Ukraine has told the International Atomic Energy Agency (IAEA) that technicians have started repairing damaged power lines in an attempt to restore external electricity supplies to the site of the Russian-controlled Chornobyl Nuclear Power Plant (NPP) that were entirely cut earlier in the week, Director General Rafael Mariano Grossi said today.
Ukraine's regulatory authority said work that began on the evening of 10 March had succeeded in repairing one section, but off-site electrical power was still down, indicating there was still damage in other places. The repair efforts would continue despite the difficult situation outside the NPP site, it added.
Emergency diesel generators have been providing back-up power to the site since 9 March, and the regulator has reported that additional fuel had been delivered to the facility. However, it remains important to fix the power lines as soon as possible, it said.
Adding to the challenges in managing the Chornobyl NPP, the regulator lost communications with the site on 10 March. As a result, it cannot provide information to the IAEA about the radiological monitoring at the facility. Despite this, the regulator has continued to receive information about the situation there through senior off-site management of the plant.
As reported in the IAEA's Update 17, the diesel generators are powering systems important for safety, including those for spent nuclear fuel and water control and chemical water treatment, the regulatory authority said, adding that the operator was not able to maintain some functions such as radiation monitoring, ventilation systems, and normal lighting.
Nevertheless, also as previously reported, the disconnection from the grid will not have a critical impact on essential safety functions at the site, where various radioactive waste management facilities are located, as the volume of cooling water in the spent fuel facility is sufficient to maintain heat removal without a supply of electricity.
However, staff at the Chornobyl NPP are facing increasingly difficult conditions. The 211 technical personnel and guards have in effect been living at the site for more than two weeks, the regulator said, expressing concern also about the availability of food reserves.
Elsewhere in Ukraine, the Zaporizhzhya NPP site power supply situation is unchanged from that reported in recent updates. The site has four high voltage (750 kV) offsite power lines plus an additional one on standby. Two of the four have been damaged. The operator has informed the IAEA that the NPP off-site power needs could be provided with one power line available. In addition, diesel generators are ready and functional to provide back-up power.
At the same NPP, work is ongoing to detect and dispose of unexploded munitions found in its damaged training centre and other places after the events there on 4 March, when Russian forces took control of Ukraine's largest nuclear power plant with six reactors, the regulator said.
Staff operating the plant were rotating according to their usual schedule, without interference in their day-to-day activities, the regulator said. However, the presence of foreign forces in the area was affecting work morale and causing pressure, it added. The regulator is maintaining contact with the plant, but the IAEA is experiencing difficulties in reaching the Zaporizhzhya NPP management.
In the city of Kharkiv, a new nuclear research facility that was also previously hit has suffered additional damage, the regulator said. The facility is used for research and development and radioisotope production for medical and industrial applications. Because its nuclear material is subcritical and the inventory of radioactive material is very low, the IAEA has assessed that the damage would not have had any radiological consequence.
Nevertheless, it highlighted once again the risks facing Ukraine's nuclear installations during the armed conflict, adding urgency to an initiative of Director General Grossi aimed at ensuring nuclear safety and security in the country.
On the status of Ukraine's operational nuclear power plants, the regulator said eight of the country's 15 reactors remained operating, including two at the Zaporizhzhya NPP, three at Rivne, one at Khmelnytskyy, and two at South Ukraine. Radiation levels at the four sites were normal, it said.
Regarding the partial loss of remote data transmission from safeguards systems installed to monitor nuclear material and activities at nuclear power plants, reported in Update 16, the IAEA said it was now back online from the Zaporizhzhya NPP but still down from the Chernobyl NPP, while there were intermittent problems with data transfer from the South Ukraine NPP.
