International Atomic Energy Agency (IAEA) experts at Ukraine's Zaporizhzhya Nuclear Power Plant (ZNPP) have not yet been given access to the reactor halls of units 1, 2 and 6, hindering their ability to monitor the nuclear safety and security situation at the plant, as well as the five concrete principles established at the United Nations Security Council, IAEA Director General Rafael Mariano Grossi said today.
Following a successful rotation of IAEA experts yesterday - the fifteenth team of experts to arrive at the plant since the IAEA Support and Assistance Mission to the ZNPP (ISAMZ) was established in September 2022 - the new team repeated the request for access to the reactor hall of unit 6.
The ZNPP did not give permission for that access today, stating that the reactor hall is "sealed". The ZNPP informed the team that it was not denying access and has instead proposed that the team access the area in about a week's time.
In December 2023, the ISAMZ team was refused access to the reactor hall of units 1, 2 and 6 which was the first time that the IAEA experts have not been granted timely access to a reactor hall that was in cold shutdown. Until then, all ISAMZ teams had been able to access the reactor hall of any unit in cold shutdown, without the plant making any reference to the status of containment as being "sealed".
"These restrictions on the experts' timely access to the ZNPP are impeding the IAEA's ability to assess the safety and security situation, including confirming the reported status of the reactor units, spent fuel ponds and associated safety equipment, independently and effectively," Director General Grossi said.
Also, since 18 October last year, ISAMZ teams have been unable to access parts of the turbine hall of each unit. Most recently, access was again restricted at the turbine halls of units 1 and 2 on Wednesday, 10 January.
"The nuclear safety and security situation remains very precarious, and I reiterate my request for unhindered access so that the IAEA can assess the Seven Pillars for nuclear safety and security and monitor adherence to the five concrete principles to help ensure nuclear safety and security at the ZNPP in order to prevent a nuclear accident and ensure the integrity of the plant," Director General Grossi added.
The new team of IAEA experts will observe the ongoing maintenance situation at the ZNPP. Following observation of deposits of boric acid on the valves, a pump and on the floors of several of the safety system rooms of unit 6 on 22 December, the IAEA team conducted a follow-up walkdown on 9 January to assess the status. Borated water is used in the primary coolant to help maintain nuclear safety functions. Although leaks may occur, prompt investigation, repair, and clean-up are crucial to prevent further damage and avoid any impact on safety.
During its walkdown, the team noted a significant reduction in boric acid deposits compared to the December 22 walkdown, with the leak also considerably diminished. However, some deposits persisted in three rooms of the unit 6 containment building, one at the same level and two showing significantly reduced levels.
The team was informed that the cause of the leak was due to micro-cracks in the boron tank due to ageing, and a blockage in the leak detection pipe. Whilst the blockage has been repaired, some smaller leaks persist as a result of the micro-cracks in the boron tank. The ZNPP stated that the leak rate is currently within technical specifications, and that the micro-cracks can be repaired after draining the tank, which will be addressed during scheduled maintenance. The IAEA team will continue to monitor the situation.
Additionally, this week the IAEA experts at the ZNPP accessed the pumping stations for units 3 and 4 and the main control rooms of units 1 to 6. All nine mobile diesel boilers installed at the plant were utilised during the past week to provide additional heating needs during winter.
As the winter weather gets colder, IAEA experts reported that the ambient temperature at the ZNPP has dropped as low as -10°C in the mornings. The team reported that this fall in temperature had no impact on the operation of the 11 wells providing cooling water for the sprinkler ponds used for reactor cooling and other nuclear safety and security functions. The flow level of water remained constant.
Five of the ZNPP's six reactors remain in cold shutdown, while unit 4 is in hot shutdown to produce steam and heat, including for the nearby town of Enerhodar, where most plant staff live.
The new ISAMZ team continues to pay close attention to the staffing situation at the plant, in particular the staff operating in the main control rooms and those responsible for maintenance of critical safety infrastructure and processes.
Today, the new team of experts conducted a walkdown of the site including the four new diesel boilers. They observed the new equipment and were informed that the installation has been completed and commissioning activities have commenced. These new diesel boilers are intended to generate steam to meet the ZNPP's needs.
In daily reminders of the physical proximity of the conflict to the ZNPP, the IAEA experts there continue to hear loud explosions at varying distances to the plant.
The IAEA teams at the Rivne, Khmelnitsky, South Ukraine nuclear power plants (NPPs) and the Chornobyl site continue to report that nuclear safety and security is maintained despite challenges related to the multiple missile attacks on Ukraine in the past week.
The IAEA experts at the Khmelnitsky NPP were once again required to take shelter several times over the weekend of 6 and 7 January. The teams at the Rivne and South Ukraine NPPs were also required to take shelter last Saturday. At the Chornobyl site, the team reported hearing explosions in the distance throughout the past week.
Director General Grossi has reiterated that everything should be done to prevent a nuclear accident during this war. "It is essential that nuclear power plants and their related infrastructure are not impacted. No one would gain from a nuclear accident and it must be avoided," he said.
Also this week, the IAEA delivered radiocommunication systems to the Rivne and South Ukraine NPPs. The equipment was procured using funding from the United Kingdom. This was the 34th IAEA delivery of nuclear safety and security-related equipment to Ukraine that aims at ensuring diverse and reliable communication means are available at the sites when needed.
