Ukraine's energy system was severely damaged by a massed campaign of Russian air strikes last winter, making it more reliant on its ageing nuclear power stations, which supplied about half the country's power before the war.
"This guarantee that we will be providing is to help Ukraine ensure that ... their nuclear fuel doesn't have to come via Russia in future," Shapps told Reuters.
"This money will guarantee that it will come from much more secure sources."
He said that one of those sources would be Urenco, a part-British nuclear fuel consortium.
Ukraine currently controls three of its four active nuclear plants.
The fourth, in the southern region of Zaporizhzhia, was captured by Russia last March, after Russia's Feb. 22, 2022, invasion. Both sides have since repeatedly accused each other of endangering the facility's safety.
