The use of nuclear energy carried out safely — the regulatory reform is progressing
Based on STUK’s supervision, the use of nuclear energy did not pose a risk to the population, society, the environment or future generations in 2024. The reform of the nuclear safety regulation proceeded as planned. STUK developed and expanded its competencies related to small-scale nuclear power plants in various ways. The processing of the operating permit application material of the spent nuclear fuel encapsulation and final disposal plant and the preparation of the safety assessment continued.
Reform of the nuclear safety regulation is progressing
STUK is reforming the nuclear safety regulations as part of the overall reform of the Nuclear Energy Act led by the Ministry of Economic Affairs and Employment. The nuclear safety regulations refer to the safety regulations issued by STUK pursuant to the Nuclear Energy Act. The reform includes a clear distinction between recommendatory guidelines and binding requirements. The regulations are applied throughout the life cycle of nuclear facilities, from planning to decommissioning and other uses of nuclear energy (incl. the transportation and supervision of nuclear material). The safety requirements apply to different nuclear plants, the plant location, the organisation that operates the nuclear plant and various different functions. The aim of the reform is to create modern, risk-aware legislation that enables new operating methods — without compromising the level of safety.
"Compared to the current YVL guidelines, the total number of requirements will be reduced to about one-fifth. The aim is to enable different, even new, technical solutions and organisational operating methods in the future, with more goal-oriented requirements. Put differently, regulation should not unnecessarily limit operations. Now is a good time to reconsider the basis and proportionality of regulation. At the same time, we must be careful to preserve the basics of nuclear safety along with models that have been found to work well," says Jussi Heinonen, Director responsible for the regulatory reform.
STUK prepared the first drafts of almost all new regulations during 2024. The drafts are primarily intended for STUK’s internal preparatory process, but key stakeholders were also given the opportunity to comment already at this stage. The draft regulations are updated based on the first round of statements and finalised in terms of content and presentation. The next version will be sent to the electronic statement service (lausuntopalvelu.fi) for an external statement round during 2025. The intention is to submit the new Nuclear Energy Act to Parliament for consideration in late 2025. STUK’s new regulations will enter into force at the same time as the Act at the earliest.
Reform of the Nuclear Energy Act and the regulations is one of STUK’s most important projects at the moment. In total, STUK spent approximately 13 man-years on the reform work last year. Approximately 40 people actively participated in supporting the Ministry of Economic Affairs and Employment and preparing the regulations.
Updated expertise for new types of nuclear plants
Last year, STUK received additional funding from the Government to develop the licensing of small modular reactors (SMR), enabling it to participate in a wide range of activities promoting this goal. During the year, STUK developed and expanded its expertise related to small-scale nuclear power plants in many ways, such as studying different plant concepts and their safety and licensing questions. The familiarisation and competence development are in preparation for carrying out safety assessment of potential new nuclear power plants as well as for use in international co-operation. So far, STUK has no applications regarding small modular reactors under processing.
In 2024, STUK organised internal information events related to small modular reactors for its entire personnel as well as separate more technical training courses targeted at the nuclear facility supervision departments to expand SMR competence and understanding.
On the international level, STUK participated in the activities of international working groups discussing SMR technologies and developing supervisory principles and operational models. STUK also participated as an external observer in the monitoring of the ongoing Generic Design Assessment (GDA) of the Rolls Royce SMR in the UK. The authorities present as observers participate in the GDA meetings between Rolls Royce and the UK authorities without intervening in the discussion between the parties.
STUK communicated actively with Finnish operators, such as current nuclear power companies and cities interested in the utilisation of nuclear energy, nuclear power plant suppliers and parties new to the industry. Discussion were held regarding the prerequisites and expectations for the operations, technology and location of plants. This work constitutes early-stage official guidance.
In terms of paid supervision work, STUK conducted preliminary assessments for Fortum Power and Heat Oy on separate technical issues concerning several nuclear power plant concepts and initiated a concept assessment of the LDR-50 SMR plant requested by Steady Energy Oy. In addition, STUK participated in the preliminary assessment of the French NUWARD plant concept together with the French and Czech nuclear safety authorities.
STUK promoted knowledge and understanding by the public, the media and other stakeholders about the placement and operation of nuclear power plants by participating in various public events (Kuntamarkkinat, municipalities’ own events) and by holding a media event in January 2024 about the regulation change concerning the precautionary action zone and emergency planning zone of nuclear power plants.
No major surprises in the monitoring of plants in operation
No serious incidents affecting nuclear and radiation safety occurred in the currently operating nuclear power plants during 2024. Every year, there are some incidents that nuclear power plants report to STUK, based on which the companies take corrective measures and develop their operations to avoid similar incidents in the future. Typically, the safety significance of such events is minor (INES class is typically 0 or 1) and they have no effect on the radiation exposure of employees or the environment. The incidents are described in more detail in the "Safety supervision of the use of nuclear energy" annual report for 2024, which was published in March.
STUK processed the conceptual plan for projects of a potential power uprate of Olkiluoto 1 and 2, the related safety assessments and the reports and analyses provided as appendices. A decision on the plan was made in October 2024. Based on STUK’s processing, the materials TVO submitted for the conceptual plan were comprehensive and they describe matters that are essential for the safety of the project in the manner required by the nuclear and radiation safety regulations. In its inspection, STUK drew attention to certain matters in relation to which TVO must either supplement the conceptual plan or which they must further clarify in a possible operating licence application. Based on its processing, STUK did not identify any issues that would constitute a fundamental obstacle to implementing the power uprate.
The supervision of the first annual maintenance of the Olkiluoto 3 unit was carried out as planned. Since this was the first annual maintenance of the unit, STUK specifically monitored TVO's preparations for the annual maintenance and ensured that the maintenance was carried out safely. STUK also examined the reports submitted to it by TVO and supervised the inspections, testing and maintenance work carried out on site.
In the annual maintenance of OL1 and 2 plants, TVO mainly carried out ordinary maintenance and inspection tasks and replaced spent nuclear fuel with fresh fuel. According to STUK's observations, the annual maintenance was carried out safely.
The progress of changes related to extending the service life of the Loviisa 1 and 2 plant units and other measures related to ageing management was supervised as planned. The annual maintenance of the Loviisa nuclear power plant carried out between August and October 2024 also went smoothly and in accordance with regulations. Approximately 30 experts from the Radiation and Nuclear Safety Authority (STUK) supervised the annual maintenance.
Evaluation of the operating licence of the final disposal facility continued
In 2024, STUK continued to process the operating licence application materials for the encapsulation and final disposal plant for spent nuclear fuel and to preparing the related safety assessment. At the end of 2021, Posiva submitted to the Ministry of Economic Affairs and Employment of Finland an application for an operating licence for an above-ground encapsulation plant for spent nuclear fuel and final disposal facilities to be built into bedrock. Originally, the Ministry of Economic Affairs and Employment expected a statement from STUK by the end of 2023, if possible. However, the deadline has been postponed twice, most recently in the autumn of 2024.
Overall, STUK has progressed well in processing the operating licence application. The extent of the material and, on the other hand, needed updates have delayed the process. In the last third of 2024, STUK received several updated licence application materials from Posiva for review. STUK’s preparation of the safety assessment progresses as the material is established to be in compliance with regulations.
If everything goes well, STUK can complete the assessment of the operating licence for a Finnish final disposal facility for spent nuclear fuel and submit its statement to the Ministry of Economic Affairs and Employment well before the end of 2025.
Safeguards of nuclear materials are one of the prerequisites for the peaceful use of nuclear energy. STUK carried out nuclear material safeguards in accordance with the national monitoring plan. Based on the results of STUK’s supervision and inspections, the operators fulfilled their obligations for the safeguarding of nuclear material in 2024.
In June 2024, the Radiation and Nuclear Safety Authority decided that Terrafame Ltd's uranium recovery plant in Talvivaara, Sotkamo, is ready for commissioning. STUK confirmed that the safety requirements for the use of the plant are met as long as the documented procedures are followed. The uranium recovery plant is under STUK’s supervision, but the substances handled and produced at the plant are not very radioactive. However, international agreements and Finnish legislation require that all uranium products are closely monitored in Finland.
Nuclear safety oversight : Annual report 2024 (Julkari.fi, only in Finnish)