Evidence of multiple meltdowns at Japan's crippled Fukushima nuclear plant has forced officials to change the way they hope to shut down the earthquake and tsunami-ravaged facility. The Tokyo Electric Power Company said on Tuesday that work is starting immediately on a new system to reduce the risk of radioactive water contaminating groundwater.TEPCO said a new drainage system will pump the water to a reprocessing facility to be cleaned before being sent back into the cooling system. It also plans to build new structures around three reactors to prevent radiation from leaking out and to shield the reactors from typhoons. Recent findings have confirmed fears that fuel rods inside one reactor were fully exposed to the air and melted. Other reactors could be in a similar condition. Officials said they still expect to bring the Fukushima plant under control by next January as previously planned.The United Nations nuclear agency said that it is sending an international delegation to Japan on a fact-finding mission next week. The International Atomic Energy Agency said a group of about 20 nuclear experts will visit Japan, including the crippled plant, from May 24 to June 2. The experts will give their assessment of the crisis to a four-day ministerial conference of IAEA member nations later in June.