TOKYO -- Japan has agreed to build a floating treatment facility to help Russia properly dispose of the liquid nuclear waste it has been dumping into the Japan Sea, a Foreign Ministry official said Friday. The two governments have agreed in principle that Japan will pay for most of the plant's cost with money from a $95.24 million grant already extended to Russia for dismantling nuclear warheads, he said. Russia has estimated the cost of building such a plant, which concentrates the liquid waste into solid form for easier disposal, at 10 billion rubles ($8.4 million). The waste comes from nuclear warships in Russia's Pacific Fleet.