Long-term safety of Ascó plant reviewed by IAEA

A SALTO peer review is a comprehensive safety review addressing strategy and key elements for the safe long-term operation (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, although according to the IAEA the most suitable time lies within the last ten years of the plant's originally foreseen operating period. SALTO and OSART reviews are carried out at the request of the IAEA member country in which the review is to take place.

The Ascó plant comprises two Westinghouse pressurised water reactor units with an installed capacity of about 1030 MWe each. Unit 1 entered commercial operation in 1984, with unit 2 following in 1986. Operator Asociación Nuclear Ascó-Vandellós II (ANAV) plans to extend the operation of both units beyond the initial 40-year lifetime. Unit 1 is currently authorised to operate until 2030, while unit 2 is licensed until 2031.

During a 5-8 September mission - requested by the plant's operator, Asociación Nuclear Ascó-Vandellós II (ANAV) - 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.

The review team - comprising four experts from the Czech Republic, the Netherlands and Sweden, as well as two IAEA staff members - concluded 12 of the 14 recommendations and suggestions made in 2021 have already been resolved by ANAV and work is being done with an appropriate progression for the complete implementation of the remaining two: a comprehensive programme to confirm the resistance of electrical components to harsh conditions (equipment qualification programme) and a comprehensive strategy for managing the aging of structural elements of electrical cabinets and panels.

The IAEA said 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," said Jorge Martínez Casado, director of the Ascó plant. "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 five years carrying out three 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."

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.