Les cahiers de l'ASN #03 - 10 years after Fukushima

Global mobilisation for a momentous event The Fukushima accident sent a shockwave around the world, raising questions about the robustness of nuclear installations. A few days after the accident, mobilisation was under way nationally, Europe-wide and internationally, in order to learn lessons from what had happened. Ten years later, here is an overview of the progress made in the safety of nuclear installations in France and around the world. In Europe, stress tests were initiated on the nuclear power plants Less than two weeks after the disaster, the European Council asked that stress tests be performed to evaluate the robustness of the European NPPs to the extreme conditions to which they could be subjected: earthquake, flooding, loss of electrical power, loss of heat sinks, combination of these events, reactor core melt. In the following weeks, WENRA * drafted specifications to address this request and enable each Member State to conduct a national review of the robustness of its installations against an identical requirements baseline. In April 2012, on the basis of these data, ENSRE G* and the European Commission then asked that national action plans be put into place so that these tests would result in tangible safety improvements. In December 2012, ASN drew up the national action plan identifying the necessary improvements. These concerned: • protection against internal and external hazards; • electricity supply and water make‑up means; • the means for the prevention of accidents with core melt; • the means for preventing uncovering of fuel assemblies in the pool; • the management of accidents with core melt; • crisis management; • the means for providing an on-site response by deploying a nuclear rapid intervention force (FARN*). In France, the stress tests are expanded to cover all nuclear facilities In parallel, on 23 March 2011, the Prime Minister asked ASN to conduct an audit on the safety of the nuclear facilities in the light of the Fukushima accident. The French approach to the stress tests (called complementary safety assessments (ECS* in French), was integrated into the European stress tests approach, but with a broader scope, encompassing all nuclear facilities (research, fuel cycle, waste management facilities and decommissioning sites). Questions regarding social, organisational and human factors were also raised and examined in greater depth. An innovative approach in France: the concept of the “ hardened safety core *”, an ultimate safety measure to deal with extreme situations, was prepared and made mandatory ( see page 8 ). * See glossary page 24 THE FUKUSHIMA NUCLEAR ACCIDENT 6 • Les cahiers de l’ASN • March 2021