Automating strategies of emergency operation for optimal shutdown in pressurized water reactors

In this paper, the automating strategies of emergency operation are proposed for achieving optimal shutdown in pressurized water reactors. These strategies can make emergency operation optimal, and as well they considerably lengthen the operator response time. Decision making and control are investigated in order to develop the automating strategies. In decision-making, diagnostic trees are established to automate the diagnostic tasks for selecting appropriate emergency operations, and the decision-making procedure is developed to automate some decisions which must be made on a plant- and event-specific basis. In control, cooldown is planned by establishing operational goals, forming strategies, and specifying operational means and constraints. The reference set points of the controlled parameters are adaptively adjusted through fuzzy reasoning for optimal cooldown and depressurization. The validation of the proposed strategies was carried out using the micro-simulator for the Kori Unit 2 with steam generator tube rupture events. The results indicated that the automated emergency operation successfully drove the plant at full power to a cold shutdown state with all the operational constraints satisfied.