Tech | March 12, 2011 | 59 comments

Fukushima Prefecture Nuclear Plant: Japan Floods Nuclear Reactor to Avert Full Meltdown

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EthicalVegan
[3:08 a.m. ET, 5:08 p.m. Tokyo]

An explosion has been reported near a nuclear plant in northeastern Japan's Fukushima prefecture, Japanese public broadcaster NHK reported, citing the country's nuclear and industrial safety agency.

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59 comments // Fukushima Prefecture Nuclear Plant: Japan Floods Nuclear Reactor to Avert Full Meltdown

  • queenofit
  • EthicalVegan
  • crunchynuts
  • EthicalVegan
    • +2
      EthicalVegan  

    • http://www.nytimes.com/2011/03/13/science/13radiation.html?hp

      The New York Times...

      March 12, 2011

      Danger Posed by Radioactivity in Japan Hard to Assess

      By WILLIAM J. BROAD

      The different radioactive materials being reported at the nuclear accidents in Japan range from relatively benign to extremely worrisome.

      The central problem in assessing the degree of danger is that the amounts of various radioactive releases into the environment are now unknown, as are the winds and other atmospheric factors that determine how radioactivity will disperse around the stricken plants.

      Still, the properties of the materials and their typical interactions with the human body give some indication of the threat.

      “The situation is pretty bad,” said Frank N. von Hippel, a nuclear physicist who advised the Clinton White House and now teaches international affairs at Princeton. “But it could get a lot worse.”

      In Vienna on Saturday, the International Atomic Energy Agency said Japanese authorities had informed it that iodine pills would be distributed to residents around the Fukushima Daiichi and Daini plants in northeast Japan. Both have experienced multiple failures in the wake of the huge earthquake and tsunami that struck Friday.

      In the types of reactors involved, water is used to cool the reactor core and produce steam to turn the turbines that make electricity. The water contains two of the least dangerous radioactive materials now in the news — radioactive nitrogen and tritium. Normal plant operations produce both of them in the cooling water, and they are even released routinely in small amounts into the environment, usually through tall chimneys.

      Nitrogen is the most common gas in the earth’s atmosphere, and at a nuclear plant the main radioactive form is known as nitrogen-16. It is made when speeding neutrons from the reactor’s core hit oxygen in the surrounding cooling water. This radioactive form of nitrogen does not occur in nature.

      The danger of nitrogen-16 is an issue only for plant workers and operators because its half-life is only seven seconds. A half-life is the time it takes half the atoms of a radioactive substance to disintegrate.

      The other radioactive material often in the cooling water of a nuclear reactor is tritium. It is a naturally occurring radioactive form of hydrogen, sometimes known as heavy hydrogen. It is found in trace amounts in groundwater throughout the world. Tritium emits a weak form of radiation that does not travel very far in the air and cannot penetrate the skin.

      It accumulates in the cooling water of nuclear reactors and is often vented in small amounts to the environment. Its half-life is 12 years.

      The big worries on the reported releases of radioactive material in Japan center on radioactive iodine and cesium.

      “They imply some kind of core problem,” said Thomas B. Cochran, a senior scientist in the nuclear program of the Natural Resources Defense Council, a private group in Washington.

      The active core of a nuclear reactor splits atoms in two to produce bursts of energy and, as a byproduct, large masses of highly radioactive particles. The many safety mechanisms of a nuclear plant focus mainly on keeping these so-called fission products out of the environment.

      Iodine-131 has a half-life of eight days and is quite dangerous to human health. If absorbed through contaminated food, especially milk and milk products, it will accumulate in the thyroid and cause cancer. Located near the base of the neck, the thyroid is a large endocrine gland that produces hormones that help control growth and metabolism.

      Dr. von Hippel of Princeton said the thyroid danger was gravest in children. “The thyroid is more sensitive to damage when the cells are dividing and the gland is growing,” he said.

      Fortunately, an easy form of protection is potassium iodide, a simple compound typically added to table salt to prevent goiter and a form of mental retardation caused by a dietary lack of iodine.

      If ingested promptly after a nuclear accident, potassium iodide, in concentrated form, can help reduce the dose of radiation to the thyroid and thus the risk of cancer. In the United States, the Nuclear Regulatory Commission recommends that people living within a 10-mile emergency planning zone around a nuclear plant have access to potassium iodide tablets.

      Over the long term, the big threat to human health is cesium-137, which has a half-life of 30 years.

      At that rate of disintegration, John Emsley wrote in “Nature’s Building Blocks” (Oxford, 2001), “it takes over 200 years to reduce it to 1 percent of its former level.”

      It is cesium-137 that still contaminates much of the land in Ukraine around the Chernobyl reactor. In 1986, the plant suffered what is considered the worst nuclear power plant accident in history.

      Cesium-137 mixes easily with water and is chemically similar to potassium. It thus mimics how potassium gets metabolized in the body and can enter through many foods, including milk. After entering, cesium gets widely distributed, its concentrations said to be higher in muscle tissues and lower in bones.

      The radiation from cesium-137 can throw cellular machinery out of order, including the chromosomes, leading to an increased risk of cancer.

      The Environmental Protection Agency says that everyone in the United States is exposed to very small amounts of cesium-137 in soil and water because of atmospheric fallout from the nuclear detonations of the cold war.

      The agency says that very high exposures can result in serious burns and even death, but that such cases are extremely rare. Once dispersed in the environment, it says, cesium-137 “is impossible to avoid.”

      http://graphics8.nytimes.com/images/2011/03/13/world/Radiation-1299957390029/Rad...

    • 1 year ago
  • EthicalVegan
    • +2
      EthicalVegan  

    • http://current.com/technology/93067367_fukushima-prefecture-nuclear-plant-japan-...

      An 8.9-magnitude earthquake hit northern Japan early Friday, triggering tsunamis that sent a wave filled with boats and houses toward land. Are you in an affected area? Send an iReport. Read the full report on how the quake hit Japan and generated a Pacific-wide tsunami.

      [6:45 p.m. ET, 8:45 a.m. Tokyo] 15 more people in the vicinity of Fukushima Daiichi's nuclear power plants have been exposed to radioactivity, the Fire and Disaster Management Agency has confirmed, according to Kyodo News.

      [6:34 p.m. ET, 8:34 a.m. Tokyo] An aftershock was just felt in Sendai, CNN staff in Japan reports, the latest in a series of aftershocks to rock the quake zone since Friday's 8.9-magnitude earthquake triggered a devastating tsunami.

      "People here in Japan are quite used to earthquakes," CNN's Anna Coren said. "The concern is more quakes, more aftershocks could cause more tsunamis. That's what people are worried about."

      Since the initial earthquake, there have been 250 aftershocks above 5.0 and almost 50 above 6.0, CNN's Chad Meyers said.

    • 1 year ago
  • Tartan10
  • ArchDruid
  • EthicalVegan
  • ArchDruid
  • EthicalVegan
  • EthicalVegan
  • EthicalVegan
    • +1
      EthicalVegan  
    • ThatCrazyLibertarian:

      I'm also with you on this. It's bloody frightening... just the POTENTIAL.

      And... for me, personally, I'm so sad and worried for all the animals who survived the earthquake, then the tsunami. Wildlife and domesticated animals... sigh.

    • 1 year ago
  • EthicalVegan
    • +1
      EthicalVegan  

    • Reuters...

      The Japanese nuclear safety agency is saying there is a possibility at least nine people were exposed to radiation from the Fukushima facility

      Japan's nuclear safety agency says Fukushima Daiichi Nuclear Plant No. 3 reactor's emergency cooling system not functioning

    • 1 year ago
  • EthicalVegan
  • EthicalVegan
  • EthicalVegan
  • EthicalVegan
  • EthicalVegan
    • +2
      EthicalVegan  
    • Image

    • http://www.msnbc.msn.com/id/42047458/ns/world_news-asiapacific/

      msnbc.com
      updated 3/12/2011 1:46:31 PM ET

      As the operator of an earthquake-damaged nuclear reactor in Japan raced to try and prevent the core from melting down, experts on the health effects of radiation described the situation as worrisome but not yet posing a serious threat to public safety.

      Japan’s Asahi Shimbum newspaper reported early Saturday that radiation levels per hour in the area near the front entrance of the No. 1 Fukushima plant reached 0.59 micro Sievert, which is eight times the normal levels. The central control room of the reactor recorded radiation levels 1,000 times the normal level, which would be approximately 70 microsieverts per hour, or 7 millirems, according to calculations by msnbc.com.

      But prior to an explosion at the reactor late Saturday, the hourly radiation level had reached 1,015 microsievert, or 102 millirems, an amount equivalent to that permissable for a person in one year, the Kyodo News Agency quoted he Fukushima prefectural government as saying. It was unclear whether that reading was form the control room or outside the plant.

      Officials of Japan's nuclear safety agency said there was no sign that radiation levels had jumped after the explosion. In fact, Japan's government spokesman Yukio Edano said the radiation around the Fukushima Daiichi plant had in fact decreased. He did not say why that was so.

      Radiation exposure is often measured in units called “millirem,” which is 1/1000 of a rem. The average American is exposed to about 620 millirem each year, with about half from natural sources and half from manmade sources, according to the Nuclear Regulatory Commission.
      Interactive: How a nuclear plant works

      By comparison, normal exposure rates range from approximately 0.03 microsieverts (a microsievert is one-tenth of a millirem) per hour to 0.23 microsieverts per hour in La Paz, Bolivia, the highest city in the world.

      A chest X-ray results in an exposure of about 8 to 10 millirems per film. A cross-country airplane flight results in a dose of 4 millirems.

      Exposures of less than 50 rem typically produce changes in blood chemistry, but no symptoms, according to the U.S. Environmental Protection Agency.

      That makes it unlikely that someone exposed to the radiation level reported at the plant prior to the blast would be immediately affected, said Dr. Fred Mettler, emeritus professor of radiology at the University of New Mexico.

      "People don't become acutely sick until they're over 50 rem and more like 100 rem," he told msnbc.com.

      Iodine distributed to residents

      But virtually any increase in ambient radiation can raise long-term cancer rates, and authorities were planning to distribute iodine to residents in the area, according to the International Atomic Energy Agency. Iodine can be taken to prevent the absorption of radiation by the thyroid.

      After the 1986 Chernobyl disaster, thousands of cases of thyroid cancer were reported in children and adolescents who were exposed at the time of the accident.
      Open Channel blog: 2007 Japan quake was wake-up call on nuclear safety

      Mettler noted that Japanese scientists studying health effects since Hiroshima have determined that some health effects can start to occur at exposures of 15 rem, even if the results aren't apparent for 10 years.

      There were about 80,000 survivors of the atomic bomb, for instance, with an average exposure of 23 rem, Mettler said. During the next 50 years about 9,000 of those survivors died of cancer. However, Japanese scientists concluded that the toll included about 500 excess deaths, that is, deaths that would not otherwise have been expected.

    • 1 year ago
  • EthicalVegan
    • +2
      EthicalVegan  
    • Image

    • http://www.npr.org/blogs/thetwo-way/2011/03/12/134486565/at-crippled-japanese-nu...

      NPR...........

      At Crippled Japanese Nuclear Plant, 'Last-Ditch Effort' To Prevent Meltdown

      11:10 am

      March 12, 2011

      by Mark Memmott

      Police officers wore gas masks as they patrolled near the nuclear power plant in Fukushima prefecture today (March 12, 2011).

      Yomiuri Shimbun /AFP/Getty Images

      .

      The scope of the disaster in Japan makes it difficult to focus on any one aspect. More than 1,700 people are said to be dead or missing. Many more are suddenly homeless. Millions are without power. We've been tracking development here.

      One part of the story today, though, is being followed particularly closely around the world: The rush to keep a crippled nuclear power plant in Fukushima from suffering a meltdown. As we reported earlier, there was an explosion at that plant today.

      The good news at this hour, The Associated Press reports, is that a radiation leak at the plant "was decreasing despite fears of a meltdown ... officials said. Government spokesman Yukio Edano said the explosion destroyed the exterior walls of the building where the reactor is placed, but not the actual metal housing enveloping the reactor."

      Still, the situation is serious. NPR's Jon Hamilton has been following what he says is the "last-ditch effort to protect the reactor's radioactive core," and said a short time ago on the NPR Newcast that:

      "The reactor in Fukushima prefecture has had problems with its cooling system since the earthquake. Now it appears efforts to keep the system working have failed.

      "A spokesman for the Japanese government said the reactor's core would be flooded with sea water and boric acid. The boric acid helps to suppress any lingering nuclear reaction. The spokesman also explained an explosion that destroyed a building at the Fukushima plant early this morning. He said efforts to add cooling water to the reactor core had resulted in the production of hydrogen gas. The gas built up inside the building and then exploded."

      NPR's Jon Hamilton

      On Weekend Edition, Jon told host Linda Wertheimer that the plan to flood the core with seawater and boric acid may be unprecedented and will effectively destroy the power plant. If the plan fails and the core does meltdown, Jon said, the only thing left to do will be to "seal it up with concrete. You sort of entomb it."

      Linda Wertheimer speaks with NPR's Jon Hamilton

      And it would be the containment structure that would be entombed — hopefully with any radioactive material still inside. In theory, NPR's Science Desk tells us, if there were a meltdown that destroyed the steel and ceramic around the fuel rods, the containment structure would still be able to prevent any material from being released into the environment. That was not what happened during the Chernobyl disaster because there was no such containment structure at that Soviet-era plant. At Three Mile Island in Pennsylvania, the containment structure prevented a disaster when part of the core melted during a 1979 accident.

      The situation likely won't be resolved quickly. According to Japan's Kyodo News:

      "The top government spokesman said Tokyo Electric Power has begun operations to fill the reactor with sea water and pour in boric acid to prevent an occurrence of criticality, noting it may take several hours to inject water into the reactor. In addition, it will take about 10 days to fill the container with sea water, he said."

    • 1 year ago
  • EthicalVegan
    • +2
      EthicalVegan  
    • Image

    • FACT SHEET: Fukushima Nuclear Plant

      Published March 12, 2011

      March 11: Fukushima Daiichi power plant's Unit 1 is seen in Okumamachi, Fukushima prefecture, Japan. The nuclear power plant affected by a massive earthquake is facing a possible meltdown, an official with Japan's nuclear safety commission said Saturday. (AP/The Yomiuri Shimbun)

      March 11: Fukushima Daiichi power plant's Unit 1 is seen in Okumamachi, Fukushima prefecture, Japan. The nuclear power plant affected by a massive earthquake is facing a possible meltdown, an official with Japan's nuclear safety commission said Saturday. (AP/The Yomiuri Shimbun)

      IWAKI, Japan – The Fukushima plant is located 150 miles away from Tokyo, 40 miles from the earthquake's epicenter.

      - About 30% of electricity in Japan is produced by 55 nuclear power units in 17 plants
      Japan is the world's third largest producer of nuclear power.

      - The earthquake has led to the shutdown of 11 of the Japan's 55 nuclear power plants, representing nearly 20% of the country's capacity.

      - The Fukushima Daiichi unit is just one of five reactors severely imperiled by the earthquake.

      - The Fukushima plant covers about 865 acres and it is built on solid bedrock.

      - Opened in 1971 -- the Fukushima Daiichi Nuclear Power Station (No.1) would be marking its 40th anniversary on March 26.

      - Some 40,000 people had evacuated from the areas around two Fukushima plants as of Saturday afternoon, according to reports.

      - Authorities evacuated a 12.5 mile radius around the reactor, and told residents within 16.5 miles to remain indoors.

      - Virtually any increase in ambient radiation can raise long-term cancer rates.

      - A partial meltdown in one of the light water reactors at Three Mile Island in 1979 resulted in the release of radioactive gases in the most serious incident in the history of the U.S. nuclear power industry.

      (Source: "Japan Officials Probe Nuclear Plant Collapse," The Wall Street Journal: 12 March 2011)
      (Source: "Damage to cooling system had sparked warning of meltdown," MarketWatch: 12 March 2011)
      (Source: "Japan Officials Probe Nuclear Plant Collapse," The Wall Street Journal: 12 March 2011)
      (Source: IAEA, http://www.iaea.org/cgi-bin/db.page.pl/pris.powrea.htm?country=JP&sort=&...)
      (Source: "Explosion at Japan nuke plant, disaster toll rises," Associated Press: 12 Mar 2011)
      (Source: "Explosion rocks Japanese power plant," The Washington Post: 12 Mar 2011. http://www.washingtonpost.com/wp-dyn/content/article/2011/03/11/AR2011031103673_...)
      (Source: "Fukushima nuclear plant blast puts Japan on high alert," Guardian Unlimited: 13 March 2011)

    • 1 year ago
  • EthicalVegan
    • +2
      EthicalVegan  
    • Image

    • http://www.reuters.com/article/2011/03/12/us-japan-quake-nuclear-cooling-idUSTRE...

      Japan's Fukushima nuclear plant faces new reactor problem

      Related News

      Analysis: How bad is the nuclear accident in Japan?
      2:47pm EST
      Q&A-Dangers posed by Japan's quake-hit atom plant
      1:54pm EST
      Snapshot: Developments after major Japan earthquake
      12:24pm EST
      Japan may hand out iodine near nuclear plants: IAEA
      11:59am EST
      Analysis: Nuclear power growth at risk if Japan plant leaks
      9:48am EST

      03/11/2011

      Police officers wearing respirators guide people to evacuate away from the Fukushima Daiichi nuclear plant following an evacuation order for residents who live in within a 10 km (6.3 miles) radius from the plant after an explosion in Tomioka Town in Fukushima Prefecture March 12, 2011. REUTERS/Asahi Shimbun

      TOKYO | Sat Mar 12, 2011 4:17pm EST

      (Reuters) - A quake-hit Japanese nuclear plant reeling from an explosion at one of its reactors has also lost its emergency cooling system at another reactor, Japan's nuclear power safety agency said on Sunday.

      The emergency cooling system is no longer functioning at the No.3 reactor at Tokyo Electric Power Co's Fukushima Daiichi nuclear power facility, requiring the facility to urgently secure a means to supply water to the reactor, an official of the Japan Nuclear and Industrial Safety Agency told a news conference.

      On Saturday, an explosion blew off the roof and upper walls of the building housing the facility's No. 1 reactor, stirring alarm over a possible major radiation release, although the government later said the explosion had not affected the reactor's core vessel and that only a small amount of radiation had been released.

      The nuclear safety agency official said there was a possibility that at least nine individuals had been exposed to radiation, according to information gathered from municipal governments and other sources.

      (Reporting by Risa Maeda; Editing by Edmund Klamann)

    • 1 year ago
  • ArchDruid
  • EthicalVegan
    • +2
      EthicalVegan  
    • ArchDruid:

      I just love you for contributing so much valuable information. All I do is submit something -- with all the deepest concern in my heart -- and then I see there are folks such as you who pull forward and bring in important updates, as well as much-needed information, such as all the sources you've been contributing.

      I'm stuck, because today I have to really, REALLY get back to working (luckily, from my home). I want to stay on top of all this, but I can't afford to give up any more time. And besides, I'm really needing to devote more time to Dear Prudence, my rescue bird who was in critical condition for six days, and who is now home -- in a specially-designed hospital box -- in serious condition, where I'm administering to her every need, including providing her her meds, etc.

      Thank you for the ofttimes first-hand experiences you've been sharing with the rest of us, along with all the other incredible input.

      And I appreciate the couple of you who acknowledged my efforts. It's not necessary, but at the same time, it means the world to me, and I'm damn grateful for the little glows of warmth you've given me.

    • 1 year ago
  • MikeMaddigan
    • +1
      MikeMaddigan  

    • As the only people ever to feel the effects of nuclear war, what's up with going heavily nuclear in energy policy? I understand the lack of natural resources, but nuclear? If the unthinkable happens now...oh, the irony.

      Did the Marshall Plan have anything to do with how their energy policy developed? Anyone know?

    • 1 year ago
  • jzimet
  • Saladin
    • +2
      Saladin  
    • MikeMaddigan:

      Japan is utterly barren when it comes to natural resources, I imagine that has something to do with it.

      But, honestly, there are lots of nuclear plants in nearly every industrialized country on the planet. This one, unfortunately, got hit by a tsunami, which I'm pretty sure is something that they didn't plan for.

    • 1 year ago
  • CalPal
    • 0
      CalPal  
    • Saladin:

      Why wouldn't have they planned for it? They know their land is prone to earthquakes and tsunamis, you would think they'd have even more rigid building codes to deal with high-threat natural disasters, especially with something as important and dangerous as nuclear energy?

    • 1 year ago
  • Saladin
    • 0
      Saladin  
    • CalPal:

      Because one, tsunamis are incredibly rare and two, there is no existing technology that can stop them.

      You can't plan for every contingency and even if you could, you can't stop 90% of them.

      Disasters happen.

    • 1 year ago
  • Malikskyy
    • +2
      Malikskyy  

    • A nations power must not be judged by how quick they can bring another nation down, but how willing they are to help lift a down nation up.

    • 1 year ago
  • CalPal
    • +3
      CalPal  

    • Chernobyl, anyone?

      On a more personal note, I feel so bad for the Japanese people... Tsunami's destroying their homes, and now they're going to be suffering from more nuclear damage. As if Hiroshima and Nagasaki wasn't enough...

    • 1 year ago
  • the1union1man2organize
  • savroD
    • 0
      savroD  

    • Well republiCONs and corporate welfare democRATs....

      How is that nuclear power working out for you now! You know Neil DeGrass Tyson said recently, probably not originally, that the rules of science don't really care what people BELIEVE!

    • 1 year ago
  • Saladin
    • +1
      Saladin  
    • savroD:

      This has nothing to do with the safety of nuclear power, the fucking thing got hit by a tsunami, what were they supposed to do?

      And I'm really not sure you understand the relevance of what Tyson said.

    • 1 year ago
  • DianaCancer
  • the1union1man2organize
  • the1union1man2organize
  • tverdell
    • -1
      tverdell  

    • I have been on the fence in regards to nuclear power for many years.
      Despite this event, I do not see how we get around using nuclear power especially in regards to peak oil.

      I think a solution may be fusion, and I have read that scientists are getting closer to this solution.

    • 1 year ago
  • ArchDruid
  • OrbViper
  • wyndesonge
  • kvb1
    • +6
      kvb1  

    • This is a major problem, not just for the Japanese but fro the rest of the world as well. If there is a melt down massive doses of radiation will be released, spread cross parts of Japan, the Pacific and reach the US.

      The big problem for us is that many of our Nukes are built on fault lines. Indian Point just outside of NYC (35 miles north) is constantly failing its safety and security plans. There are nuclear power plants on the New Madrid fault line as well as the San Andreas fault lin in California. Non of these plants were built to withstand a 3.0 earthquake let alone a massive 8.9

    • 1 year ago
  • wally60
  • CarlosBobthe3rd
  • artemis6
  • CarlosBobthe3rd
  • EthicalVegan
    • +5
      EthicalVegan  

    • http://www.latimes.com/news/nationworld/world/la-fgw-japan-quake-nuclear-2011031...

      Los Angeles Times...

      Meltdown Fears Rise as Walls Crumble at Japan Nuclear Site

      From the Associated Press

      March 12, 2011, 12:40 a.m. PT

      The walls of a building at nuclear power station crumbled Saturday as smoke poured out and Japanese officials said they feared the reactor could melt down following the failure of its cooling system in a powerful earthquake and tsunami.

      It was not clear if the damaged building housed the reactor. An official said the utility that runs the Fukushima Daiichi plant was reporting that several workers may have been injured.

      Fukushima Prefecture official Masato Abe said the cause of the rattling and smoke was unclear, declining to say whether an explosion had occurred.

      Footage on Japanese TV showed that the walls of one building had crumbled, leaving only a skeletal metal frame block standing. Puffs of smoke were spewing out of the plant.

      Pressure has been building up in the reactor -- it's now twice the normal level -- and Japan's Nuclear and Industrial Safety Agency told reporters Saturday that it was venting "radioactive vapors" to relieve that pressure. Officials said they were measuring radiation levels in the area.

      The reactor in trouble has already leaked radiation: Operators at the Fukushima Daiichi plant's Unit 1 detected eight times the normal radiation levels outside the facility and 1,000 times normal inside Unit 1's control room.

    • 1 year ago
  • EthicalVegan
    • +2
      EthicalVegan  

    • From ArchDruid...

      ArchDruid

      Japan's NHK TV showing before and after pictures of the Fukushima-Daiichi plant. It appears to show that the outer structure of one of four buildings at the plant is no longer there.

      The Associated Press cites Fukushima Prefecture official Masato Abe as saying the cause of the white smoke seen above the plant is still under investigation, and that it's unclear whether there was an explosion.

      Tepco says explosion may have been hydrogen used to cool Fukushima plant - Kyodo; Tepco says 4 people taken to hospital after reported explosion, no word on condition

      Fukushima prefecture says Tepco's no.1 reactor ceiling has collapsed

      NHK TV says the number of dead across Japan has reached 1,000.

      Some 5.6 million Japanese homes are reported to be without power, and more than one million without water.

    • 1 year ago
  • Tartan10
  • EthicalVegan
  • Tartan10
  • tverdell
  • Tartan10
  • EthicalVegan
    • 0
      EthicalVegan  

    • From Twitter...

      BreakingNews Breaking News

      Japan nuclear plant update: Walls and roof of a building at site destroyed by blast - NHK via Sky News
      8 minutes ago

    • 1 year ago
  • EthicalVegan
  • EthicalVegan
    • +2
      EthicalVegan  
    • EthicalVegan:

      From Guardian UK...

      8.35am: The nuclear plant's operators say four people were injured in the explosion, Kyodo news agency reports.

      NHK is advising people in the Fukushima area to stay inside, close doors and windows and turn off air conditioning. They have also been advised to cover their mouths with masks, towels or handkerchiefs

      7.56am: My colleague Justin McCurry in Japan says explosion reported at Fukushima Daiichi (No 1) reactor at 15:36 local time (06:36GMT). TV footage shows smoke rising from plant.

      7.52am: Japanese media reporting that explosion heard at TEPCO's Fukushima Daiichi plant around 0630 GMT - more soon

    • 1 year ago
  • EthicalVegan
  • EthicalVegan
    • 0
      EthicalVegan  
    • Image
    • EthicalVegan:

      http://www.nytimes.com/2011/03/13/world/asia/13nuclear.html?_r=1&hp

      The New York Times

      March 12, 2011

      Japan Floods Nuclear Reactor Crippled by Earthquake to Avert a Full Meltdown

      _______________________________

      By MICHAEL WINES and MATTHEW L. WALD

      TOKYO — Japanese officials took the extraordinary step on Saturday of flooding a nuclear reactor with seawater in a last-ditch effort to avoid a nuclear meltdown, after an explosion there escalated the emergency caused by the huge earthquake and tsunami that destroyed parts of the country’s northeastern coast on Friday.

      Officials said late Saturday that leaks of radioactive material from the plant, in northern Japan, were receding and that a major meltdown was no longer imminent. But the government doubled its evacuation radius around the plant to 12 miles, and the worries about radiation and chaos from tens of thousands of people fleeing the area hampered efforts to search for survivors and forced Japan’s leadership to grapple with two major crises at once.

      Although safety officials described the release of radioactive materials as small, they also told the International Atomic Energy Agency that they were making preparations to distribute iodine, which helps protect the thyroid gland from radiation exposure, to people living near two nuclear plants that suffered damage in the quake. Japanese news media said three workers at the Fukushima Daiichi Nuclear Power Station had suffered radiation exposure.

      Government officials and executives of Tokyo Electric Power, which runs the plant, gave confusing accounts of the causes of the explosion and the damage it caused. Late Saturday night, officials said that the explosion occurred in a structure housing turbines near the No. 1 reactor at the plant rather than inside the reactor itself.

      The blast, apparently caused by a sharp buildup of pressure or of hydrogen when the reactor’s cooling system failed after the quake, destroyed the concrete structure surrounding the reactor but did not collapse the critical steel container inside, they said. They said that raised the chances they could continue cooling the core, and prevent the release of large amounts of radioactive material and avoid a full core meltdown at the plant.

      “We’ve confirmed that the reactor container was not damaged. The explosion didn’t occur inside the reactor container. As such there was no large amount of radiation leakage outside,” Japan’s chief cabinet secretary, Yukio Edano, said in a news conference on Saturday night. “At this point, there has been no major change to the level of radiation leakage outside, so we’d like everyone to respond calmly.”

      Mr. Edano said that, in addition to filling the reactor with seawater, Tokyo Electric Power workers also added boric acid to the containment vessel on Saturday night to poison the nuclear chain reaction. Mr. Edano said that the operation could “prevent criticality.”

      He said radioactive materials had leaked outside the plant before the explosion, but that the explosion did not worsen the leak and that, in fact, measured levels of radioactive emission had been decreasing. He did not specify the levels of radiation involved.

      Officials said even before the explosion that they had detected radioactive cesium, which is created when uranium fuel is split, an indication that some of the nuclear fuel in the reactor was already damaged. Experts said the plant probably experienced some fuel damage. But officials insisted that the fuel damage was limited and that the prospect of more radioactive leaks had receded.

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    • 1 year ago
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      PART TWO...

      Naoto Sekimura, a professor at Tokyo University, told NHK, Japan’s public broadcaster, that “only a small portion of the fuel has been melted. But the plant is shut down already, and being cooled down. Most of the fuel is contained in the plant case, so I would like to ask people to be calm.”

      The crisis at the aging plant, located 160 miles north of Tokyo, confronted Japan with its worst nuclear accident — and one of the biggest malfunctions at a nuclear plant since the Chernobyl nuclear disaster in 1986.

      Japanese nuclear safety officials and international experts said that because of crucial design differences, the release of radiation at the Fukushima plant would most likely be much smaller than at Chernobyl even if the Fukushima plant had suffered a complete core meltdown, which they said it had not. But the problems at the plant are likely to increase concerns about the safety record and reliability of Japan’s extensive nuclear power facilities, which have been criticized for major safety violations in the past.

      The vulnerability of nuclear plants to earthquakes was also underscored by continuing problems at the cooling system of reactors at a second nearby plant, known as Daini, which prompted a smaller evacuation from surrounding communities.

      Tokyo Electric Power said the first explosion happened “near” the No. 1 reactor at Daiichi around 3:40 p.m. Japan time on Saturday. It said four of its workers were injured in the blast.

      The decision to flood the reactor core with seawater, experts said, was an indication that Tokyo Electric and Japanese authorities had probably decided to scrap the plant, because the salt water would corrode its delicate metal innards. “This plant is almost 40 years old, and now it’s over for that place,” Olli Heinonen, the former chief inspector for the I.A.E.A., and now a visiting scholar at Harvard, said on Saturday.

      Mr. Heinonen lived in Japan in the 1980s, monitoring its nuclear industry, and visited the stricken plant many times. Based on the reports he was seeing, he said he believed that the explosion was caused by a hydrogen formation, which could have begun inside the reactor core. “Now, every hour they gain in keeping the reactor cooling down is crucial,” he said.

      But he was also concerned about the presence of spent nuclear fuel in a pool inside the same reactor building. The pool, too, needs to remain full of water, to suppress gamma radiation and prevent the old fuel from melting. If the spent fuel is also exposed — and so far there are only sketchy reports about the condition of that building — it could also pose a significant risk to the workers trying to prevent a meltdown in the core.

      Both the Daiichi and Daini plants were shut down by Friday’s earthquake. But the loss of power in the area and damage to the plant’s generators from the subsequent tsunami crippled the cooling systems, which need to function after a shutdown to cool down nuclear fuel rods.

      Malfunctioning cooling systems allowed pressure to build up beyond the design capacity of the reactors. Early Saturday, officials had said that small amounts of radioactive vapor were expected to be released into the atmosphere to prevent damage to the containment systems and that they were evacuating tens of thousands of people living around the plants as a precaution.

      Those releases apparently did not prevent the buildup of hydrogen inside the plant, which ignited and exploded Saturday afternoon, government officials said. They said the explosion itself did not increase the amount of radioactive material being released into the atmosphere. But safety officials also urged people who were not evacuating but still lived relatively near the plants to cover their mouths and stay indoors.

      David Lochbaum, who worked at three reactors in the United States similar to the Fukushima design, and who was later hired by the Nuclear Regulatory Commission to teach its personnel about that technology, said that from pictures he had seen of the stricken plant, the explosion appeared to have occurred in the turbine hall, and not the reactor vessel or the containment that surrounds the vessel.

      The technology used at Fukushima is called a boiling-water reactor, in which the reactor, inside a containment, sends its steam out of containment to a turbine. The turbine converts the steam’s energy into rotary motion, which turns a generator and makes electricity.

      But as the water goes through the reactor, some water molecules break up into hydrogen and oxygen. A system in the turbine hall usually scrubs out those gases. Hydrogen is also used in the turbine hall to cool the electric generator. Hydrogen from both sources has sometimes escaped and exploded, he said, but in this case, there is an additional source of hydrogen: interaction of steam with the metal of the fuel rods. Operators may have vented that hydrogen into the turbine hall.

      Earlier Saturday, before the explosion, a Japanese nuclear safety panel said the radiation levels were 1,000 times above normal in a reactor control room at the Daiichi plant. Some radioactive material had also seeped outside, with radiation levels near the main gate measured at eight times normal, NHK quoted nuclear safety officials as saying.

      The emergency at the Daiichi plant began shortly after the earthquake struck on Friday afternoon. Emergency diesel generators, which had kicked in to run the reactor’s cooling system after the electrical power grid failed, shut down about an hour after the earthquake. There was speculation that the tsunami had flooded the generators and knocked them out of service.

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      PART THREE...

      For some time after the quake, the plant was operating in a battery-controlled cooling mode. Tokyo Electric said that by Saturday morning it had also installed a mobile generator at Daiichi to ensure that the cooling system would continue operating even after reserve battery power was depleted. Even so, the company said it needed to conduct “controlled containment venting” in order to avoid an “uncontrolled rupture and damage” to the containment unit.

      Why the controlled release of pressure did not succeed in addressing the problem at the reactor was not immediately explained. Tokyo Electric and government nuclear safety officials also did not explain the precise sequence of failures at the plant.

      Daiichi and other nuclear facilities are designed with extensive backup systems that are supposed to function in emergencies to ensure the plants can be shut down safely.

      At Daiichi, a pump run by steam, designed to function in the absence of electricity, was adding water to the reactor vessel, and as that water boiled off, the steam was being released. Such water is usually only slightly radioactive, according to nuclear experts. As long as the fuel stays covered by water, it will remain intact, and the bulk of the radioactive material will stay inside. But if fresh water cannot be pumped into the containment vessel and the cooling water evaporates, the nuclear fuel is exposed, which can result in a meltdown.

      Japan, with no substantial coal or oil, relies heavily on nuclear power, which generates just over one-third of the country’s electricity. Its plants are designed to withstand earthquakes, which are common, but experts have long expressed concerns about safety standards, particularly if a major quake hit close to a reactor.

      Michael Wines reported from Tokyo, and Matthew L. Wald from Washington. Martin Fackler contributed reporting from Nakaminato, Japan, and David E. Sanger from Washington.

    • 1 year ago
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