Prsentation PowerPoint

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STORAGE OF TRITIATED WATER IN SALT CAVERNS
Pierre Bérest, LMS G.3S, Ecole
polytechnique Benoît Brouard, Brouard Consulting
LMS
6th Workshop KIWIR Paris, November 28-30, 2001
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Tritium and Tritiated Waters Characteristics
Titrium Half-Life 12.4 years
Tritiated waters H2O THO TO2

• Disintegration ? b-Radiation not very sharp
• Direct contact, or indigestion,
• can lead to severe health problem

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Objectives for Tritiated Water Storage

• The storage must remain safe for a period
• of, typically, 100 to 200 years.
• The required volume is several thousands
• of cubic meters.
• The tritiated waters released from the
• storage must be nil.
• The handling of waste during storage
• operations must be as simple as possible.

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An Appealing Solution ?
Not release in the atmosphere or in the ocean !
BUT
Storage in salt caverns
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Salt Deposits in the World
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Salt Deposits in France
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Solution Mining Principle
Man-made Caverns !
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Examples of solution-mined caverns
1. Tersanne (France) 2. Etrez (France)
3. Atwick (Grande-Bretagne)
4. Kiel (Allemagne) 5.
Huntorf (Allemagne) 6. Epe (Allemagne)
7. Eminence (USA) 8. Melville
(Canada) 9. Regina (Canada)
10. Manosque (France) 11.
Hauterives (France) 12. Salies de Béarn (France)
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Main Characteristics
300,000 m3
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Main Use of solution-mined Cavities

• Hydrocarbons storage
• liquids (Oil, LPG )
• Example US Strategic Reserve, 1 billion barels
• gas (natural gas, )
• Brine production for chemical industry (PVC,
  soda ).
• Industrial and radioactives wastes disposal ?

Many caverns are already (or will be soon)
abandoned
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Existing Wastes Disposals in the USA
NOW Industrial wastes NORM Radioactives wastes
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Handling is very simple
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No Tritiated Waters Released from the Storage
The system must prevent any (even extremely
small) permeation of waste from the cavern

• Salt permeability is very small (10-21 m²)
• Cavern pressure lt Pore pressure

The flow will be directed toward the cavern,
preventing any waste release
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Cavern Shrinkage due to Salt Creep

• CAVERN CREEP rate is governed by
• difference between geostatic pressure and cavern
  pressure
• temperature

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Creep Parameters for different Salts
Table 1 Paameters for diffrent salts
Norton-Hoff Law
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Fuel-oil-filled Well
Cavern Depth (m)
Cavern volume loss ( per year)
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Conclusions

• Fluid flow from the cavern to the rock mass is
  NIL.
• Cavern creep is accelerated but remains
  acceptable.
• Toxic fluids can be stored at relatively small
  pressure in salt caverns.