Research On DEC Of Emergency Operation Procedures For NPPs

The Emergency Operation Procedures for NPPs are effective tools for dealing with the accidents and limiting the consequence.When an accident happened,if the operators could not see through the appearance to perceive the essence,it will affect the processing of the accident,and operators need to find which it is,immediately.DEC(Diagnosis et Consigne,it is Diagnosis and Procedure)is a method to help operators find the most possible emergency procedure by using information of accidents.This work researched the method to build DEC based on EOP.The significance of accidents dealing for NPPs,the concept of EOP and DEC are introduced.The methods of fault diagnosis based on knowledge are summarized.The questions and details of this work are proposed.The symptoms and rules are extracted from EOP,and the symptom groups of each accident have also been extracted based on the characters of procedures.The mathematical model of accident-symptom system is built,and the complicated relationship between accidents and symptoms is described clearly in a way of accident-symptom matrix.A two-stage method is proposed based on this model,the algorithm is defined to find the possible accidents in stage-I,the results of stage-I are evaluated by geometric distance between the observation vector and the reference vector in stage-II.Software for DEC has been overall designed,and the modules are detailed designed based on software engineering.Visual C# 2010,MATLAB R2012 b,Access 2010 and Win7 are chosen to implement the software for DEC based on the two-stage method.Finally,and the online diagnosis simulation is tested by connecting with PCTRAN/PWR.Under the condition of the three accidents,test results indicated that the “two-stage method” is correct,and software for DEC could diagnose the right accident with the cooperation of an operator for the three accidents,quickly.