IAEA experts observe continuous decrease in water level at Ukraine’s Zaporizhzhya Nuclear Power Plant cooling pond

VIENNA, Austria, (IAEA) – The water level in the cooling pond at Ukraine’s Zaporizhzhya Nuclear Power Plant (ZNPP) continues to decrease. Despite all reactors remaining in a state of cold-shutdown, availability of this water is important for nuclear safety of the plant, director general Rafael Mariano Grossi of the International Atomic Energy Agency (IAEA) said today.

The IAEA director-general statement – Update 240, August 2, 2024, says that, over the past weeks, IAEA experts at the plant have observed a continuous decrease in the water level of the plant’s cooling pond. If this trend continues, ZNPP staff confirmed that it will soon become challenging to pump water from the pond. Maintaining the level of the pond is made more difficult by the hot summer weather.

Following the destruction of the Kakhovka dam last year, the ZNPP dug 11 groundwater wells to provide approximately 250 cubic meters of cooling water per hour to the sprinkler ponds. These ponds supply sufficient water to cool all six reactor units in their current cold shutdown state. During a site walkdown last week, the IAEA team observed that the sprinkler ponds are functioning well, with water at nominal levels. Any compromise to the availability of water to the sprinkler ponds might necessitate using the cooling pond as a backup source.

“The dwindling water levels in the cooling pond remains a potential source of concern, and we will continue to closely monitor and observe the situation at the site to ensure the availability of a sufficient supply of cooling water for the plant’s needs at all times,” director general Grossi said.

The IAEA experts also continue to monitor vital maintenance activities across the site over the past week. They were informed that the majority of the maintenance work at the plant is being performed by contractors. The team observed tests of the emergency diesel generator for a safety train of unit 6, from both the emergency diesel generator room and the emergency control room. Similarly, they observed the emergency diesel generator testing for a safety train of unit 5 from both the emergency diesel generator room and the main control room. No issues related to nuclear safety and security were noted during these tests.

Additional walk-downs were carried out across the ZNPP site to monitor nuclear safety and security. The team also noted that the three main fuel tanks at the diesel fuel farm can only be filled to a maximum of 90 percent of their capacity and that maintenance is planned on the tanks.

On Wednesday, the team visited the 750 kilovolt (kV) switchyard and did not observe any new issues with respect to safety and security. Also, last week the team conducted a series of walkdowns and discussions on the topic of the safety and security of radioactive sources.

During a walkdown of the reactor hall and safety system rooms of unit 5, the team observed the switching of the spent fuel pool pump and confirmed that both the pumps and safety system rooms were in good condition.

The IAEA team continues to hear military activity at varying distances from the plant. The team also observed smoke in the distance multiple times in the past week, which the ZNPP reported was caused by fires.

The IAEA experts present at the Khmelnytskyy, Rivne and South Ukraine nuclear power plants (NPPs) and the Chornobyl site reported air raid alarms on several days over the past week but confirmed that nuclear safety and security is being maintained despite the effects of the ongoing conflict. Separately during the last weeks, the Agency continued delivering its comprehensive assistance programme in Ukraine by supporting in various areas. As part of the medical assistance program, an ultrasound system was provided to the local hospital near to the South Ukraine NPP, ensuring that personnel operating the plant have access to the necessary medical services for maintaining their fitness for duty.

Additionally, four remote workshops were conducted focusing on mental health. These sessions trained supervisors, managers, and mental health teams from all Ukrainian nuclear facilities to recognize signs of distress, offer peer and psychological support to colleagues dealing with trauma or stress, and effectively plan and manage mental health support initiatives.

“The delivery of the equipment and workshops have been supported by the United Kingdom and the United States,” concludes Update 240.