Mr Kotin said he had discussed the issue of Ukrainian nuclear power plants with IAEA director-general Rafael Grossi.
Mr Kotin said there are movements of Russian columns of military equipment near nuclear plants and shells have been fired.
He said: “This can lead to extremely undesirable threats on a planet-wide scale.”
Mr Kotin called on the IAEA to help put pressure on Russia and the end of the war in Ukraine.
Earlier, denying a Russian claim of control of the Zaporozhye nuclear station, Energoatom said that “Russian propaganda media reports that the invaders allegedly took control of the facility are a cynical fake”.
Zaporozhye, in the east of the country near the disputed region of Donetsk, is Ukraine’s largest nuclear power station, with six operating reactors each rated at 1,000 MW gross (950 MW net). It is also Europe’s largest nuclear power station and Ukraine’s largest electricity-generating asset.
A statement on the website for the Zaporozhye station indicates at as of 17:00 local time on Tuesday, the facility was continuing to operate “normally”. The statement added: “The physical protection service of Zaporozhye NPP operates on a full-time basis. Military unit 3042, which guards the Zaporozhye NPP, is in combat readiness.”
All four of Ukraine’s commercial nuclear stations (Zaporozhye, Rivne, Khmelnitski and South Ukraine) remained under the control of Ukraine and operating normally. Zaporozhye has six reactors and Ukraine has 15 in total, with nine in operation and the rest either offline for scheduled outages or in reserve.
Energoatom said: “There are no violations of safe operation conditions. Radiation, fire and environmental conditions at all nuclear power plants and adjacent territories have not changed and are within the current norms.”
A statement on the website of the Zaporozhye station indicated it was continuing to operate normally. Courtesy Zaporozhye NPP.
Mr Grossi said any military or other action that could threaten the station’s safety or security must be avoided.
“I continue to follow developments in Ukraine very closely and with grave concern, especially the conflict’s potential impact on the safety and security of the country’s nuclear facilities, Mr Grossi said. “It is extremely important that the nuclear power plants are not put at risk in any way.”
He added: “An accident involving the nuclear facilities in Ukraine could have severe consequences for public health and the environment.”
Underlining such risks, Ukraine’s nuclear regulator SNRIU told the IAEA on Sunday that missiles had hit the site of a radioactive waste disposal facility in the capital Kyiv, but there was no damage to the building and no reports of a radioactive release.
Ukraine last week confirmed that Russian forces had taken control of the facilities of the State Specialized Enterprise Chornobyl NPP, within the exclusion zone set up after the 1986 accident.
SNRIU said the shift supervisor at the site had not been replaced since 24 February but that he continued to perform his duties. SNRIU also provided radiation readings from the site which the IAEA assessed as low and in line with near background levels.
Mr Grossi said staff at all nuclear facilities must be able to work and rest. He reiterated his call upon those in effective control of nuclear sites not to take any actions that could compromise their safety or put them under undue pressure.
