Development of nodal diffusion code RAST-V for Vodo–Vodyanoi Energetichesky reactor analysis

This paper presents the development of a nodal diffusion code, RAST-V, and its verification validation for VVER (vodo–vodyanoi energetichesky reactor) analysis. A analytic solver has been implemented in an in-house RAST-K. The new RAST-K version, uses triangle-based polynomial expansion method. code provides stand-alone two-step computation modes steady-state transient calculations. An lattice (STREAM) with updated features analysis is also utilized method cross-section generation. To assess calculation capability formulated module, various studies have performed Rostov-II, X2 multicycles, Novovoronezh-4, Atomic Energy Research benchmarks. In comparing multicycle operation, rod worth, integrated temperature coefficients, RAST-V found to agree measurements high accuracy which RMS differences each cycle are within ±47 ppm operations, ±81 pcm worth reactor. Transient calculations were considering two different ejection scenarios. was observed be comparable that conventional codes (DYN3D, BIPR8, PARCS).