Influence of cladding materials on fuel performance at high burn-up

The cladding for fuel pins in a commercial fast reactor must endure lengthy service in high temperature irradiation conditions if the fuel is to achieve the target burnup of 15-20%. The choice of cladding should not only ensure a low probability of pin failure, but also optimise the operational performance of the fuel. Using the TRAFIC2.1 code we have studied pin behaviour in the European Fast Reactor for two candidate cladding materials: 15/15 Ti and STA PE16. The cladding influences fuel temperatures and fuel-cladding interaction stresses. These effects arise because of different swelling and irradiation creep properties of the cladding. (author)