The PAA in an international joint regulatory review of a new reactor technology
19.01.2026
The National Atomic Energy Agency is beginning its participation in the international Joint Early Review (JER) of the LDR-50 reactor design. This technology is being developed by the Finnish company Steady Energy. The process is being coordinated by the Finnish nuclear regulatory authority - STUK.
The aim of the recently launched LDR-50 international regulatory review, involving, among others, the PAA, is to gain experience in the field of new nuclear technologies. Another important aspect is the development of practical models of cooperation between nuclear regulators from different countries at an early stage of a new reactor technology development. An important element of the initiative is to examine the extent to which the safety analysis carried out by the nuclear regulatory authority in one country can provide valuable support for safety analyses carried out by regulators in other countries, while maintaining full autonomy of national regulatory competence. These activities are part of broader international efforts to harmonize and standardize the regulatory approach to new nuclear technologies.
In addition to the PAA, nuclear regulatory authorities from Sweden (SSM), the Czech Republic (SÚJB), and Ukraine (SNRIU), as well as technical support organizations supporting SÚJB and SNRIU, are participating in the review of the LDR-50 reactor. As part of the review, experts will conduct a preliminary analysis of key design assumptions of the LDR-50 reactor, such as the design basis and safety objectives, the means of ensuring safety functions, the approach to defence in depth, and protection against internal and external hazards. Solutions important from the point of view of operation and emergency preparedness will also be verified.
The first technical meeting within the framework of this project took place in December 2025. The joint review is expected to last until May 2026, and its results will be summarized in a final report. The participation of the PAA in this process provides an opportunity not only to deepen international cooperation in the field of nuclear safety, but also to familiarize itself with the new technological solutions of the LDR-50 reactor at an early stage.
The Finnish nuclear regulatory authority has so far carried out a conceptual assessment of the LDR-50 reactor, as required by the new Finnish Nuclear Energy Act. This assessment is a preliminary step in the licensing process.