Development and Verification of a Leningrad NPP Unit 1 Living PSA Model in the INL SAPHIRE Code Format for Prompt Operational Safety Level Monitoring

摘要

The first part of the paper presents results of the work, that was carried out in complete conformity with the Technical Assignment, which was developed by Leningrad Nuclear Power Plant. The initial scientific and technical information, contained into the In-Depth Safety Assessment Reports, was given to the author of the work. This information was received within the framework of the cooperation between the USA Pacific North-West National Laboratory (PNNL), Leningrad NPP and RRC "Kurchatov Institute". This information included graphical Fault Trees of Safety Systems and Auxiliary Technical Systems, Event Trees for the necessary number of Initial Events, and also information about failure probabilities of basic components of the nuclear unit. On the basis of this "paper" information the author of the paper, using the USA Idaho National Laboratory (INL) SAPHIRE code: (1) firstly, have developed an electronic version of the Data Base for failure probabilities of the components of technical systems, (2) secondly, have developed an the electronic versions of the necessary Fault Trees, (3) thirdly, have developed an electronic versions of the necessary Event Trees and, (4) at last, have carried out the linkage of the Event Trees. In the result there was received an Living PSA(LPSA) Model of Leningrad NPP Unit 1. The LPSA-model is completely adapted to inclusion it into the USA INL SAPHIRE Risk Monitor. The second part of the paper results in analysis of fire consequences in various places of Leningrad NPP Unit 1. The computations were carried out with the help of the LPSA-model, developed in SAPHIRE code format. On the basis of the computations the order of priority of implementation of fire prevention measures was established. Besides it was shown, that this LPSA-model may be applied for prompt monitoring of operational safety level of Leningrad NPP Unit 1.