In his latest update, International Atomic Energy Agency (IAEA) Director General Rafael Mariano Grossi said that the Zaporizhia NPP (ZNPP) is transitioning a second reactor to hot shutdown to provide warm water and district heating. Since April, it has kept five reactors in cold shutdown and just one, currently unit 4, in hot shutdown to generate steam to process liquid radioactive waste and to heat water for Energodar, where most plant staff live. Ahead of the upcoming winter season, it has begun transferring unit 5 to hot shutdown after carrying out safety maintenance and testing at this unit.

The IAEA experts were told that a decision regarding how long unit 5 will remain in hot shutdown will be made once Energodar’s heating systems have stabilised after the beginning of the heating season. They were also informed that there are no plans to transfer additional units to hot shutdown. The IAEA has strongly encouraged the ZNPP to find an alternative, external source of steam generation to cover its needs and allow for all the reactors to be maintained in a cold shutdown state, in part because the destruction of the Kakhovka dam four months ago limited the site’s supplies of cooling water.

The IAEA experts at the site were earlier informed that the ZNPP has initiated a process to buy an external steam generator by sending technical requirements to possible vendors. However, the installation of this equipment is not expected until the first part of 2024, possibly not until after the end of the heating season.

ZNPP’s six VVER-1000 power units have not been producing electricity since September 2022. Plant operator is Zaporizhia NPP Operating Organisation JSC, established by Rosenergoatom (part of Russia’s Rosatom). As previously reported, Ukraine’s national regulator, the State Nuclear Regulatory Inspectorate of Ukraine (SNRIU), issued regulatory orders in June to limit the operation of all six units of the ZNPP to a cold shutdown state.

Since Russia took control of ZNPP in March 2022 as part of its special military operation in Ukraine, the Russian national guard, Rosgvardiya, has been protecting the station. In October 2022, Russian President Vladimir Putin signed a decree formally transferring ZNPP to Russian jurisdiction under nuclear utility Rosenergoatom (part of Rosatom). A Russian Federal State Unitary Enterprise. Zaporizhia NPP was established by Rosenergoatom to operate the plant. However, Ukrainian nuclear utility Energoatom still claims ownership of the plant. IAEA has maintained a permanent presence at the plant since September 2022.

Russia and Ukraine have blamed each other for shelling that has repeatedly downed power lines vital to cooling the reactors, which are shut down but which need a constant supply of electricity to keep the nuclear fuel inside cool and prevent a possible meltdown. Russia and Ukraine also accused each other of destroying the Nova Kakhovka dam, drastically reducing levels in the Kakhovka reservoir, which provides cooling water for the plant.

In his previous update, Grossi said IAEA experts had been granted access to the rooftop of reactor unit 2 of ZNPP and did not observe any mines or explosives there. From the top of the building, the IAEA team could also observe the entire rooftop of its turbine hall as well as parts of the rooftops of the reactor buildings and turbine halls of units 1 and 3, also without seeing any mines or explosives.

The team will continue making its long-standing request to also visit the rooftops of reactor units 1, 5 and 6 to monitor compliance with the five concrete principles for protecting the plant during the military conflict in Ukraine, which state that it should neither be attacked nor be used as a base for heavy weapons.

In August IAEA experts were allowed access to the rooftops of units 3 and 4, following reports that explosives may have been placed there. Also at that time, they did not observe any mines or explosives. “After repeated requests in recent months, we were at last able to go to one more reactor rooftop. While this is a step in the right direction, we still need more access to assess adherence to the five principles, which were presented and gained support at the United Nations Security Council. We will continue to insist until this is granted,” Grossi said.

The IAEA experts also require access to all six turbine halls to be able to confirm the absence of any materials and equipment that may contravene the five principles. This request has not yet been approved and the IAEA team can only confirm the status of one turbine hall at a time.

Highlighting the risks facing the plant during the military conflict, the IAEA team at the site has continued to hear explosions almost every day. Usually, they appear to occur some distance away from the plant, but yesterday four blasts took place closer to the site. “Without any doubt, the nuclear safety and security situation at the ZNPP remains highly precarious. We will continue to do everything we can do help prevent a nuclear accident during the war in Ukraine,” Grossi said.

The IAEA experts are also continuing to monitor the water situation at the plant following the destruction of the downstream Kakhovka dam in early June. To find alternative sources of cooling water for the reactors and used fuel, the plant has recently completed the construction of 11 underground wells which are together supplying around 250 cubic metres per hour, which the site had estimated would be sufficient to maintain the level of all 12 sprinkler cooling ponds, which have remained steady following some issues with their levels in late September.

The IAEA team has conducted walkdowns across the site, including within the site perimeter, in the main control room and reactor building of unit 5 and in the reactor building of unit 6. The experts have also observed testing of the safety system of unit 2 and maintenance activities on the transformer of unit 6. During these walkdowns, the team did not observe any new mines or explosives.

As part of these activities, the IAEA experts also closely observe the performance of the operating staff as the team collects more information about the status of staffing and the training and licensing of staff at the plant.

Meanwhile, Ukraine has admitted that three unsuccessful attempts have been made so far to take over the ZNPP. The head of Ukraine's Main Directorate of Intelligence agency (GUR) General Kyrylo Budanov told Ukrainian publication NV that the first operation took place in August 2022. He said the primary objective was the establishment of a bridgehead on the left bank of the region. Several dozen commandos undertook this mission, crossing the Kakhovka reservoir aboard high-speed boats. The operation, however, did not yield the desired results, leading to a forced withdrawal. Ukrainian Intelligence units undertook two more landing operations on the left bank of the Dnipro River which also failed, Budanov said.

Image courtesy of Rosatom