IAEA assesses operational safety at Dutch reactor

A 12-member team comprising experts from Czech Republic, France, Japan, Hungary, Slovakia, Spain, Sweden, Switzerland, the UAE and the UK, as well as two IAEA officials, completed an 18-day Operational Safety Review Team (OSART) mission to Borssele on 9 February. The mission was carried out at the request of the Dutch government and aimed to evaluate progress in addressing the findings of an IAEA OSART mission that took place in 2017.

OSART missions aim to improve operational safety by objectively assessing safety performance using the IAEA's Safety Standards and proposing recommendations for improvement where appropriate. Follow up missions are standard components of the OSART programme and are typically conducted within two years of the initial mission.

During the review at Borssele, the team met with representatives from the plant's operator EPZ, as well as governmental and local community representatives, and officials from the Dutch Authority for Nuclear Safety and Radiation Protection (ANVS).

"Managers and employees of the Borssele NPP are very committed to further improving the operational safety and reliability of their plant," said team leader Yury Martynenko, Senior Nuclear Safety Officer at the IAEA.

"Throughout the review, the exchange of information between the OSART experts and plant personnel was very open, professional and productive. This allowed us to truly assess the effectiveness of operational safety to compare the plant's performance against IAEA Safety Standards."

The team found areas of good performance that can be shared with the nuclear industry globally, including the following: the plant has developed an easily applicable matrix to visualise ageing management activities to ensure effective ageing management; the plant's use of a unique risk-informed application that analyses risk benefits to categorise safety improvements is effective as a method to concentrate efforts in areas most beneficial to safety; and the plant implemented a passive reactor coolant pump (RCP) seals isolation valve to reduce the risk of RCP seal failure and subsequent primary coolant loss in station blackout situations.

A number of proposals for improvements in operational safety were offered by the team, including: the plant should enhance implementation of operator support systems to prevent the use of non-authorised operating documentation; plant radiation protection practices for contamination control, dose planning and control of radioactive sources should be enhanced to meet the requirements of the plant's radiation protection programme; and the plant should optimise its chemical practices to ensure the correct identification, labelling, storage and use of chemicals, as well as accurate results of chemical analyses.

"In recent years we put a lot of effort into continuously improving the way we operate our plant. I'm pleased to see that reflected in the results of this review," said EPZ CEO Carlo Wolters. "EPZ will also take the opportunity to proactively address the proposals for improvement from this review in the coming period."

ANVS said it will monitor EPZ's follow-up on the mission's recommendations. ANVS will also study the final report and compare it with its own findings to see if there are any other lessons to be learned. ANVS said it intends to ask the IAEA to visit the Borssele nuclear power plant again within two years in a so-called follow-up mission.

Nuclear power has a small role in the Dutch electricity supply, with the 485 MWe (net) Borssele pressurised water reactor providing about 3% of total generation. The plant has been in operation since 1973 and is scheduled to close in 2033.

In December 2022, the Dutch Council of Ministers designated the Borssele site as the preferred location for two new reactors. It also called for a feasibility study into extending the operation of the existing Borssele plant beyond 2033.