"Rapport environnemental Chalon Saint-Marcel 2007" [FR]
COMURHEX II: meeting tomorrow’s challenges
The chemistry of uranium
In addition to natural uranium conversion services, the Chemistry business unit (BU) is also active in other stages of the fuel cycle. For example, AREVA Pierrelatte converts depleted uranium generated during the enrichment phase and recycles the uranium recovered after the treatment of used fuel. Due to the BU’s expertise in all aspects of uranium chemistry, this complementary offer represents a strong added value for its customers.
Defluorination of uranium hexafluoride
Depleted uranium hexafluoride (UF6) is generated over the course of the enrichment process. Its U-235 isotope content is very low.
AREVA Pierrelatte uses defluorination to convert depleted uranium hexafluoride into uranium oxide (U3O8).
U3O8 is non-combustible, insoluble in water, non-corrosive, and chemically stable. It can therefore be stored under ideal safety conditions, while remaining respectful of the environment, to be reused later in this state or after a new enrichment stage.
U3O8, stored and owned by the customer, constitutes an important reserve of energy resources and allows preservation of primary materials.
Recycling of uranium from used fuel
When the nuclear fuel is removed from reactors after a period of approximately 3 to 4 years, it contains around 95% uranium. AREVA's Recycling business unit transforms this uranium into liquid uranyl nitrate during its treatment operations for used fuel.
Transported to the Tricastin site, the uranyl nitrate is either:
- converted into stable uranium oxide (U3O8) by denitrification for storage. In this case, it represents an energy material reserve that can be reused by the customer.
- or transformed back into uranium hexafluoride (UF6) reprocessed (hence, known as reprocessed uranium, or URE) for the purpose of reusing it as fuel in the reactor.
Certain European reactors are stocked with fuel produced from recycled uranium, notably those found in Switzerland, Germany, the Netherlands, or in France (for example, the Cruas nuclear plant in Ardèche).
