Safety analysis of nuclear power plants during low power and shutdown conditions

摘要

The Technical Committee Meeting on Safety analysis of Nuclear Power Plants during Low Power and Shutdown Conditions held in Vienna, Austria, 1-5 December 1997, was organized by IAEA within the framework of the Technical Co-operation project RER/9/046. The 23 participants from 14 Member States presented 18 technical papers devoted to various aspects of low power and shutdown conditions (LPS): safety assessment studies; description of particular phenomena; calculational analysis of individual events; contents of safety reports; hardware modifications; experience from plant operation, etc. A number of events at nuclear power plants, as well as from probabilistic safety assessment (PSA) studies for different types of NPPs (PWRs, WWERs, RBMK, CANDU) indicated that events occurring during shutdown modes may contribute significantly to the overall risk associated to NPP operation. It is recognized that a great deal of work over the past years in the worldwide nuclear power community was focused upon reducing the risk associated with LPS operation by analysing specific phenomena occurring during LPS conditions, improving analysis methodology, implementing additional administrative measures and hardware modifications, and starting incorporation of the LPS conditions in the safety analysis report. Detailed recommendations were adopted in the field of probabilistic safety assessment, deterministic analysis methodology as well as NPP operation