg U)

mwto

FIGURE 5: SPENT FUEL STORAGE FACILITY

"i-

L

iv

= r5?

PLAN WITH CONCRETE SLABS ANDSTAINLESS STEEL LINERS REMOVED

PLAN

1.37m .76mW-6") 6.55m (21--6") <2'-6")

i i6.25m |20'-6") | | 6.25m (2O'-6") |1.07m

PLAN

WATER LEVEL

6.2Sm (20'-6"> (5'V

SECTION WITH CONCRETE SLABS ANDSTAINLESS STEEL LINERS REMOVED

FIGURE 6: STORAGE BAY

SECTION

PLAN

!

si

STAINLESS STEEL COVbRiilII!

. ! i !Hl! J.

iJJÀ.

-WEATHER PROOF AIR INTAKE

WATER, SEWAGE LEAKAGECOLLECTION RETURNRAD WASTE

PLAN

AGE I1 •

SCALE IN METRES

FIGURE 7: SECTION OF STORAGE BAY

E-35

DISCHARGE STACK

SPENT FUEL BAYS (TYPI—»-j

I J.II t

WEATHER RESISTANT HOUSING-»}"?- ""

INTAKE jFILTER

FIGURE 8: FLOW DIAGRAM - VENTILATION SYSTEM

2 2275 rr.3 1500.000 IMPERIAL GALLON!-DEMINERALIZED WATER

STORAGE TANKS ' I

-SERVICE & CONTROL CENTRE

FIGURE 9: FLOW DIAGRAM — COOLING SYSTEM

J

LOADING CELL

24 GAUGE STEEL FACEDI 7.62mm iZ") THICK POLYURETHANE

FOAMED CORE PANELSOBSERVATIONWINDOW

RETRACTABLE LADDER-THAVEL RAIL i ~

7sTEEL ROOF DECK fI AND SIDING PANELS »

10.2 mm (4") FIBERGLASSINSULATION STEEL PLATEINTERIOR PANELS

SCALE IN MCTNES

FIGURE 10: LOADING CELL

CONCEPT DEFINITION

0

AQUISITION

COWMISSIOIIIHC

7OPERATION

__ - . .E FIUHW »SIIUNG VIUIT H* 1 IAVST0TA1 OF 11 TEARS TD COMttlH.Stf DWG 5CHGS I I I I I - I 1 S I

ISIIIHIESS StlElLIHtR IHSIAUED

. VAUU H* 1I COICflETI' COMPIEK

FIGURE 11: PROJECT LIFE CYCLE — SPENT FUEL STORAGE FACILITY

T—i—i—i—i—i—i—i—i—i—r—i—i—r—I—i—r—i—i—i—i—i—i—i—r—i—i—i0 1 2 3 « 3 « 7 • • 10 I I 1 13 14 IS 1» 17 » 1* 20 21 22 23 24 25 26 2

1 1 1 1 1 1 1— I 1 1 1 1 1—" 21 2» 30 31 32 33 34 39 1 * 37 3» 3*

CALENDAR ITEMS

LONG TERM SPENT FUELFACILITY

PRELIMINARY ENGINEERING

SITE IMPROVEMENTSPROCUREMENTCONSTRUCTION

a"1VAULT Nt 1FILLEO tSEALED

VAULT N91

FIUWS « 0 SEALING IAYS

INSTALLATION OF STAINLESS STEEl LINERS a i BLUE aVAULT N?2FILLED ï SEALED

VAULT N? 2

FILLING AND SEALING MVS

ENGINEERING

CONSTRUCTION

INSTALLATION OF STAINLESS STEEL LINERS

mma LU H msa

I i

TTVAULT NI 3FILLED «SEALED

w

VAULT N° 3

FILLING AND SEALING IAVS

ENGINEERING

CONSTRUCTION

INSTALLATION OF STAINLESS STEEL LINERS

BE

mm E. H

i

VAULT N MFILLED «SEALED

VAULT NP 4

FILLING AN» SEALING H V S

ENGINEERING

CONSTRUCTION

INSTALLATION OF STAINLESS STEEl LINERS

H• 1 * 1 * 1 * 1 » 1 «

SHi LUiSi IB!

FIGURE 12: CONSTRUCTION SCHEDULE - SPENT FUEL STORAGE FACILITY

E-40

L

PLAN

FUELLING MACHINE DUCT

FIGURE 13: EXISTING SPENT FUEL BAY AT BRUCE GS A

E-41

LSECTION SECTION

34.93m,. (114--6"). .

, • 7 7 . T

SPENT FUELPORTS

PLAN

NEW FUEL ROOM

WINDOW

\ WL 636.0

J^^W^W1

,-r1

PLAN

1FUELLING MACHINE OUCT

MALE IN MCTRES

FIGURE 14: ONE YEAR SPENT FUEL BAY

E-42

L

PLAN

CN

JSECTION

SPENT FUELPORTS

r—NEW FUEL ROOM |

II \ || WINDOW |

I 615.0

______ *v--'*.2 k|'

FUELLING MACHINE DUCT-

WWWK^T****»

PLAN

FIGURE 15: THREE YEAR SPENT FUEL BAYSCALE IN METRES

E-43

L

PLAN

FUELLING MACHINE DUCT- 0 10 «0

SCALE IN METRES

FIGURE 16: FIVE YEAR SPENT FUEL BAY

, , ~ ~ _ _ ~ ~ J_, _A]CONCRETEL 1 J EMERGENCY BASKET STORAGE ^SHIELDING

FUEL STORAGEBASKET ONINDEX TABLE

MAN-BRIDGE-GANTRY & HANDRAILING| NOT SHOWN ON THIS VIEW FOR CLARITYJ

J

EQUIPV -NT IS SYMMETRICAL ABOUTNORTH/SOUTH WITH THE EXCEPTIONOP THE PERISCOPE

FUEL STORAGEBASKET POSITIONED *ON INDEX TABLE

PLAN

-SPENT FUEL PORT

— FUEL TROUGH

HYDRAULIC RAM

HANDRAILING & EMERGENCYSTORAGE BASKETS OMITTEDFOR CLARITY IN THIS VIEW

O I 8 3 4 5

SCALE IN METRES

FIGURE 17: RECEIVING BAY LAYOUT AND FUEL HANDLING EQUIPMENT

Fuel Sheaih Failu

'n-.nmn Fiom tmliMii len.^'nonnit.it D.im.itu; IDroppinq.» Fl.isk)

Failure

Activity collection point

®J Mattim Structural Boundaryà FaHura (Concrtt* Bay and

SS L i w l Resulting in Lossof Coolant

AcB. y Wai PI

k ®XF \ Boundary Failute / Z \ o.erflowof

1 Circul.ting Coolin9 < F > Waicr Bays

erfili.Tiq Bays 1ikp tip Wjteo I

Acnviiv in HayAimosphere

©1/v\f

\ Bound/ Ventila

CiuseEjrthnMissileCorrnsAccideMech.i

ry Failure /tian System \

on1t.il O.lltld()BIC.ll We.lr

• Scrubber and/orMomtoniq

FIGURE 18 ACTIVITY RELEASE PATHS

F-l

APPENDIX F

STORAGE OF SPENT CANDU FUEL IN CONCRETE CANISTERS

by

S.C. Bhatia and D.R. McLean

1. INTRODUCTION

Concrete canisters are potentially useful for interim storage

of spent fuel. In the concrete canister method, the fuel is stored in

small units which are self-shielding and self-cooling. Once placed in

storage, they do not require any elahorate mechanism for operation,

surveillance, or maintenance. The canisters are easily handled and can

be replaced easily. In an act of war, sabotage or natural catastrophe,

the damage may be limited to only a small number of the canisters.

2. GENERAL DESCRIPTION

2.1 CANISTERS

A concrete canister is a reinforced hollow concrete cylinder

2.29 m (7.5 ft) in diameter and 4.88 m C16 ft) high (see Figure 1). The

all-welded mild steel can within the canister contains 4.4 Mg of spent

F-2

fuel arranged in 37-hundle clusters, the 2.54 cm (1 in) layer of lead

between the fuel-can and the thick concrete walls provides additional

radiation shielding, reducing the surface dose to 15 mR/h.

The canister is stored outdoors. Decay heat from the fuel

flows by radiation and conduction through the air spaces within the fuel-

can and then by conduction through the can wall, the lead, and the concrete;

the outside surface is cooled by natural convection. Heat absorbed from

the sun must also be dissipated from this surface. This additional source

of heat limits the amount: of decay heat that can be handled in the canister

and makes it necessary to pre-cool the fuel at the reactor site for five

years. The use of lead which is a much better shielding material than

concrete, reduces the thickness of concrete required. The temperature

gradient across the canister is shown graphically below the canister in

Figure 1.

Approximately 15,000 canisters are required to handle the

68,000 Mg of fuel being considered for this study. This requires a storage

area of about 0.809 km2 (200 acres). Each canister weighs about 50 Mg

and for most soil conditions only a gravel base is required to carry the

load.

The canisters are fabricated indoors, on-site, in re-usable

metal forms and are cured for approximately 30 days before being given a

final inspection. It is assumed that concrete is supplied from an off-

site batching plant. (If this is not possible, a small batching plant

can be built at the site.) At least 30 canisters will always be in process

in the fabrication building. It was assumed for costing purposes that

5% of the canisters will be rejected because of defects.

2.2 FUEL HANDLING AT THE REACTOR SITE

To minimize handling at the reactor site, the fuel bundles

are stored in baskets. Each basket holds 2.2 Mg of fuel (111 bundles

F-3

stacked in 37-bundle clusters) and is fabricated from stainless steel to

permit storage in the reactor pools. The baskets are filled as the fuel

emerges from the reactor and, after five years of cooling, are placed in

the mild steel storage cans Ctwo baskets per can) for shipment to the

central site. The design of the basket and the fuel-can are shown in

Figure 2.

The cans are filled in a hot cell (not shown). The baskets are

lifted from the pool and allowed to dry in the hot cell before they are

placed in the fuel-can. After the cover has been welded in place (by a

remote welder), the can is inspected and monitored. It is then air-cooled

in a temporary storage cell until ît can be loaded into a shipping flask.

A device for lifting the fuel baskets and the fuel-can is also

shown in Figure 2. It has a circular ring in which three spring-loaded

retractable pins are fixed. When this ring is placed in the top of the

basket or fuel-can, the retractable pins are released and fit into the

three holes in the basket or the can frame which can then be lifted by

eye bolts attached to the ring.

An allowance for the cost of the hot cell and extra handling

for the canning operation is included in the cost of the fuel storage can.

2.3 FLASK AND CANISTER HANDLING AT THE CENTRAL STORAGE SITE

The operations involved in transferring fuel from shipping

flasks to the canisters and moving the canisters out to storage are shown

in Figure 3. The hot cell where the unloading takes place is shown in

Figures 4, 5, 6, and 7. The design permits the fuel to be transferred

without taking either the flask or the canister into the hot cells. This

is achieved by parking the flask (on rail cars or trucks)and the canister

(on a flat bed truck) under the hot cell, where shielding collars are

lowered to their top surfaces (see Figure 6). After the shielding plugs

have been removed, the fuel cans are transferred with, an overhead crane.

Two flask unloading ports are provided to speed up operations. If a

F-4

canister is not ayailable, the fuel cans are stored temporarily in an

air-cooled storage cell Cspace for 16 cans).

In the first few years of operation, the frequency of shipments

to the site will be low. To reduce -manpower requirements in this period,

the flask unloading crew will simply transfer all the fuel to the temporary

storage cell. This same crew can then transfer the fuel to the canisters

between flask shipments.

The hot cell is equipped to handle fuel cans that fail during

shipment. If the monitoring operations reveal that a newly arrived flask

is badly contaminated within, it is removed from the transport vehicle

and unloaded in the isolation cell. The fuel cans are repaired or replaced

in the repair cell.

When a canister has been loaded, lead shot is poured into the

space around the fuel can and the shielding plug is inserted. The shielding

collar is raised and the canister is moved forward below a ring-shaped

gamma scanner. This scanner is slightly larger in diameter than the

canister and is lowered automatically over the canister to check the

radiation field from top to bottom. If the canister passes inspection,

it is moved forward again and an automatically operated welder is lowered

to weld the shield plug in place. The canister is then hauled on the

flat bed truck to the outdoor storage area.

The canisters are placed outdoors in a storage area on gravel

beds suitable for withstanding the load of the canisters. Gravel roads

are provided around each bed for trucks and the canister handling crane.

Each bed is 7.62 m (25 ft) wide by 464.8 m (1525 ft) long and provides

space for 200 canisters placed in a square pitch arrangement. A layout

of the storage site and the area around the main buildings is shown in

Figure 8.

The truck carrying the canister is brought near the storage

spot over which a canister handling crane (Figure 9) is positioned. The

F-5

canister is lifted from the truck by the crane and placed in position on

the gravel hed.

The cabins of the truck and the crane are lined with lead to

ensure that under normal operating conditions workmen will not received

more than 2 R/a.

The storage area is to be monitored as follows:

1. Runoff flowing from the storm sewers will be sampled andmonitored.

2. Zone monitors will monitor the air and the radiation fieldsfrom the canisters.

3. A portable truck-mounted monitor will be used on a routinebasis to check the site for the presence of abnormalradiation fields which might indicate that a serious crackhas developed in a canister.

2.4 PERSONNEL REQUIREMENTS

The canister handling load will increase from three per week

in 1982 to 27 per week in 2004. The canister arisings and the canister

handling capability are plotted against calendar years in Figure 10.

In 1982, 15 persons will be employed. They will be able to

handle a nominal throughput of 7 canisters per week initially but this

will gradually improve to 10 per week by the year 1992 through experience

and by standardization of the handling procedures. The personnel required

will increase to 29 by 1993 and to 59 by 2001. A breakdown is shown in

Table 1 for the last period. Beyond the year 2004, only routine surveil-

lance will be required for the storage area and this will require 10 people.

2.5 OVERALL SCHEDULE

As a result of the four additional years of cooling required

at the reactor site for fuel stored in canisters, the first arisings are

not sent to the central site until 1982 and the last shipment of fuel is

made in 2004. (In schemes where one-year-cooled fuel can be stored, the

first shipments are sent in 1978 and the last in 2000.)

The hot cells and some of the auxiliary facilities must be

ready before the first shipment arrives. Construction should be completed

between 1981 - J.982. The canister storage area will be prepared as

required. Three rows of storage plots (i.e. 9. plots) will be prepared

at a time.

The life of the canister handling facility and the canisters

is expected to be about 50 years. Then a new canister handling facility

will be built and the canisters will be replaced gradually.

3. COST SUMMARY

3.1 CAPITAL COSTS

3.1.1 GENERAL CAPITAL EXPENDITURES

Approximately $9 million must be spent on design and construc-

tion of facilities between 1979 and 1981 to prepare the site for the first

fuel shipments. A breakdown of this cost is shown in Table 2. "Land and

Yard Development" includes roads, railroads, parking lots, fencing,

lighting, perimeter roads required at the canister storage area, a portion

of the low-level waste burial grounds, and the first three rows of canister

storage plots (nine plots in total) with adjoining roads. "Buildings

and Building Equipment" includes all buildings shown in Figure 8 except

the canister fabrication plant and the administration, cafeteria, and

stores buildings.

The cost of the canister fabrication plant is included in the

unit costs for the canisters which will be described subsequently.

The administration building, cafeteria, and stores will be

built in 1992 to coincide with an increase in personnel required to

F-7

handle the growth in fuel shipments to the central site. The entire

expenditure in 1992 amounts to $1.5 million. It includes expansion of

the low-level waste burial grounds, completion of the storm sewers and

monitoring systems required at the canister storage area, replacement of

some worn-out rolling stock, and some additional mobile equipment (see

Table 3).

This brings the total general capital expenditures to about

$10.5 million. An additional $3.3 million will be spent in stages between

1982 and 2004 for new storage plots to handle the new canister arisings.

The spending schedule for these plots is shown in Table 7.

3.1.2 CAPITAL EXPENDITURES FOR FUEL CAMS AND CANISTERS

Two baskets are required per fuel-can at a cost of $777 per

basket. The unit cost per fuel-can (4440 kg U), including filling charges,

amounts to $3600 per can; canisters including the lead shot cost about

$4500 each (see Table 4). The total capital expenditure for baskets, cans,

canisters, and lead during the site filling period is $147 million.

3.2 ANNUAL OPERATING COSTS

To illustrate the cost of the various items that make up the

annual operating cost, a breakdown for the year 2004 is given in Table 5.

The total expenditure for that year is $1.2 million. The total values

for each year are shown in Table 7.

3.3 PERPETUAL CARE COSTS

Annual operating costs beyond the year 2004 were estimated to

be $0.6 million (see Table 6). To provide this sum in perpetuity, a

sinking fund of $21 million must be established by 2004.

It was assumed that the site facilities, the canisters, the

lead shot, and 5% of the fuel-cans would be replaced at 50 year intervals.

F-8

The replacement costs in 1972 dollars were assumed to be the same as the

initial costs with the following adjustments;

1. The old lead shot could be sold for 50% of its initial valueand the resultant income applied to the cost of the new lead.

2. Operating costs for the replacements would be 1.5 times greaterthan the total operating expenditures in the first site fillingperiod (1982 - 2009).

3. The old canisters would be disposed of at a cost of $1000/canister.

The total expenditure for replacements at the end of each 50

years was estimated to be $111 million. This cost can be covered in

perpetuity with a sinking fund valued at $35.0 million in 2004.

The total investment in perpetual care is $56 million.

It can be shown that if canister storage is used for 100 years

rather than in perpetuity the investment required is $54 million. If, after

100 years the fuel is shipped to a salt mine for final disposal an

additional investment of $17.73 million is required.

3.4 LEVELIZED STORAGE PRICE AT CENTRAL SITE - $/kq U

The capital, operating, and perpetual care cost data that are

required to estimate the levelized storage price are shown in Table 7.

The levelized price amounts to $2.7I/kg U for capital and

operating expenses. Perpetual care costs are $0.67/kg U. If canister

storage is used for 100 years the sinking fund costs are $0.65/kg U. The

additional amount required to switch to salt storage at the end of the

100 year period is $0.21/kg U. A breakdown of the levelized price is

shown in Table 8.

3.5 PENALTY FOR STORAGE FOR FOUR EXTRA YEARS

As mentioned previously, this scheme requires five year cooled

fuel. Ontario Hydro has calculated that the cost of storing fuel for an

extra four years at a reactor site is $0.47/kg U.

F-9

3.6 SHIPPING

WIRE has calculated that the cost for shipping fuel from the

reactor site to a central storage site amounts to $2.20/kg U (see

Appendix I).

3.7 DEVELOPMENT COSTS

A development program for a surface storage facility has been

considered to cover a 10 year period prior to the emplacement of fuel on

a routine basis at a selected site. It includes funds for development

work, site selection, public, information, and capital and operating

expenditures for pilot work. The total cost is $4.0 x 106. If the

development costs are charged against the fuel arisings to the year 2004,

the additional cost to the total scheme is $0.10 kg U.

3.8 TOTAL COST FOR MANAGEMENT OF SPENT FUEL IN CONCRETE CANISTERS

A breakdown for the total levelized cost of the management

of spent fuel in concrete canisters is given in Table 9.

4. GENERAL COMMENTS ON CANISTER STORAGE

1. A canister is an independent, self-contained unit for thestorage of spent fuel. Canisters are easy to handle, transport,repair or replace. They mav be safer with respect to acts ofwar, sabotage, or natural catastrophes than large vaults.They should require very little care during their entireservice life except for minor routine surveillance. Thisadvantage is offset somewhat by the large number of canistersrequired.

2. Since the canister offers dry storage in a sealed container,there is little chance that a major leak may occur causinglarge scale spread of contamination, because it is not likelythat all the canisters will leak at the same time.

3. The design of the fuel-can, and the concrete canisters maybe improved even during the filling period without causingmajor changes in the project.

F-10

4. Loss of cooling by natural or artificial means is unlikely.

5. The spent fuel can be retrieved easily.

6. Defective canisters vjill be rejected by quality controlprocedures at the manufacturing stage. A rejection rate ofabout 5% is included in the cost of the canisters.

7. Development work is essential to confirm the temperaturegradients and the dose rates estimated in this report and toexamine the thermal stresses in the concrete.

In this phase of the study, only relatively simple and basic

concepts were examined. Suggestions for further study which might improve

the concept are as follows:

1. The emissivity of the canister surface could be improved and,therefore, its heat load from the sun could be reduced, bypainting the surface of the canister with metallic paint.This may allow the decay heat load to be increased, eitherby storing younger fuel or by increasing the cluster size from37 bundles to 61. To ensure that the centerline temperatureof the fuel-can does not exceed 300°C, the temperature dropacross the cluster can be reduced by filling the air spacesin the can with fine sand. Because of the self-shieldingeffect of the bundles, the required increase in shieldingthickness of the canister will be small. If 61-bundle clusterscan be used, the storage price per kg U will be loweredsignificantly.

2. The life of the canister may be greatly increased if theconcrete surface is waterproofed and covered with an aluminumskin to slow down weathering.

3. Monitoring would be facilitated by putting a roof over eachstorage bed occupied by canisters. This would cost about$0.20/kg I). If the roof is peaked and an opening is providednear the peak, warm air rising from the canisters could bemonitored for activity as it leaves the roof opening. Afurther advantage would be a reduced sun heat load.

4. A canister made from steel and concrete would have a longerservice life than an all concrete canister. If steel aloneis used a 33 cm thickness would be required for a 37-bundlecluster at five years cooling and 25 cm after 50 years cooling.Thus a canister with 25 cm thick steel walls plus additionalconcrete shielding could handle five year cooled fuel. Thishas the advantage that after 50 years when the integrity ofthe concrete is in doubt, the all steel shielding will provideservice for a further period, which may extend to a few hundredyears. Also, the steel canister may serve as a shipping flaskat the end of the first 50 years, thereby providing some savingin shipping costs. This type of canister might be useful forstoring fuel at the reactor site for 50 years before shippingit to a central surface or geologic storage site.

F-ll

TABLE 1

MANPOWER REQUIREMENTS FOR THE PERIOD 2001 TO 2004

CATEGORY OF PERSONNEL

Site Superintendent

Hot Cell Fuel Handling Operations(12 persons per shift x 2 shifts)

Hot Cell Services(2 persons per shift x 2 shifts)

General Maintenance

Health and Safety: Head

Health and Safety Surveyor

Traffic and Records Clerk

Accountant

Accounts Clerk

Stenographer

Janitors

Miscellaneous Duties

Guards

TOTAL PERSONS REQUIRED

SHIFTALLOCATION

Day Shift

2 Shifts

2 Shifts

Day Shift

Day Shift

Day Shift

Day Shift

Day Shift

Day Shift

Day Shift

Day Shift

Day Shift

2 Shifts

NUMBERREQUIRED

1

27

5

3

1

1

1

1

1

2

2

2

_9

59

V-12

TABLE 2

SUMMARY OF GENERAL CAPITAL EXPENDITURES - 1979 - 1981(All Costs tn 1972 dollars)

CONSTRUCTION COSTS

Land and Tard DevelopmentBuildings and Building EquipmentOther Services: Storm Sewer, Electrical

Substation and Distribution, StorageArea Monitors

Rolling Stock

TOTAL

ENGINEERING SERVICES

Canister DesignSite Facilities: 12% of Construction

Costs dhown Above

TOTAL

OWNERS1 EXPENSE: 2.5% of Construction Costs

CONTINGENCIES: 15% of Construction Costs,Engineering and Owners' Expense

TOTAL CAPITAL EXPENDITURES - 1979 - 1981

MILLIONS

2.373.30

0.570.48

0.03

0.81

OF DOLLARS

6.72

0.84

0.17

1.16

8.89

F-13

TABLE 3

SUMMARY OF GENERAL CAPITAL EXPENDITURES IN 1992CA11 costs tn 1972 dollars)

MILLIONS OF DOLLARS

CONSTRUCTION COSTS

Buildings and Building Equtpment -Administration, Cafeteria, Stores 0.25

Expansion of Services at Storage Area;Roads to Low-Level Vaste Burial Grounds,Storm Sewers, Monitor for Canister Storage 0.63

TOTAL 0.88

ENGINEERING: 12% of Construction Costs 0.11

OWNER'S EXPENSE: 2.5% of Construction Costs 0.02

CONTINGENCIES: 15% of Above Costs 0.15

TOTAL FOR FACILITIES BUILT AT SITE 1.16

ROLLING STOCK: Replacements and SomeAdditional Equipment 0.39

TOTAL GENERAL CAPITAL EXPENDITURES 1992 1.55

F-14

TABLE 4

UNIT COST FOR BASKETS, FUEL-CANS AND CANISTERS

BASKETS C2 per fuel-can)

FUEL CANS

Material, Fabrication Labour, Inspectionand Overheads

Capital Charges for Hot Cell at ReactorSite and Hot Cell Services

TOTAL FOR FUEL-CAN

CANISTERS

Materials, Labour, Inspection andOverhead in Canister ManufacturingPlant Plus 5% for Defects

Lead Shot

UNIT

1400

2200

25701900

TOTAL FOR ONE FUEL-CAN AND ONE CANISTER

COST, $

1554

3600

4470

9624

$/kg U

0.35

0.81^

1.01

2.17

If stainless steel rather than mild steel cans are used thecost may be about 20-30ç/kg U higher. (Assumed a thinnerwalled can if fabricated from stainless steel)

TABLE 5

SUMMARY OF ANNUAL GENERAL OPERATING COSTS IN 2004

MILLIONS OF DOLLARS

MANPOWER - 50 People @ $10,000/a 0.50

UTILITIES - Fuel Oil, Electrical Power andWater Supply 0.03

OPERATING SUPPLIES, 25% of Manpower Costs 0.13

MAINTENANCE, 1.0% of General Capital InvestmentPlus 0.25% of Cost of Filled Canisters 0.35

TAXES AND INSURANCE, 1.5% of General CapitalInvestment 0.20

TOTAL GENERAL OPERATING COSTS IN 2004 1.21

F-15

TABLE 6

PERPETUAL CARE COSTS

ANNUAL OPERATING EXPENSES

Manpower, 10 Men @ $10,000/aUtilities, $1000/monthOperating Supplies, 15% of Manpower

CostsMaintenance, 0.5% of General Capital

Investment Plus 0.25% of Cost ofCanisters

Taxes and Insurance, 1.5% of GeneralCapital Investment

TOTAL ANNUAL OPERATING COST

INVESTMENT IN PERPETUAL CARE FUND IN YEAR2004 TO COVER ANNUAL OPERATING EXPENSE

REPLACEMENT OF SITE FACILITIES^ CANISTERSAND FUEL CANS AT 50 YEAR INTERVALS

Replacement Cost: Site FacilitiesReplacement Cost: Canisters

$100$ 12

$ 15

$220

$200

$613

$14 x$97 x

TOTAL REPLACEMENT COSTS $111 X

INVESTMENT REQUIRED IN PERPETUAL CAREFUND IN YEAR 2004 TO COVER REPLACEMENTS

TOTAL INVESTMENT REQUIRED IN PERPETUALCARE FUNDS IN YEAR 2004

000000

000

000

000

000

$21.3 x 106

106

106

106

$34.7 x 106

$56.0 x 106

TABLE 7

SUMMARY OF EXPENDITURES FOR CAPITAL, OPERATING AND PERPETUAL CARE

NUMBER OFCANISTERS

164

182

205

225

259

236

277

331

383

446

511

581

658

730

818

903

973

1060

1131

1198

1263

1333

1426

15302

DATE

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

GENERAL

0.40

4.85

3.64

1.55

10.41

CAPITAL, MILLIONS

EXPAND STORAGEPLOTS AND ROADS

0.43

0.43

0.43

0.43

0.43

0.43

0.43

0.29

3 . 3 0

OF DOLLARSFUEL CANSCANISTERS

AND BASKETS

1.59

1 . 7 5

2.00

2.17

2.49

1.42

2.67

3.18

3.68

4.29

4.92

5.59

6.33

7.02

7.87

8.69

9.36

10.19

10.87

11.88

12.20

12.88

13.71

147.25

TOTALCAPITAL

OPERATING,MILLIONS OF

DOLLARSGENERAL

PERPETUAL CARE, MILLIONS OF DOLLARSANNUAL OPERATING AND REPLACEMENT

CAPITAL FACILITIES

0.421

0.421

0.431

0.431

0.448

0.448

0.458

0.458

0.468

0.474

0.696

0.706

0.723

0.733

0.744

0.759

1.05

1.06

1.08

1.11

1.15

1.19

1.21 56

160.99 16.67 56.0

i

F-17

TABLE 8

LEVELIZED COSTS FOR CAPITAL, OPERATING AND PERPETUAL CARE

COSTS,MILLIONS OF DOLLARS

CAPITAL

Expenditure for GeneralFacilities and StoragePlots 13.74

Interest Charges forBorrowed Money ^5.96

TOTAL 19.7

Expenditures for Baskets,Cans and Canisters 147.3

GENERAL OPERATING 16.7

TOTAL fpR CAPITAL AND GENERALOPERATING 183.7

PERPETUAL CARE (Use of Canisters inPerpetuity)

Total Value of Sinking Fund inYear 2004 56.0

Interest Earned to Year 2004 -10.5

Deposits to Sinking FundDuring Filling 45.5

TOTAL COST FOR CAPITAL, OPERATING 229.2AND PERPETUAL CARE

LEVELIZED COST,$/kg U

0.29

2.17

0.25

2.71

0.67^

3.38

If canister storage is used for 100 years, future care costswould be $0.65/kg U. The additional investment required tocover the cost of switching to salt storage at the end of this100 year period Vould be $0.21/kg U.

F-18

TABLE

SUMMARY OF

Development

Penalty for

Shipping

Capital and

COSTS FOR MANAGEMENT OF SPENT FUEL IN CONCRETE CANISTERS

LEVEHZEDCOSTS, $/kg U

, Site Selection and Public Information

4 Extra Years of Storage at Reactor

Operating Costs During Site Filling

Perpetual Care

TOTAL

Sites

Period

0.10

0.47

2.20

2.71

0.67

6.15

F-19

2.32 m.

JêL

4.87 m

«W »•••: ft* V 4I>/

lf>. . . . J»

-PLUG-

FUEL CAN2.54 cm SPACE (filled with lead shot)

3.35 m

76 cm

REINFORCING STEEL

TEMP. °C

TEMPERATUREPROFILE

"ADIAL DISTANCE

CANISTER SEALINGMETHOD-

FIGURE 1: CONCRETE CANISTER

FUEL BASKETS15.24 m 18 cm I.D.

!S< 5.08 x 5.08 xR>0.95 cm

cm O.D.73.7 cm O.D.LIFTING DEVICE(with retractable pins)

1.56 m

. 3.28m

10.1 cm

I1 ,|

1 »

1

|

HI|U—- typ.1 \ .?5 cm

70.5 cm dia.

iTMTnT37 FUEL BUNDLE

CLUSTER(3 per basket)

49.5 cm

2,54 c m — sq. pitch grating7.62 cm

SECTIONAL ELEV. "?';

-STORAGE POOL-(at Reactor Site)

FUEL BASKETS

-FUEL CAN-

-FUEL BASKET-

FIGURE Z-FUEL BASKET ANDSTORAGE CONTAINER-

FLASK RECEIVING AND DESPATCH

1. Check Flasks Physically2. Prepare to Locate Under

Hot Cells3. Despatch to Empty Flasks

back to Reactor Stations

Flaskson Cars

Canisterson Trucks

Unit Train Engine

1. Reverse Unit TrainEngine on a Turn-table and Park

2. Assemble Empty FlaskRail Cars into UnitTrains

CANISTER CONSTRUCTION PLANT

1. Construct ConcreteCanisters

2. Cure Canisters3. Quality Control4. Load Canisters on

Trucks

HOT CELLS OPERATIONS

1. Pre-Monitor Flasks2. Transfer Contaminated Flasks/Fuel Cans to

Isolation/Repair Cells3. Liquid Wastes go to Treatment Cells4. Locate Flasks/Canisters under Shield Collars5. Transfer Fuel Cans from Flasks to Concrete

Canisters or Can Storage6. Post Monitor Flasks/Canisters7. Transport Canisters to Storage Area

CANISTER STORAGE

1. Lift Canisters from Trucks and Place Themon Storage Beds with a Crane

AUXILIARY SERVICES

1.2.3.4.

5.6.7.8.9.10.

Boiler HouseElectrical SubstationWater Treatment PlantMaintenance Shop/GarageStoresAdministrationCafeteriaFire StationGate HouseParking

FIGURE 3: CANISTER HANDLING OPERATIONS

kRAILWAY TRACK

30.48 m AL.

1-SERVICES

91 cm

A

OPERATINGAREA

CHANGEROOM

1REPAIRHOT-CELL

J,ISOVATION

HATCHÏ2.44 m

» • •

HOT CELLSERVICE

> AREA

BU -FLOOR PLAN-ELEV. 30.48 m

76 cm PIPE(30" SCH 10 S PIPE)

MAIN ENTRANCE

OVERHEAD DOOR

FIGURE 4-CONCRETE CANISTER STORAGE-

HOT CELL DETAILS

34.7m

25.9m

STAIRS'

VENTILATIONAND OTHERSERVICES

HOT CELLSERVICEAREA

f \ ( '••-'• i \ 1 •' i \ !

7.9m

l

FIGURE 5 FLOOR PLAN OF HOT CELLSELEV. 37.2m

34.7 m-

HOISTROOM

VENTILATIONANDOTHERSERVICES

15.9 m

OPERATINGAREA

'yyyyyyT,

7.5 m

WASTEOPERATINGAREA

•••'•»•:•»••»*•••' «•:*••

SHIELDINGCOLLAR

TRAVELLINGCRANE

SHIELD PLUG

ELEV. 37.2 m

RAIL CARS

ELEV. 22.6 in

ELEV. 52.4 m

0.61 m

ELEV. 46.3

0.91 m

TEMPORARY STORAGEFUEL HANDLING SHAFT

yyyyyyyy//yFIGURE 6

-CROSS SECTIONAL ELEVATION A-A -OFHOT CELLS

POT.ACTIVE HOLD-UPTANKS & PUMPS

OPERATINGAREA

fi*

1 « y ••»••*•.

IEVAPORATp

ROOM

MED. ACTIVEHOLD-UP TANKS& PUMPS

-FLOOR PLAN-ELEV. 22.6 m

ELEV. 46.3 m

ELEV. 37.2 m

S/ST. COVERS/ST. LINER

ELEV. 30.5 m

EQUIPMENTREMOVAL HATCHES

S/ST. LINERELEV. 22.6 m

tn

FIGURE 7

-CROSS SECTIONAL ELEVATION B-BOF HOT CELLS

RADIO-ACTIVE HASTE

STORAGE TRENCHES 30 m GRAVEL(CANISTERSTORAGE BED)

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FIGURE 10

G-l

APPENDIX G

STORAGE OF SPENT FUEL IN LARGE AIR-COOLEC VAULTS

by

W.M. Campbell and D. Radojkovic

1. INTRODUCTION

At AECI,Power Projects, two closely related schemes for storing

spent fuel, - the Convection and Conduction schemes - have been studied

in sufficient depth to be able to compare them with the schemes being

studied elsewhere. An essential feature of both schemes is the removal

of heat by natural air circulation with the chimney effect of the hot air

rising from the fuel providing the circulation. With this system, fans,

pumps, etc. are eliminated, which reduces the operating costs to a minimum,

and at the same time eliminates the potential hazard due to failure of

mechanical or electrical equipment.

A basic assumption was made that all the fuel produced in

Canada up to the year 2000 would be stored at one central site. A 1969

estimate of spent fuel production, which is about half that of recent

estimates, was used. The difference does not change the cost per kilogram

of uranium significantly, Tut the capital costs are about half those using

the latest estimates.

Secondary containment is required for all storage schemes. In

these it is provided by casting zinc around the fuel bundles in an

aluminum mold, the solidified zinc and, to a certain extent, the aluminum

acting as the secondary containment (Figure 1). If the fuel is reprocessed

at a later date, the casting process can be reversed by heating the

assembly and pouring out the zinc. The process uses zinc which is not one

of the most plentiful metals, but the quantities required will be small

compared with production at least in the short term. Aluminum is plentiful,

however, and may be an acceptable substitute.

The operations can be divided into two parts:

1. Preparation of spent fuel at the reactor site which is commonto both schemes, and

2. Storage at the central site where the facilities are somewhatdifferent.

These are discussed below.

One essential step in the whole process is shipping the fuel

between the reactor and the storage site. This has not been considered

in detail, but there does not appear to bp any significant cost difference

for this step in any of the schemes being considered; with the two schemes

discussed here, there may be a slight safety advantage since the fuel

bundles are cast in metal blocks and will have considerably better

resistance to mechanical damage than bare bundles.

2. REACTOR SITE OPERATIONS

In the spent fuel receiving bay at the reactor, an empty

aluminum extrusion with a perforated bottom welded on is located in front

of the spent fuel discharge mechanism and six bundles are loaded into it.

The loaded extrusion is then raised into the zinc casting position just

G-3

above the water level in the bay. The water drains out, the fuel and its

aluminum container are heated to about 300°C by self heating or by an

external induction heater, and then the molten zinc is poured in (Figure 2).

The extrusion or module is then lowered into the water at a rate of about

5 cm/s (1.95 in/s), which promotes solidification from the bottom up

and avoids shrinkage cracks in the zinc. At this pnint, an extra operation

may be required if the conduction scheme is to be used. This involves

sawing off the top of each module to give a flat contact surface for uniform

heat conductivity. Development work will be required to prove whether

this is lecessary. Finally, the module is lowered into the bay and placed

in a six-module basket (Figure 3). These are stored in the bay until they

are shipped to the storage site (l-r> years) .

In preparation for shipping, the baskets are moved back under

the casting - loading cell (Figure 2), raised up and placed in the decon-

tamination area, washed down, dried and then loaded into the shipping

flask. As indicated in Figure 2, the shipping flask is not removed from

the railway car or truck, and in order to prevent radiation beams during

loading, a shielding collar is lowered to connect the flask and the

casting - loading cell.

3. CENTRAL STORAGE FACILITIES

The storage building at the central site is similar for the

Convection and Conduction schemes as shown in Figure 4. It consists of

two storage vaults, 48.2 m (158 ft) long x 20.7 m (68 ft) wide, connected

by a 15.2 m (50 ft) long unloading bay. The shipping flask on its rail-

way car or truck is positioned in the unloading bay, the cover is unbolted

and remotely removed, and the fuel basket lifted out into the bottom-loaded

transfer flask. This is then moved over the storage site being loaded,

the flask door is opened, and the basket is lowered into the storage site

(Figure 5). Since there may be some residual activity on the outside of

the modules, and there is the possibility of dropping a basket (with fuel

G-4

rupture) during loading, a temporary ventilation and filter system is

provided as shown in Figure 5. Once a site is loaded, the possibility

of activity release is thought to be negligible, so the temporary ventilation

facility is removed and used for the next site to be loaded.

4. CONVECTION SCHEME VAULT

1'igure 6 shows a cross section of the vault. The air inlets

are along both sides of the building just above ground level, and are

provided with screens to keep out coarse, airborne particles. The air

passes into the lrwer distribution plenum and up past each fuel stack.

The stacks are ten baskets (11.2 m (36.6 ft)) high, and are kept vertical

by three 5 cm (1.9 in) diameter pipes which act as supports. The exit

air at about 63°C (1.5 year-cooled fuel with an air inlet temperature of

21°C) then passes out the exits located along both sides of the vault.

With the ten-basket stack, there is sufficient'chimney effect to provide

adequate cooling without any mechanical assistance. Air flow patterns

are likely to dictate the spacing of the buildings and the location of

air inlets and outlets to prevent air recirculation, but these have not

been studied.

Each two-vault building holds 478 000 spent fuel bundles or

9576 Mg of uranium. By the year 2000 seven such buildings will be required.

5. CONDUCTION SCHEME VAULT

Figure 7 shows a cross-section of the vault. The primary

difference between this and the previous scheme is the way the heat is

removed from the fuel. Here the baskets are stacked into concrete cubicles,

each closed at the top by a finned aluminum shield plug. The cubicles

are packed tightly into the vault as shown. Heat is conducted from

G-5

module to module up through the stack, through the shield plug, and into

the air stream above. Again the air inlets with their screens are along

the sides of the building and the exits are along the top centreline.

Airflow, as before, is by natural draft. To keep the maximum fuel

temperature below the specified 300°C, the fuel stacks are only five

baskets (5.6 m (18.3 ft)) high and the fuel is cooled in the reactor bay

for five years before storage. The air outlet temperature is somewhat

lower (35 C) than in the previous scheme.

One two-vault building will hold 335 160 bundles or 6650 Mg

of uranium, so by the year 2000 ten such buildings will be required.

6. GENERAL STORAGE CONSIDERATIONS

The temperatures of the concrete in the vault are higher than

recommended by conventional civil engineering practice. This situation

has not been studied in detail, but it is thought that any problem can

be overcome by the use of appropriate insulation and by modifying the

vault layouts.

Retrievability of the spent fuel is a basic requirement for

all storage schemes. In the above designs, the site loading procedures

can be reversed - the baskets can be removed, and can be restored in

another facility, or reprocessed to recover the plutonium.

Fuel failure during storage is an unknown factor but it is

clear that the evolution of radioactive gases such as krypton-85 and

tritium will not be a problem. Under extreme conditions, the oxidation

of VOz to U3O6 and the formation of a fine radioactive dust is a possibility.

For these reasons, the main purpose of monitoring the fuel storage facility

is to detect the release of solid radioactive particles. A periodic

scanning of the exit air is considered sufficient with a more detailed

check to pinpoint the failure if a release is detected. The development

G-6

program will show more clearly just how failures might occur and how they

can best be detected.

The greatest potential hazards from stored fuel are the release

of radioactivity due to missile impact, or overheating and barrier failure

due to loss of coolant. These have not been evaluated in detail, but it

is difficult to see how loss of coolant can be complete enough to allow

the fuel to overheat to a dangerous level, i.e., there will always be

some cooling and a higher fuel temperature can be tolerated for a

considerable tine.

7. DEVELOPMENT REQUIRED

Host of the uncertainty in the two schemes centres around the

casting step and the behaviour of the fuel during and subsequent to it.

The following are the main questions that would have to be answered.

1. What casting conditions will give a satisfactory productCspent fuel bundles would have to be used for development)?

2. What inspection is required to ensure a satisfactory product?

3. Hot; much loose or fixed activity is left on the surface ofthe castings?

4. Are ruptures in the fuel sheathing likely to occur during thecasting step?

5. How are the Zircaloy properties changed during casting?

6. Is there any interaction between the zinc and Zircaloy duringcasting or later in storage?

7. Can the zinc be melted easily to allow recovery of the bundles?

8. Will the castings withstand stacking, 10 bundles high, atstorage temperatures and for long periods? Present predictionsare that creep and bundle strength are quite adequate butthese need to be checked experimentally.

9. Are the heat transfer calculations for both schemes correct?

10. How much reduction in air flow for both schemes can be tolerated?

11. Is the corrosion of zinc and aluminum acceptable under all theoperating conditions that they will have to withstand?

G-7

12. What type of concrete must be used and how must it be designedto give the maximum facility life?

13. What types of fuel failures might occur and what would theconsequences of such failures Be?

The above development is estimated to require 3 engineers

with supporting staff for 2 years. This means about $300 000 for salaries

with about $500 000 for equipment giving a total development cost of

$800 000. This does not cover the cost of a pilot project - an essential

final requirement.

8. ESTIMATED COSTS

Except where noted, the costs are in 1972 dollars.

The Cominco Product Research Centre at Sheridan Park worked

out the zinc casting process (on paper) and provided a cost estimate for

the capital and the operation.

AECL Power Projects (Peterborough) did a preliminary design

of the handling equipment required for both the reactor sites and the

central storage site and provided a cost estimate.

Assistance was obtained from Ontario Hydro on the design of

the storage buildings and the costs were estimated by AECL-Power Projects.

Table 1 gives the capital costs of facilities required to

handle all Canadian spent fuel production up to the year 2000 by the two

schemes.

Table 2 gives the operating costs both at the reactor and

storage sites during the loading period, i.e., up to the year 2000.

G-8

Table 3 gives the annual costs of spent fuel storage once

the facility is full and includes replacement of the facility at two

time intervals, 50 and 100 years. As far as capital is concerned, the

calculation method is only approximate since a straight-line apportionment

of cost over the life of the facility was used.

Table A shows the perpetual care fund that would be required

at the year 2000 to cover annual operating costs and facility replacement

for an indefinite period beyond the year 2000.

Table 5 summarizes the cost on the basis of dollars per kilogram

of uranium using the perpetual care fund principle. This means that when

the deposit Is made to the perpetual care fund at the year 2000, there

would be no further charges against the uranium.

Table 6 summarizes the cost where the perpetual care fund

system is not used. This shows the costs from the year 2000 to 2050, a

period when facility replacement will not be required, i.e., this is the

period of minimum storage cost. Beyond the year 2050, facility replacement

will be required, assumed here to be at 50 and 100 year intervals. Table 6

gives the costs in dollars per kilogram ->.-r year for an indefinite period

beyond the year 2050.

9. CONCLUSIONS

1. The two schemes are very simple and since they depend onnatural air circulation for cooling there is no mechanical orelectrical equipment. This gives a very low labour cost andwith no equipment to fail, the safety is high.

2. Neither scheme has been proven out but there do not seem tobe any insurmountable problems that cannot be resolved bydetailed design and a development program.

3. Removal of fuel bundles from the cast modules has not beendone, but it should be feasible to do this by inverting themodule and heating it in a furnace to a temperature where thezinc would melt and run out.

G-9

4. Either scheme might be used for storage of solidified, high-level, fission product wastes from a reprocessing plant, althoughthe primary containment would have to be developed.

5. The storage costs as summarized in Tables 5 and 6 are low evenwith a 50-year life for the storage facility - and it is to be hopedit would last much longer. Thus, storage until year 2050would only add about 0.05 U$/kWh to the power cost.

6. As shown in Table 6, taxes and insurance amount to almost 90%of the cost during the 2000 - 2050 period and 40-50% afterthat. At this point it is not clear that these are coststhat would be incurred with a publicly owned facility.

7. The difference in cost between the two schemes is not enoughto outweigh other factors such as development required, safety,etc. The hotter exit air from the convection scheme alighteven be used profitably.

8. Dry storage of spent fuel as proposed is not attractive forshort-term storage where there is a prospect of reprocessing,say up to 20 years, but it has a real attraction for interimstorage due to its simplicity and low operating cost.

G-10

TABLE 1

CAPITAL COSTS(1972 Dollars)

Reactor Site Equipment

Storage Building and Handling Equipment

Miscellaneous Buildings

Electrical Supply

Site Layout and Yard Development

Rolling Stock

Sewers and Water Supply

TOTAL CONSTRUCTION COST

Engineering, Design, Administration,Safety Analysis

Start-up

Owner Costs

Financial Expense

Contingency

TOTAL FIXED INVESTMENT

MILLIONSCONVECTIONSCHEME

6.80

26.00

0.20

0.20

2.00

0.10

0.50

35.80

3.22

0.10

1.87

4.78

7.21

52.98

OF DOLLARSCONDUCTIONSCHEME

6.80

32.20

0.20

0.20

2.00

0.10

0.50

42.00

3.76

0.10

1.92

5.59

8.40

61.77

G-ll

TABLE 2

OPERATING COSTS (1972 $) DURING LOADING PERIOD (TO YEAR 2000)(Except as noted they are the same for both Conduction and Convection Schemes)

Reactor Site Labour

Reactor Site Maintenance Labour

Storage Site Labour

Storage Site Maintenance Labour

Storage Site Overheads

Taxes and Insurance- Convection Scheme

- .Conduction Scheme

Zinc and Aluminum

Storage Baskets

Reactor Site .Equipment Replacement

Conduction Scheme 5 year Storage at Reactor Site

TOTAL COSTS

- Convection Scheme

- Conduction Scheme

$/kg U

0.090

0.027

0.029

0.009

0.325

0.070

0.082

0.784

0.374

0.022

0.50

1.730

2.206

G-12

TABLE 3

COSTS AFTER LOADING PERIOD (AFTER YEAR 2000)(1972 $)

Labour

Taxes and Insurance >

Storage Site Capital Replacement

(a) 50-year vault life

Cb) 100-year vault life

Total (a) 50-year life

(b) 100-year life

(DOLLARS PER kg

ConvectionScheme

0.00177

0.0117

0.0167

0.0090

0.0302

0.0225

U PER YEAR)

ConductionScheme

0.00177

0.0136

0.0194

0.0105

0.0348

0.0259

TABLE 4

PERPETUAL CARE FUND REQUIRED AT YEAR 2000 (1972 $)

Operations

Taxes and Insurance

Facilities Replacement

50-year life

100-year life

Total - 50-year replacement

100-year replacement

MILLIONSCONVECTION

4.11

27.2

17.6

3.7

48.9

35.0

OF DOLLARSCONDUCTION

4.11

31.6

20.5

4.3

56.2

40.0

G-13

TABLE 5

OVERALL FUEL STORAGE COSTS (1972 $)

Loading Period - to Year 2000

Capital

Reactor Site Equipment'Replacement

Operating Labour

Maintenance Labour

Storage Site Overheads

Taxes and Insurance

Zinc and Aluminum

Storage Baskets

Reactor Site Storage, 1 - 5 years

TOTAL to year 2000

STORAGE BEYOND YEAR 2000

Perpetual Care Fund

- 50-year facility life

- 100-year facility life

Total Storage Cost

- 50-year facility life

- 100-year facility life

CONVECTIONSCHEMEC$/kg U)

0.780*

0.022

0.119

0.036

0.325

0.070

0.784

0.374

0

2.510

0.455

0.326

2.97

2.84

CONVECTIONSCHEME($/kg U)

0.908*

0.022

0.119

0.036

0.325

0.082

0.784

0.374

0.32

2.970

0.522

0.372

3.49

3.34

* These values are somewhat high since the reactor site equipmentwill have many years of useful life after year 2000.

G-U

TABLE 6

COST FOR STORAGE BEYOND YEAR 2000

;.."V

Storage From Years 2000 - 2050

Labour

Taxes and Insurance

TOTAL for period

Storage Beyond Year 2050

Labour

Taxes and Insurance

Facility Replacement

- 50-year life

- 100-year life

Total annual cost

- 50-year facility life

- 100-year facility life

CONVECTION$/kg U

0.089

0.585

0.674

$/kg U*

0.00177

0.0117

0.0167

0.009

0.030

0.022

CONDUCTION$/kg U

0.089

0.680

0.769

$/kg U*

0.00177

0.0136

0.0194

0.0105

0.035

0.026

Annual Costs

G-15

•ALUMINUM EXTRUSION

LIFTING LUG

• FUEL BUNDLE•

B

• PLUG •

B

22,8 cm (9.0")

FIGURE 1 CASTING MODULE«7.00000 - M

1*73

G-16

G-17

LIFTING PIN CASTING MODULE

DIVIDER BAR

CENTRAL PIPE

TUBULAR RING

VERTICAL TUBE

FIGURE 3 STORAGE BASKET97.00000 • 38

1973

M'(26.2i»

CONVECTIONBUILDING VAULT

>- -^ j l> •^••^r

S | — CONTHOL DOOM

LAYDOWNAREA

UNLOADING CONDUCTIONBUILDING VAULT

58(17.4i»|

FIGURE 4 FUEL STORAGE BUILDINGS

G-19

BUILDINGCRANE

BASKET LOWERINGMECHANISM

TRANSPORTING

FLASK CLOSURE

TEMPORARYSHIELDING

SLEEVE

TEMPORARY VENTILATION SLEEVE

LOADEDCHANNEL

EXHAUST AIR

INACTIVITY MONITOR

SHIELD PLUG

NORMAL AIR FLOW

„ GUIDE Pli 1;

EMPTY CHANNEL

FIGURE 5STORAGE SITE LOADING WITH

TEMPORARY VENTILATION97 . 00000 . 33

«IV.2.1974

G-20

AIR OUTLET

AIR INLET

CHARGING PLUG

UPPER SHIELD

10 BASKETSSTACKED FUEL

FIGURE 6 DRY STORAGE FACILITY - CONVECTION COOLINGt r ooooo.it

lt?3

G-2J

EXHAUST

COOLING AIR

CONCRETE

FUELSTACK

COOLING FINS

CONDUCTING METALSHIELD CAP

CONCRETE

FUEL STACK

INSULATION 4' • 6" (137 cm) THICK CONCRETE

FIGURE 7 DRY STORAGE FACILITY - CONDUCTION COOLING97 00000 25RfcV. 4 1974

H-l

APPENDIX H

THE STORAGE OF SPENT CANDU FUELS IN SALT MINES

by

D.R. McLean and R. MacFarlane

1. INTRODUCTION

If the reprocessing option is not exercised for CANDU fuel,

two waste management possibilities are open: storage in surface facilities

or burial in geologic formations. Salt was chosen as the geologic option

since it is the only disposal scheme advanced to date which has been

examined in any detail. Active salt disposal programs exist in the U.S.A.

and Germany.

Disposal of radioactive wastes in salt was suggested first by

the U.S. National Academy of Sciences - National Research Council (USNAC)

in 1957 . Since that time, considerable experimental work has been done

and a demonstration of the concept has been completed . Cost estimates

have also been made . Recently (1970), all pertinent work on salt

disposal was re-examined by the USNAC and it has been concluded that bedded

salt is a satisfactory disposal medium for radioactive wastes . As the

USNAC points out, all questions regarding salt disposal have not been

answered. Nevertheless, they judged it to be a sound concept for the

disposal of wastes.

No experience exists in Canada with respect to disposal of

wastes or fuel in salt. It was necessary for this work to rely heavily

H-2

on published reports, mainly from the U.S. Thus the work contained in

this Appendix is mainly the adaptation of American work to CANDU fuel, plus

an independent audit and -up-dating of costs. It should reflect the cost

of disposal of CANDU fuel in salt formations within the limits of accuracy

required for this study.

2. GENERAL CONCEPTS

2.1 MINE LAYOUT

The study is based on a simple mine layout and conventional

mining techniques.

The mine is assumed to be 300 m below the surface in suitable

salt strata and to cover 2.6 km2 (one square mile). This area is divided

into four quadrants, each surrounded by a set of double peripheral tunnels.

The inner peripheral tunnels are used exclusively for mining and mining

ventilation, and the outer tunnels for spent fuel handling and spent fuel

ventilation.

All services and access to the surface are provided by three

shafts:

1. A 4.87 m diameter mining and mining-ventilation shaft (venti-lation supply for mining and spent fuel handling, and miningexhaust air).

2. A 2.44 m diameter shaft for exhausting air from spent fuelhandling tunnels (also used for initial mine development).

3. A 76 cm diameter shaft for lowering spent fuel from the surface.

Storage rooms, each holding 564 Mg of fuel, extend across each

quadrant. There are 32 rooms/quadrant. A typical quadrant is shown in

Figure 1. Mine specifications are listed in Table 1. Container spacings

were estimated from data in reference 4.

H-3

2.2 MINING OPERATIONS

The development sequence for a quadrant is as follows: Starting

at the central region, peripheral tunnels and cross-over tunnels are

excavated around the quadrant. Two storage rooms are then excavated and

fuel insertion begins. Mining of storage rooms continues on an as-required

basis. Mining of peripheral tunnels for an adjoining quadrant is scheduled

such that they are completed when two rooms remain in the previous quadrant.

The techniques used for mining and disposal of salt are described in detail

in Figure 2.* The manner in which the mined salt is disposed of on the

surface is shown in Figure 3.

2.3 WASTE HANDLING

The assumed movement of spent fuel from a reactor site to a

storage hole in a salt mine is discussed in the following paragraphs.

At the reactor site, fuel is packaged in carbon steel pipe

3 m long (9.9 ft.) x 30 cm diameter (11.9 in) (42 bundles/containers)

with plates welded on the ends. These containers are loaded into flasks

and shipped on railway flat cars to the central storage site.

This site has the facilities to unload fuel, check its integrity,

lower it to mine level, transport it to its storage location and store it

in a safe state. Equipment is available to check for contamination and

handle it adequately if the need arises. When flat cars arrive at the

site, they are shunted under the shielding collars of the surface hot cell.

These shields are lowered to form a seal between the hot cell and the

flask top. This allows the flask covers and spent fuel containers to be

removed without taking the flasks inside the hot cell. Facilities are

available in the hot cell to check containers for contamination,

* The drill and blast mining technique was described in ORNL-3358, reference4. An alternative method would be the use of the large boring machinesused in potash mining. This would avoid potential damage to the geologicstructure, that may be caused by blasting.

H-4

decontaminate, handle residue from decontamination, stdre fuel (65

containers), and/or lower fuel to mine level. Sketches illustrating

these features are given in Figures 4, 5, 6, and 7.

Assuming the fuel is being moved to storage at mine level, it

is lowered 304.8 m with a hoist to a hot cell. This mine level hot cell

serves as a distribution centre for fuel containers and an isolation area

in the event of an accident in the waste handling shaft. Details of this

hot cell are shown in Figure 8.

Transportation of fuel to its storage location is done with a

specially designed transporter shown in Figure 9 (schematic view of trans-om

porter used in USAEC Project Salt Vaultv ' ) . It is backed under the front end

of the mine level cell, the transporter shield raised, the shielding plug in

the hot cell removed, and the transporter loaded from a travelling crane.

Once loaded, the transporter drives down an outer peripheral

tunnel (spent fuel handling tunnel) to a prepared storage hole (see

Figure 10). The prepared hole includes an asbestos cement liner which

protects the fuel bundle container from contact with the salt.* The

transporter discharges its fuel through the bottom of its shield, places

a shielding plug in the hole, and drives away. A more detailed description

of fuel handling operations is given in Figure 11.

In addition to the mining and waste handling facilities

mentioned above, some auxiliary surface facilities are required. They

are listed in Table 2 along with the main surface facilities.

2.4 PERSONNEL REQUIREMENTS

During the fuel insertion period (year 1982-2004), salt mining

and waste handling operations require varying numbers of people. Require-

It has been pointed out that asbestos - cement materials are hazardousto handle. This factor must be taken into consideration when materialsfor liners are being selected in any development work.

H-5

ments grow from 87 people in the year 1982 to 120 in the year 2004. An

indication of the numbers and types of personnel required in the year

2004 is given in Table 3.

2.5 OVERALL SCHEDULE

To put the scheme into perspective, it is necessary to look

at the various phases involved and the time scale of each phase.

1. Fuel Arisings Phase (1978-2004)

Arisings for one-year-cooled fuel would normally begin in theyear 1978.

Our scheme requires five-year-cooled fuel (an additional fouryears cooling at the reactor site), so that the first fueldoes not reach the site until 1982.

2. Initial Construction Phase (1980-1981)

Hot cells, shafts, peripheral tunnels, and surface buildingsare constructed prior to first fuel insertion.

3. Fuel Insertion Phase (1982-2004)

During this phase, the mine is gradually being filled with fuel.

4. Mine Surveillance Phase (2004-2054)

The mine (filled with fuel) is left open as a final check onthe integrity of the salt containment. Surveillance of thefuel continues throughout this period.

5. Site Surveillance (2054-indefinlte future)

In the year 2054, the mine is backfilled with salt, shaftssealed, surface facilities dismantled, and the site cleaned.Surveillance continues indefinitely.

A chart showing the above phases is given in Figure 12.

3. COSTS

An economic study of the salt mine scheme is presented to

allow comparison with other schemes. Costs are grouped into four main

divisions :

1. initial investment coat,

K-6

2. salt mining and disposal cost during fuel insertion period,3. spent fuel handling costs,4. perpetual care costs.

A breakdown of the major Items in each category is given

below.

3.1 INITIAL INVESTMENT

These costs are mainly due to site preparation, initial

construction, and machinery purchases in the first two years before fuel

insertion. Table 4 gives a cost breakdown of the items involved.

3.2 SALT MINING AND SALT DISPOSAL COSTS

Costs were divided into mining costs and disposal cost.

Neither one includes machinery which shows as a capital expenditure. A

breakdown is given In Table 5.

Yearly salt handling costs are calculated by multiplying the

total cost for salt handling ($2.955/Mg) by the amount of salt mined in

that year. Yearly and cumulative salt mining quantities are given in

Figure 13.

3.3 SPENT FUEL HANDLING COSTS

A major item in the spent fuel handling costs is that of spent

fuel containers. This cost includes:

1. two baskets,2. mild steel can,3. packaging,4. asbestos cement liner,5. base plug,6. shield plug.

The above costs are detailed in Table 6.

H-7

3.4 PERPETUAL CARE COSTS

Beyond the last year of active mine life (year 2004), three

operations require funding:

1. fifty-year surveillance (year 2004-2054),2. backfilling, etc. of mine (year 2054),3. indefinite surveillance (year 2054 - ?).

To cover these costs, three funds were set up with the initial

investment made in the year 2004. The size of each fund is described

below.

1. 50-Year Surveillance Fund

Annual costs of operation during this phase were calculated(see Table 7).

The amount of money invested in the year 2004 to meet thesecosts over the period was calculated to be $9.1 x 106.

2. Backfilling and Dismantling Fund

After 50 years, extensive repairs might be required for themine and its equipment to permit backfilling. The costs forrepairs, backfilling and other items were assumed to be thesame as the costs for the entire mining operation ($40.0 x 106).To generate this amount, an investment of $9.7 x 106 in theyear 2004 is required.

3. Indefinite Surveillance Fund

An annual expense of $50 000 is assumed for the final phase,beginning in 2054. An investment of $0.4 x 106 in the year2004 will provide this amount in perpetuity.

4. Total Investment for Perpetual Care Required in Year 2004

50-year surveillance $9.1 x 106

Backfilling, etc. $9,7 x 106

Indefinite surveillance $0.4 x 10s

TOTAL $19.2 x 106

3.5 LEVELIZED COSTS, $/kg U FOR CAPITAL, OPERATING AND PERPETUAL CARE

Annual cash flows for capital, operating, and perpetual care

during the initial and fuel emplacement stages are shown in Table 8. An

explanation is given in the footnotes which follow.

H-8

A levelized cost in $/kg U is given in Table 9. These values

were determined using present worth, techniques and 1972 dollars.

3.6 PENALTY FOR FOUR EXTRA YEARS OF STORAGE

As mentioned previously, this scheme requires five-year-cooled

fuel. The cost of storing fuel for an extra four years at a reactor site

has been calculated by Ontario Hydro. This cost amounts to $0.47/kg U.

3.7 SHIPPING

Cost for shipping fuel from the reactor site to a central storage

site has been calculated by WNRE in Appendix I. This cost amounts to $2.20/kg U.

3.8 DEVELOPMENT COSTS

A development program for storage in salt has been advance by

WNRE. The plan covers a 15-year period at a carefully chosen site prior

to the emplacement of fuel on a routine basis. It includes money for site

selection, public information, and capital expenditures. The program involves

general salt research as well as a 5-year program. The total cost is

^$25 x 106. Of this money, $13 x 106 is required for mine shafts, hot

cells, land, etc. These facilities can be used again during the routine

emplacement period so that net costs for development are reduced. If the '

development costs are charged off against the fuel arisings to the year

2004, the additional cost to the total scheme is $0.38/kg U.

3.9 TOTAL COST FOR MANAGEMENT OF SPENT FUEL IN SALT MINES

Total salt mine costs are summarized in Table 10. These values

were arrived at using present worth techniques and 1972 dollars, (see

Appendix B).

H-9

4. GENERAL COMMENTS ON SALT STORAGE

One of our objectives in this series of studies was to examine

each scheme from engineering, safety, and cost points of view.

We were not in a position to assess fully the engineering

aspects of salt mining and relied extensively upon the work done by the

United States Atomic Energy Commission. It is evident from their work

that the concept of storing highly active wastes in bedded salt is

feasible. However, the use of this concept is strongly dependent upon

the geology, hydrology, etc., of the site. Therefore, we have been able

to look at the concept of storage only in broad generalities. A more

detailed examination cannot be carried on until one or more possible sites

have been selected.

From a safety point of view, there are a number of advantages

to this type of storage.

1. It appears that loss of cooling is highly improbable.

2. The spent fuel is shielded beneath 300 m of overburden andtherefore prospects for complete loss of shielding are veryremote. Thus this mode of storage appears to be much lessvulnerable to earthquakes, acts of war, or sabotage thansurface storage concepts.

3. We are not able to predict, at the present time, the lifetimeof the primary containment (fuel container and sleeve) in thesalt. However, in view of the plastic qualities of the saltand because of the thickness of the overlying strata, extremelygood secondary containment is provided. Since the age of thesalt bed could be of the order of hundreds of millions ofyears, the 250 000 years required for the decay of the spentfuel is only a small extension of the age of the bed.

A further containment advantage of salt storage lies in the

fact that planned retrievals of the fuel are not required every 50-100

years as in the case of man-made vaults on the surface. Thus, there is

less chance of activity being released to the environment.

Although having advantages not present in surface storage,

this scheme puts new stresses on the geology of the area. These stresses

are due to mining operations, decay heat production, and radioactivity,

and may create some difficulties.

Mining involves penetrating (within mining shafts) the

protective layers of shale and overburden which isolate the salt from

water. Once the mine is filled with fuel, can these shafts be plugged

in such a way that the exclusion of water is guaranteed? Mining also

involves removing large volumes of salt. It is realized that even after

backfilling, the remaining salt will flow to fill the void, But what is the

effect of this flow? Could this flow cause a break of the overburden or

protective shales? If the mined salt is left on the surface over the

mined-out area, will this cause a stability problen?

The integrity of the containment may also be affected by old

drillings or boreholes in the storage area. Careful investigation of the

site is required to be sure that such holes do not exist, or if they do

exist, that they can be safely sealed.

Decay heat produced by the spent fuel will cause an increase

in the temperature of the salt and overburden resulting in some degree of

thermal expansion. Will the increase in temperature change the physical

properties of the salt to such an extent that mine stability is threatened?

Will the higher temperatures cause accelerated deterioration of the mild

steel can? Is it possible that the thermal expansion of the salt could

cause a breach in the protective shales and overburden? Will thermal

expansion cause mine stability problems? How will the heat affect the

small amount of water trapped in the salt?

The rock salt and any water present may undergo some radiolytic

degradation in the vicinity of the stored fuel. Products formed may lead

to increased corrosion of the fuel containers; hydrogen produced from

radiolysis of the water could, during the mining process, create a minor

explosion hazard. The question of stored radiation energy in the salt

H-ll

crystals has been raised, with some concern about the effects caused by-

sudden release of the energy.

From a general point of view of environmental impact, it

would appear that one of the important concerns is the disposal of the

mined salt. A technique illustrating what might be done is given in

this report, primarily as a means of estimating the cost of salt disposal.

Depending on the quality of the salt, it may be possible to sell it,

dispose of it in the ocean, inject it as a brine into deep strata, or

store it in other abandoned mines.

These and other difficulties were examined by the United

States Atomic Energy Commission in Project Salt Vault. Although some

difficulties at the Kansas site arose, it was concluded that the use of

salt mines per se was a safe method of storage.

From an economic point of view, the cost of storing fuel in

salt is of the same order of magnitude as surface storage.

H-12

5. REFERENCES

(1) "Disposal of Solid Radioactive Wastes in Bedded Salt Deposits",Report by the Committee on Radioactive Waste Management,National Academy of Sciences - National Research Council,November, 1970.

(2) R.L. Bradshaw et al, "Results of a Demonstration and ccherStudies of the Disposal of High Level Solidified, RadioactiveWastes in a Salt Mine", Health Physics, Volume 18, pp 63-67, 1970.

(3) R.L. Bradshaw, W.C. McLean (editors), "Project Salt Vault: ADemonstration of the Disposal of High-Activity SolidifiedWastes in Underground Salt Mines", Oak Ridge National Laboratory,OFNL - 4555, April, 1971.

(4) R.L. Bradshaw et al, "Evaluation of Ultimate Disposal Methodsfor Liquid and Solid Radioactive Wastes: VI Disposal of SolidWastes in Salt Formations", Oak Ridge National Laboratory,ORNL - 3358, March, 1969.

H-13

TABLE 1

SALT MINE SPECIFICATIONS

Depth

Overall area underground

Overall area on the surface

storage room width

305 m (1000 ft.)

2.6 km2 (1 mi2) (divided into0.65 km2 (1/4 mi2)quadrants)

4.9 km2 (1.9 mi2)(includes 305 m(1000 ft.)buffer zone)

31% (ORNL = 50%)Mining ratio = . , , ,,storage room width + pillar

Pillar width to height ratio 16.9 m/4.6 m (55ft/15ft) 3.7

Storage rooms/quadrant

Buried fuel bundle containers/room

Bundles/container

(ORNL

32

3.3)

671 (5 year cooled)arranged on a triangularpitch, 3.1 m (10 ft.)center to center spacing)

42(0.84 Mg U)

H-14

TABLE 2

SURFACE FACILITIES

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

Main hot cell

Mining head frame

Electrical substation

Gate house

1.2 km road

1.2 km railroad spur

Garage

Maintenance shop

0.64 km2 salt disposal area

Parking lot

TABLE 3

PERSONNEL REQUIRED IN YEAR 2004

Mining

Surface salt handling

Waste handling

Maintenance

Miscellaneous

Administration

TOTAL

28

12

35

25

7

13

120

H-15

TABLE 4

INITIAL INVESTMENT COSTS(1972 Dollars)

YEAR Z98O

Land (1>

Site DevelopmentSite clearingWater systemSewer systemElectricalParking lotFenceLightingRailroadRoadHeating plantGate house

TOTAL

Mining shafts and equipment16 ft. shaft8 ft. shaft2.5 ft. shaftShaft equipmentMiscellaneous

TOTAL

Ventilation

Surface hot cellHot cell properS tack (*•)

Office areaEquipment and instrumentation

.TOTAL

Taxes and Insurance

TOTAL

YEAR 1981

Mine level hot cell

1

1

3

1

3

Miscellaneous mine level equipmentMining Machinery*1)Initial mining <*)Surface salt handling machinery

TaxesInsuranceMine heat

TOTAL

2569765260581802626339013025

750

62597925641594

369

73293633643

101

(i)

DOLLARS

000000000000000000000000000000000

000

000000000000000

000

000000000000

000

1

3

3

9

DOLLAR!

1

3

710

750

369

41

101

180

151

i

41024399556242513013044

939

000

000

000

000

000

000000(ii)(iii)

000000000000000000000000

ooo(ii>

(1) Cost extracted from reference 4.

(ii) The costs shown above for constructed facilities include costsfor overhead, engineering, and contingencies.

(ill) The cost of some of the above items is shown to occur in asingle year, whereas the costs may actually be distributed overmore than one year. This approach was taken to simplify thepreparation of the cash flow chart in Table 7. The resultanteffect on interest and/or escalation charges for the constructionperiod is negligible compared with total expenditures involvedfor the entire construction and mine filling period.

H-16

TABLE 5

SALT MINING AND SALT DISPOSAL C O S T S ^

SALT DISPOSAL (SURFACE HANDLING) COSTS

Fuel

Wages

Maintenance

Liner

Oil (waterproofing)

Overheads and contingencies

TOTAL

SALT MINING COSTS (1972 Dollars)

Fuel

Wages

Power

Explosives

Maintenance

Overheads and contingencies

TOTAL

Total Salt Handling Cost

C1972 Dollars)/Mg

0.048

0.196

0.114

0.425

0.245

0.196

1.225

0.048

0.604

0.082

0.114

0.278

0.604

1.731

2.956

Ci) Extracted from reference 4 with the exception of linerand waterproofing costs.

K-17

TABLE 6

SPENT FUEL BASKET AND CONTAINER COSTS

2 Stainless steel baskets

Carbon steel container3 m of 0.3 m (12") Schedule 40 pipe2 end platesWelding and testing, plus allowance forremote welding and testing of the topend plate

Hot cell operation at reactor siteCapital charges and operating costsfor hot cell

Asbestos cement liner, shielding plug and baseLiner - material

installationoverheads and contingencies

Shield plug and base- installed costs0.37 m3 @ $l96/m3

TOTAL

Cost per Container

(Dollars)

336

7836

370

484

436

1123232

176

72

1504

$/kg u

0.40

0.58

0.51

1.09

0.21

0.09

1.79

TABLE 7

ANNUAL COST FOR 50-YEAR SURVEILLANCE PERIOD

Labour

Utilities and supplies

Taxes

Insurance

Maintenance

15% Contingency

TOTAL

Dollars

100 000

20 000

65 000

65 000

50 000

300 000

50 000

350 000

H-18

TABLE 8

SALT MINE CASH FLOWS (1972 DOLLARS)

YEAR

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

TOTALS

Mining CostsCapital (i)Expenditures

5870

1663

308

584

158

425

836

584

885

11313

- 103 Dollars jOperating (ii)Expenditures

90

1736

382

405

433

459

502

473

525

593

659

739

821

2128

1006

1098

1209

2535

1339

1514

1605

2729

1779

1868

1979

28606

Waste Disposal Costs: 103

Capital(iii)Expenditures

3101

410

375

63

375

375

375

63

375

375

375

375

375

375

375

375

8137

Spent Fuel(iv)Baskets andContainers

1307

1449

1628

1789

2058

1880

2201

2631

3043

3544

4063

4618

5227

5799

6497

7178

7733

8413

8986

9522

10077

10632

11331

121606

DollarsOperating(v)Expenditures

90

Perpetual(vi)Care Costs:103 Dollars

130

562

562

572

572

572

572

572

572

809

810

810

819

820

820

878

978

1035

1035

1036

1207

1208

1208

1208

19457

19200

19200

H-19

CASH FLOW FOOTNOTESMINING

Ci) Capital Expenditures

In the first two years O980-1981), expenses are due to miningmachinery, shafts, hoists, salt handling equipment, etc. Lateron, these costs indicate money spent in replacing existingequipment.

(ii) Operating Expenditures

These costs include all salt mining and handling costsexclusive of machinery, which is a capital expenditure.Mining Costs $1.731/Mg of saltSurface Handling $1.225/Mg of salt

TOTAL $2.956/Mg of salt

Other costs included are heating, insurance, and taxes.

WASTE DISPOSAL

(iii) Capital Expenditures

Capital expenditures in the first two years (1980-1981) are dueto construction of two hot cells.

1980 - Surface Hot Cell1981 - Nine Level Hot Cell

All other expenditures are due to purchases of transportersand hole drillers.

(iv) Spent Fuel Baskets and Containers (Figure 10)

The cost per container is $1504. A breakdown of this cost isgiven in Table 6.

Annual costs are arrived at by multiplying the number ofcontainers required per year by the individual container costs.

(v) Operating Expenditures

Wages, salaries, overhead, and contingencies were taken fromreference 4 and were adjusted to suit our requirements. Checkswere made in which the people required for all jobs were listedand a 15% contingency added. Agreement with the adjusted 0KNLvalues for the years 1982 and 2004 was good. On this basis,the adjusted ORNL values were accepted. Other items includedin these costs are:a) transporter maintenanceb) transporter fuelc) taxesd) insurance

(vi) Perpetual Care Costs

These costs are described in section 3.4.

H-20

TABLE 9

LEVELIZED COST FOR MINING, FUEL HANDLING, AND PERPETUAL CARE

Mining

Capital per cash flow chartInterest charges on borrowed moneyTotal

Cost: 106 Dollars

11.34.8

Total

Perpetual Care

Total value of funds in year 2000Interest earnings to year 2000Deposits to sinking funds during

filling

Total Cost for Mining, Fuel Handlingand Perpetual Care

152.6

19.2- 3.6

15.6

212.9

Levelized Cost$/kg U

0.170.07

Operating

Total

Waste Handling

Capital

General facilities as per cashflow chart

Interest chargesTotal

Baskets and spent fuel containers

Operating

28.6

8.13.4

121.6

19.5

44.7

0.42

0.120.05

1.79

0.29

0.66

2.25

0.23

3.14

H-21

TABLE 10

SUMMARY OF COSTS FOR MANAGEMENT OF SPENT FUEL IN SALT MINES

Development, site selection and public

Penalty for four extra years of storage

Shipping

Capital and operating costs during site

Mining costsWaste handling and emplacement

Total

Perpetual care

Total

relations

at reactor site

filling period

0.662.25

$/kg U

0.38

0.47

2.20

2.91

0.23

6.19

H-22

CENTRAL AREA(HOT CELL)(76 cm dia. FUEL HANDLING SHAFT)(2.4 m dia. FUEL HANDLING VENTILATION SHAFT)(4.9 m dia. MINING & MINE VENTILATION SHAFT) .-.-

'•'/ •••

CROSS-OVER TUNNELFUEL HANDLING TUNNEL (OUTER)SALT MINING TUNNEL (INNER)STORAGE ROOMPILLAR, 16.7 m

HEIGHT 4.6 mWIDTH 7.6m

-807.7 nv

PLAN VIEWAT

MINE LEVEL FIGURE 1

SALT MINE QUADRANT

809.2 m

DRILL WITHJUMBO RIGS

UNDERCUT WITHGOODMAN SHORT WALLUNDERCUTTER

LOAD POWDER USINGWAGNER MOBILEWITH CHERRYPICKERATTACHED

*HAUL TO GRIZZLEYAND CRUSHER WITHDIESEL SHUTTLE

CARS

HAUL SALT FROMCRUSHER TOSHAFT BOTTOM

HAUL TOSURFACE ANDLOAD ON TRUCK

BLAST(3m /BLAST)*

HAUL SALT TOBURIAL SITE

LOAD SALT INTOVEHICLE WITHJOY LOADERS

EXCAVATE BURIALSITE

COVER BURIALSITE BOTTOMWITH PLASTIC

LINER

SPREAD ATHIN LAYER OFSALT ON THELINER AND SPRAYSALT WITH OIL

BUILD PILE TODESIRED SHAPEWITH MORE SALT,PACKING WITHPACKER AS REQUIRED

!J

SPRAY SURFACEWITH ASPHALTAND COVERWITH PLASTIC

COVER PILEWITH THREEFEET OFEARTH FILL

COVER FILLWITH SOD

**

NOTES: *MINING RATE 3m /SHIFT

** SALT WOULD BE REPLACED IN THE MINE BY REVERSING THE PROCESS.

FIGURE 2SALT HANDLING OPERATIONS

GRASS

ceho

FIGURE 3 SALT DISPOSAL SCHEME

34.7 m

RAILWAY TRACK B ff^

\_^DOOR^.

SERVICES

91 \

t_'••:i*#

OPERATING!AREA

30.5 m

REPAIRHOT CELL

DOOR(!^ri-ISOLATION

CELL

CHANGE | HOT-CELLROOM v SERVICE

L AREA

.SHIELDDOOR

! I

HATCH

RECEPTION AREA

31IM

35.6 cm SCH.10 S PIPE

MAIN ENTRANCE

-FLOOR PLAN- ELEV 30.5 m

FIGURE 4 SALT MINE STORAGE- GROUND LEVEL HOT-CELL

Y+- 36.6 m-

VENTILATIONAND OTHERSERVICES

25.9 m

STAIRS OFF.

ooL.WR.

IM.WR.

OFF. OFF.

HOT CELLSERVICEAREA

TRANSFER HOT CELLFER HOT CE

OPERATING AREA

OFF. CHANGEROOM

HALLWAY

OFF. OFF. I OFF.I

OFF.

RECEPTIONAREA

FIGURE 5FLOOR PLAN OF HOT CELLS

ELEV. 37.2 m

•••*•*

OOOO8888OOOO

_ I

7.9 mto

(4.5 m *

15.85 m

VENTILATIONAND

OTHERSERVICES

'S/////////,

7.92 m

WASTEOPERATING

AREA

//////////,

32.0 m

»•••: .->«V-. ~

-T-P'-—1>»

-•

. TRAVELLING.CRANE

WASTEMANAGEMENTAREA

Ï-JT

J^^TrTi?

ELEV. 46.33 m

ELEV. 37.9 m

GROUND LEVEL

RAIL CARS

ELEV. 22.55 m

.48CANISTERTRAILER

\ ///////y£i;,y-,"FUEL-CAN STORAGE CELL

FIGURE 6

CROSS SECTIONAL ELEVATION A-AOF HOT CELLS

xi

OPERATINGAREA

-*,ACTIVE HOLD-UPTANKS & PUMPS

POT. r-i

MED. ACTIVEHOLD-UP TANKS& PUMPS I,'

EVAPORATORROOM

-FLOOR PLAN-ELEV. 22.55 m

VENTILATIONAND OTHERSERVICES

SERVICES

s//// //y/s// /s/7.

61

FUELTRANSFERHOT CELL

ELEV. 46.33 m

OPERATINGAREA

OFF,

REPAIRHOT CELL

ISOLATIONCELL

LSI \WASTE MANAGEMENT v

U AREA

OFF.

HOT-CELL SERVICEAREA

S/ST. COVERS/ST. LINER

ELEV. 30.48 m91 m dia. HATCH2.44 m2 HATCHS/ST. LINER

ELEV. 22.55 m

is

00

-CROSS SECTIONAL ELEVATION B-BOF HOT CELL

FIGURE 7

H-29

91 cm

RAMP

ir 18.3 m

///.

i

i>li

— -0- 0 0 ©

© 0 © 0

0 0 0 0

i i iU PLUG e£t

OPERATINGAREA

-FLOOR PLAN-

9.1 m

6.1 m

FUEL HANDLING SHAFT

UNDERGROUNDTRANSPORTER 11.0 m

TEMPORARY STORAGE

CROSS SECTIONAL ELEV. A-A

FIGURE 8 SALT MINE STORAGE- MINE LEVEL HOT CELL

H-30

CENTERING GUIDE

^ SHIELD

FIGURE 9 -MINE LEVEL TRANSPORTER-

15 cm "CONCRETEPLUG

4.75 m

15 cm ; •

TRANSIENT PIPE, CLASS 200(42.1 cm o/dia. x 34.5 cm i/dia.)

0.44" air gap

MILD STEEL CAN SCH. 40 PIPE(SPENT FUEL CONTAINER)

FIGURE 10 SPENT FUEL CONTAINER

FLASKSSTART

FLASKS ARRIVEON RAILWAY CARFROM REACTOR

CARS AND FLASKSARE CHECKED FORCONTAMINATION

CARS ARE PUSHEDINTO POSITIONUNDER SHIELD COLLAF

FLASKS AREOPENED, CANS LIFTEDINTO HOT CELL ANDINSPECTED FOR LEAKSETC.

FUEL

NORMAL

SHIELD PLUGINSTALLEDANDCONTAMINATIONCHECK MADE

TRANSPORTERPOSITIONED OVERHOLE AND OPENED,CAN INSERTED INSLEEVE

TRANSPORTERDRIVEN TOSTORAGE HOLE

CANS ARE PLACED INTRANSPORTER WITHTRAVELLING CRANE

PERIODICLEAK CHECKSMADE

END

SALT HOLE DRILLED,SLEEVE INSERTED,BOTTOM PLUGPORED

ANNULUS AROUNDHOLE FILLED WITHFINE CRUSHED SALT

J

CANS*ARE LOWEREDDOWN MINE SHAFTINTO MINE LEVELHOT CELL

CONTAMINATED

CONTAMINATED AND/ORDEFECTIVE CANS AREREPAIRED AND/ORCLEANED .

U

TRANSPORTER TRANSPORTER

TRANSPORTERCHECKED FORCONTAMINATION

NORMAL>•—

CONTAMINATED

IF CONTAMINATEDTRANSPORTER IS CLEANED

TRANSPORTER ISDRIVEN UNDERHOT CELL

* CAN = FUEL CONTAINER

CARS ARE RETURNEDTO REACTOR FOR ANOTHERLOAD

FLASKSARE CHECKEDAND COVERS REPLACED

FIGURE 11FUEL HANDLING OPERATIONS

PHASES

SiteSurvei1 lance

H-32

YEAR

©O

OPERATIONS

J2054

MineSurvei1 lance

2004

Fuel loaded into mine.Mining done as required.

Mine backfilled withsalt, shafts sealed,surface facilitiesdismantled.

Mine filled with spiritfuel

1

Fuel Five yearcooled atreactor site.

1982

1981

1980

1979

1978

Insertion of firstfuel

Construction of minelevel cell, mineperiferal tunnels;and initial storagerooms.

Construction of shafts,surface hot cells etc.

-1— First fuel arisings.

FIGURE 12

GEOLOGIC STORAGE SCHEDULE

H-33

1.0

0.9

08

0.7

0 6

0.5

0.4

0.3

0.2

0.1

8 0

70

6 0

5 0

40

30

2 0

10

I 1 1 1

SALT MINED -YEARLY AMOUNTS

-

-

- i

-

SALT MINED -CUMULATIVE AMOUNT

—

—

—

— — ——^""^

1 I

A A» A A\J* ^ PEAKS ARE DUE

TO EXCAVATIONOF PERIPHERALTUNNELS AROUNDQUADRANTS

/

i i

1984 1988 1992

YEAR

FIGURE 13SALT MINING SCHEDULE

1996 2000

APPENDIX I

TRANSPORTATION

1. INTRODUCTION

Transportation is a vital aspect of any fuel storage scheme.

The committee has not examined transportation in detail but has discussed

the logistics problem and aspects related to siting. In the following

sections, estimates have been made based on what appear to be reasonable

.-sumptions at the present time.

DISTRIBUTION OF CANADIAN SPENT FUEL ARISINGS IN THE YEAR 2000

It is necessary to examine the transportation requirements in

the year 2000 in order to determine mature costs and practices. The

distribution of arisings was obtained from Foster's data on installed

capacity . This was fitted to the CAFS arisings, as shown in Appendix B.

The results are shown in Table 1.

3. SHIPPING SYSTEM

Fuel can be shipped by road, rail, barge, or possibly air.

CAFS did not examine all shipping modes, but instead assumed that rail

1-2

transport was the most likely. In addition, it was assumed that only

unit trains would be used. It was felt that shipping by standard freight

would unnecessarily increase shipping time.

3.1 GENERAL ASSUMPTIONS

Various assumptions were made regarding flask weight, number

of cars per unit train, number of flasks per car, average travel distance,

and so on. These are summarized in Table 2.

3.2 FLASK AND UNIT TRAIN REQUIREMENTS

From the preceding data, flask requirements and numbers of

unit train trips can be calculated. These data are shown in Tables 3 and

4. For the weighted average shipping distance of 1358 km (one way), 48

flasks and 6 unit train systems are required in the year 2000.

4. COSTS

4.1 CAPITAL COSTS

The major nuclear industry capital requirement for shipping

will be for flasks. Capital is also required for unit trains and although

the railway will probably provide this investment, the sums are of interest.

These costs were calculated from the data in Table 4. It was assumed that

an 8-car unit train would cost $1.5 million and the flask cost is $4.40/kg .

The results are shown in Table 5. These data apply to a single site in

Canada located north of Lake Huron.

4.2 UNIT SHIPPING COSTS

Unit freight costs, (see Figure 1) were derived from freight rates

for radioactive shipments obtained from a Canadian railway company. These data

1-3

applied to the use of regular trains. However, comparison with limited

data for unit trains indicated that rates would not be significantly

different. The best line was drawn through the data ignoring the two

points which appear to be anomalous.

To obtain total costs, flask capitalization and insurance

must be added to the freight costs, and these in turn will both depend

upon the shipping distance. These data have been calculated as a function

of distance and are shown in Table 6. The assumptions used are as follows:

1. flask cost = $0,203 x 106 ($4.40/kg weight),

2. insurance cost = 1/2 capitalization cost,

3. flask write-off is at 8% over 10 years.

The total shipping cost is also shown and is plotted in Figure 1.

Based on the distances and fractional arisings quoted in Table

1, the weighted average shipping cost to a single storage site located

north of Lake Huron, is $2.20/kg U. This value was taken as the shipping

cost in all other sections of this report.

4.3 WEIGHTED AVERAGE SHIPPING COSTS FOR MORE THAN ONE SITE

It is obvious that if more than one storage site is established,

the weighted average shipping cost will be reduced. Assuming sites are

chosen in lower mainland B.C., Ontario north of Lake Huron, and central

New Brunswick, the weighted average shipping cost will reduce to $1.40/kg U.

Obviously, however, the cost of establishing and maintaining three sites

will be greater than the cost of one. On the other hand, shipping safety

will be improved, and fuel will spend less time on the road. These items

must all be considered in a study to optimize freight costs and safety.

However, they were beyond the scope of this work.

1-4

5. SUMMARY

A power and spent fuel distribution has been calculated by-

applying Foster's power distribution to CAFS fuel arisings. The distance

and turnaround tiires indicate 6 unit trains carrying eight 192-bundle

flasks per train would be adequate to handle spent fuel in the year 2000.

The cost of transporting fuel to a single central site is $2.20/kg U.

The cost using three specific sites is $1.40/kg U.

6. RECOMMENDATIONS

A study of the shipping problems should be undertaken in all

future studies of waste storage methods. This study should include the

following:

1. Methods for integration of all spent fuel handling operationsfrom the reactor site to the storage site should be investigated.

2. Alternatives to conventional flasks lor moving spent fuelshould be considered.

3. Flask design criteria should be reviewed. For example, presentregulations set the radiation field at a maximum of 10 mR/hat 2 metres from the edge of the transport vehicle. This mayresult in unacceptably high doses to flask handlers at acentral site, whops sole job is flask unloading.

4. Some nethod of rating the risk of shipping as a function ofdistance and as a function of the age of fuel for comparisonwith risks at the reactor and storage site is desirable.

5. The logistics of shipping the fuel across the country by road,rail, unit trains, etc., from the potential reactor sitesshould be examined.

6. The advantages of storing spent fuel at the reactor site toavoid shipping should be considered. The advantages thatmay arise if fuel shipment is postponed until after the reactorhas been shut down and the fuel has undergone 25' to 30 yearsof decay should also be assessed.

7. The cost of shipping should be estimated as accurately aspossible. This will require collaboration with the shippingindustry.

1-5

REFERENCES

Cl) J.S. Foster, "Financial Resources Required for Future NuclearPower Program", Canadian Nuclear Association, CNA 73-502, June 1973.

(2) A.G. Trudeau, D.E. lïaagensen, "An economic and engineeringanalysis of a unit train concept for the transportation ofspent fuel assemblies from commercial Nuclear Power Plants",Bartelle-Northwest, Pacific Northwest Laboratory Report,BNWL-SA-3906, August 1971.

1-6

TABLE 1

ANNUAL SPENT FUEL ARISINGS IN THE YEAR 2 0 0 0 ^

Area

Atlantic ProvincesNew BrunswickNova Scotia

QuebecSt. Lawrence Area 1St. Lawrence Area 2St. Lawrence Area 3

OntarioSudbury DistrictNiagara PeninsulaBruce PeninsulaLake. Ontario Region

Prairie ProvincesSaskatchewanManitoba

British ColumbiaLower MainlandVancouver Island

TOTAL

Distance FromCentral Site,

(km)

1 6832 118

6531 030869

225869740451

2 7041 979

5 1825 375

MW(e)Installed

21

926

4589

11

42

58

400200

400400200

600600000600

000000

800400

600

Mg SpentFuel per Year

266133

1 017260671

492600856

1 027

114114

525263

6 338

% of TotalSpent Fuel

4.22.1

16.14.110.6

7.89.513.516.2

1.81.8

8.34.2

100.

(i) Foster's data indicate about twice this quantity of power and fuelarisings.

The data used to derive these values were:

1. Burnup = 9000 MWd/Mg U2. Availability = 80%3. Conversion, thermal to electric « 30%4. Fuel arisings in the year 2000 = 6330 Mg

1-7

TABLE 2

ASSUMPTIONS USED IN SHIPPING CALCULATIONS

(i)

(iii)

Fuel shipment size

Flask weight

Flasks per flat car

Cars per unit train

Flask shipments in year 2000(iv)

,(iv)Unit train shipments in 2000

Weighted average shipping distance

Flask loading time

Flask unloading time

(v)

3

46

1

8

1648

206

1358

5

5

.84 Mg U

Mg

km

hours

hours

(i) A 192-bundle package was chosen. For higher loadings, the fueltemperature may be too high. This point should be checked insubsequent studies.

(ii) Assumes a flask/fuel ratio of 12. This may be slightly conservative.

(iii) Ontario Hydro information suggests road bed loads as low as 73 Mg.Thus, only one flask per car is possible.

(iv) Calculated from Table 1 and note (iii) above.

(v) Calculated from Table 1; assumes only one site in Canada locatednorth of Lake Huron.

(vi) Estimated time, also checked with some experience and consideredto be reasonable.

TABLE 3

FLASK TURNAROUND TIME IN 2000 VERSUS SHIPPING DISTANCE

Distance(km)

402

804

1287

1609

3219

4828

Travel toReactor(days)

0.95

1.90

3.00

3.75

7.50

11.30

Loading

(days)

1.75

1.75

1.75

1.75

1.75

1.75

Travel toStorage Site

(days)

0.95

1.90

3.00

3.75

7.50

11.30

Unloading

(days)

1.75

1.75

1.75

1.75

1.75

1.75

TotalTurnaround Time

(days)

5.30

7.30

9.50

11.00

18.50

26.00

1-8

TABLE 4

FLASK AND UNIT TRAIN REQUIREMENTS IN 2000 VERSUS SHIPPING DISTANCE

One WayDistance

(km)

402

804

1287

1609

3219

4828

Train TripsRequired Per Year

61

46

35

30

18

13

TrainsRequired

3.37

4.47

5.89

6.£7

11.44

15.84

Total Fl,Requir

27

36

47

55

92

127

TABLE 5

CAPITAL REQUIREMENTS FOR SHIPPING IN THE YEAR 2000

One Way Distance(km)

402

804

Ï287

1609

3219

4828

Unit(1972

Train Cost$, Millions)

5.0

6.7

8.S

10.3

17.2

23.8

Flask Cost(1972 $, millions)

5.5

7.3

9.5

11.2

18.6

25.7

Total(1972 $, will

10.5

14.0

18.3

21.5

35.8

49.5

TABLE 6

TOTAL SHIPPING COST AS A FUNCTION OF ONE WAY SHIPPING DISTANCE

One WayDistance

(km)

402

804

1287

1609

3219

4828

FlasksRequired

27

36

47

55

92

127

CapitalizationCharges($/kg U)

0.13

0.17

0.23

0.26

0.44

0.61

InsuranceCost

($/kg U)

0.07

0.09

0.12

0.13

0.22

0.32

Freight

($/kg U)

1.35

1.95

2.70

3.20

5.60

8.05

Total

($/kg U)

1.55

2.21

2.95

3.59

6.26

8.98

5.0 -

i i rA SHIPPING BY RAIL (Jan. 16. 1974)

B SHIPPING & FLASK AMORTIZATION

1 1 11000 2000 3000

ONE WAY DISTANCE (km)

SHIPPING COSTSFIGURE I

4000 5000

J-l

APPENDIX J

RETRIEVABILITY

by

John Coady

1. INTRODUCTION

The potential toxicity of spent CANDU fuel requires that it

be contained for hundreds of thousands of years. It is unlikely that

current generations will be prepared to leave to future generations a

legacy of continual rebuilding of surface storage facilities and rehandling

of spent fuel wastes. However, until methods suitable for the long term

have been selected and evaluated, there will be a need for interim retrie-

vable storage facilities on the surface; retrievability being defined as

the ability to recover fuel from storage using substantially no more energy

than was required to place it in storage.

The length of time for which spent fuel could continue to be

stored in this manner is difficult to define. The question is often raised,

however, and although it has been the subject of much debate, opinions

differ widely on just when it might become a problem to maintain an ongoing

system of rebuilding, rehandling, and supervision. One of the reasons for

the lack, of agreement is that there has also been a lack of useful data

from which to draw conclusions.

J-2

The aim of this appendix is to outline, in terms of projected

arisings for the CANDU fuel cycle, what the probable dimensions of such

a system would he, and in so doing provide a quantitative basis for further

discussion. It must Be emphasized that this is not meant to be an exhaus-

tive examination of retrievability since this would require, among other

things, a detailed safety analysis of each scheme.

In going through the calculations, using both pools and

canisters as examples, the costing ground rule of 50 years was used as

the lifetime of each facility. This somewhat conservative assumption is

offset, however, by the choice of the lower set of values for projected

CANDU arisings. It should be noted that the assumption of a short life-

time really only influences the rate at which fuel must be rehandled and

therefore has no effect on other observations drawn from the results of

the calculations.

No attempt has been made to draw hard and fast conclusions

from this exercise and it is probable that more questions have been raised

than can be answered at this time. However, it was possible to identify

certain problem areas, mainly logistical in nature, that might arise if

surface storage facilities were to be in use for a prolonged period of time.

2. PROJECTED ARISINGS OF SPENT CANDU FUEL

Two sets of calculations were carried out. Both provide

predictions of arisings to the year 2120, assuming the continuous use of

natural uranium reactors over this period (approximately 150 years of

nuclear energy). The values and the assumptions on which they are based

are given in Table 1.

Figure 1 shows the cumulative production for each prediction

and includes for comparison the values derived from the estimates of

energy consumption to the year 2050, given in "An Energy Policy for Canada".

J-3

It can be seen that the latter values coincide with the higher of the two

CAFS predictions.

According to the "high" estimate, the uranium needs of a

"throwaway" fuel cycle would be about 30 million tonnes over the next 150

years. This is about 1% of the uranium probably contained in the sea.

All calculations in the remainder of the appendix are based

only on the "low" prediction. It should be noted that although the values

up to the year 2000 are very close to those used in the rest of this report,

they were derived in a different way than, and are not intended to be the

same as, the standard CAFS projection.

3. STORAGE REQUIREMENTS

Tables 2 and 3 show what the predictions mean in terms of the

number of pools and canisters required to store the fuel. Pools increase

from one per year in 2000 to an equilibrium requirement of four per year

after 2035. In the same period, the number of canisters for storing five-

year-cooled fuel increases from about 1100 per year to just over 6000 per

year. In the 150 years covered by the predictions, the total number of

facilities increases from 8 to 366 in the case of pools and from 9 000 to

680 000 for canisters.

These values represent minimum requirements for the set of

predictions used. Ideally, in a mature fuel handling economy there will

always be standby capacity. In addition, as time passes, there will be

an increasingly significant group of vaults or pools in process of being

decommissioned, and sites being reclaimed.

J-4

4. CONSEQUENCES OF REHANDLING

One of the consequences of adopting a policy of retrievable

storage is that as each building reaches the end of its useful life its

contents must be removed and placed in a new building. Presumably, old

facilities will be demolished and their sites reclaimed for further building.

In addition to cost and logistical burdens, this technique

could impose an undesirable radiation burden on future generations. Under

normal conditions, the maintenance of handling facilities, the loading and

unloading of flasks, and the trasport of active material all give rise to

the accumulation of man-rem. Being forced to retrieve the fuel, in itself,

increases the amount of handling and will, therefore, lead to increases

in dose. In addition to this, the damage incurred by the fuel during each

movement will increase the possibility of the spread of contamination.

Table 4 and Figures 2 and 3 illustrate the extent of the

rehandling requirements. In 2035, the first year in vxhich rehandling takes

place, the total handling rate is 5% higher than the rate at which fuel is

committed to storage in that year. By 2060, the rate at which fuel is being

rehandled reaches 50% of the rate at which new fuel is being put into

permanent storage. The two rates become equal in about 2085. From that

time on, the amount of fuel in process of relocation in any one year will

be greater than the fuel production in that year. This is based on a 50

year lifetime for each facility and would be different if another value

were used.

5. EMERGENCY RETRIEVAL

One of the arguments made in favour of retrievable storage is

that in an emergency there would be ready access to the fuel so that it

3-5

could be moved to a new location. Apart irom the possibility that any

eventuality requiring the evacuation of a fuel storage site might also

affect the mechanism for retrieval, this gives rise to two important

considerations. If it p.ver becomes necessary to move all or part of the

fuel at a particular site, where would it go and how lor.? would this take?

5.1 STANDBY STORAGE

True retrievability can only be said to exist if there also

exists sufficient standby storage capacity to absorb the fuel which must

be relocated. Little consideration has been given to the question of

whether such standby facilities should be available at all times or

whether in a properly managed system there would be sufficient time in

which to build new facilities.

5.2 RELOCATION TIME

At some time in the future, it may become necessary to move all

or part of the fuel in storage. For instance, the whole inventory may have

to be shifted if a more suitable form of management is adopted or if a

decision is made that the fuel should be reprocessed. The need to move a

part of the fuel could result from an accident or from the deterioration

of some of the facilities. In the case of an emergency relocation,

presumably it would be desirable to move the fuel out of the impaired

repository as quickly as possible. It is therefore worthwhile examining

the time required to completely relocate the existing inventory. These

times are shown in Table 6.

The assumption here is that the equipment available to move

the fuel is equal in capacity to the equipment in existence for handling

the arisings of the current year Csee Appendix I). This could be available

in two ways. Either all existing equipment could be directed completely

to the relocation operation or there could be a backup of 100% of existing

equipment. The first of these is probably impossible to do and it is

extremely unlikely that the second procedure would ever be adopted. Yet

any smaller availability of equipment will increase the moving time.

J-6

6. OBSERVATIONS

1. There is no doubt that a continuing system of retrievablestorage will be viable for many decades. It is also evidentthat such a system will eventually assume massive proportionsdue mainly to inherent rehandling requirements.

2. If it is assumed that each facility has a lifetime of 50 yearsthen, around 2060, the rate at which fuel is being rehandledreaches 50% of the rate at which new fuel is being put intopermanent storage. The two rates become equal in about 2085,just over 100 years from now. From that time on the amountof fuel in the process of relocation in any one year will begreater than the fuel production in that year. For facilitieswith longer lifetimes the crossover point will occur at a laterdate.

3. A consequence of the use of engineered surface facilities toachieve retrievability is that the structures themselves wearout making continued retrieval and relocation a necessity.Because of the additional risks involved, the adoption of acourse of action requiring continual rehandling may place anunreasonable burden on future generations.

4. In an accident situation the damage incurred by a storagefacility could impair or even prevent retrieval. The proba-bility of this occurring and the effects that it might haveis a subject which requires further consideration.

5.. The time required to retrieve and relocate whole inventoriesbecomes so large that it is questionable whether, in an emer-gency, a truly effective retrieval operation could be carriedout. It may be necessary, for example, to restore coolingwithin a few weeks or days after an incident, but to moveeven one hundredth of the inventory in 2000 could take aslong as one month. This is another aspect of retrievabilitywhich needs to be further evaluated.

6. This study raises serious questions concerning the logisticsof retrievable storage for the long term. No commitment tosuch a system should be made without concurrent investigationand development of alternative methods for disposal.

J-7

TABLE 1

PROJECTED ARISINGS OF SPENT CANDU FUEL

2000

2035

2070

2100

2120

LOW PREDICTION

RATE OF FUELPRODUCTIONCMg/a x 10"3)

7.1

26.3

29.2

29.2

29.2

CUMULATIVEPRODUCTION(Mg x 10"6)

0.071

0.68

1.68

2.55

3.43

HIGH PREDICTION

RATE OF FUELPRODUCTION(Mg/a x 10"3)

9.9

106.3

305.6

405.6

405.6

CUMULATIVEPRODUCTION(Mg x 10"6)

0.088

1.72

8.94

19.9

27.9

The assumptions used to compile these projections are as follows:

LOW Population

Power Consumption

HIGH Population

Power Consumption

i) growth rate drops to 0 over 50years from 1970

ii) Equilibrium population 36 million

i) rate of increase of consumptiondrops to 0 over 50 years from 1970

ii) equilibrium consumption 20 kW(t)/capita

i) present growth rate to 2060ii) rate drops to 0 over next 40 yearsiii) equilibrium 200 million

i) present rate of increase to 2000ii) rate drops to 0 over next 50 years

iit) equilibrium 50 kW(t)/capita

In both cases, nuclear power was assumed to supply ^ 100% of all energyrequirements by 2060.

J-8

TABLE 2

RATE OF STORAGE OF SPENT CANDU FUEL

YEAR

2000

2035

2070

2100

2120

ONE-YEAR-r.vCOOLED F U E L W

CMg/a x 10"3)

6.0

25.8

29.2

29.2

29.2

POOLSREQUIREDPER YEAR

1

3

4

4

4

FIVE-YEAR-,.MCOOLED FUEL^ '(Mg/a x 10"3)

4.9

23.9

29.2

29.2

29.2

CANISTERSREQUIREDPER YEAR

1115

5441

6637

6637

6637

(i) Rate at which one year old fuel is moved from reactor site to storagein pools at a central site.

(ii) Rate at which five year old fuel is moved from reactor site to storagein canisters at a central site.

TABLE 3

CUMULATIVE STORAGE REQUIREMENTS FOR SPENT CANDU FUEL

YEAR

2000

2035

2070

2100

2120

ONE-YEAR-, vCOOLED F U E L W

(Mg x 10"6)

0.06

0.65

1.65

2.52

3.11

POOLSREQUIRED

8

77

194

297

366

FIVE-YEAR-/..vCOOLED FUELV11''(Mg x 10"6)

0.04

0.06

1.53

2.40

2.99

CANISTERSREQUIRED

9016

12502

348182

547273

680000

(i) Fuel which was placed in storage when one year old.

(ii) Fuel which was placed in storage when five years old.

J-9

TABLE 4

REHANDLING REQUIREMENTS IN A SYSTEM OF RETRIEVABLE STORAGE

2000

2035

2070

2100

2120

FUEL PLACEP

IN STORAGE

(Mg/a x 10"3)

6.7

25.8

29.2

29.2

29.2

TOTAL HANDLING

RATE(l)

(Mg/a x 10"3)

6.7

27.0

47.3

64.4

76.J

REHANDLED

FUEL

(%)

0

5

62

120

162

(i) First rehandling assumed to occur in 2035, i.e. 50 yearsafter filling of first pool at central site. Subsequentrehandlings assumed to commence as each pool becomes 50years old.

J-10

TABLE 5

STANDBY REQUIREMENTS FOR EMERGENCY RELOCATION OF 10% STORE FUEL

YEAR

2000

2035

2070

2100

2120

FUEL INSTORAGE

(Mg x 10~6)

0.064

0.65

1.65

2.52

3.11

POOLSREQUIRED

8

77

194

297

366

STANDBYPOOLSREQUIRED

1

8

20

30

37

AREA FORSTANDBYPOOLS(tan2)

0.3

0.8

2

3

3.7

AREA FORSTANDBYCANISTERS

(km2)

0.4

0.9

2.1

3.2

3.8

TABLE 6

TIME REQUIRED TO RELOCATE FUEL IN STORAGE

YEAR

2000

2035

2070

2100

2120

FUEL IN STORAGE

(Mg x 10"6)

0.064

0.65

1.65

2.52

3.11

TIME TO MOVE FUEL

(years)

9.6

25.3

56.5

86.5

106.5

31VC10212 0113 0602 010Z 0502 0Ê02 0102 0661

MM

1

1

1

1

Mil

l 1

1

1 1

-

-

-

-

mi

» —

.——

3 aod ^nod

N0ii3ia3yd

— —

. — • —

.. — .

NVi. 0

'

NOU 3IQ3bd H9IH

Mil

l 1

1

1

II I

II 1

1

1

1

-

—

-

•rnr

—

0Z6I

,01

= eOl

gOI'

- «01

,0 8

"£ I05

io4t

10

|l 11 1 1 1 1

lllll

Mi

l

=

-

-

-

z.

- f/

IIII Mi

l Illlll 1 1

1

- 'FUEL

•PROD

PRODU(

jcTior

;TION',** 0 YEAR COOLED) .

/

/

! + RE

— -y*

HANDL

- —

^

ING

<

—»=

REHAI\

i———

DLING

— •

—

REQUIRED

-

-

•a

—

nil.

-

-

1970

C-i

h-'S3

1990 2010 2030 2 0 5 0 2070

DATE

FIGURE 2: HANDLING OF SPENT CANDU FUEL (216

2090

J.h/kg)

2110 2130

10

107 -

10° z

S io4

10

Illl 1 1 1 1

Illll 1 1 1 1

TTTT

-

z /Z J

/

*y

PROC

(1

UCTIO

^ ^FUEL

YEAR

/

N + R

PRODU

COOLf

y

/

EHANDL

CTION

I NG ~^ — •. —

^ —

^ - —

---RERE

—. —

. *

HANDL1QUIREE

..

.

NG)

—

^

—

-

-

-

-=

2090 21101970 1990 2010 2030 2050 2070

DATE

FIGURE 3 : CUMULATIVE HANDLING OF SPENT CANDU FUEL ( 2 1 6 MW.h/kg)

2 1 3 0

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