Channel Bow Constraint Option in the BWR Loading Pattern Optimization System FINELOAD-3

The boiling water reactor (BWR) loading pattern (LP) optimization system FINELOAD-3 (FL3), has been applied for actual BWR reload core design for over fifteen years in TEPCO Systems Corporation (TEPSYS) and for over ten years in several European utilities. FL3 works in combination with the advanced nodal core simulator SIMULATE-3 (S3) or other core simulators. Recently, the channel bow constraint option has been added in FL3. In the BWR reload core design work, the channel bow management is very important in order to avoid the interference between a channel and a control blade and/or to minimize the effect on critical power ratio during the operation cycle. The channel bow constraint option is applied to eliminate channel bow violation against design target. (authors)