International Atomic Energy Agency (IAEA) Director General Rafael Mariano Grossi is his latest update, said Zaporizhia NPP (ZNPP) has been drilling more wells at the site as part of efforts to find new sources of cooling water after the destruction of the downstream Kakhovka dam more than three months ago. ZNPP has built another two groundwater wells to supply the sprinkler ponds that cool the six reactors and spent fuel, bringing the total of new wells to nine.
Together they pump around 200 cubic metres of water per hour into the sprinkler ponds, representing almost all the cooling needs of the six shutdown reactors. The remainder of the water comes from the drainage system and clean water that is periodically discharged from the plant’s chemical water treatment facility. The IAEA has been informed that the water supply situation will be assessed after a tenth well has been constructed to see if more will be needed.
“Following the loss of the Kakhovka reservoir, actions have been taken to stabilise the site’s water resources, which are currently sufficient for several months of its cooling requirements in the current conditions,” Grossi said.
“However, the challenges the site has been facing in this regard are further adding to the generally precarious nuclear safety and security situation at Europe’s largest nuclear power plant, especially as our experts are reporting about further indications of increased military activities in the region,” he said.
Underlining the potential dangers for nuclear safety and security during the conflict in Ukraine, the IAEA experts have continued to hear numerous explosions some distance away from the ZNPP, which is located by the frontline.
They were also informed by the ZNPP about further drone attacks, on 11 September, in the nearby city of Enerhodar where many staff live with their families, causing minor damage to two buildings. ZNPP informed the IAEA experts that there were no casualties reported at that time.
“No action should be taken that could imperil nuclear safety and security at the Zaporizhia NPP in any way. We remain determined to do everything we can to help prevent a nuclear accident during this tragic war. The risks continue to be all too real,” Director General Grossi said.
Meanwhile IAEA experts at the plant have continued to conduct walkdowns of specific areas at the site and meet with staff there.
They have not observed the presence of any new mines or explosives but confirmed the continued presence of mines in the buffer zone between the site’s internal and external perimeter barriers. The IAEA continues to request access to the rooftops of reactor units 1, 2, 5 and 6, and to all six turbine halls, one after the other.
Over the past week, the experts visited the isolation gate at the large cooling pond and confirmed the integrity of the gate and observed the reinforcements that had been made on the side of the Kakhovka reservoir following the dam’s collapse in early June. The IAEA team also went to the main control room of unit 4, the reactor hall of unit 3, the turbine hall of unit 2 and a liquid waste treatment facility.
The six reactor units remain in shutdown, with units 1 to 5 in cold shutdown and unit 6 in hot shutdown to generate steam for various nuclear safety functions. For example, the steam from unit 6 is used in the liquid waste treatment facility that the IAEA experts visited this week.
During the visit and through discussions with ZNPP staff, the IAEA experts were informed that the inventory of liquid waste on site varies, due to the routine generation of waste together with the subsequent treatment of the waste. Currently, there is liquid waste to be treated, after which the site will also treat more such waste resulting from the regeneration of ion exchange resins, which are essential for maintaining the purity of the water, including that needed for the cooling of the used fuel.
As previously stated, the IAEA experts have strongly been encouraging the ZNPP to investigate all possible options to install an external boiler to generate the steam required, which would enable the plant to bring all units into a cold shutdown state. Also as reported earlier, the Ukraine national regulator – SNRIU – has issued regulatory orders to limit the operation of all six units to a cold shutdown state.