The International Atomic Energy Agency (IAEA) has been informed by the Zaporizhzhya Nuclear Power Plant (ZNPP) that an external radiation monitoring station was destroyed by shelling and fire this week, further reducing the effectiveness of its off-site capability to detect and measure any radioactive release during an emergency, Director General Rafael Mariano Grossi said today.
The ZNPP informed the team of IAEA experts at the site that it lost the connection to this monitoring station – located around 16 kilometres south-west of the plant – on Monday afternoon. Due to the security situation, the team was unable to access the location to confirm the damage.
Since early 2022, several radiation monitoring stations within a 30-kilometre area around the ZNPP have been out of service for varying periods of time due to damage sustained as a result of the conflict. Four stations, more than a quarter of the pre-conflict total of 14, are currently unavailable.
The latest incident came just a few days after a 16-hour loss of power in the nearby city of Enerhodar – home to most ZNPP staff – had caused a temporary halt in the operation of some of the environmental radiological monitoring stations after they ran out of back-up battery.
“The functioning of off-site radiation monitoring equipment is an essential part of nuclear safety around the world. These systems are important for continuously monitoring radiation levels and, in the case of an emergency, for quickly assessing the ongoing and potential radiological impact and what protective actions may need to be taken,” Director General Grossi said.
“The loss of one radiation monitoring station does not have a direct impact on safety at the ZNPP, but it forms part of a continuous erosion of a range of safety measures during the war that remains a deep source of concern,” he added.
Radiation monitoring is among the seven indispensable pillars for ensuring nuclear safety and security during an armed conflict, with pillar 6 stressing that “there must be effective on-site and off-site radiation monitoring systems, and emergency preparedness and response measures”.
As a major nuclear power country, Ukraine is among 51 countries participating in the IAEA’s International Radiation Monitoring System (IRMIS), which gathers radiation monitoring data from over 6000 monitoring stations worldwide, part of nationally operated networks.
The ZNPP is continuing to face other challenges related to nuclear safety and security during the conflict. On most days over the past week, the IAEA experts continued to hear explosions at some distance from the site.
They have also continued to closely monitor the cooling water situation at the site, a year after the destruction of the downstream Kakhovka dam forced the plant to look for alternative supplies of the water needed to cool its six reactors. As part of these efforts, it dug 11 groundwater wells last year that now provide sufficient water required for the current cold shutdown state of all units and its safety systems.
At the same time, the plant is trying to maintain the water level in its main cooling pond, a task that is especially challenging in hot summer weather, which has caused a decline of up to a quarter of the water it receives from other sources. Over the past year, the pond’s water level has declined by 1.5 metres to just over 15 metres.
The IAEA team recently confirmed that the total amount of water currently being pumped into the cooling pond is around 310-350 cubic metres per hour (m3/h), both from the discharge channel of the nearby Zaporizhzhya Thermal Power Plant (ZTPP) as well as excess water from the 11 wells.
“When the six reactors are all shut down, the water from the wells is sufficient for cooling. But it remains a challenging situation that requires constant monitoring and assessment,” Director General Grossi said.
The team has continued to carry out walkdowns across the site, including to all six main control rooms (MCRs) to observe the situation regarding key operational staff, some of whom have been newly appointed to their positions at the ZNPP in recent months.
Earlier this week, the IAEA team attended the testing of an emergency diesel generator (EDG) for part of the safety system of reactor unit 4. The ZNPP staff simulated a loss of off-site power that triggered the diesel generator to start up within 11 seconds, in line with the safety requirements of the EDG.
Separately, the experts confirmed with ZNPP that activities for the preservation of equipment are being undertaken in the turbine hall of unit 5 during a visit to the building, but they were again prevented from accessing its western part.
Also, this week, the team discussed emergency preparedness and response arrangements on-site during a visit to the site’s temporary on-site emergency centre.
On Sunday, 23 June, the IAEA experts performed radiation monitoring during a walkdown within the site perimeter, which it performs routinely once a week. All radiation levels on the site were normal and the results were published on IRMIS.
The IAEA experts present at the Khmelnytskyy, Rivne and South Ukraine nuclear power plants (NPPs) and the Chornobyl site reported that nuclear safety and security is being maintained despite the effects of the ongoing conflict, including air raid alarms on several days over the past week.
Early on Thursday morning, 27 June, the IAEA experts at the South Ukraine NPP went to the shelter in their hotel after hearing small arms fire nearby. They were later informed that there had been military action in the region, but that it had not targeted the hotel or the plant.
Planned maintenance and refuelling activities continue at two of the three units of the South Ukraine NPP and one of the four units at the Rivne NPP. The IAEA experts at the Chornobyl site safely rotated at the end of last week.
As part of the IAEA’s efforts to support Ukraine in maintaining nuclear safety and security during the armed conflict, the Agency this week arranged two new deliveries of equipment to the country. It brings the total number of deliveries to 51 since the start of the conflict.
This week, the Rivne NPP received auxiliary equipment important for nuclear safety. Separately, the Public Health Centre of the Ukrainian Ministry of Health received gamma spectrometers to enhance its analytical capacity to monitor radionuclides in the environment at laboratories located in the cities of Khmelnytskyy, Rivne, Kirovohrad, Kherson, Uzhorod and Mykolaiv. This week’s assistance was supported through the extrabudgetary contributions of Canada, Japan, the Republic of Korea and the United Kingdom. In total during the conflict, nuclear safety- and security-related equipment worth 9.8 million euros has so far reached various organizations in Ukraine.