WHAT IS THE PROBLEM WITH THE NUCLEAR FUEL?
For use in a nuclear reactor, the fissile materials (Uranium U, Plutonium Pu) must be tightly encapsulated in cladding material for the following reasons:
- During the fission process radioactive fission products are inevitably generated and must be prevented to leak into the reactor and the environment.
- The direct contact of hot fissile material – up to 2000 °C in the centre of the fuel rod – with coolant (e.g. water) or air has to be strictly avoided in order to prevent chemical reactions.
The basic problem of the nuclear fuel elements presently applied is its metallic cladding!
During a loss-of-coolant accident two dangerous things will happen:
- The overheated metallic fuel cladding oxidizes in water steam and generates hydrogen which, in most cases, explodes.
- Through the destroyed cladding, water/vapour or air have direct access to hot fuel starting further reactions with disastrous consequences.
We do propose as innovative solution for accident-tolerant fuel: encapsulation in ceramics!