Sizewell B cycle 5 core design with Framatome ANP's CASCADE-3D and British Energy's PANTHER

Sizewell B Cycle 5 is the first cycle, after 4 cycles with BNFL fuel, with a reload consisting of Framatome ANP HTP (high thermal performance) fuel assemblies. The impact of this fuel vendor change on the Nuclear Design area is that, according to British energy's (BE) practice, the Framatome ANP's nuclear design code system CASCADE-3D is used for the majority of the cycle specific safety case calculations. However, other parts of the safety submission (e.g. 3D transient analyses) are made by using the BE code PANTHER. Before using in parallel two different code systems for reload core licensing extensive comparisons of applied methodologies and obtained results were required to ensure an acceptable level of agreement. (orig.)