Atmea
| Company type | Joint venture |
|---|---|
| Industry | Nuclear power |
| Founded | 2006 |
| Headquarters | Paris , France |
| Parent | Mitsubishi Heavy Industries, EDF Group |
Atmea was a joint venture formed by Mitsubishi Heavy Industries (MHI) and EDF Group in 2006, with the purpose of developing, marketing, licensing, and selling the ATMEA1 reactor—a generation III+, medium-capacity pressurized water reactor (PWR). The company was based in Paris and ceased operations in 2019.
History
The establishment of Atmea originated from a memorandum of understanding signed between AREVA and MHI on 19 October 2006, with the joint venture’s name officially revealed on 3 September 2007. The European Commission gave its approval in October 2007, recognizing that AREVA and MHI served distinct geographic markets and that Atmea would not diminish their competitive positions.
Following the 2018 restructuring of the French nuclear sector under EDF, Atmea’s partnership was renewed. Initially created by AREVA NP and MHI to advance the ATMEA1 reactor, ownership transitioned to an equal partnership between EDF and MHI, while Framatome held a special share. This arrangement was designed to enhance the Franco-Japanese nuclear technology offering for nations focusing on low-carbon energy solutions.
The collaboration ended in 2019 after the French-Japanese ASTRID fast reactor initiative was also discontinued that year.
The ATMEA1 reactor
The ATMEA1 reactor was a generation III+ pressurized water reactor delivering around 1200 MWe, equipped with three coolant loops and a thermal output of 3,150 MWth. It provided roughly 10% improved thermal efficiency compared to earlier reactors, featured a 60-year operational lifespan, and supported load-following operation. Its fuel cycles varied between 12 and 24 months.
Its design incorporated technologies from AREVA’s EPR and MHI’s APWR models, including steam generators fitted with axial economizers and TT690 tubes, advanced accumulator systems, and heavy neutron reflector internals. Safety measures included three independent emergency core cooling systems and a core-melt retention mechanism.
Aimed at markets new to nuclear power seeking medium-sized reactors, the ATMEA1’s output of approximately 1200 MWe positioned it below Mitsubishi’s APWR (1700 MWe) and Areva’s European Pressurized Reactor (1600 MWe), providing a competitive solution for emerging nuclear programs.
Compliance
In 2013, the Canadian Nuclear Safety Commission (CNSC) determined that the ATMEA1 reactor design met Canadian regulatory standards for new nuclear facilities.
The French Nuclear Safety Authority (Autorité de sûreté nucléaire or ASN) validated in 2012 that the ATMEA1’s safety features and design complied with French regulatory requirements.
On 7 July 2008, the International Atomic Energy Agency (IAEA) completed a conceptual safety assessment of the ATMEA1, concluding it conformed with IAEA’s fundamental safety principles and essential design criteria.
Planned construction
On 3 May 2013, Turkish Prime Minister Recep Tayyip Erdoğan and Japanese Prime Minister Shinzo Abe signed an agreement valued at US$22 billion to construct the 4400 MWe Sinop Nuclear Power Plant in Turkey. The Turkish government approved the project in April 2015. Ownership was planned as a consortium including Japan's Mitsubishi Heavy Industries (MHI) and Itochu, alongside France's Areva and GDF Suez, collectively holding 51%, with Turkey's state power entity EUAS owning the remaining 49%. The facility was to house four ATMEA1 reactors, with construction expected to begin in 2017 and the first unit operational by 2023.
An Environmental Impact Assessment was submitted in 2018; however, location permits and construction licenses were still pending from the Turkey Atomic Energy Agency.
In April 2018, Nikkei reported Itochu’s withdrawal from the project; nonetheless, MHI and other investors proceeded with feasibility evaluations through mid-2018. By December of that year, remaining Japanese partners abandoned the initiative due to financing disagreements with Turkish authorities. Construction expenses had nearly doubled to approximately $44 billion following post-Fukushima safety enhancements and depreciation of the Turkish lira.