DEVELOPMENT OF A 3RD-GENERATION SUPERHOMOGENIZATION METHOD FOR THE HOMOGENIZATION OF A PRESSURIZED-WATER REACTOR ASSEMBLY

Proposals are made for improving current second-generation superhomoge neisation (SPH) methods in three different ways and to use them in het erogeneous and homogeneous diffusion procedures for reactor design and operating calculations. The first improvement consists of using a sur face radial leakage model in the flux calculation to represent the mac roscopic flux curvature in the assembly. The second improvement is acc omplished by the introduction of the Selengut normalization in the SPH equivalence procedure replacing the flux-volume normalization current ly used with second-generation methods. Finally, the buckling calculat ion is improved to better represent the target color-set. Second- and third-generation SPH techniques for heterogeneous or homogeneous diffu sion procedures are now implemented as a unified algorithm in a lattic e code. Two-group benchmarks are proposed to measure precisely the equ ivalence effectiveness and the improvement gained with third-generatio n methods.