Adjustments to the WIMS-ATR nuclear data library

not registered; not registered; Fukumura, Nobuo*

Calculational accuracy of the WIMS-ATR code is analized based on post irradiation examination (PIE) data of Fugen MOX fuel and micro-parameter data of DCA fuel assemblies. In order to minimize discrepancies between calculational results by the WIMS-ATR and experimental ones, the nuclear library data in the WIMS-ATR are adjusted or added. The results are as follows. (1)The errors of heavy nuclide number density ratio by the WIMS-ATR burn-up calculation were max. 0.002% for uranium isotope ratio and max. 2% for isotope ratio at 16 GWd/t burn-up. (2)The error of Pu ratio was much decreased by adding Pu burn-up and product chain to the WIMS-ATR nuclear daTa library. (3)The effects of Pu or U cross section changes were calculated. The adjustments to the WIMS-ATR nuclear data library were proposed to decrease the error of Pu isotopic ratio to max. 1%. (4)The error of micro-parameter calculation was decreased by the adjustments.