| http://english.kyodonews.jp/news/2011/03/80273.html TOKYO, March 22, Kyodo All six reactors at the quake-stricken Fukushima Daiichi nuclear power plant have been reconnected to external power, plant operator Tokyo Electric Power Co. said Tuesday, although smoke detected at the No. 2 and No. 3 reactors the day before had temporarily hampered efforts to restore power and cool down spent nuclear fuel pools. Tokyo Electric said that it has restored lighting in the control room for the No. 3 reactor, a move that is expected to allow for more intensive work to bring the nuclear crisis under control and to restore the reactors' key cooling functions. Tokyo Electric Executive Vice President Sakae Muto said, ''I think the situation will head toward a better direction, but it is too early to say that things have stabilized sufficiently.'' The spokesman of the government's nuclear safety agency, Hidehiko Nishiyama, told a separate press conference in the afternoon that if electricity starts to work, the actual condition of the plant would become ''visible'' and authorities would be able to check whether the current measures are sufficient to contain the crisis. He also gave reassurance that a critical full-scale ''meltdown'' -- in which fuel rods melt completely or reach criticality again -- is unlikely. While the prospects for an end to the crisis remain uncertain, executives of the utility known as TEPCO apologized in person for the first time since the March 11 quake crippled the nuclear plant to people who had been living near the plant and have now been evacuated. Although white smoke, possibly steam, was found to be billowing from the buildings of the No. 2 and No. 3 reactors from Monday, TEPCO resumed the work to restore electricity in the morning as it found radiation levels had not surged markedly at the site. Regaining power supply is needed for the restoration of equipment such as a ventilation system to filter radioactive substances from the air and some measuring tools in the control room, as well as to eventually restore the reactors' key cooling functions that were lost in the quake and ensuing tsunami. At present, workers cannot remain in the room for long hours due to high radiation levels and power outages. The number of reactors to which external power has been connected increased from Sunday, with the last being the No. 3 reactor, but workers need to check the condition of each piece of equipment before transmitting power, according to the Nuclear and Industrial Safety Agency. Efforts to cool down spent fuel pools, which could create the risk of radioactive substances being released if water is not replenished, also resumed in the afternoon and firefighters sprayed a massive amount of water onto the spent nuclear fuel pool at the No. 3 reactor. The water-spraying mission for the No. 4 reactor, meanwhile, was joined by trucks with a concrete squeeze pump and a 50-meter arm confirmed to be capable of pouring water from a higher point after trial runs. After the magnitude 9.0 quake and massive tsunami waves knocked out power at the plant, the cooling functions failed at the No. 1, No. 2 and No. 3 reactors and their cores are believed to have partially melted. The three were operating at the time of the quake. The pools storing spent nuclear fuel outside the reactors at the No. 2, No. 3 and No. 4 units have all lost their cooling functions, requiring water to be pumped in, while hydrogen explosions have blown off the roofs and upper walls of the buildings housing the No. 1, No. 3 and No. 4 units. Defense Minister Toshimi Kitazawa told a news conference that he believes the smoke rising from the No. 2 reactor is vapor caused by water-discharging operations and that blackish smoke was briefly detected Tuesday at the No. 3 reactor as some debris caught fire following the rise in temperature. Japanese defense authorities have also asked for support of the U.S. military to jointly tackle the ongoing nuclear crisis and coordination is under way, Kitazawa said. Self-Defense Forces helicopters will begin measuring ''drastically changing'' temperatures at the plant every day except for rainy days to ''relieve people's concerns,'' instead of the earlier planned twice a week, he added. On Tuesday, however, bad weather prevented the choppers from monitoring temperatures at the site. The head of the Nuclear Safety Commission, which has a supervisory function over the nuclear safety agency, admitted to a parliamentary committee that its preparations to prevent nuclear accidents were based on optimistic projections and said it must review nuclear safety regulations ''drastically.'' Prime Minister Naoto Kan ordered the safety commission and the nuclear safety agency to step up cooperation, Haruki Madarame, chair of the commission, said. TEPCO, meanwhile, confirmed the spread of seawater pollution near the nuclear plant Tuesday, a day after detecting highly concentrated radioactive substances such as iodine and cesium in seawater near the plant's water discharge outlets, which the nuclear safety agency said do not pose an immediate danger to health. The No. 5 and No. 6 reactors have been less problematic than the others and achieved what is called ''cold shutdown'' on Sunday, meaning that the reactors have stopped safely with the temperature of the water inside the reactors falling below 100 C. ==Kyodo |