A new team of experts from the International Atomic Energy Agency crossed the frontline this week to replace their colleagues in monitoring nuclear safety and security at Ukraine’s Zaporizhzhya Nuclear Power Plant (ZNPP), the thirteenth such mission since the IAEA last year established a permanent presence at the site to help prevent a nuclear accident during the military conflict, Director General Rafael Mariano Grossi said today.
Also on Thursday – when the rotation of IAEA experts took place – there were Russian reports of drone attacks in the town of Enerhodar, where many plant staff live.
Almost every day in recent weeks and months, the IAEA experts have continued to hear explosions some distance away from Europe’s largest nuclear power plant (NPP), underlining ever-present dangers to nuclear safety and security.
“For fourteen months now, we have had IAEA experts present at the Zaporizhzhya Nuclear Power Plant, monitoring nuclear safety and security and informing the world about developments there. Their work is vital for efforts to keep this major nuclear facility safe and protect people and the environment in Ukraine and beyond. However, the risk remains. Our important work continues as long as it is necessary,” Director General Grossi said.
Over the past week, the IAEA experts have continued to perform walkdowns at the site, visiting its facilities for storing fresh fuel, the emergency diesel generators of unit 1, the open switchyard of the 750 kilovolt power line, the central warehouse and the temporary emergency response centre. They were informed that an emergency exercise is planned for November, the first since before the conflict.
The experts have also been at the ZNPP’s cooling pond and associated areas, where they observed cleaning of the outlet channel of the cooling towers. The IAEA team was informed that the current shutdown status of the ZNPP’s six reactors provided an opportunity to perform this cleaning work.
Following last month’s closure of the reactor vessel of unit 3, which had been left open following maintenance in 2022, the plant informed the IAEA experts that pressure testing of the unit’s steam generators was under way and would be completed over the weekend, after which testing on the primary and secondary cooling circuits will be conducted. Today, the ZNPP confirmed to the IAEA experts that unit 3 would be kept in cold shutdown following the completion of the pressure tests.
An open reactor vessel together with the adjacent spent fuel storage pool contains borated water which might be pumped and used for cooling of fuel in any of the six units, if needed. However, additional volumes of borated water are also stored in two special buildings at the ZNPP site. The reactor vessel closure improves the nuclear safety status of the unit.
The ZNPP confirmed to the IAEA experts this week that there are no plans to re-start any of the units, four of which are in cold shutdown and two in hot shutdown to generate steam for various nuclear safety functions and heating for Enerhodar during the winter.
The IAEA continues to pay close attention to maintenance activities at the site, with maintenance of equipment essential for plant safety a continued source of concern.
“The reduced number of maintenance staff at the plant and the limited availability of all necessary spare parts have the potential to impact the operation of safety systems. It is essential that all necessary maintenance is performed,” Director General Grossi said.
Related to such activities, the IAEA experts were informed that maintenance of part of the safety system of unit 6, as well as hydraulic testing of its primary cooling circuit, was completed this week.
The IAEA experts are also continuing to collect information on the status and condition of staff, as well as on the training and licensing of operating staff at the plant under Russian Federation regulations.
As part of preparations for the winter, the ZNPP has begun to insulate the ground water wells that have been constructed near the water sprinkler pond area as an alternative source of cooling water following the destruction of the Kakhovka dam in June. The insulation is intended to ensure that the wells continue to provide cooling water to these ponds, which in turn provide essential cooling of the six reactors, during the winter.
The IAEA team has continued to request access to the rooftops of reactor units 1, 5 and 6, after in recent months being able to go to those areas of the ZNPP’s three other units.
The IAEA experts also need access to all six turbine halls together. However, they were only granted partial access to the turbine hall of reactor unit 2 on 27 October, after earlier the same month receiving similarly restrictive access to the turbine halls of units 1 and 4.
Eight of the plant’s nine mobile diesel boilers are currently operating to generate more heating during the winter, their usage depending on the requirements for steam at the plant and for heating in Enerhodar.
The IAEA teams at Ukraine’s three other NPPs – the Khmelnitsky, Rivne and South Ukraine NPPs – and the Chornobyl site report safe and secure operations of these nuclear facilities despite the continuation of the conflict.
This week, the IAEA carried out its 31th delivery of equipment to Ukraine to support nuclear safety and security in the country. State enterprise USIE Izotop and the Institute for Safety Problems of Nuclear Power Plants of the National Academy of Sciences of Ukraine received portable gamma-radiation detectors donated by Greece.