Burnup analysis of rock-like oxide fuel disks irradiated in the Japan Research Reactor No. 3

Burnup analysis of rock-like oxide (ROX) fuel disks has been carried out an d the results have been compared with measured values. Two kinds of ROX dis ks: zirconia and thoria, were fabricated and irradiated in an irradiation h ole of the Japan Research Reactor No. 3 (JRR-3). After irradiation, several post-irradiation examinations (PIE) were performed. Computer codes used fo r the calculations were the SRAC and the MVP-BURN codes. Firstly, the neutr on spectrum in the irradiation hole was calculated using the SRAC code syst em. Fixed source problems were solved to obtain the neutron spectra and eff ective cross-sections of the disks and burnup calculations were performed. The calculated results of burnup, isotopic abundance of plutonium and produ ction of americium and curium were compared with measurement values. Calcul ations overestimate the measured burnup by 7 similar to 15% and both codes largely underestimate the measured production of americium and curium isoto pes. The calculated plutonium abundance agrees moderately well with the mea sured values. (C) 1999 Elsevier Science B.V. All rights reserved.