Verification and validation of isotope inventory prediction for back-end cycle management using two-step method

This paper presents the verification and validation (V&V) of a calculation module for isotope inventory prediction to control back-end cycle spent nuclear fuel (SNF). The method presented herein was implemented in two-step code system lattice STREAM nodal diffusion RAST-K. generates cross section provides number density information using branch/history depletion branch calculations, whereas RAST-K supplies power history three indices (boron concentration, moderator temperature, temperature). As its primary feature, this can directly consider three-dimensional core simulation conditions operating conditions. Therefore, reduces computation time by avoiding recalculation depletion. calculates densities Lagrange interpolation correction factors, which are applied correct effects decay fission products generated at different levels. To assess reliability developed analysis, study performed with 58 measured samples pressurized water reactor (PWR) SNF, code-to-code comparison conducted STREAM-SNF, HELIOS-1.6 SCALE 5.1. V&V results that provide reasonable comparable confidence intervals. result, successfully demonstrates be used analysis.