Some twenty years elapse between the mining of uranium and the reprocessing step subsequent to in-reactor exposure.
Uranium ore comes mainly from North America, Africa and Australia. Approximately 950 tonnes of the uranium are mined in these regions each year and concentrated for use in Belgian nuclear power plants.
At the enrichment plant, the uranium is
enriched to 4% uranium 235.
As a result of this process, 950 tonnes of natural uranium produce 110 tonnes of enriched
uranium. The depleted uranium is stored.
Compared with other raw materials, the quantity needed for electricity production is small.
Production of 1000 kWh requires :
350 kg of coal
The enriched uranium is transported to the fuel fabrication plant. It is converted to powder, compacted and sintered in the form of pellets. Pellet stacks are inserted into fuel rods which are then assembled to give fuel assemblies, ready to be loaded in the nuclear reactor.
The fuel remains in the nuclear power plant
for approximately 4 years.
The potential power of the Belgian nuclear plants is 5700 MW. Nuclear energy provides 60%
of Belgium’s electricity requirements.
Every year, part of the fuel is replaced with fresh assemblies. The spent fuel assemblies are stored in a cooling pond to decrease the radioactivity and the heat generated.
After several years, the spent fuel is packed and stored in interim surface storage sites. Later, it is buried in long-term deep underground storage galleries.
Interim storage prior to final disposal is one solution but the nuclear plant operators can also choose the reprocessing option. This permits selective processing of nuclear waste, and recycling of uranium and plutonium produced in a nuclear reactor.
Reprocessing and recycling make it possible to separate and recover uranium (95% by weight of spent fuel) and plutonium (1%) that still have a high energy content. Moreover, the non –recyclable waste, 4% of the spent fuel (fission products), can be sorted in function of the level of radioactivity, vitrified and stored.
The recovered uranium will be re-enriched and used.
The plutonium recovered is sent directly to the fuel manufacturing plant. Both uranium and plutonium oxides will be used in the production of MOX fuel rods for nuclear power plants.
