Regulatory oversight of nuclear safety in Finland : Annual report 2023

Abstract

Introduction This report is the Radiation and Nuclear Safety Authority’s (STUK) account to the Ministry of Economic Affairs and Employment (MEAE) of regulatory oversight in the field of nuclear energy, to be supplied once a year under Section 121 of the Nuclear Energy Decree (161/1988). The report is also provided to the Ministry of Social Affairs and Health, the Ministry of the Environment, the Finnish Environment Institute and the environmental authorities of the municipalities where the relevant nuclear facilities are located. The report is an overview of the regulatory oversight of nuclear safety carried out by STUK, and of the results of this oversight, in 2023. The nuclear safety oversight by STUK discussed in this report covers the essential oversight data that relate to design, construction, commissioning preparation, operation and decommissioning planning with regard to nuclear facilities. Additionally, the report covers the equivalent data on other use of nuclear energy, including nuclear waste management and nuclear materials. In addition to the actual oversight of safety, the report describes, among other topics, how the regulations that govern the use of nuclear energy were developed and implemented during the year, as well as discussing the main characteristics of the safety research programmes in Finland that deal with nuclear safety and nuclear waste management. As required by the Nuclear Energy Decree, the report is accompanied by a summary of the licences that STUK granted in 2023 under the Nuclear Energy Act. Based on the oversight undertaken by STUK, the use of nuclear energy in 2023 did not pose a risk to the population, society, the environment or future generations.

Management’s view The regulatory oversight of nuclear facilities and safety assessments carried out by STUK play a key role in society’s decision-making and the implementation of nuclear safety. The objective of the regulatory oversight of nuclear facilities is to ensure the safe use of nuclear energy in such a way that the operation of nuclear facilities or their possible accidents do not pose a danger to society and the environment. There were a great deal of familiar aspects to the Radiation and Nuclear Safety Authority’s oversight of nuclear energy use and the safety of nuclear waste management, but we were also faced with new things in some areas of oversight. We oversaw the safety of operating nuclear facilities and ensured that the waste management of nuclear power plants met the applicable safety requirements. We also oversaw nuclear safeguards according to the national oversight plan and supervised the first decommissioning of a nuclear facility in Finland – VTT’s FiR 1 research reactor. What were the things that particularly stuck in our minds from 2023? Certainly, one of the most significant events in the nuclear energy sector was Olkiluoto 3 becoming Finland’s fifth operating nuclear power plant unit in the spring. STUK oversaw the power tests of the plant unit’s commissioning phase and the first operating cycle. From the perspective of nuclear safety, the commissioning tests were successful overall, and no significant discrepancies were found in terms of operational safety. Another long-term project also progressed: the operating licence for the world’s first encapsulation and final disposal facility for spent nuclear fuel was processed and the preparation of the relevant safety assessment was continued in 2023. The process of reviewing the extensive documentation was not yet completed, but good progress has been made. At the same time, STUK has made sure that the Olkiluoto final disposal facility has been built safely and the commissioning and operational preparations adhere to the safety requirements. At the beginning of 2023, STUK’s statements and safety assessments were completed on the continued operation of the Loviisa nuclear power plant units until the end of 2050 and the continued operation of the final disposal facility for low- and intermediate-level waste until the end of 2090. In STUK’s assessment, Fortum has the required capabilities, procedures, competences and resources to continue safe operation. The final disposal facility for low- and intermediate-level waste in Olkiluoto was also assessed in 2023. According to STUK’s periodic safety assessment, the operation of the Olkiluoto final disposal facility can be safely continued in its current form. In addition to traditional nuclear safety oversight, year 2023 involved discussions around new kinds of small modular reactors with designers and other operators. The most significant of these were the regular meetings with Fortum on the study, which involves Fortum examining the preconditions for constructing new nuclear power in Finland and Sweden and exploring questions related to various reactor options, and the participation in the assessment of the French Nuward reactor with French and Czech nuclear safety authorities. We did not yet receive any applications or documents for processing with regard to small modular reactors in 2023, but we are looking forward to the coming years with great interest. The renewal of the nuclear safety regulations, which was initiated in STUK in 2022, was continued by working on the regulations and their justifications and drafting the regulatory structure. The aims of the renewal are to emphasise operator responsibility, to correctly dimension the requirements in terms of safety significance and to enable effective focusing of oversight based on risk significance. The aims are related to STUK’s efforts to develop oversight in accordance with its strategy. Renewing the nuclear safety regulations will be among the most important work efforts of our experts in the current decade.

Tapani Virolainen Director, Nuclear Reactor Regulation

Jaakko Leino Director, Nuclear Waste Regulation and Safeguards