Generic initiating events for PSA for WWER reactors

The objective of this document is to present the results of defining the initiating events (IEs) for WWERs which were obtained within the framework of the TC Project RER/9/005, 'PSA for WWER Type Reactors'. Generic IE lists and IE frequencies based on operational experience are presented and discussed. The purpose of this document is in a way similar to that of the widely used EPRI 2230. The scope of the report is limited to the results accomplished within the framework of the project. National activities related to the topic are described when relevant for the overall project. The report is not intended to give detailed guidance to perform definition of IEs for plant specific PSA. Other IAEA documents are available for this purpose (e.g. Manual for Defining Initiating Event for PSA Uses). This report present the generic lists of initiators for both WWER reactor types (440 and 1000) which has been agreed upon by all WWER operators. In addition, the frequencies of more frequent initiators (transients) fully based on collected operating experience are presented. Frequencies of rare events (LOCAs) as used in several on going PSA projects are also tabulated. 11 refs, 1 fig., tabs