The oil and gas that Russia loses each year in leaks and spills could provide enough energy to allow the country to close its nuclear power plants, Greenpeace said yesterday. Between 70 million and 140 million barrels of oil are spilled annually in Russia, out of the approximately 2.1 billion barrels the nation produces, the group says. Greenpeace’s announcement came on the eve of the 14th anniversary of the Chernobyl nuclear disaster. About 1,500 Ukrainian survivors of Chernobyl marched with their families through Kiev on Sunday to protest against diminishing government assistance. The Ukrainian government has promised to shut down the Chernobyl plant, but has not committed to a date.