STATUS OF FRENCH REGULATIONS CONCERNING NUCLEAR CRITICALITY SAFETY

摘要

Hitherto, in France, licensees used to demonstrate compliance with Fundamental Safety Rule I.3.c. This Rule sets out the principles for demonstrating Nuclear Criticality Safety in all nuclear facilities (excluding reactors). Although there is a good level of consensus between the licensees and the Regulator, this Rule is now somewhat dated (it came into force in 1984) and does not cover all aspects. The French Nuclear Safety Authority (ASN) used the 2006 Law on Transparency and Nuclear Safety as the catalyst for a thorough revision and updating of its regulatory documentation. Thus, in 2010, ASN decided to set up a "criticality working group" involving ASN, the licensees (AREVA, CEA, EDF...) and the Technical Safety Organization (IRSN). This group was tasked with drafting a regulatory text (a "resolution") and a criticality guide. The objectives were to update Rule 1.3.c, clearly defining the scope for reactors and transport packages of fissile material, to further develop areas not covered in the existing rule and to take account of the feedback and lessons learned from past events. Thus, this paper presents the status of French regulations concerning Nuclear Criticality Safety (NCS). Firstly, it focuses on the existing Rule I.3.c and then explains how this will be modified by the forthcoming improvements to the resolution and the criticality guide. It in particular addresses the scope of the new regulations (concerning reactors and the transport of fissile material), how the principle of defence in depth is to be applied to criticality safety, the double contingency principle, control modes, the reference fissile medium, the organization, the role of the Criticality Engineer, admissibility criteria, validation, etc.