Ukraine informed the International Atomic Energy Agency (IAEA) on 19 March that Ukrainian engineers had repaired and reconnected one of three previously disconnected power lines linking the Zaporozhye nuclear power plant to the electricity grid.

The repair of the power line means that the plant now has three off-site lines available, Ukraine’s regulatory authority added. Nuclear power plants use the lines to send the electricity they generate to the grid and, if required, to obtain power themselves.

The Zaporozhye NPP has four high voltage (750 kV) external power lines plus one on standby. It has in recent weeks lost connection to three of them, but the regulator said one was reconnected in the evening of 18 March. It had earlier said it was expected to be reconnected on 22 March.

The regulator reiterated that the nuclear power plant safety systems were fully functional. It was not known when the two other non-operational lines could be reconnected, it added.

Russian forces took control of the Zaporozhye nuclear power plant on 4 March. Of its six reactors, two are operating. These two reduced power generation to 500MWe from 1000MWe each after a break on 17 March in an on-site power line, but they increased it again to 600MWe after it was fixed and reconnected later the same evening, the regulator said.

In an official note to the IAEA on 19 March on the “current situation of safety of Ukrainian nuclear facilities”, the Russian Federation claimed that at the Zaporozhye NPP “the rotation of personnel is carried out in a regular mode” and that “there are no problems with spare parts”. It also said that “explosive objects ….  on the territory” of the nuclear power plant after events on 4 March “were eliminated”.

Staff allowed to rotate at Chernobyl

In northern Ukraine, the Chernobyl nuclear plant remained connected to the power grid after engineers on 14 March restored power supplies that had been lost for five days, Ukraine's nuclear regulator told IAEA. 

In its note to the IAEA, the Russian Federation said that since 14 March, “the situation with the power supply of the Chernobyl nuclear power plant is completely stabilised”.

Russian forces took control of the Chernobyl site on 24 February. The same work shift had been on-site since the day before the Russian forces entered the area. However, Ukraine informed the IAEA on 20 March that "around half of the staff" at the Chernobyl Nuclear Power Plant had finally been able to rotate and return to their homes after working at the Russian-controlled site for nearly four weeks.

“It is a positive – albeit long overdue – development that some staff at the Chernobyl NPP have now rotated and returned to their families," said IAEA director general Grossi. "They deserve our full respect and admiration for having worked in these extremely difficult circumstances. They were there for far too long. I sincerely hope that remaining staff from this shift can also rotate soon.”

Operating status of Ukraine nuclear plants

On the status of Ukraine’s four operational nuclear palnts, the Ukrainian regulator said eight of the country’s 15 reactors remained operating, including the two at the Zaporozhye, three at Rovno, one at Khmelnitsky, and two at South Ukraine. The radiation levels at all sites are in the normal range and safety systems are operating, it said.

In relation to safeguards, the Agency said that the situation remained unchanged. The IAEA was still not receiving remote data transmission from its monitoring systems installed at the Chernobyl site, but such data was being transferred to IAEA headquarters from the other nuclear sites in Ukraine.

Director General Grossi said he is continuing his consultations with a view to agreeing on a framework on the safety and security of Ukraine’s nuclear facilities. “With this framework in place, the Agency would be able to provide effective technical assistance for the safe and secure operation of these facilities,” he said.

In Kharkov, IAEA said on 18 March, citing the regulator, that there was no external power supply to a nuclear research facility that was previously damaged by shelling, but its personnel were still maintaining the operability of its equipment. Radiation levels remained within background levels, it said. The facility is used for research and development and radioisotope production for medical and industrial applications. As such, the IAEA has assessed that the reported damage or loss of external power would not have had any radiological consequence.