Investigation of MOZART experimental data and analysis of MOZART experiment using JFS-3-J3.2R group constant

Kaise,Yoichiro*; Osada, Hiroo*

Various critical experiments have been analyzed and avaluated in Japan Nuclear Cycle Development Institute(JNC) to improve the accuracy of prediction for nuclear characteristics of fast breader reactors. This report describes update of the analysis of Monju Zebra Assembly Reactor Test (MOZART) reflecting a recent development of JNC analysis scheme. THe main results are as follows: (1)Compilation of Spectrum Measurements: Spectrum mesurement data are newly compiled including energy structure and geometrical information. (2)Reevaluation of atomic number density data: Atomic number density data were reevaluated considering impurities that had been neglected in the past analysis and reflecting a JNC standard analysis scheme. The revision of the data successfully reduces core type dependence of C/E values for criticality from 0.4%dk to 0.1%dk. (3)Analyses using JFS-3-J3.2R group constant set: The base-calculation and correction factors were fully reevaluated using JFS-3-J3.2R group constant set and the results were compared with those using JFS-3-J3.2. For criticality, C/E values become smaller by 0.1%dk, which tendency is consistent with that observed in the analysis of JUPITER experiment. Reduction of B-10 concentration dependence from 7% to 1% is observed in C/E values for control rod worth, and 10% improvement are for Na void reactivity. These improvements are attribute to the revision of the proup constant set and analysis scheme. The correction factors are confirmed to be insensitive to the revision of group constant sets.