1Bridging French Experience on Nuclear Waste Disposa l R&D to CGSCEA-DEN/DTN

Mini-curso CEPAC – PUCRS

23/09/2008

Part 3: Bridging French Experience on Nuclear Waste Disposal R&D to

Carbon Geological Storage

michel.jullien@cea.fr

2Bridging French Experience on Nuclear Waste Disposa l R&D to CGSCEA-DEN/DTN

French facilities for underground storage

Keuper :grès

Keuper :grès

Dogger :carbonates

Dogger :carbonates

CO2 Injection Pilote site atSMB(-2000 m)

French NSFGeocarbonprojects

fieldfield

�Bridging CEA experience from High Level Nuclear Was te management ? Knowledge transfers on confinement systems and mate rial reactivity

for performance and safety assessment

UndergroundResearchLaboratory Andraat Bure(-500 m)NuclearWastemanagement

Paris basin

3Bridging French Experience on Nuclear Waste Disposa l R&D to CGSCEA-DEN/DTN

Long interim storage or

deep underground geological storageon studies

Wastes C

highactivity

(108-1010 Bq/g)

Wastes Bmedium activity

(105-108 Bq/g)

Sub-surface, on studies(graphite, radium rich wastes)

Surface storage(Storage Centre Aube, in

exploitation)

Wastes A

low activity(102-105 Bq/g)

Surface storage(Storage Centre VLA, in exploitation)

recycling

Very lowactivity

(1-102 Bq/g)

Long lifeperiod > 30 years

Short lifeperiod < 30 years

Nuclear waste classification and french issues

4Bridging French Experience on Nuclear Waste Disposa l R&D to CGSCEA-DEN/DTN

(Andra, 2005)

French concept for HLNW underground storage

≈≈≈≈ 1170 (S2, 60-90 years)

1800 (S1b,c) to 5200 (S2)

spentfuel

≈≈≈≈ 500 (S1a, 60-70 years)

1400 (S2) to 4800 (S1a,c)

C

≈≈≈≈ 100 (S1a)32 (S2) to 38(S1a)

B

Surface area(x104 m2)

Number ofdrifts

5Bridging French Experience on Nuclear Waste Disposa l R&D to CGSCEA-DEN/DTN

C

(Andra, 2005)

Sealing French concept for HLN glass C Waste

- 500 m

�Multi-barriers system�Engineered or site clays

Challenge ?How to have a robust prevision of long term

behaviour ?Functional component

Clay PlugConfinement function

Concrete Plugmechanical function

Steel PlugBiological protection

HLNW Drift Head

6Bridging French Experience on Nuclear Waste Disposa l R&D to CGSCEA-DEN/DTN

Temperature• Low to high temperatures for radioactive waste disposals (from 25 to 150°C )• Moderate-high temperatures for reservoirs exploitat ion & gas sequestration (up to 250°C)Pressure• Atmospheric to low pressure for nuclear waste• Moderate to high pressure for reservoirs (up to 800 bars)Time scale• Decennial life expectancy for oil and gas exploitat ion well• 10000 years for nuclear waste disposal safety assessments • Geological time for ultimate disposals and sequestration

Temperature, pressure and time scale

• Repository evolution – genericexample

00 10000 20000 30000 40000 50000

resaturation (HLW)

EDZ reconsolidation / bentonite swelling

pore pressure recovery high pH plume / HLW

release of repository gas

Time (a)

Long-term evolutionThermal pulse

From Marshall 2007

7Bridging French Experience on Nuclear Waste Disposa l R&D to CGSCEA-DEN/DTN

Common target level for HLNW & CO2

• Clay-rich material (CMR) is widely implied in sequest ration,

confinement and trapping in geological settings (acid

gas, oil, pollutants radioactive wastes…)

• Properties such as low permeability, high sorption and ion

exchange capacity, and swelling abilities determine t he sealing

function of natural or engineered materials

• The persistence of the CMR sealing function over time

depends on the interactions between clay (caprock, ho st-rock)

and surrounding materials (concrete, steel, other clay

materials…) for safety assessment

8Bridging French Experience on Nuclear Waste Disposa l R&D to CGSCEA-DEN/DTN

Example of clay-rich material reactivity

Identification of clay material reactivity under su pply of

metallic iron from structures, canister or wells an d

implication for safety assessment and radionuclide

migration in the near field

Metallic iron clay reactivity impact on safety for deep geological disposals ?

9Bridging French Experience on Nuclear Waste Disposa l R&D to CGSCEA-DEN/DTN

Meteorites as analogue of Metallic iron - clays reac tivity

7 Å layer spacing serpentines, and 2x5,5 = 11 Å Fe-ric h tochilinites (Sulphides)

• Metallic iron alteration produce

7 Å phases like berthierine,

cronstedtite or Mg-serpentine

Conditions ?Temperatures : 25 to 150°C

Very low pressureMetallic iron and accreted water

Courtesy B. Devouard Clermont-Ferrand B. Pascal Univ

10Bridging French Experience on Nuclear Waste Disposa l R&D to CGSCEA-DEN/DTN

Expected smectite conversion into chlorite / berthieri ne in Fe-rich diagenetic environments :

CEC (Cs) :

Density :

Unit cell volume :

0.8 à 1 meq.g-1

2.30 à 2.60 g.cm-3

~ 700 Å3 (anhydrous)

0.014 meq.g-1(Chlorite)

3.5 g.cm-3

~ 330 Å3

Main question :

Criteria : (1) cation exchange capacity and (2) 7Å phase new crystallisation

Choice of an experimental approach

State of art on smectite to serpentine conversion

Conditions of smectite to chlorite conversion and i ts impact on the EBS or host-rock confining properties

11Bridging French Experience on Nuclear Waste Disposa l R&D to CGSCEA-DEN/DTN

* Perronnet et al., 2008

Experimental metallic iron - clays reactivity in batch system (80°C / 45 days) 1/2

cation exchange capability

Mössbauer

Significant decrease of CEC for iron/clay ratio

between 1/10 and 1/7.5 (1)

• Evidence for reactivity associated to metallic iron and

iron oxides consumption• Evolution in reducing

microsystem environments inducing mixed FeII/FeIII phases

12Bridging French Experience on Nuclear Waste Disposa l R&D to CGSCEA-DEN/DTN

Altered clay + FeII

7 Å phase Fe-rich phase like Berthierine

(2)

7 Å

20 nm

50 nm

Up to 90% clay alteration

Lantenois et al., 2003 , * Papillon et al, 2003

Experimental metallic iron - clays reactivity in batch system (80°C / 6 months)

Smectitic corrosion *

Gel from altered smectite

13Bridging French Experience on Nuclear Waste Disposa l R&D to CGSCEA-DEN/DTN

Smectites Gels phases BerthierineAlteration New crystallization

Key parameters :Presence of smectite clay, temperature, time, metal lic iron

content and iron/clay ratio

Final product : Si-Al-Fe 7 Å berthierine-like phase

Corrosion / Clay reactivity impact on safetySteel corrosion in argillaceous media in reduced en vironment

Possible loss of clay materials confining properties induced by decrease in swelling capabilities, loss of ion exchange

properties and potentially preferential pathways creating

Validation of criteria SA operational conseq uences

14Bridging French Experience on Nuclear Waste Disposa l R&D to CGSCEA-DEN/DTN

Safety assessment > safety criteriaFailures analyses: Potential pathways for CO2 leakage

Diffusive transport (dissolved CO 2 , CO2-SC?),

chemical reactions

Transport in fractures (pre-existing or reactivated)

(modified from Damen et al, 2003)

Component function failure

Impact studies

15Bridging French Experience on Nuclear Waste Disposa l R&D to CGSCEA-DEN/DTN18/03/2008

Cálculo de performancepreliminar

Avaliação preliminarda segurança e dos riscos

. Dados sÍsmicos

. Dados geológicos

. Falhas maiores

. Profundidade

. Cartografia

. 1a campanha de campo

. Condições iniciais (T, P)

. Volumes esperados

. Proximidade de fontesde CO2

Cálculo de performance paracenário nominal

Descrição detalhada

dos locais e das rochas

. Dados sísmicos

. Dados geólogicos

. Experiênciase modelagem :- Geoquímica- Geomecânica- Hidrogeologia- Microbiologia. Campanha de perfuração e de coleta de amostras. Extrapolação da bacia. Integração geoestatística

Análise das funções

de armazenamento e selamento:Identificação dos cenários

acidentais

Avaliação de segurança

Análise de riscos e avaliação de segurança para uma injeção industrial de CO 2

Análogos naturais & industriais:

Escalas características de tempo e espaço

Seleção do locais de interesse:Decreto ou lei

. Guia metodológico

. Aspectos sanitários e legais

. Aceitação pública

Avaliação de riscos do local de injeção

.Meio ambiente. PopulaçõesSIM NÃO

Seleção de novo local

Injeção de CO 2industrial

Critérios gerais de armazenamento

e selamento

16Bridging French Experience on Nuclear Waste Disposa l R&D to CGSCEA-DEN/DTN

Muito obrigado pela sua atenção…

Bon appétit !