Requirements set out for hardening French facilities

03 February 2015

The French nuclear safety regulator has specified additional post-Fukushima safety measures to be taken at the country's fuel cycle and research facilities.

Stress tests that were performed on European nuclear power reactors following the March 2011 Fukushima accident were extended in France to cover all basic nuclear installation. The aim of these stress tests was to determine the safety margins that exist on these facilities with regard to extreme hazards, such as earthquakes and flooding.

For Areva, these stress tests were performed on fuel cycle facilities at its La Hague, Romans-sur-Isère, Tricastin and Marcoule sites. Meanwhile, such tests were carried out at fuel and research facilities operated by the French Atomic Energy and Alternative Energies Commission (CEA) at Marcoule, Cadarache and Saclay.

In June 2012, following an analysis of these stress tests, France's nuclear safety regulator, the Autorité de Sûreté Nucléaire (ASN), asked Areva and the CEA to define a "hardened safety core" of systems at each facility that are incredibly robust and will provide essential safety services during even the most extreme circumstances. This should push the safety of all facilities well beyond their original design bases, and combined with enhanced management during evolving crises, help to ensure even severe accidents have limited consequences.

Having examined the proposals submitted by Areva and the CEA, ASN has now issued resolutions "establishing additional prescriptions stipulating the requirements applicable" in meeting their proposed hardened safety cores.

ASN said, "These resolutions clarify the design and sizing rules to be adopted for the structures and equipment constituting the hardened safety core. They must comply with the most demanding standards, so that their functions can be guaranteed until such time as the facility is returned to a safe state."

ASN also asked the licensees to "take the necessary steps concerning the management of emergency situations." It called for the hardened safety core equipment to be able to operate independently for the first 48 hours in an extreme situation, with provision for the supply of power and water from outside the site after this period. ASN also requires the "automatic and robust transmission of key data" on the facility's status to emergency management centres. It also asked the licensees to ensure that extra personnel and equipment is sent to the sites to ensure "long-term management of an extreme situation".

ASN has written to both Areva and the CEA specifying the exact upgrades that are required at their respective facilities as well as the deadlines, where applicable, for introducing those measures.

Researched and written
by World Nuclear News