Unit 4 on the Zaporizhzhia nuclear energy plant is being switched from sizzling shutdown to chilly shutdown following the detection of a water leak at considered one of its 4 steam mills. In the meantime, unit 6 is being moved to sizzling shutdown to proceed steam manufacturing on the positioning.
Zaporizhzhia unit 4 was switched to sizzling shutdown in late July, with unit 5 switched from sizzling to chilly shutdown to permit upkeep work to be carried out. That call was taken by the operators of the nuclear energy plant, which has been below Russian army management since early March final 12 months.
“Because of transferring energy unit 4 of the briefly occupied Zaporizhzhia NPP right into a sizzling shutdown state, in breach of the licence phrases and Energoatom necessities, an incident occurred with a primary-to-secondary water leak,” Ukrainian nuclear operator Energoatom stated. “This occurred because of a violation of the integrity of the third steam generator positioned within the containment of the unit.”
The unit is now being positioned again into chilly shutdown to find out the exact explanation for the water leak that has been detected and to conduct upkeep to restore the affected steam generator. The Worldwide Atomic Vitality Company (IAEA), which has specialists on-site to observe the plant, confirmed there was no radiological launch to the setting.
Unit 6 – which has been in chilly shutdown since 21 April to allow inspection and upkeep of the protection methods – will probably be transferred to sizzling shutdown to proceed steam manufacturing. The location makes use of the steam generated from one reactor unit in sizzling shutdown for numerous nuclear security functions together with the processing of liquid radioactive waste collected in storage tanks.
The IAEA stated its group on the positioning will carefully monitor the operations for the transition between the shutdown states of models 4 and 6. The opposite models on the plant stay in chilly shutdown, it famous.
Energoatom famous that bringing unit 6 into sizzling shutdown “is one other breach of the licence phrases and Energoatom necessities”.
The State Nuclear Regulatory Inspectorate of Ukraine issued regulatory orders in June for all six models to be positioned in chilly shutdown, given its scenario on the frontline of the warfare, and the breaching of the dam that had helped guarantee plentiful cooling water provides. The Russian operators of the plant say such a transfer isn’t required from a “authorized or technological perspective”. The IAEA has urged investigation into whether or not an exterior boiler may very well be put in on the web site to generate the steam required, so all models may very well be moved to chilly shutdown.
In the meantime, the 750kV Dniprovska energy line offering exterior energy to the Zaporizhzhia plant disconnected twice on 10 August, first for about 12 hours after which once more for nearly three hours. These disconnections meant that the plant needed to depend on its solely remaining off-site energy line, the 330 kV backup line, to produce the electrical energy that it required.
“The repeated energy line cuts underline the persevering with precarious nuclear security and safety scenario on the plant,” stated IAEA Director Normal Rafael Mariano Grossi.