| TOKYO, March 18, Kyodo Japan raised the severity level of crisis-hit reactors at the Fukushima Daiichi nuclear power plant to 5 on a 7-level international scale, the same level as the Three Mile Island accident in the United States in 1979, Japan's nuclear safety agency said Friday. The provisional evaluation stands at level 5 of the International Nuclear and Radiological Event Scale for the plant's No. 1, No. 2 and No. 3 reactors as their cores are believed to have partially melted and radiation leaks continue, the government's Nuclear and Industrial Safety Agency said. While efforts to cool down the overheating reactors and spent fuel continued a week after the plant was crippled by a massive earthquake and tsunami, Tokyo also reiterated its resolve to do everything to control the situation with International Atomic Energy Agency chief Yukiya Amano arriving in Tokyo. ''This is the largest crisis for Japan,' Prime Minister Naoto Kan told Amano at the outset of their meeting in Tokyo. ''Every organization (of the government)...is making all-out efforts to deal with the problem,'' he said, adding Japan will disclose more information to the international community. The agency put the level at 3 for the Fukushima Daiichi plant's No. 4 reactor, where an overheating spent fuel pool is also posing risks, and three reactors at the Fukushima Daini plant that have been controlled. An unprecedented cooling mission, which was launched Thursday by the Self-Defense Forces by spraying tons of water over the Daiichi plant's No. 3 reactor building, was bolstered on the second day with more pumps, after efforts were focused in the morning to restore power to some of the reactors' cooling systems, the government said. SDF fire trucks shot 50 tons of water at a spent fuel pool of the No. 3 reactor in the afternoon, along with a high-pressure water cannon truck loaned by the U.S. military, after aiming up to 60 tons of water at it along with two helicopters the day before. The Tokyo Fire Department was slated to join in the operation, likely at the plant's No. 1 reactor, with 30 trucks capable of discharging massive amounts of water to high places and some 140 disaster relief specialists of its ''hyper rescue'' team. Radiation readings at the disaster-hit nuclear plant have consistently followed a downward path through Friday morning, according to data taken roughly 1 kilometer west of the plant's No. 2 reactor, but plant operator Tokyo Electric Power Co. stopped short of calling the move a trend. The radiation level at 11 a.m. dropped to 265.0 microsievert per hour from 351.4 microsievert per hour at 12:30 a.m. Thursday. It measured 292.2 microsievert per hour at 8:40 p.m. Thursday, shortly after SDF trucks sprayed water at the No. 3 reactor pool as part of efforts to avert any massive emission of radioactive materials into the air from the facility. It also fell below 0.1 microsievert per hour to levels below those seen before the crisis in the Kanto region surrounding Tokyo, except in Tochigi, Gunma and Saitama prefectures that still measured higher figures and Miyagi from which no data were reported, the education ministry said. Edano said radiation amounts near the Fukushima Daiichi plant ''do not pose immediate adverse effects on the human body,'' after the government's Nuclear and Industrial Safety Agency released data collected by Tokyo Electric, or TEPCO. Agency spokesman Hidehiko Nishiyama noted the difficulty in properly assessing the effects of the water-pouring mission from the radiation data, while they are all below 500 microsievert per hour, which requires the operator to report an emergency to the government if surpassed. TEPCO accelerated efforts to restore lost cooling function by reconnecting electricity to the plant through outside power lines, with workers trying to recover power at the plant's No. 1 and No. 2 reactors later Friday and at the No. 3 and No. 4 reactors by Sunday, according to Nishiyama. Some of the power distribution boards at the plant have been damaged by the quake-triggered tsunami and TEPCO will use makeshift replacement equipment, he added. The spent fuel pools at the power station lost their cooling function in the wake of the March 11 killer quake and tsunami. It is also no longer possible to monitor the water level and the temperatures of the pools in the No. 1 to 4 reactor buildings. Plumes of smoke or steam have been seen rising from three of them but not the No. 1 unit, the agency spokesman said, suggesting their pools situated outside the reactor containments are boiling, with those at the No. 3 and No. 4 units no longer covered by their roofs since they were blown off by hydrogen blasts earlier this week. A rise in the water temperature, usually at 40 C, causes the water level to be reduced, and exposes the spent nuclear fuel rods, which could heat up further and melt and discharge high radioactive materials in the worst case scenario, experts say. Among the six reactors at the Fukushima Daiichi Nuclear Power Station, the No. 1, No. 2 and No. 3 reactors that were operating at the time of the magnitude 9.0 quake halted automatically, but the cores are believed to have partially melted as they lost their cooling function after the quake. The buildings housing the No. 1, No. 3 and No. 4 reactors have been severely damaged, leaving uncovered the fuel pools, and the No. 2 reactor's containment vessel suffered damage to its pressure-suppression chamber at the bottom. The government has set the exclusion zone area to a 20-kilometer radius of the plant, and urged people within 20 to 30 km to stay indoors. ==Kyodo |