In his latest update on the Zaporizhia NPP (ZNPP) International Atomic Energy Agency (IAEA) Director General Rafael Mariano Grossi said the plant has regained access to its only remaining back-up power line, following an outage of more than three weeks “that once again underlined persistent nuclear safety and security risks facing the site”.
The ZNPP’s connection to the 330 kilovolt (kV) off-site power line has been restored, providing a much-needed buffer for the plant which has suffered eight complete loss of external power events over the past year and a half. The 330 kV line was lost on 20 February due to an incident on the other side of the Dnipro River [in Ukrainian controlled territory], leaving the ZNPP entirely dependent on its only 750 kV line. Before the conflict, ZNPP had a total of ten power lines available, four 750 kV and six 330 kV lines.
This positive development should not hide the fact that the power situation at the plant continues to be extremely fragile and vulnerable to further disruptions, Grossi noted. “I remain deeply concerned about the nuclear safety and security situation at this major nuclear facility.”
In addition, IAEA experts stationed at the site have continued to report on explosions and other indications of military activity not far from the ZNPP. They heard blasts at various distances from the site every day over the past week, including explosions nearby and around 13 rounds of outgoing artillery fire. “What once seemed unimaginable – military activity near a nuclear power plant – has become a daily reality. The situation is not improving and as long as this tragic war continues, the plant remains in danger. For this reason, I again call for maximum restraint and full observance of the five concrete principles established at the United Nations Security Council in May last year,” Grossi said.
IAEA experts at the ZNPP were informed by the plant of a drone attack in an area outside the perimeter of the ZNPP site. There were no casualties reported. The IAEA experts after being informed by the ZNPP immediately accessed the location of the reported impact, roughly 550 meters from the site perimeter. The team observed a shallow cavity in the ground approximately 70cm in diameter, located just outside the concrete wall that surrounds the off-site diesel fuel storage area, some 100 metres from the diesel fuel storage tanks. The team also observed some partially burnt foil/plastic material in the area.
The off-site diesel fuel tanks store additional fuel for the emergency diesel generators (EDGs) for the six reactor units at the ZNPP. Together with the fuel stored at each EDG on-site, the plant currently has enough diesel fuel for more than 20 days operation of the EDGs in the case of a total loss of off-site power.
The impact did not cause damage to any structures, including a warehouse approximately 40 metres from the impact site, and there was no impact on nuclear safety. On the basis of the available evidence and visual observations, the IAEA is unable to confirm if the event was the result of a drone attack or other type of projectile.
The IAEA experts at the site have continued to conduct walkdowns and assess nuclear safety and security at the ZNPP. They reported that the ZNPP’s four diesel steam generators have resumed operations to treat liquid waste. These recently-installed steam generators were previously operating in early February, but were then switched off for just over a month until a sufficient volume of liquid was ready to be treated.
As part of ongoing efforts to monitor the well-being of personnel, the IAEA team was briefed by an on-site psychologist on the continuous evaluation of all staff, with some additional assessments for operators of the main reactor control rooms and turbines.
The IAEA experts also observed simulator training of operating staff in the training centre, where they held discussions with the ZNPP training centre and Rostekhnadzor, the nuclear safety regulatory body of the Russian Federation, about the process that staff must follow to obtain their operating “authorisations”.
The IAEA experts were informed that staff are being trained considering the present situation at the ZNPP, with all reactor units either in cold or hot shutdown, as well as the current status of the external power lines and cooling water. The ZNPP says it has enough authorised operating staff to maintain the reactor units in their current shutdown states. “The staffing situation at the plant remains a vital issue for nuclear safety and security that we will continue to monitor closely,” Grossi said.
The drone attack on the plant was widely reported by Russian media and also by the ZNPP press service. ZNPP said: “Ukrainian Armed Forces continue to attack Zaporizhia NPP and Energodar city. The station's critical infrastructure was shelled. A shell-free explosive device was dropped in the area of the fence, behind which diesel fuel tanks are placed. If it had hit the tanks – it could lead to sad consequences. Such attacks are unacceptable.… For our part, we ensure complete safety of the plant's operation. There are enough highly qualified personnel for this purpose. ZNPP Director Yuriy Chernychuk said that the plant's equipment and personnel were not affected. No excess of the radiation background was recorded. Chernychuk said an explosive device was dropped from a combat drone five metres from the fuel storage fence. He added that the improvised bomb, was composed of explosives wrapped in foil.
Stephane Dujarric, spokesman for United Nations Secretary-General Antonio Guterres has said all sides are responsible for maintaining security at the ZNPP. “We have stated over and again, and we’re very concerned about the situation around the nuclear power plant, and it’s incumbent on everyone to ensure and to guarantee its safety. One would hate to even think about what could happen.”
Image (top left): Zaporizhia nuclear power plant
Image (right): Impact site from the drone attack outside the plant's perimeter