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Understand everything about the RCC-MX standard

The RCC-MX standard concerns the prevention and management of nuclear accidents. It is essential for the installation of an experimental nuclear reactor. SMEPI has been producing high precision mechanical parts in accordance with this standard for several years.


The RCC-MX code to reduce the risk of nuclear accidents

The RCC-MX standard has succeeded the RCC-M code since 2008. It concerns the rules governing the prevention and management of accidents on a nuclear site. To better understand the rules enacted in the RCC-MX reference system, a reminder of the context and the elements concerning the safety of nuclear reactors is necessary.

Controlling accident risks is a crucial issue for experimental reactors, which is why their construction must meet several safety requirements:

  • the reactor must be designed so that it can be safely shut down and maintained;

  • the removal of the residual heat from the reactor vessel must be possible, or even facilitated, in the event of a shutdown;

  • the release of radioactive material should be limited while ensuring that radiation does not exceed permitted limits.


For nuclear reactors, the RCC-MX revolves around a safety approach that includes:

  • cooling of radioactive materials;

  • containment of radioactive materials;

  • and reactivity control.


This code is a set of technical rules governing the design and construction of mechanical components of experimental reactors, their auxiliary systems, as well as the associated devices. It was developed as part of the installation of the Jules Horowitz reactor. Overall, its raison d'être is to ensure the security of a nuclear site.

The RCC-MX therefore applies both to existing experimental reactors and to future projects. However, its field of application only concerns metallic mechanical components, defined as important in terms of nuclear safety and / or operability. These parts perform the function of containment, partitioning, guiding and securing, and systems containing fluids such as pressure vessels, pumps, valves or even pipes. This is to ensure that the reactors have components designed according to the RCC-MX standard and operate correctly without fear of possible accidents, since the mechanical parts meet the requirements of the industry.

Safety requirements relating to the RCC-MX code

Regarding the concrete measures to be implemented, the RCC-MX standard provides a list of requirements applicable to:

  • reactor design (stress analysis, bolts, welding, pumps, pipes, bellows)

  • welding (molded products, supply in accordance with TRS, COTS technical standards, verification of welding quality, verification of the qualification of welders and operators);

  • and manufacturing (technical manufacturing program).


To extend the application of these rules to other countries, the codes RCC-MX and RCC-MR - a standard developed for Sodium Reactors (SFR) and the Vacuum Vessel of ITER Reactors (FR-ITER) - have been merged. to become the RCC-MRx, the latter being developed by AFCEN.

The CEN Workshop Agreement aims to ensure the simultaneous adoption at European level of IEC standards (International standards for electricity, electronics and related technologies) and covers various projects. such as MYRRHA, ESS, ASTRID, ALFRED ... with partners like UK, Belgium, Italy, Sweden and Finland.

A subcontractor in precision mechanics, SMEPI manufactures parts and components intended for experimental reactors and meeting the safety and quality standards provided for by the RCC-MX code. It is recommended to use a company specializing in the manufacture of mechanical parts to ensure that the components are manufactured in the rules of the art. SMEPI has many years of experience in the machining of high precision mechanical components. It offers high-performance equipment that meets the very high safety standards of cutting-edge industries.


SMEPI, a benchmark company in the machining of precision mechanical elements

In terms of precision mechanics, in particular in the machining of mechanical parts, whatever their size or format, SMEPI is the benchmark subcontractor to call on. In the extremely specialized field of precision machining, we have a decade of presence, we are renowned throughout France. SMEPI provides you with a complete service from the study to the heat and surface treatment, including the heat and surface treatment, the choice of raw materials, machining, assembly, prototyping ... as well as a severe control of parts. Our machining company trusts a highly qualified team and has a large reserve of materials to offer our customers the quality of products. Our achievements are intended for professionals belonging to different sectors in particular: transport, chemicals, special machines, nuclear, energy, petrochemicals ...

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