IAEA Director General Issues Urgent Statement on the Escalating Crisis in Ukraine: Update 268

The International Atomic Energy Agency (IAEA) is examining data and insights acquired from its recent missions to Ukraine’s electrical substations, which took place following assaults on the nation’s energy systems. This is part of the Agency’s continuous dedication to overseeing nuclear safety and security, stated IAEA Director General Rafael Mariano Grossi today.

Recent strikes against Ukraine’s energy systems, notably a significant attack on 25 December that led to several reactor units at the country’s three operational plants having to reduce their output for multiple hours, have compromised the stability of Ukraine’s electrical grid. All impacted reactor units subsequently reinstated their nominal full power.

During its eight-day mission from 16 – 23 December, IAEA specialists collected technical insights regarding seven electrical substations crucial for the secure operation of Ukraine’s Khmelnytskyy, Rivne, and South Ukraine nuclear power plants (NPPs). A dependable and stable grid connection is vital for transferring the electricity produced by the functioning NPPs and for receiving external power, necessary for upholding nuclear safety. The Zaporizhzhya NPP (ZNPP) and the Chornobyl facility also rely on dependable and stable external power to sustain nuclear safety.

The IAEA delegation that inspected the substations recorded the destruction and accumulated essential evidence underscoring the vulnerabilities of the electricity grid caused by assaults on Ukraine’s energy systems. Throughout the mission, the team engaged with specialists from Ukraine’s grid operator, nuclear plant managers, and the nuclear regulator. Utilizing information from this mission along with two earlier assessments of substations, the IAEA aims to identify and provide targeted technical support to avert a nuclear incident.

“These assaults affect grid stability and threaten the dependability of the off-site power supply, posing risks to nuclear safety,” Director General Grossi remarked. “Our persistent missions to the substations and our presence at five nuclear power plant sites are crucial for overseeing nuclear safety and security in Ukraine, specifically the reliable and stable provision of external power to the plants.”

The IAEA Support and Assistance Mission to Zaporizhzhya (ISAMZ) has continued conducting inspections and follow-up maintenance operations to oversee the status of nuclear safety and security systems and equipment at the facility.

In another example illustrating the fragile external power predicament, the IAEA team stationed at the ZNPP was informed that the facility’s last remaining 330 kV backup power line was recently disconnected twice for maintenance from 20 – 22 December and again from 24 – 25 December. Prior to the military conflict, Europe’s largest NPP was connected to four 750 kV and six 330 kV external power lines.

The IAEA team received updates that the unit 4 circulation pump, responsible for maintaining the movement and clarity of water in the ZNPP cooling pond, was turned off on 18 December to sustain a level of water in the cooling pond. The ZNPP confirmed that water from the 11 groundwater wells is adequately feeding the sprinkler ponds, which cool the six reactor units during their current cold shutdown states. The six reactor units at the ZNPP have not been operational for over two years.

The IAEA team reported that planned maintenance tasks were accomplished last week on safety systems in units 2 and 6, in addition to one of the shared emergency diesel generators. Moreover, diesel steam generators were utilized between 12 – 30 December to process roughly 800 cubic metres of liquid waste.

The team at the ZNPP continues to report awareness of military activities near the facility. The ISAMZ team noted hearing explosions over recent days at various distances from Ukraine’s largest NPP. No damage has been reported to the ZNPP.

Independently, IAEA teams at the Khmelnytskyy, Rivne, and South Ukraine NPPs, as well as at the Chornobyl site, are also continuing to report air raid alarms, with the Khmelnytskyy team needing to take shelter several times over the past week.

In a separate occurrence in Ukraine, the State Nuclear Regulatory Inspectorate of Ukraine (SNRIU) informed the IAEA that the subcritical neutron source facility at the Kharkiv Institute of Physics and Technology lost external power on the morning of 25 December due to military activities. The facility, which remains non-operational, received power from its emergency diesel generator until external power was restored approximately five hours later.