State of Japan's Nuclear Reactors

SUBHEAD: No. 3 nuclear reactor located in the Fukushima prefecture exploded late Monday morning. No. 2 in danger now. By Tsuyoshi Inajima, Yuji Okada & Shigeru Sato 14 March 2011 for Bloomberg News - (http://www.bloomberg.com/news/2011-03-14/hydrogen-explosion-occurs-at-nuclear-power-plant-135-miles-north-of-tokyo.html) Image above: Fukushima Dai Ichi Nuclear Station before tsunami (l. to r.Reactors No.1 - No. 4). From (http://www.adelaidenow.com.au/nuclear-plant-meltdown-worries-escalate-in-japan-quake/story-e6frea6u-1226020354900).

Tokyo Electric Power Co. engineers tried to stabilize three nuclear reactors damaged by the biggest earthquake in Japan’s history after the plant was struck by a second explosion and as water levels dropped at one reactor, exposing fuel rods and increasing the threat of a meltdown.

The cooling system failed at the Dai-Ichi No. 2 reactor today, said Tokyo Electric, which runs the Fukushima nuclear plant 220 kilometers (135 miles) north of the nation’s capital. Fuel rods at the reactor may have melted after becoming fully exposed, Chief Cabinet Secretary Yukio Edano told reporters.

A hydrogen explosion occurred at the No. 3 reactor today, following a similar blast on March 12 at the No. 1 reactor that destroyed the walls of its building. The utility has been flooding the three reactors with water and boric acid to reduce the potential for a large release of radiation into the atmosphere following the March 11 earthquake-generated tsunami that smashed into the plant, disabling electricity supply and backup generators.

“They are managing the situation, they have very qualified personnel there,” Gennady Pshakin, a nuclear expert based in Obninsk, Russia, said by telephone. “We will have a week or 10 days of this uncertainty, but the situation should normalize. What we need is for the water supply to be constant.”

Radiation Concerns

U.S Navy ships and planes involved in earthquake rescue efforts were moved after radiation was detected on three helicopters.

“Low level radioactivity” was detected on 17 air crew members when they returned to the USS Ronald Reagan aircraft carrier operating about 100 miles northeast from the plant, Navy spokesman Jeff Davis said in an e-mail.

Japanese officials yesterday evacuated more than 200,000 people and handed out iodine, used to protect the thyroid from radioactivity, as they extended an exclusion zone around the plant to 20 kilometers.

Winds in the area of the Fukushima plant are blowing at less than 10 kilometers (6 miles) per hour generally in a northeasterly and northerly direction, according to a 9 a.m. update from the Japan Meteorological Agency today.

Core Intact

The vessel containing the No. 3 reactor’s radioactive core is intact after today’s blast, Edano said. The likelihood of a large radiation leak is very small, even as radiation levels at the No. 3 reactor are rising, said Edano, the government’s spokesman.

Tepco, as Asia’s biggest utility is known, said at least four employees and two contractors were injured in the blast. The company’s shares slumped 24 percent.

There are six boiling-water reactors at the Fukushima Dai- Ichi plant, three of which were shut for maintenance before the earthquake.

Unit No. 1 is a General Electric Co. (GE) model that can generate 439 megawatts of power and began commercial operation in 1971, according to the International Atomic Energy Agency. The No. 2 reactor was built by GE Toshiba and the No. 3 by Toshiba Corp.

Tokyo Electric said the sea water used to cool the two reactors is being retained at the plant. “We will look into what we will do about the water,” spokesman Shogo Fukuda said by telephone today.

Flooding the reactors with sea water renders them useless for future power production.

The disaster at Fukushima isn’t the first quake-related accident for Tokyo Electric.

A 6.8-magnitude temblor on July 16, 2007, caused a fire and radiation leaks that shut down the Kashiwazaki Kariwa nuclear plant, the world’s biggest. It took almost two years to restart.


Fukushima No.3 Reactor Explodes By Adeline Yuboco on 13 March 2011 for Digital Journal - (http://www.digitaljournal.com/article/304616#ixzz1GYS3wwNA) Japanese government confirmed that Tokyo Electric Power Co.'s (TEPCO) No. 3 nuclear reactor located in the Fukushima prefecture exploded late Monday morning.
According to Japan's Ministry of Economy, Trade and Industry, the hydrogen explosion at the building containing Dai-Ichi's No. 3 nuclear reactor occurred at 11:01 am local time. White smoke was seen rising above the nuclear facility. People situated as far as 30 miles from the site reported feeling the explosion. One of the walls of the building containing the nuclear reactor had collapsed as a result of the explosion. The container vessel surrounding the reactor is still intact according to Chief Cabinet Secretary Yukio Edano. He explained that the explosion may have been a result of the excess amount of hydrogen that accumulated within the nuclear reactor brought about by insufficient cooling of the nuclear reactor core. One operator has been injured while seven other people have been reported missing following the explosion. At least 170,000 people have been evacuated within a 12-mile radius around the Fukushima power plants. The 600 residents that remained within the area despite the evacuation order were told to remain indoors. Initial reports have stated that radiation levels within the area surrounding the nuclear power plant have increased after the explosion. However, Edano told reporters that it is unlikely that a leak of radioactive material will happen as water continues to be injected into the nuclear reactors. Nevertheless, Edano promised that they are looking into the situation very seriously. "We are dealing with the situation as though a core meltdown has occurred," he told reporters. Prior to the explosion, government officials and workers at the power plant have worked desperately to avert the possibility of a nuclear meltdown and releasing an increase of radioactive material into the atmosphere by flooding the reactors with water and boric acid. With news of pressure building within the building of the No. 3 reactor—and water levels declining, causing the nuclear rods to become exposed—TEPCO began pumping in seawater into the facility in an attempt to restore the water supply system and prevent the rods from melting. A state of emergency was declared in the country's nuclear power plants after a fire broke out at the Onagawa nuclear power plant located in the neighboring Miyagi prefecture on Friday following the 8.9-magnitude earthquake that shook the country. On Saturday, an explosion occurred in the building housing TEPCO's No. 1 nuclear reactor resulting from a hydrogen leak. Four workers were injured as a result of the explosion. In light of the two nuclear power plant explosions in Fukushima, attention now turns to the other nuclear power plants in the country that have been affected by the massive earthquake and tsunami. One of which is the Dai-Ni plant located in Tokai, which also experienced a failure on Friday. Concerns have been raised for survivors located in the prefecture of Miyagi. Dr. Michio Kaku—a physicist—said that the Japanese government should now consider extending evacuation orders beyond the 12-mile radius after a Japanese official confirmed that 22 people have suffered radiation contamination with 190 others feared to have been exposed to increased amount of radiation. "Winds don't stop blowing at 12 miles," he pointed out. "Computer models show that the radiation doesn't disperse in a sphere or a circle. It disperses in a…pencil-like plum that..waves with the wind like a lighthouse."
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