low-level radioactive waste management the french...

Dr Gérald OUZOUNIAN

[email protected]

Low-level radioactive waste management

The French case

DINT/16-0194

LLRWM - Washington October

24-25, 2016

mailto:[email protected]

Andra

Independent from the waste producers

Placed under the supervision of the ministers in charge of

Research, Energy and the Environment

Responsible for the long-term management of all radioactive

waste produced in France

It involves about 650 employees (2/

3 engineers and managers)

and a budget of 250 M€

DINT/16-0194

The Planning Act of 28 June 2006 concerning the sustainable

management of radioactive materials and waste provides the

framework for its action.

LLRWM - Washington

October 24-25, 2016 2

Major options in France

No clearance level for the materials coming from any nuclear classified zone

Safety of the population and protection of the environment is the first priority

A national framework set by law

Inventory and forecast, leading to a National Management Plan

A safe solution for all types of radioactive waste

Reprocessing of used fuel and reuse of valuable material

Reversible geological disposal (Cigéo Project) is the reference solution for the

high-level waste

Host clay formation already studied in an underground laboratory

Vitrified waste and IL-LL (hulls and end-caps) waste to be disposed of

Alternative solution of SF direct disposal under study

3 LLRWM - Washington

October 24-25, 2016 DINT/16-0194

4

• The Objective of Surface Disposal

• The components of a surface repository

• The Safety Assessment

• The Waste Acceptance process/control

• The operations

• The features/conclusion

DINT/16-0194 LLRWM - Washington

October 24-25, 2016

French radioactive waste classification

Short-lived waste Period ≤ 31 years

Long-lived waste Period > 31 years

Graphite, radium-bearing waste

(under development)

Waste mainly from dismantling operations (CIRES since 2003)

High level

Intermediate level

Low level

Very low level

<100 Bq/g, ~10Bq/g

A few 105 Bq/g

A few 108 Bq/g

> 109 Bq/g

Waste mainly from day-to-day

operation of NPPs

(CSM from 1969 to 1994)

(CSA since 1992)

Waste stemming from UF recycling

(CIGEO geological disposal facility in France

to be commissioned in 2025)

High level

Intermediate level

Low level

Very low level

<100 Bq/g, ~10Bq/g

A few 105 Bq/g

A few 108 Bq/g

> 109 Bq/g

5

WAC

LLRWM - Washington

October 24-25, 2016 DINT/16-0194

Post Monitoring

Disposal principles

6 DINT/16-0194 LLRWM - Washington

October 24-25, 2016

A

c

t

i

v

i

t

y

Time

Limit transfer Contain and Isolate

300 years for

surface disposal

Some 105 years for

geological disposal

Operations

Monitoring

Centre de l’Aube


October 24-25, 2016

8





• The operations



October 24-25, 2016

Defence in depth: waste disposal concept

The principle of CSA disposal is to confine radioactivity and monitor

containment while radioactivity decreases to such a level that there is no

more significant radiological risk (after 300 years LILW activity is roughly

divided by 1000)

LLRWM - Washington

October 24-25, 2016 DINT/16-0194

1st barrier : Waste package,

within which a containment

material envelops the waste

2nd

barrier : disposal vault,

including the network control

galleries (RSGE) and final cover

3rd

barrier : The geological environment

Composed by a natural barrier of

impermeable clay layer topped by a

draining sand layer

9

le colis.pptx

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ouvrage.pptx

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environnement géologique.pptx




Inventory

10 DINT/16-0194

• Nuclides impacting on long term safety of disposal are

generally not assessed by the NPP operators because

these do not impact on the daily operation of a facility.

C14, Cl 36, etc (beta emitters)

• Requirement for specific characterization program for

disposal purpose

• For surface disposal , long lived nuclides are the major

contributor to the dose to the public in the long term

LLRWM - Washington

October 24-25, 2016

Waste Packages

11 DINT/16-0194

Transport regulation also to be taken into account.

LLRWM - Washington

October 24-25, 2016

Centre de Stockage de l’Aube


October 24-25, 2016

Outlet

Disposal area

Draining

layer

Water table

Impermeable layer

Surface Disposal Siting Concept


October 24-25, 2016

14





• The operations



October 24-25, 2016

Safety objective, dose limitation

15

DINT/16-0194

• Worker’s exposure under normal conditions:

• Euratom 96/29 : 20mSv/year. French Regulation idem.

• Andra objective: 5mSv/year

• Public exposure under normal situations:

• Euratom 96/29: 1mSv/year. French Regulation idem.

• Andra objective: 0,25mSv/year.

• Public and Workers exposure under accidental conditions:

• No regulation

• Andra reference : 10mSv/year or 10mSv

LLRWM - Washington

October 24-25, 2016

:

FINAL COVER STRUCTURE

1. WASTE

PACKAGES

UNDERGROUND DRIFT

IMPERMEABLE LAYER

DEEP FORMATIONS

WATER-COLLECTION

NETWORK DRAINING LAYER

2. DISPOSAL

SYSTEM

3. SITE

Identified

outlet

Redundancy between

functionsof

engineered barriers:

containment during

operational

and monitoring

phases

Safety during operational and monitoring period


October 24-25, 2016

IMPERMEABLE LAYER

DEEP FORMATIONS

DRAINING LAYER

:

:

Waterborne

transfers

Airborne transfers

During the post-

monitoring phase, the

safety of the repository

relies on :

– the activity of long-lived

emitters contained in

disposed waste.To be

controlled at acceptance

stage

– the retention capability

of the system (design and

site)

Long-term safety (model)


October 24-25, 2016

For each phase , need to describe/establish: Operations/process

Behaviour of component

Air and water pathways scenarii (normal and accidental/altered )

Exposure modes :

External exposure : Straight-Line or Sky effect

Dust and gas inhalation

Ingestion

contamination

Illustration - Air Pathway Scenarii

Operational phase :

external exposure , outgassing

Consequences of a waste package

destruction by an accidental event

Post monitoring phase

Consequences of human intrusion

in the repository ( road

construction, house)

external

exposure ,

outgassing Waste

package

waste

package

destruction

truck

18 DINT/16-0194

LLRWM - Washington

October 24-25, 2016

Post

Closure

Phase

AES

Inadvertent

intrusion Road Construction

Land pollution

following up on

an intrusion

Residential area,

Child on playground

NES : Normal Evolution Scenario

AES : Altered Evolution Scenario

Operational

Phase

NES

Workers exposure at their normal position

Public exposure due to normal releases

AES Drop, Fire Workers, Public

Post Closure Phase

Road Construction

300 years

Examples of scenarios involving air pathways


October 24-25, 2016

Waste acceptance

LLRWM - Washington

October 24-25, 2016 DINT/16-0194

Safety requirements on waste packages

Waste acceptance criteria for disposal

Andra’s technical specifications for packages

20

Waste package specifications

LLRWM - Washington

October 24-25, 2016 DINT/16-0194

Leaching rate

(Range of 10-3

per year)

Diffusion coefficient

(Range of 10-14

– 10-12

m²/s )

+

minimum thickness

Waste matrix

(homogeneous waste)

Additional “embedding”

layer

(homogeneous and

heterogeneous waste)

Two ways to achieve long-term containment

Two types of

containers

“Short-lasting”

containers

(Metallic)

“Long-lasting” &

confining containers

(Concrete)

Containment performance

21

Waste package safety-related specifications

LLRWM - Washington

October 24-25, 2016 DINT/16-0194

Activity limitation

Containment properties

(diffusion coefficient,

leaching rate, i.e, chemical

resistance)

Lifetime performance of the

envelope (durability)

Radiation shielding

(dose rate, surface contamination)

22

Waste package specifications - principles

Specifications address the following :

Waste form

Activity limits

Toxic thresholds

Physical characteristics of package (geometry, weight, etc.)

Specifications related to waste form :

Forbidden waste : free liquids, putrescible materials, explosives, …

Restricted waste / materials :

Wood

Powder-type waste

Aluminium

Spent radioactive sources

Etc.

LLRWM - Washington

October 24-25, 2016 DINT/16-0194 23

• Maximal weight

• Maximum dose rate and external contamination

• Fire resistance

• Drop resistance

• Radiation resistance

•3H gas release

A representative package is tested

according to a specific protocol

each package

checked

Drop test

General technical specifications

LLRWM - Washington

October 24-25, 2016 24 DINT/16-0194

Test_chute.jpg

Radiological capacity and activity limit

LMA site

UNIFORMITY

LMA disposal

unit

LMA package

Hypothesis

regarding the

number of RN that

contribute to dose

constraint

DOSE

CONSTRAINTS

Long-term

Human intrusion

Scenarii

Operational

scénarii

INVENTORY Scenarii Radiological

Impact

DOSE

CONSTRAINTS

ACCEPTABLE

RN Capacity ( Bq) in

line with acceptable

Inventory

YES

NO

RADIOLOGICAL CAPACITY ( Bq)

SPECIFIC ACTIVITY LIMIT (Bq/g)

LLRWM - Washington

October 24-25, 2016 DINT/16-0194 25

Operational Safety :

Single package

scenarios

Long Term Safety : a large number of

packages, or the whole repository

scenarios

Uniform distribution

assumption

No hot spots

Activity limit per package Activity limit per

disposal unit

Global

Radiological

capacity

Activity limit acceptance: a key part of the WAC


October 24-25, 2016

Element

Radiological

capacity of

the facility

TBq

Activity limit

per package

(Bq/g)

36Cl

60Co

63Ni

79Se

99Tc

107Pd

108mAg

129I

135Cs

137Cs

151Sm

total alpha

(after 300 years)

4. 10-1

4. 105

4. 104

3.72 10-2

1.23 101

3. 103

2.47 101

3.03 10-1

6. 101

2. 105

1. 104

7.5 102

2.4. 104

1,3 108

3.2. 106

5.5 104

4.4 104

3. 105

1.4 103

1.4 103

2.6 105

3.3 105

4.5 105

3.7 103

Examples of activity limits (total capacity and per package)

27

These limits

are design

and/or site

and/or

regulatory

specific (Aube

center)

LLRWM - Washington

October 24-25, 2016 DINT/16-0194

• Chemical species possibly present at significant levels in

waste or conditioning materials (concrete, radiation shields)

• Split, in some cases, into different Reference Packages

Toxics followed :

Pb, B, Ni, Cr( III, VI, total), Sb, Se, Cd, Hg, Be, As, U, Free

CN-, Asbestos,

nitrates (non toxic, but regulated in drinkable water)

sequestering agents (chelating agents) coming from

decontamination products (EDTA, oxalate, …)

waste degradation (cellulose)

polymer and bitumen degradation

LLRWM - Washington

October 24-25, 2016 DINT/16-0194

Chemical inventory

28

29





• The operations


DINT/16-0194

LLRWM - Washington

October 24-25, 2016

Constraints applied to the waste package

30 DINT/16-0194

Constraints to the waste package before entering the

repository:

• Radiological content

• Physical characteristics

• Chemical stability

• Gas generation

• Expected performances for long period of times

• Low leaching rate when in contact with site water

• No hot spot of activity

LLRWM - Washington

October 24-25, 2016

Features and requirements of waste control

31 DINT/16-0194

• A rigorous waste acceptance process. (Impact on Safety)

• Parameters important for safety are sometimes difficult to

control in the production line

• Requirement for detailed waste acceptance criteria with

possibility to control them

• Inspections to be performed at the waste conditioning plant

• Controls to be performed at the repository site

LLRWM - Washington

October 24-25, 2016

32

Waste Acceptance Criteria Waste Package Specification QA procedures

No free liquid No free liquid Waste sorting or drying

Iodine 129 < Threshold value

( bq/g)

Cesium 137 < Threshold value

Scaling factor

Cs137 measurement

Scaling factors verification

program

Diffusion coef. < Threshold value

m2/s

Leaching ratio

Grout, water content … Supplying the grout

Conducting the process

Periodical measurements

of specified parameters on samples

Operational parameters and values

= “operational quality”

Qualification (tests…) Derivation of scaling factors

Diffusion measurements

Leaching test

Waste Acceptance Process

DINT/16-0194

LLRWM - Washington

October 24-25, 2016

Duties of the waste generator

• Manufacturing waste packages

• Keeps records

• Reports to Andra on the physical and radioactive characteristics

of the waste packages before shipment

• Gets an authorization from the waste disposal facility’s

operator for identified packages.

• Identifies deviations and isolates related packages, declares to

the waste disposal facility’s operator

• Performs controls according to QA procedures

LLRWM - Washington

October 24-25, 2016 DINT/16-0194 33

34





• The operations


DINT/16-0194

LLRWM - Washington

October 24-25, 2016

:

Control of water flows

LLRWM - Washington

October 24-25, 2016 35 DINT/16-0194

Filling of disposal cells

LLRWM - Washington

October 24-25, 2016 36 DINT/16-0194

Centre de stockage de l’Aube : vesselhead disposal


October 24-25, 2016

Active and passive monitoring period

LLRWM - Washington

October 24-25, 2016 38 DINT/16-0194

Regulations

Fundamental safety rules for LILW disposal

• 1984 : Fundamental Safety Rule I.2

• 1985 : Fundamental Safety Rule III.2e

Safety of LILW surface disposal concept

Radiation protection criteria

LLRWM - Washington

October 24-25, 2016 39 DINT/16-0194

low-level radioactive waste management the french...

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