Computational and experimental study of RBMK load fragment with vertically shaped fuel assembly.

Davydova, G.; Degtyarev, A.; Zhitarev, V.; Zakharova, L.; Kachanov, V.; Krayushkin, A.; Myasnikov, A.; Sergevnin, A.; Chikunov, V.

A series of experiments has been performed on the RBMK critical stand at the National Research Center - Kurchatov Institute using assemblies which included single models of shaped fuel assemblies. The neutron fields computed with the MCNP and MCU-KNV codes over the height of a fuel assembly and reactivity effects after it is put into place are compared. It is shown that on the whole Monte-Carlo calculations secure high-quality matching to the measured neutron flux distribution. It is found that the neutron spectrum varies over the height of shaped fuel assemblies, which variation results in discrepancies of the thermal neutron flux distribution and U fission rate and must be taken into account when interpreting the experimental data. When a uniform fuel assembly is replaced with a shaped assembly, the computed reactivity effect is close to the experimental effect.

NUCLEAR reactors; NUCLEAR fuels; NUCLEAR fission; COMPARATIVE studies; MONTE Carlo method; NEUTRON flux

Atomic Energy, 2013, Vol 113, Issue 4, p236

1063-4258

Academic Journal

10.1007/s10512-013-9623-0