IAEA reports shift in shutdown status of besieged Zaporizhzhia reactors

spray ponds Zaporizhzhia Spray ponds of the Zaporizhzhia NPP. The photo was taken during the visit of the head of the IAEA to the station on June 15, 2023 Credit: IAEA

Operators carrying out maintenance at Ukraine’s Zaporizhzhia nuclear plant have switched the shutdown mode of two reactors, the Moscow-installed administration of the plant, located on the war’s front-line, said last week.

Europe’s largest nuclear plant was captured by Russian forces in March 2022, placing the facility and its six reactors on the front lines of the war. Ukraine and Russia have repeatedly accused each other of shelling around the station and the International Atomic Energy Agency, or IAEA, has since the war’s beginning been trying to establish a safety zone around it to prevent accidents.

One of the plant’s six reactors, according to Russian plant administration, needs to be kept in a hot shutdown mode in order to produce steam required for nuclear safety, including the processing of liquid radioactive waste in storage tanks.

“In order to conduct a scheduled technical inspection of the equipment of power unit No. 5, the management of the Zaporizhzhia nuclear power plant decided to transfer it to the ‘cold shutdown,’ state,” the Russian-run administration said on its Telegram channel. “And in order to provide steam for the station’s own needs, the reactor plant of power unit No. 4 was transferred to the ‘hot shutdown’ state.”

All six of Zaporizhzhia’s Soviet built VVER-1000 reactors have been in various stages of shutdown since September of 2022, nine months after Russia invaded. Experts have said that fallout from a military strike on the reactors themselves would be significantly lessened with the reactors in shutdown mode.

Bellona’s experts have specifically called for all of the Zaporizhzhia reactors to be placed in cold shutdown — a recommendation consonant with orders from Ukraine’s national nuclear regulator, as well as urgings from the IAEA.

In a statement last week, the agency encouraged plant management to install external boilers to generate the steam required for nuclear safety purposes — which in turn would allow for all reactors to be kept in cold shutdown.

The IAEA said in its statement that the plant administration had informed the agency about the transition.

“The other units remain in cold shutdown,” the IAEA said in the statement.

None of the plant’s six reactors has been producing electricity. Ukraine has vowed to retake the plant and all land in Ukraine that is now occupied by Moscow.

IAEA inspectors stationed at the plant had noted mines in a buffer zone between the site’s internal and external perimeter barriers and had also observed mines during previous checks, Rafael Grossi, the agency’s director general, said last week.

On July 29, the inspectors visited reactor No 5 to inspect the core, spent fuel pool, and steam generator and reported in a statement that “all equipment seemed to be in normal condition,” adding that no mines had been discovered inside the reactors.