Our codes

AFCEN codes form a consistent set of rules that:

  • Encompasses a broad spectrum of technical fields, including mechanical engineering, electricity and I&C systems, nuclear fuel, civil engineering works and fire protection systems.
  • Has been evolving over the last 35 years to reflect changes in safety requirements, technological progress and international feedback based on users' practices.
  • Offers an overarching approach to nuclear facility design and construction without specifically targeting a given type of project.
  • Can adapt to the specific local regulations applicable in different countries.
  • Helps unify and rally a country's entire nuclear industry around the same reference framework.

Nos codes

Codes are continually updated to incorporate feedback from international industry best practices and changes to legislation, while striving to achieve harmonization with the other nuclear codes used around the world.

This ongoing activity is driven by an organizational and operational structure in response to AFCEN's Quality Management Policy, whose key goals are to:

  • Prioritize the quality of its publications, which contribute to the safety and economic performance of sustainable nuclear facilities.
  • Deliver a fast response to users' enquiries.
  • Encourage members and customers to adopt a safety culture.
  • Disseminate and promote uptake of the codes, especially through training and information systems.

AFCEN codes are published in English and French.

AFCEN codes are based on standards.

When drafting codes, ISO international standards are the first port of call when available, otherwise European EN standards are used.

If there are no existing ISO and/or EN standards for a given field, other standards serve as inspiration for the codes.



RCC-M : Design and construction rules for mechanical components of PWR nuclear islands

Purpose and scope

AFCEN's RCC-M code concerns the mechanical components designed and manufactured for pressurised water reactors (PWR).

It applies to pressure equipment in nuclear islands in safety classes 1, 2 and 3, and certain non-pressure components, such as vessel internals, supporting structures for safety class components, storage tanks and containment penetrations.

RCC-M covers the following technical subjects:

  • Sizing and design rating.
  • Choice of materials and terms of procurement.
  • Fabrication and control, including:
    • Associated qualification requirements (procedures, welders and operators, etc.)./li>
    • Control methods to be implemented.
    • Acceptance criteria for detected defects.
  • Documentation associated with the different activities covered, and quality assurance.

The design, fabrication and inspection rules defined in RCC-M leverage the results of the research and development work pioneered in France, Europe and worldwide, and which have been successfully used by industry to design and build PWR nuclear islands. AFCEN's rules incorporate the resulting feedback.


The RCC-M code has been used or served as a baseline for the design and/or fabrication of certain Class 1 components (internal vessel, steam generator, primary motor pump, primary valves and fittings, etc.), as well as Class 2 and 3 components for:

  • France's last 16 nuclear units (P’4 and N4).
  • Four M310 reactors in South Africa (2) and Korea (2).
  • 36 M310 (4), CPR-1000 (24), CPR-600 (6), EPR (2) reactors in service or undergoing construction in China.
  • Four EPR reactors in Finland (1), France (1) and the UK (2).


AFCEN drafted the first edition of the code in January 1980 in for application to France's second set of four-loop reactors with a power rating of 1,300 MWe (P’4).

Export requirements (Korea, China and South Africa) and the need to simplify contractual relations between operators and building contractors quickly prompted the code to be translated and used in English, followed by Chinese and Russian.

Subsequently, the code was thoroughly updated and modified to reflect feedback from France's nuclear industry, as well as regular interactions with international stakeholders. Six editions ensued (1981, 1983, 1985, 1988, 1993 and 2000) with a number of addenda between each edition.

The 2007 edition took account of changes to European and French regulations (Pressure Equipment Directive 97/23/EC and France's Nuclear Pressure Equipment Regulation), with the harmonised European standards that were subsequently released.

To date, the 2007 edition is widely used in France and China for EPR projects and replacement steam generators.

Edition available as of 1 January 2015

2012 edition, with two addenda in 2013 and 2014

The 2012 edition is supplemented by two addenda (2013 and 2014).

Revisions of the code are aimed at integrating tried-and-tested international approaches as far as possible and allowing for the possibility of alternatives to the code's basic rules.

RCC-M dernière édition 2015

2013 addendum

This addendum features the addition of a sixth section, entitled Probationary Phase Rules (RPP), in addition to the existing sections, which are divided into subsections, including general rules, components, design, examination methods, welding and fabrication.

As an alternative to the ISO 9001-based quality assurance requirements in Chapter A 5000, the first RPP introduces IAEA GS-R-3 safety requirements for nuclear management systems.

2014 addenda

In 2014, the RCC-M Subcommittee published the French version of the 06/2014 addendum in September and the English version in November. It integrates 31 modification files covering every part of the code.

This addendum introduces several changes to European and international standards, thereby aligning the code with applicable standards and the latest tried-and-tested technologies. Changes include:

  • ISO 9712: 2012 for the qualification of non-destructive testing personnel.
  • The introduction of sub-size specimens for destructive testing.
  • The introduction of requirements for qualifying design methods in the chapter relating to quality management systems for manufacturers.

Outlook and the future 2016 edition

2015 addendum

The 2015 addendum currently being drafted will include over 40 modification files and will be published in June 2015 (French version).

As an example of the different fields, this addendum incorporates:

  • The introduction of radiographic testing with Selenium 75.
  • The requirement for pendulum impact tests, including for low-thickness materials.
  • Design of finished elements for Class 2 valves and fittings.

Furthermore, after initially testing the code against the essential requirements of France's Nuclear Pressure Equipment Regulation, the first changes were made to the components (permissible stress values, destructive testing requirements for low thicknesses and density examination requirements).

2016 edition

A new edition to supplement the code is scheduled for 2016. It will cover between 50 and 60 modification files.

In addition to the routine activity of incorporating feedback on the code's use in current projects (EPR UK, TSN, FA 3, GV R) and reflecting new work (qualification of active mechanical components), the new 2016 edition of the code will draw significantly on the results of the studies being monitored by ASN and international groups (UK, China, Europe and MDEP).

RCC-M criteria

The RCC-M criteria, prepared by Jean-Marie Grandemange and approved by the Subcommittee members, were published late 2014.

This 550-page document, produced in both English and French, takes a look back at the code's background since the decision was taken for its creation.

The technical origins of the code and the changes made to the recommendations until publication of the 2007 edition are explained from the point of view of an engineer who was required to draft a design specification in alignment with the RCC-M code.

Other work in progress

Qualification of active mechanical components

In 2014, a new editorial group was created within the RCC-M Subcommittee to address active mechanical components (valves and pumps).

Their work will form the basis of the new "Q" subsection in the RCC-M code, which is scheduled for late 2015 and which is being drafted in close liaison with the RCC-E Subcommittee.

The code will broaden its scope, which is currently restricted to the integrity of pressure-bearing structures, to encompass the operability and operation of so-called "active" equipment, namely pumps and valves.

Preparation of PTAN (AFCEN Technical Publications)

In 2015, AFCEN is planning to publish:

  • A radiation protection guide for the design of nuclear pressure components in PWR plants in France.
  • A practical guide to applying the probationary rule for "Nuclear management systems".
  • Recommendations for qualifying the tools used to calculate and model physical phenomena as part of the studies carried out according to RCC-M.

Technical studies to prove conformity with the PED Directive / France's Nuclear Pressure Equipment Regulation

The Editorial Committee has launched 10 working groups to demonstrate how the RCC-M code can be used to meet the essential safety and radiation protection requirements stipulated in France's Nuclear Pressure Equipment Regulation and the European PED Directive.

These groups have the following missions:

  • Risk analysis, uncertainties and margins.
  • Specific evaluations for nuclear components.
  • Unacceptable defects (including defects beneath the cladding and sequential penetration).
  • Toughness of low-thickness materials.
  • Inspectability.
  • Vulnerability criteria.
  • The dimensions required to ensure conformity with requirements.
  • Qualification of design methods.
  • Proof of compliance with essential safety and radiation protection requirements.

A significant amount of work has culminated in studies that will be released as PTAN technical publications in 2015 (for example, a comparison between harmonized European standards and the requirements of RCC-M 2007) and which may lead to a revision of the code in 2015 and 2016.

The aim is to finalise such work in 2015, allowing for a few exceptions if testing and/or in-depth rating investigations need to be carried out.

RCC-M is the only AFCEN code with the objective of proving compliance with the essential safety requirements stipulated in European (PED Directive 97/23/EC) and French legislation (Class 1 essential safety and radiation protection requirements of the Nuclear Pressure Equipment Regulation).

Work progress reports are shared with ASN approximately every three months.

The objectives and detailed progress of this programme are presented in Box below.

Work on the RCC-M code in relation to the Nuclear Pressure Equipment Regulation (ESPN)

  • Risk analysis according to ESPN: the ESPN Regulation requires a risk analysis to be carried out prior to design and fabrication. Work is focusing on producing guidelines for carrying out ESPN risk analyses. An initial draft was produced and submitted to ASN. This study is being supplemented by an investigation into vulnerability. The purpose of this new investigation is to define the appropriate course of action when the analysis identifies a risk and the area in question is not available for inspection.
  • Uncertainties and safety factors: this study involves checking that the safety factors in the RCC-M code conform to the requirements of the ESPN Regulation and proving that application of the RCC-M code satisfies the requirement of taking uncertainties into account in the sizing and safety factors. In respect of the first point, the study shows that the safety factors generally conform to the requirements of the regulation. The second point is being examined by comparing the requirements of the RCC-M code against harmonized standards, since the uncertainty requirement is stipulated in European Directive 97/23/EC. Therefore, if the RCC-M code offers dimensional requirements for vessels at least equivalent to EN 13445 and piping at least equivalent to EN 13480 (harmonized standards), the requirement will be satisfied. In addition to this ongoing study, two special investigations have been launched, one of which into the dimensional control of components and the other into fatigue damage.
  • Inspectability: this study is aimed at producing a guide on how to write the inspectability report. It is based on an analysis of two test cases: the first is where the analysis identifies a risk without any possible remedy and where inspectability is absolutely necessary (in the example, the steam generator tubes need to be inspected), and the second is where only the inspectability requirement is necessary without any risks detected during the analysis (in the example, steam is escaping from a steam generator).
  • Specific evaluation for nuclear materials: note that this evaluation is intended to explain the reasons for which a given material was chosen for a given application. The study involves documenting test cases for performing a specific evaluation on the materials used in a steam generator, which can then be used as an example.
  • Toughness of low-thickness materials: The ESPN Regulation requires fast fracture resistance guarantees, irrespective of the material's thickness. The study involves defining a method for measuring the resilience of products with a thickness between 5 and 10 mm and demonstrating that the resilience measurement is negligible for austenitic products whose dimensions are less than 5 mm.
  • Unacceptable defects: the ESPN Regulation specifies that non-destructive testing must be capable of detecting defects of concern. In this particular case, a distinction is made between defects of concern in terms of construction quality (a discrepancy in the manufacturing process) and defects of concern in terms of the structure's mechanical integrity. In 2010, AFCEN released an initial document addressing the first point. The study currently in progress is aimed at verifying that the non-destructive tests in the code are capable of detecting defects of concern relating to the equipment's mechanical integrity. The study is initially focusing on nine test cases.
  • Verification that the RCC-M satisfies the different essential safety requirements: the purpose of this study is to produce documents that examine all the requirements in the ESPN Regulation, determine whether the requirements in the code satisfy the ESPN's requirements (either directly or by using the other AFCEN studies above) and propose amendments to the code if such is not the case. To date, an initial document covering the fabrication of vessels and piping has been completed and submitted to ASN.

- Qualification of the mechanical design methods in RCC-M: Methods for qualifying mechanical design methods were introduced into the RCC-M code following an examination by ASN.

All of these studies have already generated many dozens of suggested amendments to the RCC-M code, which are currently being investigated or have already been introduced into the code.

Continuation and finalisation of studies into the technical qualification of components

In 2013, the RCC-M Subcommittee created a working group and a committee to validate the risk analyses carried out when preparing materials in order to identify the risks of any inconsistencies.

The group is being monitored by ASN's Nuclear Pressure Equipment Department (DEP) and will finalise some 43 risk analyses for the material families in the code mid-2015, and those analyses will be vetted by a validation committee featuring experts from outside AFCEN.

The technical qualification methods will then be incorporated into the reference technical specifications for the materials in the code, including the new demonstration tests identified in the risk analyses.

Continued activities to address international challenges

In 2014, the RCC-M Subcommittee:

  • Organized three meetings for the UK Users Groups (February, July and November) led by AFCEN member TWI.
  • Followed up the activities of the "Group for the Convergence of Mechanical Codes and Nuclear Coding Organizations" organized by ASME ST LLC, following MDEP's actions for Codes and Standards (see Section 2.4.1).
  • Held two kick-off meetings for the European Prospective Group CEN WS 64 - Phase 2 - PG 1 (see Section 2.4.3).

Meetings for Users Groups in China are scheduled for March 2015.



RSE-M : In-Service Inspection Rules for Mechanical Components of PWR Nuclear Islands.

Purpose and scope

The RSE-M code defines in-service inspection operations.

It applies to pressure equipment used in PWR plants, as well as spare parts for such equipment.

The RSE-M code does not apply to equipment made from materials other than metal.

It is based on the RCC-M code for requirements relating to the design of mechanical components.


The inspection rules specified in the RSE-M code describe the standard requirements of best practice within the French nuclear industry, based on its own feedback from operating several nuclear units and partly supplemented with requirements stipulated by French legislation.

To date:

  • The 58 units in France's nuclear infrastructure enforce the in-service inspection rules of the RSE-M code.
  • Operation of the 17 commissioned units in China's nuclear infrastructure, corresponding to the M310, CPR-1000 and CPR-600 reactors, is based on the RSE-M code (since 2007, use of AFCEN codes has been required by NNSA for Generation II+ reactors).


AFCEN drafted and published the first edition in July 1990.

This initial edition served as a draft for preparing the 1997 edition, which extended the code's scope to encompass elementary systems and supporting structures for the mechanical components concerned.

This edition was updated on a number of occasions (in 2000 and 2005) before undergoing a complete overhaul in 2010.

Edition available as of 1 January 2015

2010 edition, with addenda in 2012, 2013 and 2014

RSE-M dernière édition 2015

In particular, the 2010 edition modifies the way in which pressure equipment is divided into different subsections to reflect the new French regulation governing pressure equipment.

The 2010 edition was supplemented by the following three addenda.

2012 addendum:

  • For the section on "Implementation of a maintenance operation", elements were included from the inter-operator professional guide for classifying modifications or repairs to nuclear pressure equipment subject to Appendix 5 of France's ESPN Regulation.
  • Additional information on test coupons.
  • Further details about pre-service inspections.

2013 addendum:

  • Incorporation of changes to requirements and practices for qualifying NDT applications.
  • Further details about fatigue analysis methods.
  • Clarification concerning the terms for applying RSE-M: company qualification and use of a test coupon.

2014 addendum:

  • Updating of the zones subject to examination in case of magnetic particle testing.
  • Definition of the requirements for qualifying design and modeling tools.
  • Further details concerning regulated pressure equipment, including the small lines in the main primary and secondary systems.
  • Modification to the standard deviation value to be taken into account for the upper envelope and the predicted upper envelope for embrittlement under the effects of irradiation for monitoring the effects of neutron radiation on the containment vessel materials.
  • Integration of tapped screw holes not involved in pressure resistance.
  • Description of the maintenance operation file, by identifying the necessary elements according to applicable regulations (Appendix 1.6).
  • Revision of the inspection tables and associated figures for RSE-M Class 1 components (Appendix 3.1.1).
  • Further details concerning the analytical methods for calculating stress intensity factors and J integral (Appendix 5.4).

Outlook and the future 2017 edition

AFCEN is aiming to prioritize development of the RSE-M code in the following directions:

  • Incorporate future developments in technology and legislation.
  • Factor in the constraints facing operators-partners.
  • Deliver support for all international practices.

The next edition of the code is scheduled for late 2017 and will be preceded by an addendum in 2015.

The 2017 edition is in keeping with the work that has been pursued since the 2010 edition by:

  • Continuing to update the existing version to reflect the latest changes in technology and legislation.
  • Incorporating EPR aspects into the entire code by enhancing the components and practices specific to Flamanville 3.
  • Taking account of the components that have been built according to the requirements of the RCC-M code other than those used in France's nuclear infrastructure (especially in China).

AFCEN criteria and technical publication for RSE-M

Sizing components, checking their fitness for service and analysing the impact of a defect detected during operation are generally based on mechanical analysis methods and criteria involving safety factors that are chosen to reach a fixed severity level.

The publication entitled "Principles of and background to the formulation of the criteria in Appendix 5.5 of RSE-M", relating to the fast fracture resistance of pressure equipment presenting an operational planar defect, describes the basic principles and background to the process of defining the criteria for Appendix 5.5 of the RSE-M code, especially the characteristic values of the main variables and the partial safety factors.

This document was published in 2014.



RCC-E : Design and construction rules for electrical equipment of PWR nuclear islands

Purpose and scope

RCC-E describes the rules for designing and building electrical assemblies and I&C systems for pressurised water reactors.

The code was drafted in partnership with industry, engineering firms, manufacturers, building control firms and operators, and represents a collection of best practices in accordance with IAEA requirements.

The code's scope covers:

  • Architecture and the associated systems.
  • Materials engineering and the qualification procedure for normal and accidental environmental conditions.
  • Facility engineering and management of common cause failures (CCFs) (electrical and I&C) and electromagnetic interference.
  • Practices for testing and inspecting electrical characteristics.
  • Quality assurance requirements supplementing ISO 9001.


RCC-E has been used to build the following power plants:

  • France's last 12 nuclear units [1,300 MWe (8) and 1,450 MWe (4)].
  • Two M310 reactors in Korea (2).
  • 36 M310 (4), CPR-1000 (24), CPR-600 (6) and EPR (2) reactors in service or undergoing construction in China.
  • One EPR reactors in France (1).

RCC-E is used for maintenance operations in French power plants (58 units).

RCC-E has been chosen for the construction of the EPR plants in Hinkley Point, UK.

Users include:

  • Equipment suppliers.
  • Engineering firms responsible for designing, building and installing equipment and systems.
  • Control and inspection organisations.
  • Safety authorities.


The editions published between 1981 and 2002 address Generation II reactors.

The 2005 edition incorporated the requirements stipulated in the design codes specific to the EPR project - ETC-I and ETC-E, which focus on I&C and electrical systems respectively (ETC: EPR Technical Code Instrumentation and Electrical).

The 2005 and 2012 editions concern Generation II and III reactors. As from the 2005 edition, project specifications must be written to supplement and implement the rules in RCC-E and allow the code to be used in the project.

The various editions of the code have been published in French and English.

The 2005 edition was translated into Chinese.

Edition available as of 1 January 2015

The 2012 edition is the most recent version

RCC-E dernière édition 2015

Outlook and the future 2016 edition

The following sources are used when revising the code:

  • Feedback from facilities under construction and in operation.
  • The safety authorities' investigation process.
  • User enquiries.
  • Changes to the standards used or IAEA's requirements.
  • Changes to industry's maturity.

The 2016 edition will:

  • Represent a departure from previous editions, which have been updates instead of overhauls.
  • Address Generation II, III and IV reactors, research reactors and naval reactors.
  • Organize requirements into four key areas for easier identification and greater clarity: monitoring, systems, equipment, and component and systems installation. Each key area will cover all the activities in the lifecycle.
  • Ensure conformity with IAEA requirements.
  • Clearly define the supplements to the requirements in the chosen IEC standards for I&C systems.

Reasons for overhauling the code include:

  • Changes to IAEA requirements SSR-2/1, GSR Parts 2 and 4, and recommendations for designing and building electrical and I&C systems (SSG 34 and DS 431), which are used as inputs to the drafting process.
  • The WENRA handbook on the design of new reactors.
  • Changes to IEC standards relating to the SC 45 Technical Committee and IEC industry standards.
  • Feedback from current projects: EPR, ITER, RJH and ASTRID.
  • Lessons learned following the British safety authorities' investigation into the UK's EPR as part of the generic design assessment into the electrical and I&C systems.
  • Feedback following Fukushima.

Requirements are adapted so that they can be applied to nuclear projects other than pressurized water reactors, and harmonized and coordinated with the requirements of the relevant IEC international standards.

The structure of the code will feature seven chapters:

  • Safety, quality and inspection management.
  • General requirements.
  • Architecture of:
    • I&C systems.
    • Electrical systems.
  • Materials engineering.
  • Installation.
  • Inspection and test methods.

Technical publication of the RCC-E Subcommittee:

AFCEN has published a document that compares the 2012 and 2005 editions of the code entitled:

"Nuclear Codes & Standards: RCC-E 2012 Gap analysis with the RCC-E 2005"



RCC-CW : Design and construction rules for civil works in PWR nuclear islands

Purpose and scope

RCC-CW describes the rules for designing, building and testing civil engineering works in PWR reactors.

It explains the principles and requirements for the safety, serviceability and durability of concrete and metal frame structures, based on Eurocode design principles (European standards for the structural design of construction works) combined with specific measures for safety-class buildings.

The code is produced as part of the RCC-CW Subcommittee, which includes all the parties involved in civil engineering works in the nuclear sector: clients, contractors, general and specialized firms, consultancies and inspection offices.

The code covers the following areas relating to the design and construction of civil engineering works that play an important safety role:

  • Geotechnical aspects.
  • Reinforced concrete structures and galleries.
  • Prestressed containments with metal liner
  • Metal containment and pool liners.
  • Metal frames.
  • Anchors.
  • Concrete cylinder pipes.
  • Containment leak tests.

The RCC-CW code is available as an ETC-C version specifically for EPR projects (European pressurized reactor).

Background and use

AFCEN published the first civil engineering code (RCC-G) in 1980.

This edition included feedback from France's 900 MWe nuclear reactors and mainly drew inspiration from the French BAEL regulation (limit state design of reinforced concrete) and BPEL regulation (limit state design of prestressed concrete). It has been used for the M310 projects in Korea and China.

AFCEN updated the edition in 1985 and again in 1988 to reflect the latest developments in civil engineering technology.

In particular, the 1988 edition served as a roadmap for France's 1,450 MWe PWRs.

In April 2006 in response to the specific needs of its Flamanville 3 EPR project in France, EDF published a reference document called ETC-C for the design and construction of civil engineering works.

The reasons that prompted the development of the ETC-C code are as follows:

  • Cover both French and German legislative requirements and practices.
  • Consider new load cases to represent severe accident conditions or events of a more serious nature.
  • Integrate application of Eurocodes into the design of nuclear structures.
  • Take account of the latest feedback on the operation of in-service nuclear power plants and updated requirements for safety analyses.
  • Incorporate the latest knowledge on the behaviour of materials and structures (obtained through laboratory and model testing).

The EDF document was not published by AFCEN, but acted as a blueprint for a civil engineering code that AFCEN produced in 2009 as part of the RCC-CW Subcommittee, which led to:

  • Initially, the publication of a specific code for EPR projects: ETC-C edition 2010, followed by ETC-C edition 2012.
  • Subsequently, the publication of a generic civil engineering code, called RCC-CW, that is not specific to any given project.

The ETC-C 2010 edition, which was the first version prepared and published by AFCEN, was used for the generic design assessment of the EPR project in the United Kingdom.

Edition available as of January 2017

Edition ETC-C 2010 and 2012

ETC-C 2010, first edition published by AFCEN has been used for the Generic Design Assessment of EPR in UK.

ETC-C 2012 integrates the feedback of Flamanville 3 and of the Generic Design Assessment.

Edition: RCC-CW 2015

Publication of the RCC-CW 2015 code early 2015 is the first edition that AFCEN has prepared and published of a generic civil engineering code that does not relate to any specific project.

It takes account of the latest changes in European standards.

It includes technological possibilities and improvements:

  • Bonded prestressing has been supplemented with unbonded prestressing.
  • The code covers the design and development of seismic isolation devices.
  • The section on external hazards has been updated to include tornadoes.

The design approach has been expanded to provide greater focus on the design extension situations in the complementary field.

Edition: RCC-CW 2016

In addition, the following improvements have been incorporated in RCC-CW 2016:

  • Correction of editorial mistakes, including those published as Errata 2016 of RCC-CW 2015;
  • Significant evolution of DANCH chapter to implement the new release of EN 1992-4.


As already initiated by AFCEN in preparing the RCC-CW code, development of the civil engineering code is continuing in the following directions:

  • Integrate feedback from projects currently under development or construction.
  • Broaden the scope of robust technologies covered by the code (anchors, metal liners, and so on).
  • Encourage application of the code in the European and international arena by offering greater coverage of the latest international standards and promote the code as a civil engineering benchmark for the Prospective Groups that CEN set up to prepare the future nuclear codes.
  • According to AFCEN's requirements and development objectives, develop appendices and addenda specifically addressing how the code can be adapted to the countries targeted by AFCEN.

Technical publication on seismic isolation

Technical publication "PTAN - French practice and experience of seismically isolated nuclear facilities" was released in 2014.

It presents the best practices and experience of French industry resulting from the last 30 years in designing and installing seismic isolation systems beneath nuclear facilities.

This publication enables European industry to:

  • Codify the industrial design and construction practices according to AFCEN: in this respect, RCC-CW 2015 includes a section on seismic isolation.
  • Showcase its experience within international organizations and bodies (IAEA, OECD, WENRA ...).


RCC-C : Design and construction rules for fuel assemblies of PWR nuclear power plants

Purpose and scope

The RCC-C code contains all the requirements for the design, fabrication and inspection of nuclear fuel assemblies and the different types of core components (rod cluster control assemblies, burnable poison rod assemblies, primary and secondary source assemblies and thimble plug assemblies).

The design, fabrication and inspection rules defined in RCC-C leverage the results of the research and development work pioneered in France, Europe and worldwide, and which have been successfully used by industry to design and build nuclear fuel assemblies and incorporate the resulting feedback.

The code's scope covers:

  • Generalities : definitions, standards, management system and treatment of non-conformities
  • Product design aspect for safety justification
  • Fabrication aspect
    • requirements about materials used,
    • qualification requirements for assemblies,
    • qualification requirements for inspection and fabrication processes,
    • control methods,
    • certification of controllers.
  • Situations out of the boiler


The RCC-C code is used by the operator of the PWR nuclear power plant in France as a benchmark when sourcing fuel from the world's top two suppliers in the PWR market, given that the French operator is the world's largest buyer of PWR fuel.

In 2011, AFCEN authorized the 2005 version of the RCC-C code to be translated into Chinese.


The first edition of the AFCEN code was published in 1981 and mainly covers fabrication requirements.

The second edition of the code was released in 1986 and supplemented the first edition by including design requirements for the fuel system.

This structure remains unchanged, and the updated edition released in 2005 prioritises the fabrication aspects.

The new French version of the RCC-C code 2015 operates major structure changes for a better user understanding. Furthermore, the technical content has been enhanced on both design and fabrication aspects.

The English version will be available early 2016.

RCC-C - Last edition available

The 2015 edition

As part of the new 2015 edition, amendments have been made based on the 2005 edition and the 2011 addenda.

Following users' feedback about the document, the 2015 edition of the code is restructured as shown in table below, the aim being for the plan to more closely mirror industry practices.

Code outline 1981 Code outline 1986 - 2005 Code outline 2015
1 - Generalities

2 - Product and part characteristics

3 - Manufacturing and related testing and inspection

4 - Tables of inspection requirements

5 - Inspection methods


1 - Generalities

2 - Product and part characteristics

3 - Manufacturing and related testing and inspection

4 - Tables of inspection requirements

5 - Inspection methods

6 - Design


1 - Generalities

2 - Description of fuel

3 - Design

4 - Manufacturing

5 - Handling and Storage

These amendments are intended to update the code and improve the level of requirements from both a quality assurance and technical point of view, as well as produce a document offering greater overall consistency and allowing for better application of the code.

In terms of the general requirements and description:

  • Quality assurance requirements have been improved compared to previous requirements by including the text of AFCEN RPP-1, which itself is based on the IAEA GS-R-3 standard.
  • The definitions used for fuel assemblies have been enhanced.
  • The procedure for managing nonconformities has been described.
  • The fuel description has been updated.

In terms of design:

  • The design chapter has been updated to reflect comments from the French safety authority in 2009 following discussions about the prospect of a draft fuel regulation. The paragraph has been restructured for improved clarity. Changes have been introduced to factor in ASN's observations in 2009 (the enthalpy value considered obsolete was removed) and take into consideration the findings of the French Group Permanent on Loss-of-Coolant Accident (further details concerning the dependence of the ECR value on hydrogen). A paragraph covering Class 2 pellet-cladding interaction studies has been incorporated.
  • The statement of functional requirements for assemblies and core components has been improved.
  • Paragraphs on thermal hydraulics and neuron transport have been added.

In terms of fabrication:

  • The paragraphs in the code covering zirconium alloy have been updated to include commercial alloys other than Zircaloy 4.
  • The chapter on materials has been structured according to the same plan as that used for zirconium alloys. The paragraphs covering absorbents and fuel pellets have been improved.
  • The code includes requirements for the following inspection and fabrication processes: automatic sorting of pellet diameters, tube expanding, lost-wax casting, component marking, thermal treatment and surface treatment.
  • The following assemblies are defined, as well as their qualification requirements: assemblies, skeleton assemblies, grids, fuel rods, bottom end fittings, rod cluster control assemblies and absorber rods.

The RCC-C Subcommittee is continuing its work in 2015, with the focus on:

  • Developing the English version of the code.
  • Managing Requests for Modification that could not be included in the work on the new 2015 edition.

Code supporting documents: technical publications and criteria

The RCC-C code currently does not have any criteria.

The supporting documents are used to describe the risks that need to be controlled, explain the demonstration objectives and clarify the methods. They will be beneficial to fuel-related matters.

A work program to establish the criteria will be defined in 2015 based on an analysis of the technical criteria used.



RCC-F : Design and construction rules for PWR fire protection systems

Purpose and scope

The RCC-F code defines the rules for designing, building and installing the fire protection systems used to manage the nuclear hazards inherent in the outbreak of a fire inside the facility and thereby control the fundamental nuclear functions.

This code's target readership is therefore:

  • Suppliers of fire protection equipment.
  • Engineering firms responsible for designing, building and installing fire protection systems.
  • Laboratories carrying out qualification testing of fire protection equipment.
  • Nuclear safety authorities responsible for approving the safety demonstration.

The code defines fire protection systems within a finite scope of service buildings in a light water nuclear power plant.

If any one of the requirements in the code is unenforceable due to specific difficulties, a design may nevertheless be implemented provided that justification is duly documented.

The code provides fire protection recommendations in terms of:

  • The industrial risk (loss of assets and/or operation).
  • Personnel safety.
  • The environment.

The code is divided into five main sections:

  • General
  • Design safety principles
  • Fire protection design bases
  • Construction provisions
  • Rules for installing the fire protection components and equipment

The RCC-F code is available as an ETC-F version specifically for EPR projects (European pressurised reactor).

Background and use

In response to the needs of its Flamanville 3 EPR project in France, EDF published a reference document called ETC-F for the design of fire protection systems.

The EDF document was not published by AFCEN, but acted as a blueprint for a fire protection code that AFCEN produced in 2009 as part of the RCC-F Subcommittee, which led to:

  • Initially, the publication of the 2010 edition of the ETC-F code for EPR projects, followed by the 2013 edition, which gave less focus to the specifics of EPR projects but which still addresses the main EPR safety principles.
  • Subsequently, the publication of a generic fire protection code, called RCC-F, that is not specific to any given project and which promotes the code's application on an international level.

The 2013 edition is compatible with British requirements and is intended for the EPR plants in Hinkley Point, UK.

Edition available as of 1 January 2015

ETC-F 2013 edition

ETC-F latest edition 2015

The 2013 edition of the ETC-F code incorporated two major changes:

  • Removal of the code's adherence to the specifics of EPR projects.
  • Inclusion of British regulations, which prompted a significant overhaul to the body of the text, as well as the creation of an appendix specifically addressing such regulations and designed to improve understanding thereof.

This exercise in anglicizing the code gave AFCEN hands-on experience in updating the code to reflect foreign regulations (in terms of the time, processes and skills required).

It also served as the ideal opportunity to integrate British practices.

Outlook and the RCC-F edition


AFCEN is aiming to develop the code in the following directions:

  • Integrate feedback from projects currently under development or construction.
  • Initially drive the code's application on a European and international level by including international standards and regulations. According to requirements, this will prompt AFCEN to develop appendices and addenda specifically addressing how the code can be adapted to the target countries (refer to the exercise already carried out for the United Kingdom).

RCC-F 2016 edition

AFCEN's aim is to produce an RCC-F code that can be used for any project, irrespective of the applicable safety rules.

The initial 2010 version of the ETC-F code included two types of adherence:

  • EPR adherence (specific characteristics of EPRs, mainly semantics (PCC, F2, etc.)).
  • Safety adherence, which is also contained in all other EDF fire codes (RCC-I, fire directives, etc.) used on France's other power plants.

The 2013 version of ETC-F has treated the adherence to specific characteristics of the EPR process existing in the 2010 version of ETC-F, but it still needs to address adherence to EPR safety.

The code must therefore be formatted and revised to identify the impact of safety principles on the content of the design, construction and installation rules defined within the code.

The work to be carried out is organized according to the following five subject areas:

Subject area 1: Analysis of adherence to safety principles (sizing and stresses)

The aim is to analyze adherence to safety principles, which involves identifying the safety criteria and principles in the code by examining any given principle (aggravating event, fire combined with thermal-hydraulic transients, combined stresses, fire outbreak following an earthquake, and so on) and how it is addressed by the code.

The analysis of adherence to safety principles may be documented in a safety principle appendix featuring two objectives: improve the code's legibility to better understand the links with nuclear safety principles and provide elements to ensure that the code can be tailored to the safety principles chosen within a specific context.

Subject area 2: Improved traceability of requirements

The purpose of this subject area is to satisfy users' need to easily identify the source of the requirements that led to the rules defined within the code.

Subject area 3: Development of requirements on conventional islands

The idea with this subject area is to inject greater flexibility into the rules for designing fire protection systems by adapting and therefore clarifying the rules applied to nuclear islands to reflect the risks relating to the conventional component (challenge of protecting the facility's production assets).

Subject area 4: Clarification of human intervention

The aim is to clarify human intervention within the code, even though such intervention is not evaluated in respect of demonstrating safety. However, human intervention can be used (evaluated) in the safety analyses. The specific prerequisites arising from international practice will need to be integrated.

Subject area 5: Position in relation to international codes and guides

This subject area aims to identify the different codes and/or guides (WENRA, IAEA, NFPA, WANO, EUR, etc.) and subsequently pinpoint the differences or similarities with the draft RCC-F code.



RCC-MRx: Design and construction rules for mechanical components in high-temperature structures, experimental reactors and fusion reactors

Purpose and scope

The RCC-MRx code was developed for sodium-cooled fast reactors (SFR), research reactors (RR) and fusion reactors (FR-ITER).

It describes the rules for designing and building mechanical components involved in areas subject to significant creep and/or significant irradiation. In particular, it incorporates an extensive range of materials (aluminium and zirconium alloys in response to the need for transparency to neutrons), sizing rules for thin shells and box structures, and new modern welding processes: electron beam, laser beam, diffusion and brazing.

Background and use

Since 2009, the RCC-MRx code created by AFCEN's RCC-MRx Subcommittee has been an amalgamation of two documents:

  • The RCC-MR code, drafted by AFCEN's RCC-MR Subcommittee together with the Tripartite Committee formed on 16 March 1978 by the Commissariat à l’Energie Atomique (CEA), Electricité de France and Novatome, to establish the applicable rules for designing components working at high temperatures. AFCEN published four editions of RCC-MR in 1985, 1993, 2002 and 2007.
  • The RCC-MX code, drafted by the RCC-MX Approval Committee formed on 31 March 1998 by the Commissariat à l’Energie Atomique, AREVA-TA and AREVA-NP for the specific needs of the RJH project (Jules Horowitz reactor). This code applies to the design and construction of experimental reactors, auxiliary systems and associated experimental devices. It can also be used for the design and construction of components and systems for existing facilities. CEA published two editions of RCC-MX in 2005 and 2008.

An unpublished preliminary version of RCC-MRx created in 2010 by AFCEN was chosen as the baseline for the CEN CWA European Workshop (entitled "CEN-WS-MRx, Design and Construction Code for mechanical equipment of innovative nuclear installations"), which was intended to familiarize European partners with the RCC-MRx 2010 code and propose modifications to satisfy the needs of their projects. The results of the workshop were incorporated into the 2012 edition of RCC-MRx published by AFCEN.

The RCC-MR code was used to design and build the Prototype Fast Breeder Reactor (PFBR) developed by IGCAR in India.

The RCC-Mx code is being used in the current construction of the RJH experimental reactor (Jules Horowitz reactor).

The RCC-MRx code is being used for the design and construction of ITER and the design of the ASTRID project (Advanced Sodium Technological Reactor for Industrial Demonstration).

Edition available as of 1 January 2015

2012 edition, with the 2013 addenda

RCC-MRx dernière édition 2015

An addendum to the RCC-MRx code was produced in 2013, incorporating 48 modification files to reflect feedback on the 2012 edition.

Outlook and preparation of RCC-MRx 2015

The focus in 2014 was preparing and producing English and French versions of the code for December 2015.

Building on the previous edition and the 2013 addenda, AFCEN will publish a new edition of the RCC-MRx code in 2015. It will include feedback from current projects, mainly the Jules Horowitz reactor and the Astrid project (Advanced Sodium Technological Reactor for Industrial Demonstration), as well as additional information about the Eurofer material used by the fusion community.

The 2015 edition will also feature the results of the initiatives aimed at harmonizing the code with other standards (harmonized standards, RCC-M).

Technological commissioned studies

The RCC-MRx Subcommittee launched two commissioned studies in 2014:

  • Improvement to the rules to take account of irradiation when levels become significant.

This commissioned study is aimed at assessing the rules currently featured in the code with a view to their improvement. The first Requests for Modification from the brainstorming process into the rules and material data should be published in 2015.

  • Terms for introducing a new material into RCC-MRx, in keeping with what had already been introduced into the code (concept of a material record).

The aim of this commissioned study is to produce a methodological guide that will be released as an AFCEN technical publication. The purpose of this guide is to explain, when introducing a non-coded material into RCC-MRx, the definition of the methods for obtaining the characteristics in Appendices A3-A9 (expected / possible tests, meaning of the data), the requirements for fabrication and welding in relation to the material properties and positioning of the characteristics codified against probabilistic analyses.


RCC-D: Design, construction and deconstruction rules for nuclear facilities

The decision to produce a deconstruction code was taken in October 2014 by AFCEN's Board of Directors, based on an opportunity assessment that showed the value on an international and especially European level of publishing such a code, and the feasibility of producing the code within three years according to the following program:

RCC-D program AFCEN

The scope of the code will cover all nuclear facilities.

A working group led by an AFCEN Member has been tasked with carrying out a draft.

Once approved by AFCEN's Board of Directors, the draft will serve as an input for the work of the new RCC-D Subcommittee, which will be created mid-2016.

The goal is to publish the RCC-D code by the end of 2017.

In particular, the code must be in keeping with AFCEN's other codes.