Oskarshamn 3 completes IAEA review of long-term operation

A Safety Aspects of Long-Term Operation (SALTO) peer review is a comprehensive safety review addressing strategy and key elements for the safe LTO of nuclear power plants. SALTO missions complement IAEA Operational Safety Review Team (OSART) missions which are designed as a review of programmes and activities essential to operational safety. SALTO peer reviews can be carried out at any time during the lifetime of a nuclear power plant, though according to the IAEA the most suitable time lies within the last 10 years of the plant's originally foreseen operating period. SALTO and OSART reviews are carried out at the request of the IAEA Member State in which the review is to take place.

A Pre-SALTO review mission was requested by the Oskarshamn plant's operator, OKG AB. Unit 3 of the plant - a 1400 MWe (net) boiling water reactor - entered commercial operation in 1985. OKG is preparing to extend its operating lifetime to 60 years.

A nine-member team - comprising experts from Argentina, Armenia, Brazil, Canada, France and the UK and two IAEA staff member - has now completed a ten-day mission to Oskarshamn.

"The team observed that OKG is implementing preparations for safe LTO in a timely manner and the staff at the plant are professional, open and receptive to suggestions for improvement," said team leader and IAEA Nuclear Safety Officer Martin Marchena. "Some ageing management and LTO activities already meet IAEA safety standards. We encourage the plant to address the review findings and implement all remaining activities for safe LTO as planned."

The team identified good practices and good performances that will be shared with the nuclear industry globally, including: the plant has developed and fully implemented a comprehensive system for the management of spare parts' obsolescence; the plant has developed and implemented performance monitoring of the cooling circuits for fouling and flow resistance; and the plant has developed and implemented a machine learning software to monitor turbine performance.

The team also provided recommendations to further enhance the preparations for LTO safety: the plant should ensure adequate resource planning to support the LTO programme; the plant should fully define the organisational arrangements for LTO; and the plant should implement an appropriate knowledge management process.

"We appreciate the IAEA's support to our plant in ageing management and preparation for safe LTO," said OKG Managing Director Johan Lundberg. "It's very important for us to get an external view of our business. The competencies and experience of the IAEA team enable it to effectively identify our areas for improvement. The results of this mission will help us to improve our activities for safe LTO and to further align them with IAEA safety standards."

The team provided a draft report to the plant management and to the Swedish Radiation Safety Authority (SSM), the country's nuclear regulatory authority, at the end of the mission. The plant management and SSM will have an opportunity to make factual comments on the draft. A final report will be submitted to the plant management, SSM and the Swedish government within three months.