Nuclear safety and security "remains in jeopardy" at Ukraine's Zaporizhzhya Nuclear Power Plant (ZNPP), Director General Rafael Mariano Grossi told this week's IAEA Board of Governors meeting, as the facility twice lost the connection to its only remaining 750 kilovolt (kV) power line within a few days.
Caused by unspecified damage that occurred approximately 17 km from the plant, the first disconnection lasted for just over 30 hours from Saturday morning until it was repaired and restored around noon the following day, Director General Grossi said, citing information from the IAEA's team stationed at the ZNPP site. The line was lost again this morning.
As a result of the disconnections, the ZNPP relied on its sole 330 kV back-up power line for the electricity it needs for reactor cooling and other key nuclear safety functions. The ZNPP's connection to this line was itself lost twice in October, further underlining the fragility of its power supplies. Before the military conflict, Europe's largest nuclear power plant (NPP) had four 750 and six 330 kV lines available.
Noting that the armed conflict this week passed its one-thousandth day, Director General Grossi said the IAEA had been supporting nuclear safety and security in Ukraine from the start, with 155 missions having so far been deployed as part of a continued presence at all five NPP sites.
The largest of them, the ZNPP, "continues to face challenges not least because of the vulnerability of its limited off-site power supply lines," Director General Grossi said in his introductory statement to the Board on Wednesday. "All six reactors remain in cold shutdown and the Agency's continued stipulation is that no reactor is to be re-started as long as the nuclear safety and security situation at the Zaporizhzhya NPP remains in jeopardy."
Ukraine's power system is also a growing concern for nuclear safety at its three operating NPPs - Khmelnytskyy, Rivne and South Ukraine - which require a reliable and stable connection to the national grid both to transmit the electricity they generate and to receive the off-site power they need for vital nuclear safety functions.
The risks they are facing were highlighted last weekend, when Ukraine's energy infrastructure was reportedly targeted in widespread attacks, less than three months after military strikes caused extensive damage to a number of electrical substations across the country, which the IAEA has identified as important for nuclear safety.
Four of these substations and their power lines were impacted again by the attacks during the night of 16 November and early morning of 17 November, prompting Ukraine's operating NPPs to reduce their power output as a precautionary measure. The NPPs in recent days gradually started restoring the power lines and began increasing output, but again lowered power generation this morning as a precaution, before it was once again restored.
Separately, the South Ukraine NPP this morning disconnected from its two 750 kV power lines for maintenance. It still received power from its back-up systems.
"The growing instability of the power grid is a deepening source of concern for nuclear safety, affecting all the nuclear power plants," Director General Grossi said.
Before the latest attacks on Ukraine's energy infrastructure, IAEA teams visited seven substations in September and October to assess the damage caused by the attacks in August, as part of their wider efforts to help the country ensure nuclear safety and security.
They "documented extensive damage to all the substations visited, concluding that the grid's capability to provide a reliable off-site power supply to Ukrainian NPPs has been significantly reduced. Repairs and additional protective measures are being implemented by Ukraine," Director General Grossi told this week's Board.
The Director General has repeatedly underlined the importance of adhering to the seven indispensable pillars of nuclear safety and security, one of which states that there must be a secure off-site power supply from the grid for all nuclear sites.
The IAEA teams present at the Khmelnytskyy, Rivne and South Ukraine NPPs and the Chornobyl site reported that nuclear safety and security is being maintained despite the grid instability and the effects of the ongoing conflict, including a number of air raid alarms over the past week.
The Agency continues to deliver on its comprehensive programme of assistance to Ukraine.
Further to Tuesday's delivery of ambulances to Chornobyl and the Varash hospital, medical equipment including blood and urine analysers, defibrillators as well as electrocardiograph, X-ray and glucose monitoring systems will help the Slavutich health centre, the Varash and Netishyn hospitals and the National Research Centre for Radiation Medicine, Haematology and Oncology strengthen their health care capabilities.
In a separate delivery, the Centralised Spent Fuel Storage Facility, a subdivision of the Ukrainian operator Energoatom, received a dosimetry system to monitor individual doses of staff.
The deliveries were supported with funding from Austria, Denmark, Switzerland and the United States. Since the start of the conflict, the IAEA has coordinated 82 deliveries of equipment and supplies to Ukraine, with a total value of more than 12.4 million euro.
