IAEA concludes long term operational safety review

The Pre-SALTO (Safety Aspects of Long Term Operation) follow up review mission was conducted at the request of the Government of Argentina from 23 until 26 November. It focused on aspects essential to the safe Long Term Operation (LTO) of Unit 1, a pressurised heavy water reactor with a net electrical output of 362 megawatts electric MW(e). It went into commercial operation in 1974 and its current operating licence expires in 2024. Unit 2 (745 MW) of Atucha NPP started its commercial operation in May 2016 and was not part of the review.

Atucha NPP, located 100 km north-west of Buenos Aires, is operated by Nucleoelectrica Argentina S.A (NA-SA). The operator is currently preparing to submit a license renewal application to the Argentinian Nuclear Regulatory Authority (ARN) to extend the operating lifetime of Unit 1 by 20 years.  

The SALTO team comprising three experts from France, Pakistan, Sweden, and one IAEA staff member reviewed the improvements in preparedness, organisation and programmes related to LTO against the IAEA safety standards, following up the suggestions by the previous Pre-SALTO reviews in 2016, and 2018.

“The team observed that NA-SA followed the recommendations of the Pre-SALTO mission in 2018 to make significant steps in improving ageing management and preparation for safe LTO,” said Gabor Petofi, SALTO Team Leader and IAEA Senior Nuclear Safety Officer. “The team encourages the plant management to complete the already commenced tasks and address the remaining findings from the 2018 mission and implement all activities for a safe LTO.”

The team concluded the plant had:

• Completed the assessment of electrical, instrumentation and control systems and components for LTO.
• Completed a comprehensive condition assessment of the plant structures, systems and components.
• Completed the identification of all components that need ageing assessment for LTO.

The team noted that further work is necessary by the plant to:

• Improve organisational arrangements and processes to ensure timely implementation of all activities required for safe LTO.
• Fully implement the proactive technological obsolescence programme.
• Develop a long term human resource plan for the entire LTO period.
• The plant management expressed a determination to address the areas identified for further improvement and to continue cooperation with the IAEA.

“With the support of the IAEA, we can further improve our preparedness for safe LTO and implement ageing management effectively,” said Atucha Site Manager Alejandro Sanda. “The results of this follow up mission show what remains to be done in order to fully align our LTO arrangements with the IAEA safety standards.”

The team provided a draft report to the plant management and ARN at the end of the mission. The plant management and ARN will have an opportunity to make factual comments on the draft. A final report will be submitted to the plant management, ARN and the Argentinian 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 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.

The IAEA Safety Standards provide a robust framework of fundamental principles, requirements, and guidance to ensure safety. They reflect an international consensus and serve as a global reference for protecting people and the environment from the harmful effects of ionising radiation.