Development of continuous energy Monte Carlo burn-up calculation code MVP-BURN

Okumura, Keisuke ; Nakakawa, Masayuki; Kaneko, Kunio*; not registered

Burnup calculation codes based on the conventional deterministic approach often encounter difficult problems because of the constraints on the geometry description, limit of approximation on the effective resonance cross-sections, failing of the diffusion approximation due to extremely strong anisotropic or heterogenity. They are, for example, the prediction of burn characteristics of plutonium spot, core design of ultra-small reactors, analysis of the sample material in an irradiation capsule of the research rector. To deal with these problems any time, a burn-up calculation code (MVP-BURN) was developed by using a continuous energy Monte Carlo code MVP. MVP-BURN was validated by comparison with the results of deterministic codes in the international benchmark problems, and by comparison with the measured values of the spent fuel composition irradiated in a commercial reactor.