Grand design and module preparation for "MAGI" code system renewal

Kawashima, Masatoshi*; not registered

"MAGI" system renewal aims at improving the prediction accuracy for the neutronic and thermal characteristics along with the plant upgrade. Present work discussed the grand design of the system and prepared neutron flux distribution calculation module. The grand design study has determined that the system would cover pre-operation prediction function and post-operation recording function. It was proposed that the prediction calculations would enhance safety confirmation for power distributions and other major nuclear and thermal hydraulic chracteristics because the MK-III core would achieve power uprating with two-zoned regions. A prototypic flux calculation module was made with finite-difference 3-dimentional diffusion formulation for the Tri-Z geometry. The basic methodology for the new system includes 24mesh points per hexagon and 18 energy groups. The module was applied to the MK-III core as sample calculations. To proceed the "MAGI" system renewal, it is required to establish items to be compared with safety criteria using the neutronic module outputs. In addition, it needs to make the basic modules of the system for calculation control, constant preparation, various characteristics calculation, and IO control modules.