France’s Authority for Nuclear Safety & Radiation Protection (ASNR – L’Autorité de Sûreté Nucléaire et de Radioprotection) has released the results of Phase 2 of a joint early review of the Nuward small modular reactor (SMR) design.
The review was conducted jointly with Dutch nuclear regulator ANVS (De Autoriteit Nucleaire Veiligheid en Stralingsbescherming), Poland’s State Atomic Energy Agency (PPA – Państwowej Agencji Atomistyki), Swedish Radiation Safety Authority (SSM – Strålsäkerhetsmyndigheten), the Finnish Radiation & Nuclear Safety Authority (STUK – Säteilyturvakeskus), and the Czech State Office for Nuclear Safety (SÚJB – Státní úřad pro jadernou bezpečnost).
The Nuward project was a joint effort launched in September 2019 by France’s Atomic Energy Commission (CEA – Commissariat à l’énergie Atomique et aux énergies Alternatives), EDF, Naval Group and TechnicAtome. The Nuward design comprises a 340 MWe SMR plant with two 170 MWe pressurised water reactors (PWRs).
In January, EDF’s Nuward subsidiary relaunched development of the SMR after announcing plans in 2024 to optimise the reactor design. According to Nuward’s original SMR roadmap, detailed design and formal application for a new nuclear facility was scheduled to begin in 2026 with first concrete in France planned for 2030. Construction of that first unit was expected to take three years. However, in July 2024 EDF said it planned to optimise the Nuward design focusing on existing and proven technologies to ensure project deadlines and budgets could be met. EDF then withdrew Nuward from Great British Nuclear’s SMR selection contest.
In June 2022, EDF had announced that Nuward would be the case study for a European early joint regulatory review led by the French Safety Authority (ASN – now ASNR) with the participation of SUJB and STUK. EDF said it was fostering European cooperation and supporting the acceleration of international SMR licensing, creating momentum towards harmonisation of SMR regulations.
This initial review covered general safety objectives; the list of design basis conditions and design extension conditions; the use of passive cooling systems; the development plan for computer codes; the integration of two reactor units in a single facility; and the Probabilistic Safety Assessment approach. After this first phase of the review was completed in September 2023, Phase 2 began joined by PAA, SSM and ANVS. This assessment covered additional areas.
ASNR said the second phase built upon the successes of the pilot phase – particularly the work of reviewing a specific project and establishing a direct dialogue with the designer – while evolving to address new challenges, notably broader participation. “During this new phase, the scope of the assessment was extended to new technical topics, particularly regarding containment barriers, the evaluation of radiological consequences of an accident, and the architecture of the electrical and instrumentation and control (I&C) systems.”
The final report of this multilateral cooperation presents the programme carried out, the working methodology implemented, as well as the main lessons learned. Discussions are currently underway to continue the joint review focusing on new topics.
“This second phase confirmed the benefits of such an initiative in enhancing regulators’ effectiveness and responsiveness in licensing new reactors,” the final report noted. It said the results confirmed that the joint regulatory approach “increases the efficiency of information exchange, accelerates the identification of technical differences and allows to address key safety issues earlier than would be possible under separate national licensing processes”. The Joint Early Review “strengthens the readiness of individual states for future assessment of SMR proposals and at the same time creates space for further harmonisation of procedures in Europe”.
Eero Virtanen, Principal Advisor for STUK, said: “The project has taught everyone involved how safety assessments can be carried out together in practice,” said. “During the project, we also saw how different interpretations of safety requirements can affect the final design of the nuclear reactor.”
