MOSCOW, April 25 (RIA Novosti) – The use of US fuel at Ukrainian nuclear power plants will negatively impact their power production, Valentin Ivanov, General Director of Bochvar High-Technology Research Institute of Inorganic Materials told RIA Novosti Friday.

“While using the US fuel, Ukrainian nuclear power plants will be working less and stopping more often," the expert said.

The cladding that surrounds Russian and American fuel assemblies are made from very different materials, he explained.

"The fuel produced by the Americans in the late 1990s to early 2000s wasn’t quite good," Ivanov said, adding that it proved incompatible with Ukrainian reactors.

“Therefore Ukrainians in their time refused to use American fuel at Soviet-designed nuclear plants,” he said.

Ukraine's state-run Energoatom and US nuclear company Westinghouse recently agreed to a contract on supplies of nuclear fuel for three Ukrainian reactors. Nuclear safety experts have raised concerns over the decision, as it could pose a threat to the safe operation of Ukraine’s reactors.

The move revealed Ukraine's desire to ease its dependence on Russia for nuclear fuel. The country has 15 VVER reactors built during Soviet times, which use fuel imported from Russia.

A Czech nuclear power plant saw depressurization of Westinghouse fuel elements several years ago, which led the Czech government to abandon the company as a fuel supplier.