• Nature and legal value of the RFS and ASN guides

On a variety of technical subjects, concerning both PWRs and other BNIs, the ASN has drafted basic safety rules (RFS). These are recommendations which specify safety objectives and describe practices the ASN considers to be adequate for compliance with them.

They are not, strictly speaking, regulatory documents. An operator may decide not to follow the specifications of an RFS if it can demonstrate that the alternatives it proposes employing enable the stipulated safety objectives to be met.

The flexibility of this type of text enables the technical requirements to evolve in line with changing technology and knowledge.

Given the restructuring of the general technical regulations described in point 2.2 above, the RFS will be gradually replaced by guides.

There are currently about forty RFS and other technical rules issued by the ASN, which can be consulted in the Texts part of the ASN's website (asn.gouv.fr).

• The RFS and guides currently being revised or drafted

RFS revision work is currently in progress, in particular concerning:
–RFS III.2.e of 31 October 1986, revised on 29 May 1995, concerning the preconditions for approval of encapsulated solid waste packages intended for surface disposal: changes to the rule should enable experience feedback from the first ten years of operation of the Aube repository to be taken into account. The ASN will ensure that the Advisory Committee for waste's examination of the revised RFS leads to conclusions that are consistent with the information obtained from examination of the safety analysis report on the Aube repository submitted by the ANDRA in October 2004.
–RFS I.4.a of 28 February 1985 on fire protection of BNIs other than reactors: a guide concerning management of the fire risk explaining the requirements of the above-mentioned order of 31 December 1999 and setting fire risk prevention goals, was drafted by the ASN in 2005.

In the industrial field, the rules of industrial and professional good practice are codified in standards by standardisation bodies or in industrial codes by professional associations. The codes and standards allow concrete transposition of the requirements of the general technical regulations, while reflecting good industrial practice, thus facilitating contractual relations between customers and suppliers.

In the particular field of nuclear safety, the industrial codes used by the manufacturers and nuclear operators are drafted by the Association française pour les règles de conception, de construction, et de surveillance en exploitation des matériels des chaudières électronucléaires (AFCEN), of which EDF and Framatome ANP are members. The RCC codes of design and construction rules were drafted for the design, manufacture and commissioning of electrical equipment (RCC-E, 4th edition), civil engineering (RCC-G) and mechanical equipment (RCC-M, 2000 edition). As of 1990, a code of mechanical equipment in-service monitoring rules (RSE-M) was drafted to deal with this subject.

Production of these documents is the responsibility of industry and not the ASN, which is nonetheless tasked with examining them to ensure their conformity with the general technical regulations, in most cases leading to drafting of an RFS, a guide or a decision, recognising the overall acceptability on the date of the edition concerned.

The new version of the RCC-E code was accepted by the ASN in 2003. The ASN in particular checked that this fourth edition of the code was consistent with RFS II.4.1.a of 15 May 2000 concerning software in PWR safety-classified electrical systems.

The 2000 edition of the RCC-M code was accepted with reserves by the ASN in a decision of 10 July 2001 (available in the Texts part of the ASN's website: asn.gouv.fr). A modification of the code is currently being examined in order to lift the reserves expressed at its acceptance in 2001 and take account of some of the new technical rules applicable to nuclear steam supply system construction.

The 2000 edition of the RSE-M code was accepted by the ASN in June 2002 and has been applicable to all nuclear power plants since January 2003. A modification to this code is also being examined in order to deal with the discrepancies observed at its acceptance in 2002, with respect to the order of 10 November 1999 concerning monitoring of operation of the main primary system and the main secondary systems of pressurised water reactors.

Until such time as it issues a position on the proposed changes to these codes, the ASN considers that the accepted versions of these codes, supplemented by any particular restrictions and measures imposed, remain in force.