Stress tests conducted by the EU have suggestd that further improvements in safety features are needed in almost all European nuclear power plants, the European Commission announced on 4 October in its most recent communiqué on the post-Fukushima safety reviews. It emphasised, however, that no closure of nuclear power plants is warranted.
The stress tests also found that international standards and best practices have not been applied in all countries, the Commission said.
Seventeen countries fully participated in the stress tests (all 14 EU countries with operating nuclear power plants, Lithuania with a plant under decommissioning, plus Ukraine and Switzerland). The tests, launched following the Fukushima disaster of March 2011, aimed to assess the safety and robustness of nuclear power plants in case of extreme natural events and their ability to deal with severe accidents. They consisted of three phases – reports by the NPP operators, reviews by the national regulators and finally international peer reviews.
In addition to numerous plant specific technical improvements, the most recent stress test report highlights a number of generally applicable areas where improvements should be made. These include assessment of earthquake and flooding risk, equipment of containment filtered venting systems and installation of emergency equipment.
Out of the 145 reactors examined, current standards for risk calculation are not being applied at 54 reactors for earthquake risk, and at 62 reactors for flooding risk. Risk calculations should be based on a 10 000-year timeframe, instead of the much shorter time periods sometimes used, the report said. The report also recommends that on-site seismic instruments should be installed or improved in 121 reactors.
It said that 32 reactors still need to be equipped with containment filtered venting systems to allow safe depressurising of the reactor containment in case of an accident.
It was also found that over half the reactors in the EU do not store the equipment needed to fight severe accidents in easily-accessible areas that are protected ‘even in the event of general devastation.’ Furthermore, 24 reactors lack a back-up emergency control room in case the main control room becomes uninhabitable after an accident.
The Commission said that the next stage is for national regulators to prepare action plans and timetables for implementation of the stress test recommendations. These will undergo nation peer reviews in early 2013. The Commission next intends to report on the implementation of the stress test recommendations in June 2014, in full partnership with national regulators.
Response to the Commission's most recent report has been mixed. The French Nuclear Safety Authority (ASN) said in a statement on its website that the conclusions drawn by the Commission 'ignore some important recommendations of the stress-test final report,' such as the consideration of multi-unit accidents at the same plant, or the need for external means of rapid response in case of an accident.
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