MUTUAL: A Computer Code for Analysing Nuclear Criticality Safety on Array System

摘要

For evaluating critical safety on array system, the solid angle method is often used as a simple method. There are, however, some demerits in the method: the effective multiplication factor of the system cannot be known and it is excessively overestimated under certain circumstances. Therefore a new method has been developed to obtain the effective multiplication factor of array system simply. In this method, neutron transportation being expressed in terms of solid angles between units arranged in the system, and effects of shadow caused by other units and effects of neutron reflection by the wall being taken into account, the eigen equation is solved and the effective multiplication factor is obtained. A computer code MUTUAL has been programmed according to this method. This report is a user's manual for the MUTUAL code. (ERA citation 12:041022)