An International Atomic Energy Agency (IAEA) Pre-SALTO (Safety Aspects of Long Term Operation) team of experts on 31 October completed a review of long-term operational safety at unit 1 of Argentina's Atucha NPP. The 362MWe (gross) pressurised heavy water reactor began commercial operation in 1974. Nucleoelectrica Argentina SA (NA-SA), operator of the plant, is preparing to extend its operating period until 2024. The review mission was requested by NA-SA.The 11-member team reviewed the plant's preparedness, organisation and programmes related to long-term operation against IAEA safety standards. The team comprised nine experts from Belgium, Canada, Finland, Spain, Sweden, Switzerland and the UK, as well as two IAEA staff members.
IAEA said the plant has made progress in ageing management and preparedness for long-term operation (LTO) and noted that the plant's LTO project already addresses several topics recommended by IAEA safety standards, with some activities partially implemented and many others already begun.
The team identified several good performances:
- The plant has implemented short-term trending of preventative maintenance activities, allowing for information to be validated and short-term abnormalities to be identified.
- Condition assessment reports in the mechanical area are well developed with regards to both traceability and completeness.
- The plant has also revalidated time limited ageing analysis (TLAA) to confirm effective management of cumulative fatigue in certain areas.
The mission offered several recommendations for further enhancing LTO safety:
- The plant should improve LTO organisational arrangements and processes to ensure timely implementation of all activities to demonstrate preparedness for safe LTO.
- The plant should establish and consistently apply a clear and unambiguous scope setting methodology for LTO assessment.
- It should fully establish and implement a comprehensive equipment qualification programme.
A final report will be submitted to the plant, the Autoridad Regulatoria Nuclear (ARN) and the government within three months. The plant management said it was committed to implementing the recommendations and requested another SALTO mission in November 2020.
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 an NPP’s lifetime, but ideally within the last ten years of the plant's originally foreseen operating period.
In April, Argentina's nuclear regulator issued an amendment to the operating licence of Atucha I, which authorises the start of Stage A of the plant's long-term operation. ARN said this phase will include preparations for the plant's modernisation project, which would make its operation viable in the longer term, at Stage B. The new permit allows Atucha 1 to operate for five years of full power generation, or until 29 September 2024, the end date of the current periodic safety review, whichever occurs first.
Atucha NPP hosts two of Argentina's three operating pressurised heavy water reactor units - Atucha I and 2, and Embalse - with total generating capacity of 1627 MWe, providing about 10% of Argentina’s electricity. A prototype domestically designed and developed 25 MWe small pressurised water reactor - CAREM - is under construction at a site adjacent to the Atucha NPP.