Power unit five of the temporarily occupied Zaporizhia Nuclear Power Plant is being transferred to cold shutdown, the IAEA press service reported.

"Once in cold shutdown, the ZNPP will carry out tests to identify why low levels of boron were found in the secondary cooling circuit of one of the unit’s steam generators," the IAEA said.

After power unit five is transferred to cold shutdown, only one of the plant's six reactors will remain in hot shutdown to produce steam and heating.