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2018 UPDATE: The ILL between 2005 and 2018
programmes (involving a continuous upgrade programme of every key reactor component) proved essential in the light of the Fukushima events.
11.3.2 Fukushima
When the enormous tsunami hit the Fukushima Daiichi nuclear power plant in Japan on 11 March 2011, resulting in a nuclear accident of a severity unparalleled since the Chernobyl disaster of 1986 (both classified as level 7 of the International Nuclear Event Scale), the French safety authorities (ASN, L’Autorité de Sûreté Nucléaire) reacted immediately by requesting a re-evaluation of safety measures at all French nuclear installations.
Subsequently the ILL undertook an extremely serious in-
depth consideration of all of its safety regulations, organisation and systems. The ASN imposed a set of extreme situations
with respect to which the ILL had to demonstrate that its installations would remain safe without any significant release of radioactivity. Notable among these was that the ILL reactor and buildings should withstand an earthquake of level 7.3 (expected roughly once every 20,000 years). In addition, the installations should resist, at the same time, the effects of a dynamic flood
of 6 m depth at the ILL site, resulting from the collapse of
four hydroelectric dams upstream on the river Drac. The ILL’s engineering staff responded to these demanding requirements with a detailed plan, the Stress Test Response (STR) programme (REX Fukushima), which was executed from 2013 and completed in 2018.
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