The ZNPP has informed the IAEA team that planned maintenance activities on one pair of backup power transformers was stopped after the LOOP, and the transformers were returned to standby mode.
Challenges related to off-site power were also in evidence at the Chornobyl site this week, where its New Safe Confinement (NSC) facility experienced a loss of power on Wednesday evening. The IAEA team based at the site was informed that the Slavutych 330 kV switchyard located around 40km away was damaged because of military activity in the area, causing the disconnection of this power line at 4:10pm local time.
Off-site power to the NSC – a large structure built to prevent any radioactive release from the reactor destroyed in 1986 and to protect it from any external hazard – was only restored some 16 hours later. During this time, the facility – which was severely damaged by a drone in February – had no access to back-up EDG electricity for some three hours on Wednesday evening, resulting in a partial blackout to the NSC.
The IAEA team was informed that radiation monitoring and ventilation of the NSC remained operational throughout the blackout, via an interconnection to the systems of reactor units 3 and 4, which remained connected to the main electrical grid. The team was also informed that radiation levels remained normal during the entire event, which was confirmed by the IAEA’s own measurements.
All other nuclear facilities at the Chornobyl site continued to receive off-site power from other power lines without interruption. However, the plant reported fluctuations in off-site power affecting the other facilities at the site during the event and continues to assess the situation.
The Slavutych 330 kV power line remains disconnected, and the town with the same name – where most plant staff live – has no electricity, relying instead on diesel generators.
The IAEA team at the Chornobyl site was also informed that temporary repairs on the outside of the NSC arch are expected to be completed today following the February attack, meaning it will be fully covered from the outside.
In the 158th delivery of equipment to Ukraine since the start of the armed conflict, the South Ukraine NPP has received two mobile portal monitors aimed at enhancing nuclear security measures at the site. The equipment was funded with contributions made by Norway.