The strike occurred at 18:18 Kyiv time, according to the State Nuclear Regulatory Inspectorate of Ukraine. A fire that broke out on the institute's grounds was quickly extinguished and no one was injured.
"The reactor itself and systems important for safety were not damaged. No changes in the radiation background have been recorded; its readings remain within the natural background (0.16–0.20 μSv/h) and have not changed," the agency said.
An investigation and assessment of the damage are ongoing. Since February 2022 the VVR-M reactor has been in a shut-down state with its core fully unloaded. Its operation is limited to scheduled maintenance of systems important for safety.
The Institute for Nuclear Research of the National Academy of Sciences of Ukraine is the country's leading research institution in nuclear physics, nuclear power and radioecology. The reactor is used as a neutron source for fundamental and applied research.
The state inspectorate called the strike an attack on a peaceful nuclear installation performing an exclusively scientific function and said it showed cynical disregard for international norms of nuclear and radiation safety.
According to National Security and Defense Council secretary Ihor Klymenko, 235 air alerts with a total duration of 261 hours have been recorded in Kyiv since August 27.
On the afternoon of September 28, a Russian drone hit the building of the National Academy of Sciences in Kyiv. A large fire broke out, people were trapped inside and escaped through windows. Two people died, including Natalia Bukalo, an assistant to the academy's vice president. Ukrainian President Volodymyr Zelensky reported six injured, including three children.