"After 20 years of negotiations we have reached an agreement and the fuel is being loaded into containers as we speak," said Vyacheslav Kuvshinov, director of Joint Institute for Power and Nuclear Research.

Kuvshinov said the spent fuel was from the now-defunct IRT-M nuclear research reactor and various research projects at the institute between 1954 and 1987, including one to develop a transportable nuclear power installation, dubbed Pamir.

Under the agreement, the spent fuel will be retrieved from Belarus by November.

Russia announced during the Washington nuclear summit in April that it would remove the remaining quantities of Russian-origin highly enriched uranium fuel from ex-Soviet states and former Warsaw Pact countries.

However, Belarusian President Alexander Lukashenko said shortly after the Washington summit that his country would hold on to its arms-grade uranium and use it for research purposes or as fuel for the future nuclear power plant.

Belarus, which was one of the countries most affected by the Chernobyl nuclear disaster in 1986, plans to build a nuclear power plant in its western Grodno region, with the first reactor expected to be put into service in 2016 and the second in 2018.

The Russian nuclear equipment export monopoly, Atomstroyexport, is to implement the project, but the signing of the contract has been delayed due to cost disagreements.