Reflective metal insulation as the new insulation standard in nuclear energy

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In France, nuclear energy plays a central role in the national energy mix. With one of the largest shares of nuclear power generation in the world, it forms the backbone of the country’s energy supply. In this dynamic and ever-changing energy sector, KAEFER WANNER’s Reflective Metal Insulation (RMI) offers a solution to further improve safety and efficiency.

Increased safety

RMI is a key safety feature, as it is one of the measures that increases the efficiency of the cooling circuits in the power plant. Why is this important? Because it can make the difference between a manageable accident and an unmanageable one.

In the event of an incident, such as a disruption in the primary circuit, the cooling circuit in nuclear facilities must still operate in a closed loop. If fibrous insulation, such as mineral wool, is used, the filling material of damaged cassettes can move around freely and block the pump inlet (strainer) of the water circuit. RMI, on the other hand, with its sheet metal filling, is less prone to creating dangerous debris and will not disintegrate when it comes in contact with water.

Reflective metal insulation

The Fukushima accident in 2011 has once again highlighted the advantages of RMI for thermal insulation. EDF, the French electricity company and the world’s second largest electricity producer, has defined reflective metal cassettes as the new standard for all its nuclear power plants in 2021.

Workshop in Pompignac

Fast, efficient solutions

Another great advantage of metal cassettes is that they are quick and easy to install. The cassettes are prefabricated, and test assembled in the workshop and then installed on site. This reduces the time spent in the plant and the parts can be easily replaced at a later date. A recent example: A recent example: The French KAEFER team has just successfully completed the first installation of cassettes to insulate the lower part of the steam generator in a nuclear power plant. In just one year, from the first thermal tests to the installation of the cassettes for the first unit, our colleagues were able to develop an industrial solution that met the specific requirements of their client.

Long-term vision

Last year, KAEFER was awarded a contract to replace the existing double-wall fibre insulation in the lower part of the steam generator as well as in the hot and cold legs of the primary circuit of the 900 MW units with RMI. With around 30 units to be upgraded by 2030, this is no small task.

By then, the RMI solution will be a standard and will serve as a reference for the insulation of the entire primary circuit of the next EPR2 nuclear power plants, as well as the Small Modular Reactors (SMRs) under development.

Our task force in Pompignac

A look behind the scenes

Our workshop in Pompignac manufactures metal cassettes, mattresses, and other fittings for the nuclear industry. To meet growing demand, we have expanded the site by 70% between 2020 and 2023. With a total area of around 6,000 m² and an impressive range of machinery, we are ensuring that we can meet our customers’ requirements not only today, but also in the future. We have invested in technology that makes a difference – and in a dedicated team. Every member of the workshop team contributes to maintaining and developing our high-quality standards.

At our Research and Development facility in Saint-Cyr-sur-le-Rhône, we do everything we can to prove the performance of our cassettes. Our thermal testing facilities are not only a sign of our commitment to quality, but also proof that we deliver what we promise.

Thinking beyond borders

Our services do not stop at the French border. Together with our German team in Bremen, KAEFER in France also markets RMI for export – proving that good solutions are international. For example, we are working on a series of primary circuit systems for SMRs for several international clients.

The aim beyond 2030 is to install the RMI standard in the 1,300 MW range of French nuclear reactors via KAEFER’s steam generator replacement contracts. For us, it’s not just about products. It’s about safety and efficiency.

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