Ukraine's Zaporizhzhya Nuclear Power Plant (ZNPP) 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, Director General Rafael Mariano Grossi of the International Atomic Energy Agency (IAEA) said today.
The ZNPP's connection to the 330 kilovolt (kV) off-site power line was restored shortly after 6pm local time on Thursday, 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, leaving the ZNPP entirely dependent on its only 750 kV line. Before the conflict, Europe's largest nuclear power plant (NPP) had a total of ten power lines available, four 750 kV and six 330 kV lines.
"Last evening's positive development should not hide the fact that the power situation at the Zaporizhzhya Nuclear Power Plant continues to be extremely fragile and vulnerable to further disruptions. I remain deeply concerned about the nuclear safety and security situation at this major nuclear facility," Director General Grossi said.
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 in the morning and evening of 8 March and again in the morning and late at night the following day. On Wednesday, the team heard 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," Director General Grossi said.
The IAEA experts at the ZNPP were informed by the plant of a drone attack in an area outside the perimeter of the ZNPP site during the week. There were no casualties reported. The event occurred at around 6pm local time on Tuesday, 12 March. The IAEA experts were first informed by the ZNPP on 13 March at 1pm, where upon they 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 meters 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 meters 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, who crossed the frontline to travel to and from the plant as part of a scheduled rotation this week, 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 "authorizations".
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 authorized 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," Director General Grossi said.
The IAEA experts present at the Khmelnytskyy, Rivne and South Ukraine NPPs as well as at the Chornobyl site have reported that nuclear safety and security is being maintained despite the challenging war-time circumstances, including the frequent sound of air raid alarms at some of the facilities.
The IAEA team at the Khmelnytskyy NPP had to go to the site's shelter four times this week, on 10 and 11 March, respectively. At the same site, the IAEA team was informed that the plant manually shut down its reactor unit 2 on Wednesday to investigate an issue with the turbine shaft. Nuclear safety and security was not affected by this event.
The IAEA experts at the Rivne, South Ukraine and Khmelnytskyy NPPs all rotated this week.
The IAEA has continued to deliver equipment to help maintain nuclear safety and security in Ukraine. This week, two deliveries took place bringing the total to 40 since the armed conflict began. Alpha and beta radiation counting systems, portable radio-communication equipment and personal protective equipment reached the Rivne NPP and the Chornobyl site. The equipment was procured using funding from the European Union and the United Kingdom.
