Hyderabad: A unit of the Zaporizhzhya Nuclear Power Plant in Ukraine is being put on cold shutdown in order to investigate the exact cause of the leak and carry out necessary maintenance to repair the affected steam generator, Rafael Mariano Grossi, the International Atomic Energy Agency (IAEA) Director General, said.
Unit 4 is the one being transitioned from hot shutdown to cold shutdown. The IAEA said there was no radiological release to the environment. In the next three days, the nuclear power plant will move unit 6 to hot shutdown to continue steam production, the statement said.
Unit 6 had been in cold shutdown since 21 April to facilitate safety system inspections and maintenance, the IAEA noted.
“The IAEA team on the site will closely monitor the operations for the transition between the shutdown states of Units 4 and 6.”
'Power challenges'-Since the beginning of Russian invasion of Ukraine, the IAEA has been monitoring the situation at Europe’s largest nuclear power plant. At present, the ZNPP is controlled by Russian forces but operated by its Ukrainian staff.
Grossi said there were power disruptions on Thursday after the 750kV power line disconnected twice during the day.
The ZNPP had to rely on 330 kV backup line, to supply the electricity required, for example, to perform safety functions such as pumping cooling water for the plant; and there was no total loss of off-site power to the site and emergency diesel generators were not needed, he explained.
The ZNPP has been experiencing major off-site power problems since the invasion began in February 2022, exacerbating the nuclear safety and security risks facing the site currently located on the frontline, according to the agency.
“The repeated power line cuts underline the continuing precarious nuclear safety and security situation at the plant,” Grossi said.
Availability of cooling water remains relatively stable, with measures to mitigate water loss from the cooling pond by pumping in water from the ZNPP inlet channel, he added.
'IAEA experts’ site inspections'-IAEA experts at the nuclear power plant have also conducted multiple walkdowns in different parts of the site, including visits to spent fuel storage and reactor control rooms.
According to the IAEA, the team did not observe any mines or usual objects in the main control. However, in the turbine hall of unit 2, the team recorded the presence of a number of military trucks parked in an area reserved for vehicle maintenance.
While the team did not observe mines or explosives in any new locations during the past week, they did confirm the presence of the mines previously observed on 23 July, the IAEA statement said.
The team was told that a drone was spotted and intercepted near the city of Enerhodar on Wednesday. It was also revealed that it had no bearing on the plant’s safety.
It is pertinent to note that the IAEA teams at other Ukrainian nuclear power plants – Khmelnitsky, Rivne, and South Ukraine, as well as the Chornobyl site – reported air-raid alarms on Wednesday. It is said there no impact on safety and security at these facilities.
