An International Atomic Energy Agency (IAEA) Pre-Operational Safety Review Team (OSART) team said plant operator Slovenske Elektrarne (SE) had strengthened operational safety at unit 3 of Slovakia’s Mochovce NPP ahead of commercial operation.

The team said the plant management had made "significant progress" in addressing the findings of a previous IAEA review in 2019. At the same time, the team encouraged the operator to improve the plant’s safety performance further.

The five day follow-up mission was conducted at the request of the Nuclear Regulatory Authority of the Slovak Republic to evaluate progress made in addressing the findings of the Pre-OSART review two years ago.

Mochovce NPP comprises two 470MWe VVER pressurised water reactors (PWR) units that have been operational since 1998 and 1999. Unit 2 was upgraded to 501MWe in 2020. Unit 3, a 471MWe reactor, started commissioning in 2018. Unit 4 is under construction. Slovakia’s four operational nuclear reactors at Mochovce and Bohunice produce 53.1% of its electricity.

“Recommendations and suggestions that come out of IAEA safety reviews are essential for continuous improvement of the safety performance at NPPs,” said Lydie Evrard, Deputy Director General of the IAEA and Head of the Department of Nuclear Safety and Security. The IAEA OSART team was led by Fuming Jiang, Head of the Operational Safety Section at the IAEA. The five-member team comprised experts from Canada, Germany, and the United Kingdom and two IAEA officials.

“The plant has implemented many actions to address the findings of the 2019 mission. We are pleased to observe significant improvements,” said Jiang. “The team encourages the plant to complete the remaining planned actions to improve its safety performance further”. The team observed that several findings from the 2019 review were fully addressed:

  • The plant has improved unit 3 operator training, for example, by using an upgraded simulator and through strengthened formal evaluations.
  • The plant has enhanced its practice in the labelling and safe use of chemical substances, for example, through additional training and regular checks.
  • The plant has improved the maintenance of its emergency response facilities and equipment.

The team noted that further efforts are required to fully implement some actions drawn up after the 2019 mission:

  • The plant should continue to improve the promotion of high standards in staff behaviours and plant conditions to ensure personnel safety.
  • The plant should continue to improve its maintenance work practices.
  • The plant should continue to enhance the coordination and internal communication for planning and execution of commissioning activities.

“Continuous improvement, openness and transparency were the reasons why we invited this mission. I am very pleased that the IAEA experts noted significant positive progress compared to the Pre-OSART mission in 2019” said Branislav Strýček, SE General Director. “Once again, we received very valuable feedback from them that will help us in our continuous improvement. We will implement all the suggestions and recommendations, and I am confident that, also thanks to them, we will achieve our ambitious safety performance targets.”

The team provided a draft report of the mission to the plant management on the final day. The plant management and the Nuclear Regulatory Authority of the Slovak Republic, which is responsible for nuclear safety oversight in the country, will have the opportunity to make factual comments on the draft. The IAEA will review them and will submit the final report within three months.