The procurement of the emergency diesel generators (EDG) for the Olkiluoto 3 nuclear power plant unit has been investigated

30/06/2011

In connection with the reviews and inspections carried out by the Radiation and Nuclear Safety Authority of Finland (STUK), attention had been drawn especially during 2010 to the repeated shortcomings in the quality management related to procurement of the Olkiluoto 3 plant unit's emergency diesel generators (EDG). In response to this the Director General of STUK launched on 26 November 2010 an investigation focusing on the procurement and supply of the Olkiluoto 3 nuclear power plant unit’s emergency diesel generators (EDG) and their auxiliary systems and equipment. The investigation is now completed. The investigation team was made up of STUK’s inspectors who had not participated in the reviews and inspections related to the diesel units, and of an external consultant with an extensive experience in similar procurements.

An emergency diesel generator is by itself a power plant which comprises auxiliary systems composed of different types of mechanical and electrical equipment (e.g. fuel feed and cooling systems). The procurement is characterized by long supply chains. The supplier of diesel generator auxiliary systems has purchased equipment from almost 30 subcontractors. The equipment contains parts and components manufactured by several subcontractors. Control of the long procurement chains and quality control of components has been a demanding task for all parties involved in the procurement of the emergency diesel generators and the adequate quality of all individual components cannot be verified afterwards without further clarifications.

In this case, in order to verify afterwards the conformance of the Olkiluoto 3 emergency diesel generators and their auxiliary systems and components to the requirements, it is necessary to assess the documentation accumulated in the course of manufacture, to evaluate the tests performed on the equipment, and to audit the manufacturers’ production processes. STUK requires that the diesel generators and their auxiliary equipment meet the required quality and safety levels before commissioning of the nuclear power plant.

STUK will verify the adequate quality of Olkiluoto 3 emergency diesel generators units in connection with its regulatory oversight. The objectives of this investigation were more general and in the framework of the investigation it was evaluated which would be the best practices of the various parties in the procurement process involving several subcontractors. Based on the investigation, the team made recommendations for the plant vendor, the licensee (TVO) and the regulatory body (STUK) in view of equivalent future deliveries.

The report of the investigation team:

Investigation of the procurement and supply of the emergency diesel generators (EDG) and related auxiliary systems and equipment.for the Olkiluoto 3 nuclear power plant unit (pdf)
Appendix 1: The investigation team (pdf)
Appendix 2: Key findings concerning the activities of TVO, Areva and STUK, Mind Map diagram (pdf)
Appendix 3: Cause-effect diagram (pdf)

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