[Decoding] Civaux: Five Points to Understand the Partnership between EDF and Defence

EDF disclosed on Monday, March 18th, that it had been commissioned by the State to conduct an irradiation service at the Civaux nuclear facility, supporting the CEA for Defence purposes. The power supplier affirmed this request will not affect the Civaux plant’s operations or its primary objective of low-carbon electricity generation.

Defence Minister Sébastien Lecronu visited the Civaux site (Vienne) on March 18th. The visit aimed to brief the facility’s workforce on the initiative to “introduce a material irradiation service at the site. The plan involves harnessing the power of Civaux’s two reactors to irradiate specific lithium-containing materials within the reactors’ cores, alongside uninterrupted electricity generation. Post-irradiation, these materials will be moved to a CEA facility to generate tritium, a scarce gas vital for deterrent weaponry,” the ministry’s press release stated. It further highlighted that “this cooperation has been under review since the 1990s.”

From its side, EDF stated in a press release that “The intended use of EDF’s production fleet nuclear reactors, including those at Civaux, is to deliver controllable, decarbonized electricity in support of the French energy transition. This ancillary activity will complement the principal electricity production mission.” Moreover, the company reiterated that the two reactors at Civaux are regulated under civilian nuclear facilities standards. A formal agreement will be established between the State, the CEA, and EDF, delineating the scope of activities, respective rights, and responsibilities, all within EDF’s governance framework.

1 – Tritium is Not Fissile

Tritium, a hydrogen isotope with an atomic mass of 3, consists of 1 proton and 2 neutrons in its nucleus. It is non-fissile and is not listed among the “fissile materials” by the Non-Proliferation Treaty (NPT), nor is it subject to International Atomic Energy Agency (IAEA) oversight. However, it is radioactive, decaying into helium-3 (3He) over a relatively short half-life of 12.3 years.

Tritium plays a pivotal role in both military and civil nuclear fusion. In fusion reactions, tritium and deuterium nuclei collide and fuse, generating helium, neutrons, and substantial energy.

To produce its required tritium, the Defence has its mechanisms. Following the decommissioning of some of these, namely the Célestin reactors at the CEA Marcoule site in 2009, it opted to leverage a civilian power plant for redundancy assurance.

2 – Lithium Production

The collaboration between EDF and Defence entails setting up a lithium-containing material irradiation service. Lithium-6, constituting 7.5% of natural lithium, absorbs neutrons to yield helium and tritium nuclei.

Thus, lithium clusters will be inserted into the core during refueling operations, subsequently removed to a pool in the next cycle. This civil reactor material irradiation technique is also employed in other sectors, like medical for producing radioactive Cobalt 60 from stable Cobalt 59. An agreement was also reached between EDF and Westinghouse in 2021 for this purpose. Selecting Civaux, the fleet’s newest plant (activated in 1997 and 1999), ensures long-term service feasibility.

3 – No Secret Defence Activities at Civaux

EDF’s role is limited to providing the irradiation service without engaging in tritium production. The plant will not conduct any Secret Defence-classified operations. Post-irradiation, lithium-laden elements will be dispatched to a CEA (Directorate of Military Applications) facility for tritium generation. Thus, the operation will not emit tritium into the environment or, as per the ongoing specification evaluation, affect production.

Being a civilian installation, this supplementary activity adheres to the prevailing safety and environmental protection regulations. Supervised by the Nuclear Safety Authority (ASN) and adhering to transparency standards, Defence Minister Sébastien Lecornu’s March 18th visit facilitated staff and Local Information Commission (CLI) engagements to field their queries.

4 – Unrelated to the Ukrainian Situation

Heloise Fayet, an Ifri researcher, notes that tritium production revitalization has been contemplated for years, independent of geopolitical dynamics: “It doesn’t convey a typical strategic signal.” The announcement is actually associated with achieving a new project milestone. The modification permission application necessary for this initiative is pending Nuclear Safety Authority (ASN) evaluation. Given the secretive nature of preceding efforts, the project’s increasing personnel and institutional engagement necessitates public disclosure.

5 – Work to Continue for Years

An agreement between the State, the CEA, and EDF must be signed setting the scope of activities, the rights and obligations of each party in compliance with EDF’s governance rules. It should be noted that testing and ramping up will likely take several years.■ 

By Valérie Faudon (Sfen)
Photo: Civaux plant (Vienne) – ©HuguetGilles/AFP