An International Atomic Energy Agency (IAEA) team of experts completed a review of long term operational safety at the Ascó Nuclear Power Plant (NPP) in Spain.
The Safety Aspects of Long Term Operation (SALTO) follow-up review mission was requested by the plant's operator, Asociación Nuclear Ascó-Vandellós II (ANAV). The mission reviewed Ascó NPP's response to recommendations and suggestions made during an IAEA SALTO mission in 2021.
The Ascó nuclear power plant is one of Spain's five operational nuclear power plants, where seven reactors produce 20 per cent of the country's electricity. Located in the north-east of Spain, Ascó has two pressurized-water reactor units with an installed power of approximately 1030 megawatts electric (MW(e)) each. Unit 1 went into commercial operation in 1984, and Unit 2 in 1986. The units are currently authorized to operate until 2030 for Unit 1 and 2031 for Unit 2.
During the 5-8 September mission, the SALTO team focused on aspects essential to the safe Long Term Operation (LTO) of both units. The team reviewed implementation of recommendations made during the July 2021 SALTO review mission which had built upon an initial Pre-SALTO mission in 2019. SALTO reviews are based on IAEA safety standards.
"Staff at the plant are addressing the SALTO team's recommendations and suggestions for improvement," said team leader and IAEA Nuclear Safety Officer Martin Marchena. "Basing its efforts on recommendations made by the SALTO team in 2021, the plant has made significant improvements in the area of ageing management. The SALTO team encourages the plant management to address the remaining findings from the 2021 mission and implement all activities for safe LTO."
The review team - comprising four experts from the Czech Republic, the Netherlands, and Sweden, as well as two IAEA staff members - said the plant had:
- Defined and implemented an appropriate scope setting methodology to identify the components and structures to be managed for a safe LTO.
- Implemented an advanced digitalization process to ensure easy retrievability, traceability and long-term preservation of ANAV's documents.
- Completed full demonstration of effective ageing management in the Ageing Management Review of passive and also of active mechanical components.
The team noted that further work is necessary by the plant to ensure that:
- A comprehensive programme to confirm the resistance of electrical components to harsh conditions, a so-called equipment qualification programme, is fully implemented.
- A comprehensive strategy for ageing management of structural elements of electrical cabinets and panels is in place.
The plant management expressed a determination to address the remaining areas and to continue cooperating with the IAEA on LTO.
"For us this is the last step of the IAEA's supporting service to ensure safe operation of our reactors in the LTO period. The IAEA SALTO missions, and technical cooperation helped to improve our focus on safe operation. We have worked together with the IAEA for the past 5 years carrying out 3 missions and several technical discussions. We appreciate the IAEA's support of our plant in managing ageing and preparation for safe LTO, and we will continue to improve our processes to further comply with IAEA safety standards," said, Ascó NPP manager.
The team provided a draft report to ANAV and to the Nuclear Safety Council (CSN), Spain's nuclear regulatory authority, at the end of the mission. ANAV and CSN will have an opportunity to make factual comments on the draft. A final report will be submitted to ANAV, CSN and the Spanish Government within three months.
Background
General information about SALTO missions can be found on the IAEA Website. A SALTO peer review is a comprehensive safety review addressing strategy and key elements for the safe long term operation of nuclear power plants. They complement OSART missions, which are designed as a review of programmes and activities essential to operational safety. Neither SALTO nor OSART reviews are regulatory inspections, nor are they design reviews or substitutes for an exhaustive assessment of a plant's overall safety status.
LTO of nuclear power plants is defined as operation beyond an established time frame determined by the license term, the original plant design, relevant standards, or national regulations. As stated in IAEA safety standards, to maintain a plant's fitness for service, consideration should be given to life limiting processes and features of systems, structures, and components (SSC), as well as to reasonably practicable safety upgrades to enhance the safety of the plant to a level approaching that of modern plants.
