The Swedish Radiation Safety Authority (SSM – Strålsäkerhetsmyndigheten), has assessed a report by Forsmarks Kraftgrupp following a systematic overall assessment of how the requirements for safety and radiation protection are met for unit 3 of the Forsmark NPP. SSM concluded that there are no obstacles to continued operation of unit 3 until the next overall assessment in 2033.
In February 2024, Forsmarks Kraftgrupp (FKA) submitted an overall assessment for the Forsmark 3 reactor. Forsmark has identified development areas within, for example, competence and staffing as well as operation and maintenance of ageing systems, structures and components.
Since the last time the authority reviewed an overall assessment for an operating NPP, new regulations have entered into force, which were used in the review. The new requirements mean, among other things, that ten specific areas must be re-evaluated to identify strengths, weaknesses and needs for improvement. This is the first time a licensee has made an overall assessment based on the new requirements and the first time the Radiation Safety Authority has carried out an examination against these requirements.
Since Forsmark 3 has passed the 40-year lifespan for which the plant was originally designed, FKA has updated the analyses carried out to show that the reactor’s ageing components are acceptable for continued operation. SSM concluded that conditions to meet the requirements for the construction even after 40 years of operation had been met
Some shortcomings were also noted, for example FKA had not taken into account the interaction between thermal ageing and neutron irradiation, partly for cast stainless steel and partly for stainless welding goods.
“Our review of the analyses of the time-limiting ageing mechanisms shows that these essentially meet the design requirements, said Lisa Ranlöf acting head of department at SSM. “The deficiencies that we have identified are about occasional minor deficiencies or accounting deficiencies in individual analyses and are judged to have little significance for radiation safety.”
