2-D burnup calculation of hexagonal lattice core with correction for the effect of axial burnup distribution for the Dalat research reactor

The paper presents results of burnup calculation by using HEXB-W code of 2-D diffusion theory for the Dalat research reactor loaded with Russian fuel assemblies of VVR-M2 type. A set of burnup-dependent 3-group constants obtained by IU. V. Petrov et al. at PINP, Russia has been used. The distribution of thermal neutron flux in the core obtained foe the first operation cycle in June 1989 is compared with the measured values, while the core burnup distribution is given for the second operation cycle in April 2002. The calculated excess reactivity with and without correction for the effect of axial burnup distribution is compared with the measured values for the two first operation cycles during the period 1984 - 2002. (author)