The first French nuclear reactor at Marcoule was commissioned back in 1955. Today, with 19 power plants and 58 working reactors, nuclear energy occupies a very important place in the national economy. These installations provide 75% of the electricity produced in the country. The government is planning to close several reactors once the European Pressurised Reactor (EPR) is commissioned in Flamanville in order to reduce the amount of nuclear power in France by 50% by 2035.

AUSY has expertise in atomic engineering, safety and nuclear materials to meet the four main challenges (see below):

  • maintaining and extending the lifespan of current nuclear power plants
  • guaranteeing the safety and security of existing nuclear installations (safety of the fuel cycle and reactor, site protection, etc.)
  • designing new PWR reactors (third-generation nuclear pressurised water reactors in order to improve nuclear safety and protect workers from ionising radiation) in French and overseas markets
  • preparing to dismantle working nuclear installations


Extending the lifespan of working plants

Thanks to their expertise in materials and equipment under nuclear pressure, AUSY teams are able to help companies implement the new post-Fukushima regulations on their facilities. Since 1999, we have been consolidating feedback on the manufacturing control of nuclear equipment, as well as setting up a dedicated organisation to enable us to check a large number of boiler-making, forged and moulded equipment (e.g. reviews of end-of-manufacturing reports, compliance with standards during the testing phases).

In recent years, to better protect people and the environment, France has tightened up regulations around its nuclear power plants even further. By confining radioactive elements or cooling the nuclear reactor’s core, equipment under nuclear pressure plays a key role in the operation of a power plant. Therefore, this equipment is subject to specific regulations governing its entire life cycle. All suppliers of equipment under nuclear pressure must comply with these new regulations. They must be able to prove to the regulatory inspection bodies that their equipment meets these new standards. AUSY supports suppliers by helping them upgrade their equipment and the associated technical documentation. AUSY also has the necessary organisational wherewithal to ensure good levels of collaboration with the various inspection bodies.


Safety and security of the installations

Basic nuclear facilities and individual facilities are subject to various risks linked to different types of radioelements, procedures and reagents. These risks, whether external or internal, can cause incidents and accidents. Given the diversity of these risks and their origins, it is necessary that the adopted safety approach is in line with the reality and level of importance.

The approach adopted for the design and safety review of facilities must evolve taking into account a prudent deterministic approach This approach involves studying the robustness of the system’s design i.e. looking at plausible defects and their consequences. It is based on the principle of in-depth defence i.e. the implementation of successive and sufficiently independent lines of defence aimed at preventing, monitoring and, where appropriate, limiting the consequences of incidents and/or accidents that may occur at a facility

AUSY is a leading French engineering company in nuclear safety thanks to its long-standing partnerships with the main players in the nuclear industry.

The accident at Fukushima once again raised questions about nuclear safety. The ASN decided to change the safety rules for all French nuclear power plants whether operating nuclear power plants or the fuel cycle. Our nuclear safety engineers review the safety reports of facilities and carry out studies on internal (fire, etc.) or external (climatic) risks. Our teams work with a range of customers to help them protect nuclear sites (focusing on security and anti-intrusion aspects, malicious acts, UAV overflights, etc.) and prototyping physical solutions.


Designing new reactors

AUSY is also involved in EPR Flamanville 3, Hinkley Point C and EPR2 (in the preliminary studies phase) with two areas of expertise being called upon: general installation (installing equipment, pipes and civil engineering) and the reactor core (criticality, neutronics, thermohydraulics and core physics).

In order to control a nuclear reaction (as produced in a reactor), it is necessary to control, the number of neutrons released as a result of fission: the number of neutrons produced in the reactor core must equal the number of neutrons that disappear in the core. The reactor is said to be "critical".

AUSY engineers are entrusted with neutron calculation and criticality missions both for working reactors those under construction, and under normal, incidental or accidental conditions, as well as conducting studies on experimental reactors (moderated heavy water reactor, etc.), laboratories, transport, etc.

This work ranges from digital modelling the different geometries in 2D or 3D to post-processing and analysing the results including sensitivity studies. The created and updated data sets are transferred to the customer at the end of the project. In addition, our customers also rely on our teams to validate the calculation codes.

AUSY engineers - neutron physicists and criticality engineers - are all graduates from specialised atomic engineering universities or have a doctorate in the field. In addition, they have several years’ experience in this type of work having completed several missions for customers on behalf of AUSY.

In a nuclear reactor, studying the behaviour of fluids is just as important as studying the neutrons. The water circulating in the primary circuit slows down the neutrons and acts as a coolant to transmit the heat caused by fission to the secondary circuit; borated water from the safety injection circuit, in the event of a major breach in the primary circuit, injects borated water into the core to stem the chain reaction. These fluids have a strong impact on the evolution of the nuclear reaction in the core: Thermohydraulics and Neutronics are therefore closely linked.

For many years, AUSY has had a Design Office in Lyon specialising in accident scenarios on the primary circuits of nuclear reactors.


Getting ready for dismantling

AUSY also participates in the dismantling of nuclear production facilities (or the fuel cycle), thanks to its expertise in decommissioning safety. A team of experts is specialised in reviewing FEM/DAM (evolution of the modification file/authorisation dossier for the modification); these are sub-contractors’ construction/deconstruction safety evaluation files drawn up for the nuclear authorities. AUSY is mainly involved in the dismantling of basic nuclear facilities on sites in The Hague and Marcoule.


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