The advantages of recycling
Recycling used fuel saves natural uranium resources (around 25%) and reduces the volume of end waste by a factor of five and its toxicity by a factor of ten (closed cycle) compared with those countries that have chosen instead to store used fuel (open cycle).
Used fuel: Still contains 96% useful material
Within a reactor, nuclear fuel assemblies release energy through the fission of uranium nuclei. Plutonium is formed as a result of this reaction.
During the time that the fuel spends in the reactor, the quantity of fission products increases and the number of fissile atoms decreases, reducing the performance of the fuel. The plutonium that is formed contributes to the energy released, but this does not fully compensate for this reduction in performance.
After three to four years, the fuel is no longer effective, but it still contains 96% of useful material. It is then replaced with fresh fuel.
Recycling the used fuel: new energy resources
Once discharged from the reactor, the used fuel contains:
- 95% uranium and 1% plutonium, both recyclable as "new" fuel for nuclear power plants in the form of MOX (based on plutonium and uranium) or re-enriched processed uranium.
- 4% is made up of non-recyclable end waste (fission products and minor actinides).
The plutonium (1%) produced over the service life of the fuel in the reactor still has significant energy potential: a single gram of plutonium holds as much energy as produced by the combustion of a ton of oil (and of 100 grams of uranium).
The worldwide population of light water reactors generates approximately 6,500 tons of used fuel each year. Stores of used fuel accumulated across the world amounted to somewhere in the region of 200,000 tons of heavy metal at this day, of which 36,000 have been recycled.
The advantages of recycling
Recycling plutonium and uranium has a number of advantages :
- A saving of 25% in the use of natural resources.
- A reduction in the volume of waste by a factor of five, and a reduction in its toxicity by a factor of ten.
- A reduction in the proliferation of nuclear materials.
- A reduction in the quantity and radiotoxicity of the end waste.
Nuclear fuel: advantages of the closed cycle
Fabrication, logistics, dismantling: AREVA’s Back End division implements the various aspects of the closed cycle, a solution for recycling nuclear fuel that proves more economical and environmentally friendly. This educational animation presents its properties.
The distinction between a closed fuel cycle and an open cycle rests on the method of managing the used fuel.
There are currently 2 ways to manage used fuel:
The open cycle: used fuel is stored with no further processingAn "open cycle" is a cycle in which the spent fuel is not recycled.
When the fuel is removed from the reactor, it is first cooled for several decades, usually in a pool, before being stored in a dedicated storage facility.
Existing storage solutions have been designed so that the nuclear generating companies can manage the storage of their spent fuel over several decades. Examples of countries that have chosen this option include Sweden, Finland, Spain and Canada.
The closed cycle: used fuel is recycled
A closed cycle is a cycle in which the spent fuel removed from the reactor is recycled.
After cooling for at least three years in a storage pool, the fuel is processed to recover the recyclable materials. These are then used to manufacture new fuel. Examples of countries that have chosen this option include France, Japan, and Germany.
Helping to combat proliferation
The nuclear activities of the countries that have signed the nuclear weapons non-proliferation treaty are monitored by the International Atomic Energy Agency. The aim of the treaty is to reduce the risk of nuclear weapons spreading throughout the world.
AREVA is contributing to the achievement of these objectives by taking a responsible approach to its activities in the following ways:
- The plutonium present in the used nuclear fuel is not of military quality.
- Its use contributes to a significant reduction in plutonium stock levels.
- Its facilities are subject to international inspection.