Nuclear power plant commissioning experience

In this paper, we present the results of the analysis of the events related to the commissioning of new nuclear power plants and reported to the IAEA International Reporting System database. These results are extracted from a study performed by the European Clearinghouse on Nuclear Power Plant Operational Feedback about the events related to the construction, the manufacturing and the commissioning of new nuclear power plants.After the initial screening of the database, we have analysed in detail 34 events in order to highlight the lessons learned specific to different components and to raise the general recommendations related to the commissioning.This paper summarizes the main lessons learned and the main recommendations concerning the commissioning-related events. These recommendations concern mainly the time of the testing, the scope of the tests, the documentation of the tests, the test acceptance criteria, the systems reconfiguration after commissioning tests and the management of the temporary devices.

► Almost half of the events relate to I&C deficiencies.
► The commissioning tests should be performed in representative conditions.
► The commissioning tests should enable to test every device or component of a system but the performance of the whole system as well.
► The commissioning tests programme should consider the potential interference between different simultaneous tests.
► special attention should also be paid to the management of the temporary devices needed for the tests and to the proper reconfiguration of the systems following the tests.