seminario enea - casaccia venerdì 12 marzo 2010 ore 10 carlo artioli [email protected]...

SEMINARIOENEA - CASACCIA Venerdì 12 marzo 2010

ore 10

Carlo [email protected]

Multi-physicsparameters optimization

of ADS corefor transmutation

Int’l Conference on Peaceful Uses of Atomic Energy New Delhi, Sept 29-Oct 1 / ENEA-BO 12 Nov 009 Carlo Artioli

Multi-physicsparameters optimization ofADS core for transmutation

IP-EUROTRANSInternational training course (ITC-9)

on

Accelerator–driven Transmutation System forEuropean and Asian Young Scientists and Engineers

Nuclear Technology and Education Center JAEA, Tokai, Ibaraki, JapanDec. 1-4, 2009


IP-EUROTRANS International Training Course (ITC-9) Dec. 1-4, 2009 JAEA, Tokai, Ibaraki, Japan Carlo Artioli

http://www.enea.it/prima.html

SIXTH FRAMEWORK PROGRAMMEEURATOM

Management of Radioactive Waste

IP EUROTRANSEUROpean Reserch Programme for the TRANSmutation of high Level

Nuclear Waste in an Accelerator Driven System (ADS)

DM0 DM1 … DM5 Management Design Nudatra

WP1.1 WP1.2 ….. WP1.6Reference Design Development and Assesment XT-ADS RemoteSpecifications of XT-ADS and EFIT Designs Handling Catalogue

U-free Core design of the EFIT-Pband of the Gas backup option

Task 1.2.1 ….. Task 1.2.4 …. Task 1.2.6(ENEA, FZK, Ansaldo, CEA,Framatome ANP, NNC, CRS4)


EFIT Pb Main featuresEFIT Pb Main features

Goal:Goal: fissioning MA, while producing energyfissioning MA, while producing energyFuel:Fuel: MA & Pu Oxide in inert matrix (MgO)MA & Pu Oxide in inert matrix (MgO)Coolant:Coolant: Lead, Tin=400 °C, Tout=480°CLead, Tin=400 °C, Tout=480°CPower:Power: several hundreds MWseveral hundreds MW

EUROTRANS DM1 Task 1.2.4:EFIT Core Design

(European Facility for Industrial Transmutation,)VI FP, IP EUROTRANS

concept developed for the transmutation of MAs


Kmax =0.97

High amount of MA allowed in the core


QpnS

Pth)/(

eff

S*

M

MS

SS 1 k

kM

eff

effeff 1 k

kM

s

s

k

k1

eff

effthprot

k

k

SQ

Pi

*

1

proti


Main questions to be answered

2) In which way the burning capability has to be optimized?

3) What about the two goals: “burner” and “energy producer”?

(should they be contradictory)

1)What exactly means “burning MA at best” ?


Core size (MW)Core size (MW)

MA

bal

ance

Kg

(MA

) /T

Wh

MA

bal

ance

Kg

(MA

) /T

Wh 1)What exactly means “burning

MA at best” ?

(e.g.400)(e.g.400)

(e.g

.65

)(e

.g.6

5)

Eur

o /

Kg

(MA

tra

nsm

uted

)E

uro

/ K

g (M

A t

rans

mut

ed)


Power density roughly invariant

Power size become geometrical size


MA

bal

ance

Kg

(MA

) /T

Wh

MA

bal

ance

Kg

(MA

) /T

Wh

Lattice ruled by linear power rating and TH constraint




MA

bal

ance

Kg

(MA

) /T

Wh

MA

bal

ance

Kg

(MA

) /T

Wh 1)What exactly means “burning

MA at best” ?

fuelPu MAPu MA Pu

MA


2f

f, )97.0(

axDBkkk

H

PuMA

PuMA

Transmutation

Transmutation

Transmutation

Transmutation

fission

fissionfission

fission

Small size, high enrichment

Large size, low enrichment

Small size = low MA reaction rate

Large size = high MA reaction rate


e = Pu / (Pu+ MA)

PuMA

FUELFUEL

- 42 0

Pu

mas

s B

alan

ceM

A m

ass

bal

ance

Pu

bre

eder

Pu

bu

rner

Kg/TWh

Ex.- 60, +18

Ex.- 30, -12Total balance ≈ - 42 kg / Twhth

(from theor. 210 MeV/fission)

e = Pu / (Pu+ MA)

PuMA

FUELFUEL

Fission product

Tra

nsm

uta

tio

ns


A MA balance lower than -42 kg/TWh (e.g. -50) means that:- 42 have been actually fissioned and- the difference (e.g. 8) have been transmuted in new Pu

A MA balance higher than -42 kg/TWh, e.g. -35, means that:- 35 have been actually fissioned and- the difference (e.g. 7) are fissions of Pu


the system would act as Pu breeder

the system would act as Pu burnerIP-EUROTRANS International Training Course (ITC-9) Dec. 1-4, 2009 JAEA, Tokai, Ibaraki, Japan Carlo

Artioli

In both the cases:-Producing new Pu and-Burning Puthe system has not been optimized because there are “expensive” neutrons used not to fission MA.


(Producing or fissioning Pu can be made in cheaper way in conventional reactor)

The best ADS, as MA burner, shows a:- MA balance of -42 kg/TWh and (of course)- Pu balance of 0 kg/TWhIP-EUROTRANS International Training Course (ITC-9) Dec. 1-4, 2009 JAEA, Tokai, Ibaraki, Japan Carlo

Artioli

or considering the velocity of burning -42kg/h /TWthe minimum cost of the power deployed

2) In which way the burning capability has to be optimized?3) What about the to goals: “burner” and “energy producer”?

(should they be contradictory)

The best ADS, as MA burner, shows a:- MA balance of -42 kg/TWh and (of course)- Pu balance of 0 kg/TWhSince looking for a MA performance “better”

than -42 kg/TWh is meaningless, the optimizationleads to the minimum cost of the TWh

which is the same optimization required for theenergy production


How to get the :- MA balance of -42 kg/TWh and (of course)- Pu balance of 0 kg/TWh

PuMA

- 42 0

Pu

mas

s B

alan

ceM

A m

ass

bal

ance

Pu

bre

eder

Pu

bu

rner

Kg/TWh

Ex.- 60, +18

Ex.- 30, -12

Suitable e = Pu / (Pu+ MA)

The burning performance depends on the mutualratio between Pu and MA i.e. on the enrichment

X kg/TWh of net Transmutations

42-X kg/TWh fissioned X kg/TWh fissioned

FP, 42 kg/TWh


kswing

INPUTto be supplied

OUTPUT

Pu and MA vectors

Search of suitedPu/ (Pu+MA)

Pellet composition

Pu, MA dioxydestechiometry and density;Matrix, density and fraction

Definition of “enrich.”Pu/ (Pu+MA)

Pin geometry definition(diameter and other by guess)

Gas releases= f (T, BU)

Fuel element definition

Max linear power, TH(Tmax, conductivity law)

Fuel density power

Core density powerKeff required

Core definitionCore size and power

Ver

ifica

tion

and

optim

izat

ion

Main statement:

DESIGN


Which are the correlationshipsamong the main core parameters

(A-BAQUS graph)

Matrix rate

Current

Power/size

Performances

Enrichment

k cycle


fuel

PuMA

e = Pu / (Pu+ MA)

Inert matrix

PELLETPELLET

%MgO = Matrix / (Matrix + fuel)

MgO

e (%)

50

%MgO50 ( %fuel )



e (%)

e = Pu / (Pu+ MA)

%MgO

PuMA

Fission productTotal balance 42 kg / Twhth

Tra

nsm

uta

tio

ns

50

FUELFUEL

50 ( %fuel )

Pu

mas

s B

alan

ceM

A m

ass

bal

ance

- 42 0

Pu

bre

eder

Pu

bu

rner

Kg/TWh

Ex.- 60, +18

Ex.- 30, -12



Approximation:No effect on the spectrum of the variation

of the matrix fraction (in the range)

e (%)

%MgO

Pu

mas

s B

alan

ceM

A m

ass

bal

ance

- 42 0

Pu

bre

eder

Pu

bu

rner

Kg/TWh

PuMA

K swing (pcm/y)

FissionFission

Tra

nsm

uta

tio

ns

k (

pcm

/y)

0

FUELFUEL

5050

e = Pu / (Pu+ MA)

( %fuel )



e (%)

%MgO

Homog. Power density rather constant

50

( %fuel )

Coolant volume fraction(depending on coolant velocity)

Linear power rating(depending on the fuel)



e (%)

%MgO


decreasing %fuel (incr. %MgO)

Increases the geometrical size(to adjust for criticallity)

Increases the Core Power

P (

MW

)

Co

re R

adiu

s (c

m)

400

200

50

( %fuel )

Coolant volume fraction(depending on coolant velocity)

Linear power rating(depending on the fuel)



Core Power

Proton current

k swing

Proton current range

50 25

P (

MW

)

Co

re R

adiu

s (c

m)

400

200

Subcriticality fixed!

Enr

ichm

ent c

onst

ant

I (mA)Which are the correlationships

among the main core parameters


EFIT-Pb Technology constraints

Fuel CERCER (Pu,MA)O2-x-MgO inert matrix

(or 92Mo , 93%enriched)

% VF of MgO>50% (to assure thermal conductivity);

Linear power <180-200 W/cm (depending on %VF MgO).

- FA residence time = 3 years (Pb corrosion is the most restricting condition)

T limit for the fuel: ~1650 K (500 K below the inert matrix melting/disintegration)

T limit for the cladding at nominal cond. (9Cr1MoVNb steel T91): 820 K

Pb speed at 1 m/s (to limit corrosion effects)

Active height = 90 cm (to limit the pressure drop)


• Maintain a low keff swing during the cycle (no oversize of target and accelerator)

• Maximize the power density

• Decrease the form factors to flatten the coolant Tout (Pb at 750 K and <820 K for

the cladding) and to maximize the avg power density by use of 3-zones with increasing active fuel volume fraction along the core radius (enr. Is fixed):

• from inner to intermediate zone by increasing the fuel/matrix from 43% to 50% (but same pin diameter)

• from intermediate to outer zone by increasing the pin diameter (and same fuel/matrix %)

• ,

• FA dimensions are driven by the size of the spallation module, Rtarget = 43.7 cm (to

replace 19 FAs)

Design choices, rationales and solutions• Maximize MA fission. The enrichment is fixed to fulfil the “42-0” approach, i.e.:

1. 42 kg/TWhth is true for any nuclear system (it comes from 210 MeV/fission)

2. what is the policy about Pu? The choice here is neither Pu production (not consistent with U-free) nor Pu reduction (net fission expensive in ADS)

3. the choice is then to dedicate all the fissions (directly or indirectly) to MAs: net balance is -42 kg/TWhth for MA and 0 kg/TWhth for Pu (which sustains in

any case the reactivity, acting as a catalizer)


Project parameters (as inputs)

– Thermal power of some hundreds of MW (to be optimized)– Pb coolant for the proton target and the core (fast spectrum). Pb temp. for the core: Tin=673 K, Tout=753 K– External proton beam of 800 MeV up to 20 mA (windowless target)– Sub-critical level of keff = 0.97 (to be verified a posteriori)– The fuel is U-free and uses Pu and MA vectors. MA come from the spent UO2 (90%) and MOX fuel (10%) of a PWR (45 MWd/kgHM) with 30 cooling years. Pu from UO2 with 15 cooling years (data from CEA).


B: pellet with different fractions of matrix

, Tout

A: reduction of coolant volume fraction (larger pin)

Radial flattening by increasing fuel volume fraction

Toutmax

Coolant volume fraction

Increasing fuel volume fraction

Outer zone

, DP

Plin

Tout


Fla

tte

nin

g T

ech

niq

ue

s

StructuralC o o l a n tF u e lP

u+

MA

Mat

rix

StructuralC o o l a n tF u e l

Pu

+M

A

Mat

rix

ReferenceIntermediate

zone

Outer zoneby different pin sizeand same matrix %

Inner zoneby different matrix%and same pin

PDfuel=max; Plin=max; Tout=max

Pin “size” to obtain the same max PDbut Tout should be unacceptable

StructuralC o o l a n tF u e l

Pu

+M

A

Mat

rix

PDfuel=max; Plin=max; Tout=max

PDfuel< max; Plin< max; Tout=max


Inner, Intermediate & Outer FA Design

Inner and Intermediate: Outer:Same pin & pitch; MgO VF (57%, 50%) > Pin - Same MgO VF

(50%)IP-EUROTRANS International Training Course (ITC-9) Dec. 1-4, 2009 JAEA, Tokai, Ibaraki, Japan Carlo Artioli

Cylindrised vertical section & H3D model384 MWth core

42

66

72


Hom. Power density at midplane

Maximum allowed, corresponding to linear power rating 207 and 180 W/cm

(calculations: M. Sarotto)(calculations: M. Sarotto)


BOC Monte Carlo Calculations(calculations Carlo Petrovich)

keff 0.97403 0.00023

Neutron source (S)

(neutrons/proton) 23.02 0.08

M = all fission neutrons / S 19.45 0.25

kS = M / (M+1) 0.95111 0.00059

0.52

Proton current 13.2 mA

SS

effeff

kk

kk

/)1(

/)1(*

To be considered in optimization step: reducing the core/spallationsize the efficiency will be increased


Pu / Pu (BOC) -0,7%

MA / MA (BOC) -

13,9%

3 yearsBU = 78,28 MWd / kg (HM) BU -40,17 kg (MA) / TWh

Total E = 10,0915 TWhth -1,74 kg (Pu) / TWh

2400

2500

2600

2700

2800

2900

3000

0 1 2 3[ years ]

[ k

g ]

Tot Pu

Tot MA

MA and Pu balances


Behaviour of MA isotopes

0

10

20

30

40

50

60

70

80

90

100

0 1 2 3

years

[ %

] Tot MA

Am241

Am243

Cm242

Cm244

Behaviour of Pu isotopes

0

10

20

30

40

50

60

70

80

90

100

0 1 2 3Years

[ %

]

Tot PuPu238Pu239Pu242

Pu, MA vectors evolutions

Pu / Pu (BOC) -0,7%

MA / MA (BOC) -

13,9%

3 yearsBU = 78,28 MWd / kg (HM) BU -40,17 kg (MA) / TWh

Total E = 10,0915 TWhth -1,74 kg (Pu) / TWh

2400

2500

2600

2700

2800

2900

3000

0 1 2 3[ years ]

[ k

g ]

Tot Pu

Tot MA

MA and Pu balances

The Pu and MA vectors evolve in the time toward equilibrium configurations; this implies:

- Calculation of the enrichment with the equilibrium vectors

- Enrichment resettings in the transitory phase


Power size optimization criterion:minimum cost / kg of fissioned Minor Actinides

minimum cost per MW deployed.

cost / MWdeployed = f(core size, accelerator size)

- Core term: decreases increasing the power (if power density is const.);

- Accelerator term: decreases increasing the power,

but the target loses efficiency.

Present criterion:

The largest size core acceptable within the currentspallation module design (max power: 11.2 MW).


3 approaches Starting M a i n p a r a m e t e r s Performancies point (kg/TWh)

(- 42 TRU)

Kzero reactivity swing ≈ 0

e k cycle P(MW) i (800 MeV)(%) (pcm) (MW) (mA)

400MW P = 400 MW

42-0 Pu ≈ 0


3 different approaches

Graphical extimations


3 approaches Starting M a i n p a r a m e t e r s Performancies point (kg/TWh)

(- 42 TRU)

Kzero reactivity 50 ~0 275 ~ 7 ~ -36 MA swing ≈ 0 ~ -6 Pu

e k cycle P(MW) i (800 MeV)(%) (pcm) (MW) (mA)

400MW P = 400 MW 27 ~ +2000 400 ~ 32-18 ~ - 65 MA ~ +23 Pu

42-0 Pu ≈ 0 45.7 ~ +500 395 ~ 16-14 ~ - 41 MA ~ -1 Pu


“42-0 Concept” Main conclusions

-Conceptual “42-0” design leads to the best MA burnerin the sense that each fission is devoted to an “atom”of MA, no matter the kind of ADS

-The doubble goal, to be a burner and a producer of energy,are not in conflict

-Both can be reached minimizing the cost of the unit of energyproduced in the “42-0” concept


“EFIT-Pb” Conclusions

The “42-0” strategy has been the fundamental approach for the neutronic design of the EFIT core. Simultaneously a low keff swing is obtained (small current excursion).

MA fission (about 120 kg/year) via an U-free lead-cooled ADS as EFIT (384 MWth) is viable, as the core is concerned: acceptable max T for fuel and cladding in nominal conditions and transients.

The safety analysis (including sub-criticality level choice) has anyway to be completed.

Use of CERMET fuel (Mo matrix instead of MgO), qualification of fuel, steel in Pb environment, cost/benefits ratio are to be investigated.


Multi-physicsparameters optimization ofADS core for transmutation

IP-EUROTRANSInternational training course (ITC-9)

on

Accelerator–driven Transmutation System forEuropean and Asian Young Scientists and Engineers

Nuclear Technology and Education Center JAEA, Tokai, Ibaraki, JapanDec. 1-4, 2009



http://www.enea.it/prima.html

seminario enea - casaccia venerdì 12 marzo 2010 ore 10 carlo artioli [email protected]...

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