Third ten-yearly periodic safety review of Fessenheim NPP reactor n°2 : ASN instructs EDF to carry out works

ASN instructs EDF to comply with new requirements following the third periodic safety review of Fessenheim NPP reactor n°2, as it had already done for reactor n°1 in 2011.

In the light of the results of the third ten-yearly periodic safety review of Fessenheim reactor n°2 and the inspections carried out by its personnel, ASN considers that the licensee must comply with new requirements. In its resolution 2013-DC-0342 of 23rd April 2013, ASN thus issued several requirements applicable to EDF. Having set these requirements, ASN has no objection to the continued operation of Fessenheim reactor n°2 following its third ten-yearly periodic safety review.

As it had already done for reactor n°1 in its resolution of 4th July 2011, ASN thus required a reinforcement of the safety of reactor n°2 by increasing the ability of its basemat to withstand corium in the event of a severe accident with reactor vessel melt-through, plus the addition of an emergency cooling water make-up system: these two projects should be completed by 31st December 2013 for reactor n°2. Generally speaking, the identical design of the two reactors on the same site led to requirements being applied to reactor n°2 that were similar to those applied to reactor n°1. ASN’s resolution also includes a number of requirements specific to reactor 2 and linked to limited deviations or modifications.

Furthermore, ASN’s resolution of 23rd April 2013 concerning Fessenheim reactor n°2 takes account of the initial lessons learned from the Fukushima Daiichi accident and the conclusions of the stress tests performed in France, which had led to its resolution of 26th June 2012, requiring EDF to comply with additional instructions applicable to the Fessenheim NPP.

ASN is verifying implementation of the required work on the reactors. In December 2012, it reviewed compliance with the requirements concerning reactor n°1 (insert link); this inspection process is continuing in 2013 and will be extended to implementation of the work required on reactor n°2. ASN will publish the results of these inspections on its website site www.asn.fr.

In France, article L593-18 of the Environment Code requires that the licensee of a nuclear reactor perform a periodic safety review of its facility every ten years, following which ASN issues a position statement regarding the continued operation of the facility.

There are two aspects to the periodic safety review: the conformity check and the safety reassessment. The periodic safety review on the one hand allows a detailed examination of the situation of the facility in order to ensure that it does indeed comply with all the rules applicable to it (conformity check) and, on the other, makes it possible to improve its level of safety with regard to the requirements applicable to facilities with more recent safety goals and practices, while taking account of changing knowledge and national and international operating experience feedback (safety reassessment). The periodic safety review also aims to check that the various ageing phenomena affecting the facilities will be managed for a minimum further period of ten years.

Fessenheim NPP reactor n°2 is the fourth French reactor to undergo a periodic safety review thirty years after it was commissioned (following Tricastin 1, Fessenheim 1 and Bugey 2). Fessenheim reactor n°2 was shut down for its third ten-yearly outage, from 16th March 2011 to 7th March 2012, during which ASN carried out 12 inspections and supervised the hydrotesting to requalify the main reactor cooling system. On 28th August 2012, EDF submitted the report giving the conclusions of the third periodic safety review for Fessenheim NPP reactor n°2 to ASN and to the Ministers responsible for nuclear safety.

Pursuant to article L.593-19 of the Environment Code, ASN issued additional instructions designed to increase the safety of Fessenheim reactor n°2. These instructions in particular include requirements applicable to facilities with more recent safety goals and practices.

This ASN resolution supplements its resolution of 26th June 2012 issuing additional instructions to the Fessenheim NPP in the light of the conclusions of the stress tests conducted in the wake of the Fukushima accident. ASN also recalls that detailed analysis of the experience feedback from the Fukushima Daiichi accident could take about ten years and may lead to modification of or additions to the first instructions and requirements it issued.

ASN’s duties will entail continued rigorous monitoring and oversight of the operation of Fessenheim NPP reactor n°2.

Press contact: Evangelia Petit, press service, tel. 01 46 16 41 42 - evangelia.petit@asn.fr