The fifth power unit of the occupied Zaporizhzhya nuclear power plant was put into "cold shutdown" mode, after the fourth power unit was put into "hot shutdown".
This is stated in the report of the International Atomic Energy Agency (IAEA), whose inspectors are at the ZNPP.
It is stated that it was decided to cool down the fifth reactor “in order to carry out maintenance activities at unit 5 that are only possible in cold shutdown”.
This happened three days after the fourth power unit was transferred from cold to hot shutdown. Now steam from the fourth power unit is used for wastewater treatment. Other reactors are in "cold shutdown" mode.
The IAEA says that the organizationʼs experts suggested installing an external steam boiler at the ZNPP in order to put all power units into cold shutdown mode, but the Russian administration apparently did not go for it. They also checked the condition of the fifth power unit after its cooling — the equipment is in normal condition.
Regarding mines, the organizationʼs experts did not find any mines or explosives inside the power unit. However, mines still remain around the perimeter of the station. Also, the occupiers do not allow experts on the roofs of power units, where, according to Ukrainian intelligence, there may be explosives.
- "Enerhoatom" said that all power units of the Zaporizhzhia NPP should be in a cold state. "Cold shutdown" is currently the safest mode of their operation, especially after the loss of a reliable source of water supply for the Zaporizhzhia NPP — the Kakhovka reservoir due to the explosion of the Kakhovka HPP.
- The "hot shutdown" mode is when the hot water generated during the stationʼs operation is used to heat buildings. The water is heated by the reactor, which is not working. In case of launching more power units, there will not be enough water in the pond to cool the reactors. "Cold shutdown" is a safe state of the reactor, as it stops the nuclear reaction.