KENO-IV code benchmark calculation, (3)

A series of benchmark tests has been undertaken in JAERI in order to examine the capability of JAERI's criticality safety evaluation system consisting of the Monte Carlo calculation code KENO-IV and the newly developed multi-group constants library MGCL. The present paper describes the results of a test using criticality experiments about array of UF6 container cylinders. In all, 81 cases of experiments have been calculated for the UF6 container cylinder arrays arranged into various configurations from the 4 x 4 array to a linear-array, where cylinders are bare or reflected by polyethylene or by concrete. The KENO-IV calculation with the 26 group MGCL library results in about 3% excess of the multiplication factor for the unmoderated array where the fission due to fast neutrons is dominant. The conclusion is that in order to obtain a better prediction of the effective multiplication factors for the experiments considered here, the finer energy group structure is needed. (author)