Four years after the reactor accident at Fukushima, the European countries have carried out a second joint review of their EU Stress Tests national action plans. As was already the case in 2013, the EU experts gave a positive assessment of the Swiss national action plan.
The experts took a positive view of the progress in implementing the action plan in Switzerland since the last review two years ago. Switzerland, they noted, had reacted quickly after Fukushima and implemented effective measures at an early stage. They also welcomed the additional investigations at nuclear power plants in Switzerland which were requested by ENSI (the Swiss Federal Nuclear Safety Inspectorate) after the accident in Japan in 2011.
The EU experts placed particular emphasis on ENSI’s supervisory culture project, which included analysis of ENSI’s own work and its activities as a supervisory authority as well as the development of a tailored package of measures. The reinforcement of the Wohlensee dam upstream of the Mühleberg nuclear power plant was also singled out as a well-documented example of how hazards can be reduced at source. The EU peers finally commended the unannounced drills performed with the accident management equipment available at the centralized storage facility Reitnau.
Status of implementation
In the course of their review, the experts scrutinized the identified changes in the national action plans, in particular the delays of implementation and the rationale behind those.
With regards to the Swiss national action plan, implementation delays with respect to the original planning were noted in connection with the installation of the new spent fuel pools cooling systems at the Beznau and Mühleberg NPPs. It was the experts’ opinion that ENSI’s representatives were able to provide adequate answers to questions on these aspects and to give a transparent justification of the technical reasons for the delays.
The Swiss national action plan for the EU Stress Tests was reviewed at a workshop in Brussels in April 2015 where national action plans from 17 European nations underwent a peer review, i.e. an assessment by experts of equal standing from other countries. The final report on the international review will be published by ENSI on the Inspectorate’s website as soon as made public at the Nuclear Safety Conference of the European Nuclear Safety Regulators Group (ENSREG) at the end of June 2015.
In parallel to the reporting within the frame of the EU Stress Tests Follow-Up, ENSI’s Fukushima action plan is updated each year with the detailed schedule and published it on the Inspectorate’s website. According to the ENSI’s Fukushima action plan all analyses and ENSI’s reviews will be completed by end of 2015 as well as the majority of the backfittings at the NPPs. ENSI plans to issue a summarizing report on its Fukushima actions in the course of 2016.