ICDE Workshop on Collection and Analysis of Emergency Diesel Generator Common-cause Failures Impacting Entire Exposed Populations

NEA/CSNI/R(2017)8

International Common-Cause Failure Data Exchange (ICDE) Project Report

This report documents a study performed on a set of common-cause failure (CCF) events for diesel generators. The events were derived from the International CCF Data Exchange (ICDE) database and the study was focused on identifying failure mechanisms that are able to affect all diesels in an exposed population in any way, i.e. all events in the ICDE diesel database with no component coded “working” in the exposed population were analysed. The study is based on a workshop performed during an ICDE Steering Group meeting in May 2013 and a number of additional workshops which were performed by the operating agent (OA). In total, 142 ICDE events have been assessed.

This report begins with an overview of the entire data set (Section 3). Charts and tables are provided exhibiting the event count for each of the event parameters such as failure modes, root causes, coupling factors, detection methods and corrective actions. In addition, the events are distributed according to their degree of severity. Generally it could be seen that the most common severity degrees are the least severe, “CCF impaired” and “Complete impairment”, which indicates the need to not only focus failure analyses on events where all exposed components have failed completely. A typical diesel event is an event with hardware related failure cause which is detected during maintenance/test and corrected by design modifications.