Japan Eyes Of The Potential Harm Of Spent Nuclear Fuel
Japanese lawmakers concerned about the damage reduces the remaining fuel from the spent activated Fukushima Daiichi Nuclear Power Plant Reactor No. 4 Thursday, said the high radiation levels reported earlier this week “probably” came from outside debris.
A reading above the pool called the factory owner, Tokyo Electric Power Company, to collect a sample of the spent fuel pool on Tuesday. However, radiation levels are well below what would be if there was damage to the fuel rods, “said Hidehiko Nishiyama, the chief spokesman for the Nuclear and Industrial Safety Commission of Japan.
“We need more analysis to identify the exact status of spent fuel from Unit 4,” he said.
Tokyo Electric said Thursday that the sample was the first time they took a reading of one of the pools of spent fuel. Water temperature at point 4 of the pool was 90 degrees Celsius, more than twice normal playback, and cooling water was poured into the reservoir on Wednesday.
The company said it suspects the fuel rods were damaged due to insufficient coolant in the time since the crisis began, but could not specify when.
Nishiyama said Thursday evening that the fuel rods have not been subjected to “any particular damage.” Officials are always looking for action from the water sample before reaching a final conclusion, but said that the radiation reading was “very likely due to dirt” blown into homes severely damaged in the reactor No. 4.
Tokyo Electric Power Company reported a cumulative radiation reading above the pool of 84 mSv Tuesday, about a third of the annual allowable dose to plant workers in an emergency. Samples of pool water showed a concentration of radioactive iodine-131, the reactor most commonly measured by-product of 220,000 becquerels per liter – more than 730 times the amount considered safe for consumption in Japan.
Outside observers have expressed concern about the status of spent fuel in reactors 1, 3 and 4 several times during the crisis a month in Fukushima Daiichi, about 240 km (150 miles) north of Tokyo. Temperature sensors in these basins has been since mid-March, workers have been spraying water into the damaged houses these reactors at a near-daily basis to keep winning.
The battle began on March 11, when Japan’s post-tsunami magnitude 9 earthquake eliminated the cooling system. Tokyo Electric estimated the height of the wall of water 14-15 meters (45-48 feet) – the level of Nishiyama said that the new standard to the barriers around the Japanese nuclear plants.
The sea wall around Fukushima Daiichi is 5 m. Following the tsunami, the cores of three of Fukushima Daiichi six reactors were damaged by overheating and explosions resulting hydrogen has exploded outside the buildings around the reactors 1 and 3.
The large amount of radiation emitted by the plant, largely in the first two weeks of the disaster, but the Japanese authorities to assess the crisis high on the international scale that measures nuclear accidents. Level 7 The term is Fukushima Daiichi on an equal footing with the April 1986 Chernobyl disaster in the former Soviet Union, but Japanese officials say their facility has only 10 percent of the radioactivity released at Chernobyl.
Plant workers are pouring hundreds of tons of water per day for three reactors, which were damaged as a result, and at least one reactor, Unit 2, is believed to be highly radioactive water leaks. A wide spread radioactive contamination around the plant in March and the adjacent Pacific Ocean, although the data published in the ministries showed radiation levels decline in recent weeks.
Engineers have taken steps this week to contain the disaster, pumping radioactive water from the trenches and tunnels of service in a storage tank for steam condensers No. 2 reactor. And they hang up is necessary to transfer approximately 10,000 tons in a facility designed to handle low-level radioactive waste Tokyo Electric said Thursday.
The company dumped water over 9,000 tonnes less radioactive in the Pacific Ocean last week to make way for the most dangerous liquid fled No. 2 reactor – a move the Japanese authorities described as a measure of emergency, but angry fishermen in the country.
The government ordered the evacuation Monday extended in several cities outside the radius of 30 kilometers was declared danger zone in the early days of the disaster, warning that prolonged exposure to levels of radiation that may pose a long-term hazard to human health. And data from the Japanese government this week reported earnings of low-level radioactive strontium, a byproduct the second reactor, in two of these cities in the days following the disaster.
Strontium-90 is considered a health risk, not only because of its radioactive half life of 29 years, but because part of it is absorbed by bone, if ingested, according the U.S. Environmental Protection Agency. There is no acceptable standard for strontium under Japanese regulations, but Japan Science Ministry said that the figures reported were not high enough to constitute an immediate hazard to human health.
The Japanese government has tried to limit the damage to farmers in Fukushima and other provincial governments from the factory is located in the contamination, lifting bans on agricultural products surrounding areas, if they pass three tests in three consecutive weeks.
Chief Cabinet Secretary Yukio Edano, government’s point man on the crisis, announced Thursday that kakina, a leafy green, Tochigi Prefecture was now safe for navigation. The decision follows a ban on outdoor shiitake mushrooms grown from 16 towns and villages damaged facility adjacent to its list of forbidden foods Wednesday.
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