[en] Several member countries of OECD/NEA decided to establish the International Common-Cause Failure Data Exchange (ICDE) Project to encourage multilateral co-operation in the collection and analysis of data relating to Common-Cause Failure (CCF) events. The project was initiated in August 1994 in Sweden and was discussed at meetings in both Sweden and France in 1995. A coding benchmark exercise was defined which was evaluated at meetings held in Germany and in the US in 1996. Subsequently, the exchange of centrifugal pump data was defined; the first phase of this exchange was evaluated at meetings in Switzerland and in France in 1997. The objectives of the ICDE Project are: - to collect and analyse CCF events in the long term so as to better understand such events, their causes, and their prevention, - to generate qualitative insights into the root causes of CCF events which can then be used to derive approaches or mechanisms for their prevention or for mitigating their consequences, - to establish a mechanism for the efficient feedback of experience gained on CCF phenomena, including the development of defences against their occurrence, such as indicators for risk based inspections. The ICDE Project is envisaged as including all possible events of interest, comprising complete, partial and incipient CCF events, called 'ICDE events' in the following. The Project covers the key components of the main safety systems, like centrifugal pumps, diesel generators, motor operated valves, power operated relief valves, safety relief valves, check valves, RPS circuit breakers, batteries and transmitters. Data are collected in an MS ACCESS based databank implemented and maintained at ES-Konsult, Sweden, by NEA appointed clearinghouse. The databank is regularly updated. The clearinghouse and the project group operate it. In the modelling of common-cause failures in systems consisting of several redundant components, two kinds of events are distinguished: a) Unavailability of a specific set of components of the system, due to a common dependency, for example on a support function. If such dependencies are known, they can be explicitly modelled in a PSA. b) Unavailability of a specific set of components of the system due to shared causes that are not explicitly represented in the system logic model. Such events are also called 'residual' CCFs. They are incorporated in PSA analyses by parametric models. There is no rigid borderline between the two types of CCF events. There are examples in the PSA literature of CCF events that are explicitly modelled in one PSA and are treated as residual CCF in other PSAs. The objectives of the centrifugal pump report are: - to describe the data profile in the ICDE data base for centrifugal pumps and to develop qualitative insights in the nature of the reported ICDE events, expressed by root causes, coupling factors and corrective actions, - to develop the failure mechanisms and phenomena involved in the events, their relationship to root causes, and possibilities for improvement. The procedure to collect Common Cause Failures for Pump events has been established. The basis for better understanding of such events is now available to the participating organisations. The database is a source for qualitative insights to root causes and failure mechanisms for preventing recurrence of events. The data were collected for a five year period. The database will be updated as more countries are delivering data. 125 ICDE events have been reported, 19 of which were complete CCFs. Root causes, coupling factor attributes and corrective actions were distributed as follows among the events with complete failure: - root causes: 70% human actions and procedural deficiencies, 20% hardware related; - coupling factor attributes: 66% operational, 33% hardware related; - corrective actions taken: >70% administrative/procedure controls, maintenance, operation and testing practices. Human performance plays an important role for most of the identified complete CCFs. Most of the events leading to complete failure involve human error; they could be corrected by better procedures and control/maintenance practices