IPSN proposal for high burnup fuel LOCA experimental programs

Safety studies performed in IPSN and elsewhere pointed out that high burn up might induce significant effects, especially those related with fuel relocation during LOCA situations. Uncertainties exist regarding how much the existing safety margins associated with peak clad temperature, clad oxidation, core coolability, clad residual ductility can be reduced by new fuels like the MOX one, burn up increases, the arrival of various alloys for fuel rod cladding. A better knowledge of specific phenomena associated to fuel effects is required in order to estimate the new margins and to resolve the pending uncertainties related to the LOCA criteria. Therefore, in addition to the programmes currently planned in the Halden reactor, IPSN is preparing the so-called 'APRP-Irradie' (High Burn up fuel LOCA) programme. One of the important aspects of this programme is In-Pile experiments involving bundle geometries in the PHEBUS facility located at Cadarache, France. (author)