Reactor coolant pump trip criteria and transient identification technique for PWRs (pressurized water reactor): Final report

A method is presented relating the reactor coolant pump inlet fluid density to measurable pump parameters in a pressurized water reactor (PWR) under transient two-phase flow conditions. This method is based on simple one-dimensional pump theory with the result that pump electrical power or pump current can be used to monitor the inlet density. This local density, in turn, is related to the average density in a PWR primary system based on extensive experimental evidence from the Loss-of-Fluid Test facility (a scaled PWR system) as well as computer calculations of commercial PWR responses (Westinghouse and Babcock and Wilcox design). General guidelines as to the range of applicability of the method are given and a pump trip criteion is proposed that will allow continued pump operation and, hence, better recovery control, during a wider range of transient conditions than is currently permitted.