Russia's Rosatom said late last month that its fuel deliveries to Ukraine remain uninterrupted, despite the ongoing political turmoil in the country. Rosatom reaffirmed that it remains a stable international partner and will fulfill all contractual obligations, including nuclear fuel deliveries.

A switch to a foreign supplier of nuclear fuel may help Ukraine diversify away from Russian energy resources, yet the country's plants were designed to work best with Russian-produced components, and the new fuel could cause serious problems in their safe operation.

In 2012, the power-generating units at a Ukrainian nuclear plant experienced problems while conducting a trial run of a special Westinghouse fuel blend made for Soviet and Russian reactors. Ukrainian technicians later traced the problems to defects on the part of Westinghouse.

US-based Westinghouse, a major multinational specializing in nuclear engineering for electricity production, had already tested its products in Soviet-built plants in Ukraine during the presidency of the pro-Western Viktor Yushchenko.

The current attempt to re-start supplies comes as the country's energy security is at stake after Russia's Gazprom has withdrawn a discount on natural gas provided by Moscow under earlier agreements to aid the country's ailing economy.