Part 3: Bridging French Experience on Nuclear Waste...
Transcript of Part 3: Bridging French Experience on Nuclear Waste...
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
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
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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
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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