The US has sensitive nuclear technology at a nuclear power plant inside Ukraine and is warning Russia not to touch it, according to a letter the US Department of Energy sent to Russia’s state-owned nuclear energy firm Rosatom last month. “It is unlawful under United States law for non-authorized persons, including, but not limited to, Russian citizens and Russian entities,” the letter says, “such as Rosatom and its subsidiaries, to knowingly and willfully access, possess, control, export, store, seize, review, re-export, ship, transfer, copy, manipulate such technology or technical data, or direct, or authorize others to do the same, without such Russian entities becoming authorized recipients by the Secretary of the US Department of Energy. ”The Energy Department’s Office of Nuclear Energy has been public about the US’ support for the plant, and stated on its website in June 2021 that “the United States helped implement new maintenance procedures and operations at the reactor that should ultimately strengthen energy security” in Ukraine