Patent Number: 046577270
Section: abstract

The present system uses measurement inputs which reveal fission product barrier functional characteristics for emergency event classification in nuclear generating stations. The process determines the functional status of barriers to fission product release under transient or emergency conditions. The first part of the present process specifies which key indicators within a nuclear plant provide data indicative of fission product barrier status, and develops a logic table or diagram relating specific key symptoms to barrier status such that a computer identifies the functional status of each fission product barrier. In the second part of the present process nuclear power plant operators utilize the computer to determine emergency event classification. The computer utilizes the present process, using the installed nuclear generating station instrumentation which indicates flow rates in fluid and air handling systems, pressures in pipes and vessels, temperatures in pipes and vessels, radiation levels and other indications of equipment status to determine whether the fission product barriers are functional at a given point in time according to the criteria established during the first part of the process. The implentation is an orderly process in which nuclear power plant operator uses the process as programmed on the computer to determine and correctly characterize the condition or status of each fission product barrier at any time. The process results in direct indication of the status of fission product barriers and of the categorization of the emergency event according to established classes of emergencies. If the computer is non-functional, the nuclear plant operator uses the process as presented in implementing procedures to determine the status of each fission product barrier and to determine the proper event clasification. The operator relies upon installed plant instrumentation to determine the functional status of the barriers according to the process.