An International Atomic Energy Agency (IAEA) team is in Ukraine this week to assess the nuclear safety impact of recent attacks on its increasingly fragile energy infrastructure, travelling to seven electrical substations on which the country’s nuclear power plants (NPPs) depend to safely generate electricity, Director General Rafael Mariano Grossi said today.

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NPPs need reliable connections to the grid both to deliver the electricity they produce and to receive off-site power for reactor cooling. But repeated attacks on Ukraine’s energy infrastructure, including the substations, have weakened its electrical grid and reduced its ability to provide stable off-site power to the NPPs, potentially endangering nuclear safety.

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Based on the IAEA’s safety standards, the seven indispensable pillars of nuclear safety and security that Director General Grossi outlined early during the military conflict stressed that “there must be secure off-site power supply from the grid for all nuclear sites”.

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“The IAEA’s safety standards stress that it is of paramount importance to ensure the availability of a stable off-site power supply system. In addition, fundamental safety principles state that all efforts must be made to prevent nuclear accidents. A reliable transmission system is a significant contributor to defence in depth for nuclear safety,” Director General Grossi said today.

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For the third time during the military conflict, the IAEA sent a team of specialists to substations that have been identified as essential for maintaining nuclear safety at the three sites that are currently producing power – the Khmelnytskyy, Rivne and South Ukraine NPPs - and the Zaporizhzhya NPP and the Chornobyl site, which do not.

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The substations function as key nodes in the energy transmission and distribution network and are located at various distances away from these sites in different parts of Ukraine.

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The previous IAEA missions to assess the situation at substations in Ukraine, conducted in September and October, documented extensive damage, and also gathered important evidence regarding the vulnerability of the electricity grid.

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“During this week’s visits to seven substations, the IAEA’s team is observing and collecting information on the impact on nuclear safety as a result of the latest attacks on Ukraine’s energy infrastructure, including those on 28 November. The growing instability of the grid is a major challenge for nuclear safety and the IAEA is taking action to help address this precarious situation,” Director General Grossi said. 

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“We will analyse the data that our experts are gathering this week, follow up with technical advice to Ukraine and also identify what additional assistance we can offer to help prevent a nuclear accident during the war,” he said.

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The IAEA team is also meeting experts from Ukraine’s grid operator, national nuclear plant operator and nuclear regulator during this week’s mission.

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A few days after they reduced electricity output for a third time in less than a month due to renewed attacks on Ukraine’s energy infrastructure, most of its nine operational nuclear reactors are once again generating electricity at full power, demonstrating the operators’ resilience in difficult circumstances. As of today, two units are still operating with reduced power due to the reduced grid capacity.

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In what has become a frequent occurrence, the IAEA teams at the Khmelnytskyy, Rivne and South Ukraine NPPs and the Chornobyl site all reported air raid alarms over the past week.

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The team at the Khmelnytskyy site was required to shelter on Monday morning due to the presence of drones in the area, the closest 900 metres away. In addition, the Ukrainian regulator informed the IAEA that cruise missiles were recorded 3.7 kilometres from the same site last Friday.

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At Ukraine’s largest NPP, Zaporizhzhya, the IAEA team reported hearing explosions on most days over the past week at various distances from the site. No damage to the plant, whose six reactors are in cold shutdown, was reported.

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The IAEA team based at the Zaporizhzhya NPP (ZNPP) has continued to observe the availability of off-site and on-site power. However, a planned visit to the ZNPP 750 kilovolt (kV) open switchyard today was cancelled by the plant, citing security reasons.

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The ZNPP informed the team that newly arrived mobile diesel generators would be used in case of a station blackout, with a total loss of off-site power and inability of the site’s 20 emergency diesel generators to provide enough power to maintain nuclear safety.

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Separately this week, as part of its comprehensive programme of assistance in support of nuclear safety and security, the IAEA arranged two new deliveries to Ukraine, bringing the total number of deliveries to 91 since the start of the armed conflict.

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The Rivne NPP received medical equipment and supplies such as oximeters, defibrillators, electrocardiographs and similar equipment and the Netishyn hospital received digital X-ray devices. The deliveries were supported with funding from Norway.

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Text Courtesy, IAEA