Zaporizhzhia NPP: pumping water that still remains accessible despite a major water loss, IAEA says
Ukraine’s Zaporizhzhia Nuclear Power Plant (NPP) is planning to resume pumping water that still remains accessible despite a major loss of water in the Kakhovka reservoir caused by the destruction of the downstream dam earlier this month, Director General of the International Atomic Energy Agency, Rafael Mariano Grossi said on Wednesday (21 June).
For the past two weeks, Europe’s largest nuclear power plant (NPP) has received the cooling water it needs from the reserves held by a discharge channel of the nearby Zaporizhzhia Thermal Power Plant (TPP). This is separate from the reservoir, whose water level has plunged since the dam was severely damaged on 6 June, IAEA said.
Water from the channel supplies the Zaporizhzhia NPP’s spray ponds, cooling the shut-down reactors and spent fuel storage. This water supply also maintains a large cooling pond at the plant, compensating for evaporation. The water level in the channel has been declining by up to 10 cm per day and currently stands at just over 17 metres. Despite this, the channel’s water is expected to provide cooling for several more weeks. The Zaporizhzhia nuclear sire informed the IAEA team that the spray ponds are replenished through pumping from an underground water drainage system.
To replenish the ZTPP discharge channel, the power plant plans to pump water from either the site’s inlet channel or a body of water in its port. The latter was created months ago by dredging the bottom of the port to ensure that some water was retained in case the water levels in the reservoir dropped below the level where water could be fed from the site’s inlet channel.
Pumping additional water into the discharge channel would give the ZNPP more time until it may be required to use the much larger cooling pond, the IAEA said.
“Together, the large cooling pond, the smaller spray ponds, and the discharge channel have sufficient water for some months, but the Zaporizhzhia Nuclear Power Plant is also taking action to preserve and replenish these reserves as much as possible,” said Director General Grossi, who visited the facility last week to assess the increasingly challenging nuclear safety and nuclear security situation there. “It is also exploring alternative ways of getting water.”
The ZNPP faces further challenges as it relies on a single operational power line for external electricity, compared to four before the invasion. The plant lacks backup power due to the disconnection of the last remaining power line nearly four months ago. The Director General observed damage at the ZTPP open switchyard and was informed about drones targeting the area.
While no mines were observed near the cooling pond during the Director General’s visit, previous placement of mines outside and inside the plant has previously been reported, IAEA said.
The loss of the Kakhovka reservoir has severely affected the ZNPP, making the nuclear safety and security situation extremely fragile. All parties involved must adhere to the IAEA’s basic principles to prevent a nuclear accident. The IAEA will intensify efforts to ensure nuclear safety, provide security assistance, and aid the affected region.
The IAEA reported earlier this month that spent fuel transports from other NPPs to the centralised spent fuel storage at the Chornobyl site had begun, with the first shipment from Rivne having arrived at the Chornobyl site in May. Director General Grossi confirmed that the spent fuel was verified and maintained under IAEA safeguards throughout the transfer from Rivne NPP to Chornobyl.