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

The INES scale, created after the accident at the Chernobyl NPP, provides information on the severity of a nuclear incident or accident. Major accident (Chernobyl, Fukushima) Severe Accident Accident Accident with local consequences (Three Mile Island) Serious incident Incident Incident Anomaly Accident with no serious local consequences 1 0 2 3 4 5 6 7 26 april 1986 CHERNOBYL REACTOR STATUS AT THE BEGINNING OF THE ACCIDENT RBMK* type reactor (high power reactor with pressure tubes), operating at low power. MAIN CAUSES OF THE ACCIDENT Low-power operating test run in unstable reactor conditions: a number of safety devices had been intentionally disabled, which led to a reactivity accident, with explosion and fire in the reactor core. LESSONS LEARNED The need to reinforce the fundamentals of safety: prime responsibility of the licensee, independence of the regulatory authority, establishment of regulations, development of a safety culture. The need to improve public information , the consequence of which was the creation of the INES* scale (see diagram) and the need to inform neighbouring countries, with rapid notification of the nuclear accident. A SIGNIFICANT STEP FORWARD IN SAFETY Management of the emergency and post-accident phases Following the Chernobyl accident, the response organisation was reinforced, both on the installation itself and in its environment. International crisis exercises are held regularly. Under the supervision of the IAEA*, international conventions were signed to provide countries with rapid notification of any nuclear accident and improve the assistance process. Finally, the management of the long-term consequences of a nuclear accident (decontamination of the environment, mitigation of exposure of persons) has progressed. 10 years after Fukushima, what safety improvements for nuclear facilities in France? • 23