DEVELOPMENT OF AN AUTOMATIC-GENERATION SYSTEM FOR BWR RE-STARTUP PLANS

A system to automatically generate re-startup plans for BWR plants has been developed. By including consideration oi high speed re-startup after reactor shutdown, where xenon concentration is still transient, the system generates the plan whose re-startup time is as short as possible according to the time interval between the reactor shutdown and startup and the current reactor conditions. For this purpose, not only BWR core managing expertise in a knowledge base, but also core simulation programs are used. To realize both higher accuracy and shorter computing time of core characteristics predictions by the simulation programs, the error tendency between the simulation results and actual plant data is learned using an artificial neural network. To make the plan for re-startup operation, first, allowable xenon concentrations and corresponding control. rod patterns that satisfy thermal constraints at the rated power are estimated. Secondly, based on the estimation results, control rod withdrawal sequence, reactor power, control rod pattern and core flow rate for each time are determined. A prototype system was developed to evaluate its performance. The system was capable of generating a plan automatically within 30 min.