TOKYO. Officials from Japan`s nuclear agency reclassified the ongoing emergency from Level 5, an \u201caccident with off-site risk,\u201d to Level 7, a \u201cmajor accident.\u201d The reassessment comes at a time when the International Atomic Energy Agency says the plant is showing \u201cearly signs of recovery\u201d but is still in critical condition.<\/p>\n
At a news conference in Tokyo, Hidehiko Nishiyama, the chief of Japan`s Nuclear and Industrial Safety Agency, emphasized that radiation released from Fukushima amounted to one-tenth the total released from Chernobyl. But the plant continues to spew radiation, and at a separate news conference, an official from the Tokyo Electric Power Co. said that \u201cour concern is that the amount of leakage could eventually reach that of Chernobyl or exceed it.\u201d<\/p>\n
The stark assessment reinforced the sense that this nuclear emergency ultimately will cause problems that exceed those first predicted by the government, which has downplayed long-term safety concerns and only Monday expanded its mandated 12-mile radius evacuation zone.<\/p>\n
Still, the upgraded severity reading does not reflect a recent deterioration at the plant. Rather, it suggests Japan`s evolving understanding of the damage that occurred there one month ago\u00a0\u2014 and the contamination that has been leaking ever since.<\/p>\n
\u201cWe are taking this extremely seriously,\u201d Tokyo Electric said in a statement signed by its president, Masataka Shimizu. \u201cWe deeply apologize for tremendous concerns and inconvenience we are causing the residents in the neighboring areas of the power plant as well as people of [Fukushima] prefecture, and further, to the people of\u201d Japan.<\/p>\n
A Level 7\u00a0accident, according to the International Nuclear and Radiological Event Scale (INES), is typified by a \u201cmajor release of radioactive material with widespread health and environmental effects.\u201d That measuring scale was established by the IAEA some 21\u00a0years ago, but its guidelines leave plenty of room for interpretations, nuclear experts say.<\/p>\n
According to the Kyodo News agency, Japan`s Nuclear Safety Commission issued a recent report claiming that the Fukushima plant, at one unspecified point after the March 11\u00a0earthquake and tsunami, had been releasing 10,000\u00a0terabecquerels of radioactivity per hour. A release of tens of thousands of terabecquerels per hour corresponds with the leakage level that the IAEA recommends as a minimum benchmark for a Level 7\u00a0accident.<\/p>\n
\u201cThis corresponds to a large fraction of the core inventory of a power reactor, typically involving a mixture of short- and long-lived radionuclides,\u201d an IAEA document says. \u201cWith such a release, stochastic health effects over a wide area, perhaps involving more than one country, are expected.\u201d<\/p>\n
Most radiation readings around Fukushima have been decreasing for several weeks now, but the plant still faces numerous risks. Thousands of tons of contaminated water has flooded key buildings adjacent to the reactors. Nitrogen gas is being injected into one unit to prevent another explosion.<\/p>\n
In the meantime, the plant faces the constant threat of aftershocks, and on Tuesday a 6.2-magnitude temblor caused a brief fire at a building near Daiichi`s No. 4\u00a0reactor. Tokyo Electric said the aftershock did not interrupt the critical injection process used to cool hot fuel rods\u00a0\u2014 but there had been a 50-minute interruption one day earlier, the result of a 6.6-magntiude quake with an epicenter just 42\u00a0miles from the plant.<\/p>\n
\u201cRight now, the situation of the nuclear reactors at the Fukushima plant has been stabilizing step by step,\u201d Prime Minister Naoto Kan said in a televised address to the nation. \u201cThe amount of radiation leaks is on the decline. But we are not at the stage yet where we can let our guards down.\u201d<\/p>\n
Though the Fukushima crisis now stands alongside Chernobyl on the INES event rating, experts note several important distinctions. No deaths have yet resulted from radiation leaked at Fukushima. At Chernobyl, a single reactor exploded, and a massive cloud of cesium, plutonium and strontium spread across Belarus, Ukraine, Russia and Europe. At Fukushima, workers have struggled to stabilize seven reactors and spent fuel pools, but so far the radioactive releases have come as byproduct of emergency cooling efforts, with the venting of radioactive steam and the leaking of contaminated water.<\/p>\n
Technically, Japan`s reassessed severity rating applies to only three of Fukushima`s six units\u00a0\u2014 Nos. 1, 2\u00a0and 3, which have all sustained core damage. Each of those units, on March 18, had been initially given a Level 5\u00a0rating. At the same time last month Japan gave a Level 3\u00a0rating to unit 4; that remains unchanged. The IAEA cautioned that Japan could still change its ratings as more information becomes available.<\/p>\n
The latest reevaluation underscores the difficulty of measuring the amount of contamination released and the danger it poses. Rather than creating a hard \u201cno-go\u201d circle around the plant, the government has instead singled out five particular towns between 12\u00a0and 19\u00a0miles from the plant for mandatory evacuation. Residents there should leave within a month, the government said.<\/p>\n
Those who stay are at risk of receiving more than 20\u00a0millisieverts of radiation in a year\u00a0\u2014 the government`s baseline for evacuations. Exposure at that level doesn`t cause immediate sickness, but it raises risk for cancer and other long-term health problems.<\/p>\n
Japan`s various nuclear regulatory groups have come up with widely differing numbers regarding the total contamination released into the environment.<\/p>\n
The Nuclear and Industrial Safety Agency, for instance, says that 6,000\u00a0terabecquerels of cesium-137\u00a0have been released. Japan`s Nuclear Safety Commission, meanwhile, quotes a number twice that. Much of that contamination, though, was released in the first week after an earthquake and tsunami knocked out Fukushima Daiichi`s primary and back-up power supplies, stopping the cooling of the reactors` cores.<\/p>\n
\u201cMonitoring data available shows that, in my view, the government probably knew around March 16, 17\u00a0or 18\u00a0that it would reach Level 7,\u201d said Hironobu Unesaki, a professor at the Kyoto University Research Reactor Institute. \u201cI just don`t understand why it took them so long to raise the level to 7. They were completely slow. \u2026 Their response has been extremely regrettable. The government is being very careful not to cause unnecessary panic, but they are being too cautious.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"
Japanese authorities on Tuesday raised the severity rating of the nuclear crisis at the Fukushima Daiichi power plant to the highest level on an international scale, on a par with the 1986\u00a0Chernobyl disaster. TOKYO. Officials from Japan`s nuclear agency reclassified the ongoing emergency from Level 5, an \u201caccident with off-site risk,\u201d to Level 7, a…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[15],"tags":[],"class_list":["post-11613","post","type-post","status-publish","format-standard","hentry","category-novosti-otrasli"],"translation":{"provider":"WPGlobus","version":"3.0.6","language":"en","enabled_languages":["ru","en"],"languages":{"ru":{"title":true,"content":true,"excerpt":false},"en":{"title":false,"content":false,"excerpt":false}}},"acf":[],"yoast_head":"\n