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D'coda Dcoda

Nuclear Expert Discusses 'Melt-Through' at NRC Meeting: I believe melted nuclear core l... - 0 views

enenews.com/hima-reactors-onto-floor-video

shared by D'coda Dcoda on 22 Oct 11 - No Cached
  • Fukushima & Japan Tokyo Area Outside Tokyo Fukushima Reactors Status of Reactors Reactor No. 1 Reactor No. 2 Reactor No. 3 Spent Fuel Pools Spent Fuel Pool No. 1 Spent Fuel Pool No. 2 Spent Fuel Pool No. 3 Spent Fuel Pool No. 4 Common Spent Fuel Pool Radiation Releases Plutonium Uranium Longterm Chernobyl Comparisons Criticality US & Canada West Coast California Los Angeles San Francisco Bay Area Hawaii Seattle Canada Midwest East Coast Florida US Nuclear Facilities North Anna (VA) Calvert Cliffs (MD) World Europe France UK Germany Chernobyl Rest of Europe South America Russia Asia China South Korea Taiwan Rest of Asia Pacific Maps & Forecasts Radiation Maps Radiation Forecasts Rad. Facts Internal Emitters Health Testing Food Water Air Rain Soil Milk Strange Coverups? Children Video Home page_
Jan Wyllie

Full Meltdown: Fukushima Called the 'Biggest Industrial Catastrophe in the History of M... - 0 views

www.alternet.org/..._in_the_history_of_mankind%27_

nuclear capability practice science biodiversity pollution emergence record risks

shared by Jan Wyllie on 18 Jun 11 - No Cached
  • Fukushima has three nuclear reactors exposed and four fuel cores exposed," he said, "You probably have the equivalent of 20 nuclear reactor cores because of the fuel cores, and they are all in desperate need of being cooled, and there is no means to cool them effectively.
  • TEPCO has been spraying water on several of the reactors and fuel cores, but this has led to even greater problems, such as radiation being emitted into the air in steam and evaporated sea water - as well as generating hundreds of thousands of tons of highly radioactive sea water that has to be disposed of.
  • "They are pouring in water and the question is what are they going to do with the waste that comes out of that system, because it is going to contain plutonium and uranium. Where do you put the water?"
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  • The water picks up enormous amounts of radiation, so you add more water and you are generating hundreds of thousands of tons of highly radioactive water."
  • "They recalculated the amount of radiation released, but the news is really not talking about this," he said. "The new calculations show that within the first week of the accident, they released 2.3 times as much radiation as they thought they released in the first 80 days."
  • a nuclear waste advisor to the Japanese government reported that about 966 square kilometres near the power station - an area roughly 17 times the size of Manhattan - is now likely uninhabitable.
  • far more radiation has been released than has been reported.
  • "We have 20 nuclear cores exposed, the fuel pools have several cores each, that is 20 times the potential to be released than Chernobyl,"
  • the exposed reactors and fuel cores are continuing to release microns of caesium, strontium, and plutonium isotopes. These are referred to as "hot particles".
  • "We are discovering hot particles everywhere in Japan, even in Tokyo," he said. "Scientists are finding these everywhere. Over the last 90 days these hot particles have continued to fall and are being deposited in high concentrations. A lot of people are picking these up in car engine air filters."
  • Clearly people in Fukushima prefecture have breathed in a large amount of these particles. Clearly the upper West Coast of the US has people being affected. That area got hit pretty heavy in April.
  • Why have alarms not been sounded about radiation exposure in the US?
  • Nuclear operator Exelon Corporation has been among Barack Obama's biggest campaign donors, and is one of the largest employers in Illinois where Obama was senator
  • Using nuclear power to produce electricity in Japan is a product of the nuclear policy of the US
  • Gundersen worries about more earthquake aftershocks, as well as how to cool two of the units. "Unit four is the most dangerous, it could topple," he said. "After the earthquake in Sumatra there was an 8.6 [aftershock] about 90 days later, so we are not out of the woods yet. And you're at a point where, if that happens, there is no science for this, no one has ever imagined having hot nuclear fuel lying outside the fuel pool. They've not figured out how to cool units three and four."
  • "With Three Mile Island and Chernobyl, and now with Fukushima, you can pinpoint the exact day and time they started," he said, "But they never end."
    • D'coda Dcoda
      D'coda Dcoda on 18 Jun 11
       
      Actually, this is exactly what I expected given the history of nuclear energy and the history of inadequate safeguards, ignoring safety regulations, etc.
  • Jan Wyllie on 18 Jun 11
     
    A "NEVER ENDING DISASTER" - A new rendition of Hofstadter's Law about how things take longer than expected ... it's always worse than expected, even when you expect the worse.
D'coda Dcoda

Shutdown of Fukushima Reactors Is Ahead of Schedule [Nov11] - 0 views

spectrum.ieee.org/...-reactors-is-ahead-of-schedule

shared by D'coda Dcoda on 28 Oct 11 - No Cached
  • Editor's Note: This is part of the IEEE Spectrum special report: Fukushima and the Future of Nuclear Power.
  • This past April, when the Japanese government and Tokyo Electric Power Co. (TEPCO) jointly unveiled their plan to bring the damaged reactors of the Fukushima Dai-ichi nuclear power plant to a cold shutdown and gain control of the release of radioactive materials, they set a tentative completion date for mid-January 2012. And "tentative" had to be the operative word, for the obstacles TEPCO faced—and to some extent still does face—are challenging in the extreme. They include:
  • Fuel rod meltdowns in reactors 1, 2, and 3 due to loss of cooling systems following the 11 March earthquake and tsunami; Severe damage to the upper levels of reactor buildings 1, 3, and 4 and slight damage to building 2, stemming from hydrogen explosions; High levels of radiation and contaminated rubble, making working conditions hazardous and difficult; Thousands of metric tons of contaminated water accumulating on the site and leaking out of the reactors.
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  • It appears, however, that the process is now ahead of schedule. Environment Minister Goshi Hosono, who is also in charge of the Fukushima nuclear accident recovery, told the International Atomic Energy Agency's annual general conference in Vienna on 19 September that Japan was now aiming to complete a cold shutdown of the Fukushima plant by December 2011, instead of mid-January 2012. Progress was already evident in July, when Hosono announced that workers had completed step 1 of the two-step road map on schedule, reducing radioactive emissions and starting to bring down the core temperatures in reactors 1, 2, and 3. Hosono attributed the success to the construction of a new cooling system, which had begun pumping water into all three damaged reactors. In addition to cooling, the system also decontaminates the water accumulating in the basements of the reactor and turbine buildings. The contamination is the result of injected water coming into contact with the molten fuel in the pressure vessels.
  • Critics, however, were quick to question the stability of the system and its ad hoc design. The combination of filtering and decontamination technologies—mainly from the French nuclear giant Areva and the U.S. nuclear waste management company Kurion—includes some 4 kilometers of piping. The critics have a point. Even with the addition of a reportedly more robust system (to be used in parallel or as backup as needed) from Toshiba and IHI Corp., TEPCO admits the system underwent 39 disruptions between 10 July and 8 September. One consequence is that roughly 100 000 metric tons of water still need to be decontaminated.
  • Disruptions and remaining challenges notwithstanding, TEPCO has been making progress toward step 2 of the road map: a cold shutdown. According to TEPCO, that means achieving and maintaining a temperature of less than 100 °C as measured at the bottom of a reactor pressure vessel—the steel vessel containing the fuel rods—which itself is enclosed inside a protective containment vessel. A major advance came at the beginning of September, when TEPCO was able to start up the core spray lines to cool reactors 1 and 3. The core spray lines apply water directly to the cores from above, while the system installed in July has been cooling the cores by injecting water from the bottom. TEPCO has also begun increasing the amount of water being injected into reactor 2. The core spray line could not be used until recently because TEPCO first had to survey the subsystem's piping and valves. Given the high radiation in the area, this was difficult, but workers completed the job in July and confirmed the system's operability in August.
  • By late September, as a result of these efforts, the temperatures in all three reactors had dropped below 100 °C for the first time since the accident. As of 29 September, the temperatures for reactors 1, 2, and 3, respectively, were 77.5 °C, 99.7 °C, and 78.7 °C. "We are steadily bringing the postaccident situation under control," says Hosono. "To achieve step 2 this year, we'll move the schedule forward and do our best." But Yoshinori Moriyama, deputy director-general of Japan's Nuclear and Industrial Safety Agency (NISA) is cautious. "We need to maintain this state over the midterm," he says. "Temporary lower temperatures and the nonrelease of radioactive substances do not immediately mean that this is a cold shutdown." In order for NISA to declare a cold shutdown, the temperatures must remain stable and below 100 °C into December. So NISA won't officially declare a cold shutdown until near the end of 2011.
  • Despite these positive developments, nuclear experts point out that achieving a cold shutdown does not make the troubled plant completely safe, given that even spent fuel continues to generate heat for years after use. And upon achieving a cold shutdown, TEPCO must take on a new series of challenges. These include finding where the injected water is escaping, stopping those leaks, dealing with the accumulated contaminated water, removing and storing the thousands of spent fuel rods from the pools in reactors 1 to 4, and then figuring out a way to remove the melted fuel. The last is a task that could take a decade or more, according to experts.
D'coda Dcoda

Secret US-Israeli Nuke Weapons Transfers Led To Fukushima Blasts [03Oct11] - 0 views

www.rense.com/secbb.htm

shared by D'coda Dcoda on 03 Oct 11 - No Cached
  • Sixteen tons and what you get is a nuclear catastrophe. The explosions that rocked the Fukushima No.1 nuclear plant were more powerful than the combustion of hydrogen gas, as claimed by the Tokyo Electric Power Company. The actual cause of the blasts, according to intelligence sources in Washington, was nuclear fission of. warhead cores illegally taken from America's sole nuclear-weapons assembly facility. Evaporation in the cooling pools used for spent fuel rods led to the detonation of stored weapons-grade plutonium and uranium.   The facts about clandestine American and Israeli support for Japan's nuclear armament are being suppressed in the biggest official cover-up in recent history. The timeline of events indicates the theft from America's strategic arsenal was authorized at the highest level under a three-way deal between the Bush-Cheney team, Prime Minister Shinzo Abe and Elhud Olmert's government in Tel Aviv.
  • Tokyo's Strangelove   In early 2007, Vice President Dick Cheney flew to Tokyo with his closest aides. Newspaper editorials noted the secrecy surrounding his visit - no press conferences, no handshakes with ordinary folks and, as diplomatic cables suggest, no briefing for U.S. Embassy staffers in Tokyo.   Cheney snubbed Defense Minister Fumio Kyuma, who was shut out of confidential talks. The pretext was his criticism of President George Bush for claiming Iraq possessed weapons of mass destruction. The more immediate concern was that the defense minister might disclose bilateral secrets to the Pentagon. The Joint Chiefs of Staff were sure to oppose White House approval of Japan's nuclear program.
  • Camp David Go-Ahead   The deal was sealed on Abe's subsequent visit to Washington. Wary of the eavesdropping that led to Richard Nixon's fall from grace, Bush preferred the privacy afforded at Camp David. There, in a rustic lodge on April 27, Bush and Abe huddled for 45 minutes. What transpired has never been revealed, not even in vague outline.   As his Russian card suggested, Abe was shopping for enriched uranium. At 99.9 percent purity, American-made uranium and plutonium is the world's finest nuclear material. The lack of mineral contaminants means that it cannot be traced back to its origin. In contrast, material from Chinese and Russian labs can be identified by impurities introduced during the enrichment process.
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  • Since the Liberal Democratic Party selected him as prime minister in September 2006, the hawkish Abe repeatedly called for Japan to move beyond the postwar formula of a strictly defensive posture and non-nuclear principles. Advocacy of a nuclear-armed Japan arose from his family tradition. His grandfather Nobusuke Kishi nurtured the wartime atomic bomb project and, as postwar prime minister, enacted the civilian nuclear program. His father Shintaro Abe, a former foreign minister, had played the Russian card in the 1980s, sponsoring the Russo-Japan College, run by the Aum Shinrikyo sect (a front for foreign intelligence), to recruit weapons scientists from a collapsing Soviet Union.   The chief obstacle to American acceptance of a nuclear-armed Japan was the Pentagon, where Pearl Harbor and Hiroshima remain as iconic symbols justifying American military supremacy.The only feasible channel for bilateral transfers then was through the civilian-run Department of Energy (DoE), which supervises the production of nuclear weapons.
  • Abe has wide knowledge of esoteric technologies. His first job in the early 1980s was as a manager at Kobe Steel. One of the researchers there was astrophysicist Hideo Murai, who adapted Soviet electromagnetic technology to "cold mold" steel. Murai later became chief scientist for the Aum Shinrikyo sect, which recruited Soviet weapons technicians under the program initiated by Abe's father. After entering government service, Abe was posted to the U.S. branch of JETRO (Japan External Trade Organization). Its New York offices hosted computers used to crack databases at the Pentagon and major defense contractors to pilfer advanced technology. The hacker team was led by Tokyo University's top gamer, who had been recruited into Aum.   After the Tokyo subway gassing in 1995, Abe distanced himself from his father's Frankenstein cult with a publics-relations campaign. Fast forward a dozen years and Abe is at Camp David. After the successful talks with Bush, Abe flew to India to sell Cheney's quadrilateral pact to a Delhi skeptical about a new Cold War. Presumably, Cheney fulfilled his end of the deal. Soon thereafter Hurricane Katrina struck, wiping away the Abe visit from the public memory.
  • The flow of coolant water into the storage pools ceased, quickening evaporation. Fission of the overheated cores led to blasts and mushroom-clouds. Residents in mountaintop Iitate village overlooking the seaside plant saw plumes of smoke and could "taste the metal" in their throats.   Guilty as Charged   The Tohoku earthquake and tsunami were powerful enough to damage Fukushima No.1. The natural disaster, however, was vastly amplified by two external factors: release of the Stuxnet virus, which shut down control systems in the critical 20 minutes prior to the tsunami; and presence of weapons-grade nuclear materials that devastated the nuclear facility and contaminated the entire region.   Of the three parties involved, which bears the greatest guilt? All three are guilty of mass murder, injury and destruction of property on a regional scale, and as such are liable for criminal prosecution and damages under international law and in each respective jurisdiction.
  • The Texas Job   BWXT Pantex, America's nuclear warhead facility, sprawls over 16,000 acres of the Texas Panhandle outside Amarillo. Run by the DoE and Babcock & Wilson, the site also serves as a storage facility for warheads past their expiration date. The 1989 shutdown of Rocky Flats, under community pressure in Colorado, forced the removal of those nuclear stockpiles to Pantex. Security clearances are required to enter since it is an obvious target for would-be nuclear thieves.   In June 2004, a server at the Albuquerque office of the National Nuclear Security System was hacked. Personal information and security-clearance data for 11 federal employees and 177 contractors at Pantex were lifted. NNSA did not inform Energy Secretary Samuel Bodman or his deputy Clay Sell until three months after the security breach, indicating investigators suspected an inside job.
  • Throughout the Pantex caper, from the data theft to smuggling operation, Bush and Cheney's point man for nuclear issues was DoE Deputy Director Clay Sell, a lawyer born in Amarillo and former aide to Panhandle district Congressman Mac Thornberry. Sell served on the Bush-Cheney transition team and became the top adviser to the President on nuclear issues. At DoE, Sell was directly in charge of the U.S. nuclear weapons complex, which includes 17 national laboratories and the Pantex plant. (Another alarm bell: Sell was also staff director for the Senate Energy subcommittee under the late Sen. Ted Stevens of Alaska, who died in a 2010 plane crash.)   An Israeli Double-Cross   The nuclear shipments to Japan required a third-party cutout for plausible deniability by the White House. Israel acted less like an agent and more like a broker in demanding additional payment from Tokyo, according to intelligence sources. Adding injury to insult, the Israelis skimmed off the newer warhead cores for their own arsenal and delivered older ones. Since deteriorated cores require enrichment, the Japanese were furious and demanded a refund, which the Israelis refused. Tokyo had no recourse since by late 2008 principals Abe had resigned the previous autumn and Bush was a lame duck.
  • The Japanese nuclear developers, under the Ministry of Economy, Trade and Industry, had no choice but to enrich the uranium cores at Fukushima No.1, a location remote enough to evade detection by nonproliferation inspectors. Hitachi and GE had developed a laser extraction process for plutonium, which requires vast amounts of electrical power. This meant one reactor had to make unscheduled runs, as was the case when the March earthquake struck.   Tokyo dealt a slap on the wrist to Tel Aviv by backing Palestinian rights at the UN. Not to be bullied, the Israeli secret service launched the Stuxnet virus against Japan's nuclear facilities.   Firewalls kept Stuxnet at bay until the Tohoku earthquake. The seismic activity felled an electricity tower behind Reactor 6. The power cut disrupted the control system, momentarily taking down the firewall. As the computer came online again, Stuxnet infiltrated to shut down the back-up generators. During the 20-minute interval between quake and tsunami, the pumps and valves at Fukushima No.1 were immobilized, exposing the turbine rooms to flood damage.
  • An unannounced reason for Cheney's visit was to promote a quadrilateral alliance in the Asia-Pacific region. The four cornerstones - the US, Japan, Australia and India - were being called on to contain and confront China and its allies North Korea and Russia.. From a Japanese perspective, this grand alliance was flawed by asymmetry: The three adversaries were nuclear powers, while the U.S. was the only one in the Quad group.   To further his own nuclear ambitions, Abe was playing the Russian card. As mentioned in a U.S. Embassy cable (dated 9/22), the Yomiuri Shimbun gave top play to this challenge to the White House : "It was learned yesterday that the government and domestic utility companies have entered final talks with Russia in order to relegate uranium enrichment for use at nuclear power facilities to Atomprom, the state-owned nuclear monopoly." If Washington refused to accept a nuclear-armed Japan, Tokyo would turn to Moscow.
  • The White House, specifically Bush, Cheney and their co-conspirators in the DoE, hold responsibility for ordering the illegal removal and shipment of warheads without safeguards.   The state of Israel is implicated in theft from U.S. strategic stockpiles, fraud and extortion against the Japanese government, and a computer attack against critical infrastructure with deadly consequences, tantamount to an act of war.   Prime Minister Abe and his Economy Ministry sourced weapons-grade nuclear material in violation of constitutional law and in reckless disregard of the risks of unregulated storage, enrichment and extraction. Had Abe not requested enriched uranium and plutonium in the first place, the other parties would not now be implicated. Japan, thus, bears the onus of the crime.
  • The International Criminal Court has sufficient grounds for taking up a case that involves the health of millions of people in Japan, Canada, the United States, Russia, the Koreas, Mongolia, China and possibly the entire Northern Hemisphere. The Fukushima disaster is more than an human-rights charge against a petty dictator, it is a crime against humanity on par with the indictments at the Nuremberg and Tokyo tribunals. Failure to prosecute is complicity.   If there is a silver lining to every dark cloud, it's that the Tohoku earthquake and tsunami saved the world from even greater folly by halting the drive to World War III.
  • D'coda Dcoda on 03 Oct 11
     
    A very important report from ex-Japanese Times reporter, Yoichi Shimatsu
D'coda Dcoda

Experts split on how to decommission Fukushima nuclear plant [29Aug11] - 0 views

mdn.mainichi.jp/...20110828p2a00m0na002000c.html

shared by D'coda Dcoda on 30 Aug 11 - No Cached
  • What is actually going to take place at the Fukushima No. 1 Nuclear Power Plant, where word is that the four reactors that were crippled in the Great East Japan Earthquake and tsunami will eventually be decommissioned? The Ministry of Economy, Trade and Industry's Nuclear and Industrial Safety Agency (NISA) defines "decommissioning" as the process of removing spent fuel from reactors and dismantling all facilities. Ultimately, the site of a decommissioned reactor is meant to be reverted into a vacant lot.
  • In 1996, the then Japan Atomic Energy Research Institute (JAERI) -- now the Japan Atomic Energy Agency (JAEA) -- finished decommissioning its Japan Power Demonstration Reactor. The decommissioning process of the Tokai Nuclear Power Plant in the Ibaraki Prefecture village of Tokai began in 1998 and is set to end in fiscal 2020, while the No. 1 and No. 2 nuclear reactors at the Hamaoka Nuclear Power Plant in the Shizuoka Prefecture city of Omaezaki are slated for decommissioning by fiscal 2036. Around the world, only around 15 nuclear reactors have thus far been dismantled.
  • The standard decommissioning process entails six major steps: 1. Remove spent fuel rods, 2. Remove radioactive materials that have become affixed to reactor pipes and containers, 3. Wait for radiation levels to go down with time, 4. Dismantle reactors and other internal vessels and pipes, 5. Dismantle the reactor buildings, and 6. Make the site into a vacant lot.
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  • "Cleaning," "waiting," and "dismantling" are the three key actions in this process. Needless to say, this all needs to be done while simultaneously containing radioactive materials.
  • In the case of the Tokai Nuclear Power Plant, the first commercial plant to undergo decommissioning, spent fuel was removed over a span of three years beginning in 1998, and was transported to Britain for reprocessing. Dismantling of the facilities began in 2001, with current efforts being made toward the dismantling of heat exchangers; workers have not yet begun to take the reactor itself apart. The entire process is expected to be an 88.5-billion-yen project involving 563,000 people.
  • Hitachi Ltd., which manufactures nuclear reactors, says that it "generally takes about 30 years" to decommission a reactor. The Hamaoka Nuclear Power Plant's No. 1 and No. 2 reactors operated by Chubu Electric Power Co. are also expected to take about 30 years before they are decommissioned.
  • In the case of the Fukushima No. 1 Nuclear Power Plant, meanwhile, the biggest challenge lies in how to remove the fuel, says Tadashi Inoue, a research advisor at the Central Research Institute of Electric Power Industry (CRIEPI), a foundation that conducts research on energy and environmental issues in relation to the electrical power industry.
  • "we must deal with rubble contaminated with radioactive materials that were scattered in the hydrogen blasts and treat the radiation-tainted water being used to cool nuclear fuel before we can go on to fuel removal."
  • Currently, the Fukushima plant's operator, Tokyo Electric Power Co. (TEPCO), is desperately trying to treat the contaminated water. Huge challenges remain with regards to the contaminated rubble, as radiation levels of over 10 sieverts per hour were found near outdoor pipes on the plant grounds just the other day. Exposure to such high levels would mean death for most people.
  • Each step in the process toward decommissioning is complicated and requires great numbers of people. It's a race against time because the maximum amount of radiation that workers can be exposed to is 250 millisieverts.
  • The breached reactor core is a bigger problem. It is believed that raising water levels inside the reactor has been difficult because of a hole in the bottom of the vessel. It will be necessary to plug the hole, and continue filling the vessel with water while extracting the melted fuel. How to fill the vessel with water is still being debated. If the reactor can be filled with water, steps taken after the 1979 Three Mile Island nuclear accident can serve as a guide because in that case, in which approximately 50 percent of the core had melted, workers were able to fill the reactor with water and remove the fuel within.
  • Two types of fuel removal must take place. One is to take out the spent fuel in the containment pools, and the other is to remove the melted fuel from the reactor cores. Because the radiation levels of the water in the spent fuel pools have not shown any significant changes from before the crisis, it is believed that the spent fuel has not suffered much damage. However, removing it will require repairing and reinstalling cranes to hoist the fuel rods out.
  • Prefacing the following as "a personal opinion," Inoue says: "Building a car that can protect the people inside as much as possible from radioactive materials, and attaching an industrial robotic arm to the car that can be manipulated by those people could be one way to go about it."
  • Inoue predicts that removal of spent fuel from the containment pools will begin about five years after the crisis, and about 10 years in the case of melted fuel from the reactor core. Work on the four reactors at the Fukushima plant will probably take several years.
  • "Unless we look at the actual reactors and take and analyze fuel samples, we can't know for sure," Inoue adds. Plus, even if workers succeed in removing the fuel, reprocessing it is an even more difficult task. A review of processing methods and storage sites, moreover, has yet to take place.
  • Meanwhile, at least one expert says he doesn't believe that workers will be able to remove the melted fuel from the crippled plant.
  • "If there's 10 sieverts per hour of radiation outside, then the levels must be much higher closer to the reactor core," says Tadahiro Katsuta, an associate professor at Meiji University and an expert in reactor engineering and reactor policy who was once a member of an anti-nuclear non-profit organization called Citizens' Nuclear Information Center (CNIC). "The fuel has melted, and we haven't been able to cool it consistently. If work is begun five or 10 years from now when radiation levels have not yet sufficiently gone down, workers' health could be at serious risk."
  • Katsuta predicts that it will probably take at least 10 years just to determine whether it is possible to remove the fuel. He adds that it could very well take 50 years before the task of dismantling the reactor and other facilities is completed.
  • What Katsuta has in mind is a Chernobyl-style concrete sarcophagus, which would entail cloaking the melted tomb with massive amounts of concrete. "How could we simultaneously dismantle four reactors that have been contaminated to the extent that they have by radioactive materials?" asks Katsuta. "Japan has little experience in decommissioning reactors, and this case is quite different from standard decommissioning processes. It's not realistic to think we can revert the site back to a vacant lot. I think we should be considering options such as entombing the site with concrete or setting up a protective dome over the damaged reactor buildings
  • what we face is a great unknown to all of mankind.
D'coda Dcoda

Japan: A Nuclear Gypsy's Tale [03Aug11] - 0 views

globalvoicesonline.org/...a-nuclear-gypsy%E2%80%99s-tale

shared by D'coda Dcoda on 04 Aug 11 - No Cached
  • Before the Fukushima accident brought to light the parlous state of the Japanese nuclear industry, for years temporary workers have jumped in and out of remunerative short-term jobs at the power plants ignoring the risk of their profession. Takeshi Kawakami (川上武志) was one of the so-called ‘nuclear gypsies’ and just like many other colleagues of his, for about 30 years he made a livelihood working at the different nuclear plants of the country for short periods. For years he earned money helping repair or replace malfunctioning parts of nuclear reactors and carrying out dangerous operations, with a high-risk of radiation exposure.
  • In his blog, Kawakami denounced the corruption and collusion between the government and the nuclear industry, focusing his coverage on the Hamaoka nuclear power plant. This power plant was recently shut down at the request of the Japanese government for remedial work after it was deemed dangerous to continue operating in light of its position on one of the major seismic faults lines in the Japanese archipelago. In the post partly translated here, he tells of his experiences as a temporary worker when he worked for the first time inside a steam generator at the Genkai nuclear power plant in southern Japan.
  • The following post was originally published on December 26th, 2010 and translated with the author's consent:
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  • I worked at Hamaoka nuclear plant for a little over 5 years, but it was not the only time I’d worked at a power plant. Before Hamaoka, I spent my 30s working at a nearby nuclear plant for about 10 years in the 1980’s. At that time, I did not work at just one site but was moving from one plant to another to do regular maintenance work. Recently, that kind of people are called “Nuclear gypsies” with a bit of contempt and in that period I was living as one of those. Two years after I began the wandering life of a gypsy, I entered for the first time the core container of a steam generator. At the time I was working at the Genkai Nuclear Power Plant in Saga Prefecture. [Editor's note: In brief, there is a containment building within the plant. This houses the core and the steam generator.] The core is the part of the reactor where uranium fuel undergoes nuclear fission. It generates heat which is then passed to The steam generator which produces the steam to power the turbines which turn the generators elsewhere in the plant . The level of radioactivity in the containment building is very high compared to elsewhere [in the plant]. My job involved entering [the generator] and installing a robot monitor that would enable examination of whether there was any damage in the steam generator.
  • Actually what happened on the day was that another person replaced me and entered the steam generator to install the robot. After the installation was completed, there was a problem in that the robot wouldn’t respond and thus could not be operated from outside. There are many small holes in the walls of the central part of the steam generator and the six (I believe there were six) ‘legs’ of a robot, operated via a remote control, should be able to survey it through those holes. The employees in charge of supervising the installation concluded that there had been a problem in properly positioning the robot’s legs.
  • If the ‘legs’ are not completely inserted and the robot is left in that position, it could fall down at any time. If that happens, it spells the loss of a precision machine that's said to be worth several hundred million yen. That’s why I was sent in to enter the generator, on very short notice, to replace the robot back to its correct operating position before that happened. I started putting on the gear to enter the housing at a spot near the steam generator. Two workers helped me put it on. I was already wearing two layers of work clothes, and on top of those, I put on Tyvek protective gear made of paper and vinyl, and an airline respirator. Plus, I wrapped a lot of vinyl tape around my neck, my wrists and my ankles, to block even the slightest opening.
  • Once I finished putting on the protective gear — which honestly looks like an astronaut suit — I headed toward the housing. When I arrived at the area near the housing, two workers were waiting. They were employees of a company called the Japanese Society for Non-Destructive Inspection [JSNDI] and, to my surprise, despite the area being highly radioactive, they were wearing nothing but plain working clothes. They weren’t even wearing masks. The person who appeared to be in charge invited me over and, after a look at my eyes inside the mask, nodded his head a few times. I guess just looking into my eyes he was able to determine that I’d be able to handle working in the core.
  • He and I went to the steam generator together.
  • The base of the steam generator more or less reached my shoulder, at slightly less than 1.5m. At the bottom, there was a manhole. The manhole was open, and I immediately realized I would have to climb up into it.
  • The JSNDI employee in charge put his arm around me and together we approached the manhole. We looked over the edge and peered in. Inside was dark, and the air was dense and stagnant. It felt as though something sinister was living inside. My expression glazed over. A slight sensation of dread came over me. As I approached the manhole, I noticed a ringing in my ears and felt reluctant to go in. When I looked inside, I saw that the robot was attached to the wall indicated by the [JSNDI] employee. It was not properly attached, which is why I had been sent in.
  • The robot was square-shaped, 40 cm on each side and 20 cm deep. It was called a ‘spider robot’. The JSNDI employee put his face at the edge of the manhole, a third of his face peering in, and diligently explained what I had to do. There was little awareness at the time of the dangers to workers of radiation exposure, but even so I was concerned about the bold act of the employee, who looked inside the housing with me. He continued looking inside, unfazed, and I remember wondering why he wasn’t scared. I was almost completely covered while he wasn’t even wearing a mask. […]
  • I stood up, climbed the ladder, and pushed my upper body through the manhole. In that second, something grabbed at my head and squeezed hard. A pounding in my ear started right away.
  • One worker said that right after he entered a nuclear reactor he heard a noise like a moving crab. “zawa,zawa,zawa…” He said that he could still hear this noise after he finished the work. Even after the inspection work, when he went back home, he couldn’t forget that noise. The man ended up having a nervous breakdown. A writer who heard this story spoke to this man and wrote a mystery novel based on that experience. The title of the book is “The crab of the nuclear reactor”. It was published in 1981 and was very popular among us.
  • I never heard such a crab-like noise but I had the feeling that my head was being tightly constricted and deep in my ears I heard very high-tempo echoes like a sutra “gan, gan, gan”. When I entered the steam generator I stood up all of a sudden and my helmet hit the ceiling. So I had to bend my neck and hold both the arms of the robot in the darkish room. “OK” I screamed. So the robot was unlocked and its feet jumped out of the hole. The entire robot was not as heavy as I had thought. After I matched its feet position in the holes I gave them another OK sign and so it was positioned in the hole. In the dark, when I verified that all the feet had entered into the holes I gave them another OK and jumped out of the manhole. […]
  • Once outside,] I was almost in shock but looked at the alarm meter and saw that it had recorded a value equal to 180, when the maximum it can record is 200. In only 15 seconds, I was exposed to an unbelievably high level of radiation, 180 millirem. At that time the unit ‘millirem' was used while now it’s different. Now everybody uses sievert. That time I was in charge of an inspection work that lasted about 1 month. After that I worked in another nuclear reactor but even on the second time I couldn’t get through the fear and experienced the same creepy noise.
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Fukushima and the Doomsday Clock | Bulletin of the Atomic Scientists [11Aug11] - 0 views

www.thebulletin.org/...kushima-and-the-doomsday-clock

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  • When dreadful events occur, reporters, readers, and interested citizens contact the Bulletin of the Atomic Scientists asking whether we will move the minute hand of the Doomsday Clock. The alarming nuclear disaster at the Fukushima Daiichi Power Station on March 11 prompted e-mails and calls to our office seeking the Bulletin's reaction as well as accurate information about what was happening in Japan. The Bulletin responded by devoting its website to daily briefings from experts in Japan and to news from Bulletin writers on what they were hearing about this second-worst disaster in the history of the nuclear power industry. Additionally, the Bulletin will take deeper dives into the lessons and impacts of Fukushima in the September/October issue of its digital journal. Still, the larger question remains: Should we move the hand of the Doomsday Clock? What does the Fukushima event imply for humanity's future on the planet?
  • How do we determine the time? In annual Clock discussions, the Bulletin's Science and Security Board -- the keepers of the Clock -- reviews the trends and current events that reveal how well or how poorly humanity regulates the perilous forces unleashed by our own ingenuity and industry. Moving the minute hand of the Doomsday Clock is a judgment, then, an assessment of the human capacity to control technologies that can lead to irreversible catastrophe -- to the end of civilization. With growing worldwide interest in nuclear energy for economic development, it's important to know how well firms and societies are handling this dangerous technology
  • Questions for a post-Fukushima world. The Bulletin's Board members are following the events at the Fukushima Daiichi nuclear power plant in Japan very closely. Questions about the continuing disaster range from the detailed and technical to the societal and ethical; the answers will have implications for any long-term commitment to nuclear power.
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  • On the technical end, it appears that the underlying cause of the three core meltdowns, the hydrogen explosions, and the subsequent release of radioactive material was the loss of coolant to the nuclear cores, which was ultimately due to the loss of electrical power to the reactors. Without power to circulate the water that cooled the fuel rods, nothing could have prevented the core meltdowns. In light of this failure, questions center on reactor design and handling of nuclear fuel. Can reactors be designed without a reliance on electrical power to maintain the proper core temperature? In the event of system failure, are there better alternatives to human intervention? Stronger safety designs have been proposed in the past -- ones that are more straightforward and less Rube Goldberg-like than the complicated systems currently used. Why haven't they been developed? Meanwhile, the handling of nuclear fuel continues to defy logic: Why is spent fuel still stored at power plants -- raising the odds of damage and the subsequent release of radioactive materials in accidents? What exactly are the obstacles to placing spent fuel in long-term storage repositories?
  • A second set of questions focuses on operations, regulation, and public knowledge about nuclear reactors. How can regulatory agencies maintain independence from the nuclear industry and enforce rigorous safety standards? What prevents the industry from being more transparent about operations, especially when leaks and mishaps occur? If existing regulatory arrangements appear inadequate, then could a different structure of economic incentives encourage utilities to make their nuclear power plants safer and more secure? In the United States, for example, current law limits industry liability in the event of an accident. Does the limit on legal liability in the event of an accident reduce firms' incentives not only to develop the safest designs possible but also to ensure the most rigorous oversight of maintenance and operations?
  • More broadly, how can societies and communities meet their energy needs with the least risk and the greatest payoff for economic development? Are there alternatives based on precautionary principles -- first do no harm -- that involve less peril to safety, health, and community than nuclear or fossil-fueled power? Are we locked into the current energy development path? How should we think about the trade-offs between injury and disruption from energy technologies and future injury and disruption from climate change?
  • But have we learned anything? These questions are difficult to answer and the trade-offs nearly impossible to calculate. Even harder, however, will be implementing policy recommendations in a world of vested interests tied to old technologies. Over the past 100 years or so, the world's "energy portfolio" did not diversify very much -- as electric and gas-fueled engines powered industrial development. Renewable energy technologies like wind, solar, and biofuels hold great potential, but require much more rapid development to substitute for fossil fuels and nuclear power in the near term. So it appears now that there are few good choices: Either warm the planet's atmosphere and oceans, with dire consequences for human societies as the climate rapidly changes, or place communities in jeopardy from nuclear plant accidents and releases of deadly radioactive materials. However, in January 2012, when the Bulletin deliberates about moving the hand of the Doomsday Clock, the most important question will be: What have governments, firms, and citizens learned from the Fukushima disaster about managing Earth-altering technologies? And will they act on what they have learned in time to avert future disaster?
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How did Fukushima-Dai-ichi core meltdown change the probability of nuclear accidents? [... - 1 views

inis.iaea.org/...search.aspx

nuclear energy europe france accident fukushima

shared by D'coda Dcoda on 03 Nov 13 - No Cached
  • D'coda Dcoda on 03 Nov 13
     
    How to predict the probability of a nuclear accident using past observations? What increase in probability the Fukushima Dai-ichi event does entail? [...] We find an increase in the risk of a core meltdown accident for the next year in the world by a factor of ten owing to the new major accident that took place in Japan in 2011. [...] Two months after the fukushima Dai ichi meltdown, a French newspaper published an article coauthored by a French engineer and an economist1. They both argued that the risk of a nuclear accident in Europe in the next thirty years is not unlikely but on the contrary, it is a certainty. They claimed that in France the risk is near to 50% and more than 100% in Europe. [...] The Fukushima Dai-ichi results in a huge increase in the probability of an accident. [...]
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Oak Ridge National Laboratory: Advancing The Nuclear Enterprise Through Better Computin... - 0 views

nuclearstreet.com/...gh-better-computing-05242.aspx

shared by D'coda Dcoda on 23 Jul 11 - No Cached
  • In the area of nuclear energy, the Nuclear Modeling staff specializes in developing and applying computational methods and software for simulating radiation in order to support the design and safety of nuclear facilities, improve reactor core designs and nuclear fuel performance, and ensure the safety of nuclear materials, such as spent nuclear fuel. The Nuclear Modeling staff is internationally known for developing and maintaining SCALE, a comprehensive nuclear analysis software package originally developed for the Nuclear Regulatory Commission with signature capabilities in the criticality safety, reactor physics and radiation shielding areas. In recent years, ORNL has placed an emphasis on transforming its current capabilities through high-performance computing, as well as the development of new and novel computational methods
  • Scientists at the Nuclear Science and Technology Division of the U.S. Department of Energy's Oak Ridge National Laboratory (ORNL) are merging decades of nuclear energy and safety expertise with high-performance computing to effectively address a range of nuclear energy- and security-related challenges.
  • John Wagner, Technical Integration Manager for Nuclear Modeling within ORNL's Nuclear Science and Technology Division (NSTD), says one of the goals of his organization is to integrate existing nuclear energy and nuclear national security modeling and simulation capabilities and associated expertise with high-performance computing to solve problems that were previously unthinkable or impractical in terms of the computing power required to address them.
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  • "Traditionally, reactor models for radiation dose assessments have considered just the reactor core, or a small part of the core," Wagner says. "However, we're now simulating entire nuclear facilities, such as a nuclear power reactor facility with its auxiliary buildings and the ITER fusion reactor, with much greater accuracy than any other organization that we're aware of." More accurate models enable nuclear plants to be designed with more accurate safety margins and shielding requirements, which helps to improve safety and reduce costs. The technology that makes this sort of leading-edge simulation possible is a combination of ORNL's Jaguar, the world's fastest supercomputer; advanced transport methods; and a next-generation software package called Denovo
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TEPCO may use 'shower spray' on troubled reactor [05Aug11] - 0 views

ajw.asahi.com/...AJ201108055286

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  • Tokyo Electric Power Co. is considering changing the method of injecting water into the No. 3 reactor at its hobbled Fukushima No. 1 nuclear power plant as the current system isn't cutting it. The No. 3 reactor is consuming nearly three times the coolant water that the No. 1 and No. 2 reactors are taking to cool down their fuel rods, as a considerable amount is missing the target. TEPCO said that the pressure vessels in the No. 1 through No. 3 reactors, where fuel meltdowns have occurred, currently have temperatures at the bottom between about 90 and 120 degrees. In the meantime, the amount of water pumped in daily to maintain the temperatures at these levels is about 216 tons for the No. 3 reactor, as opposed to 84 tons for the No. 2 reactor, which is about the same size and contains roughly the same number of fuel rods, and 91 tons for the No. 1 reactor, which is smaller.
  • The question is, why is this discrepancy occurring? TEPCO said that in all three reactors, coolant water is being injected from outside the shroud, a major component covering the core. Analysis conducted so far has hinted at the possibility that, unlike in the No. 1 and No. 2 reactors, part of the melted fuel in the No. 3 reactor did not fall through to the bottom of the pressure vessel but has stayed on the grid-like core support plate. The current injection method cannot pump water into there, resulting in inefficient cooling and increasing the amount of radioactive water. The new water injection method under consideration is based on the use of an emergency cooling system called a "core spray." It can pour water down like a shower above the fuel rods, resulting in more efficient cooling and the use of less coolant water, TEPCO said. Much has been learned about the state of the cooling pipe systems since workers regained access to the reactor buildings. On Aug. 3, TEPCO conducted tests on the operability of valves along the piping.
  • We plan to make decisions in two or three weeks," a TEPCO official said.
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Actual workers talk about Fukushima [26Sep11] - 0 views

fukushima-diary.com/...l-workers-talk-about-fukushima

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  • At the moment the conditions at Unit 1 of Fukushima nuclear power plant continues to be chaos, so Tadaharu Murakami (pseudonym), 30 years, an employee of a company that works as a subcontractor for Tokyo Electric Power. “The workers are not enough, TEPCO has recently committed even many people without experience who have never worked in a nuclear plant. As for the places of work, everything is really chaotic. It educates the people by giving them the ABCs teaches fundamental things such as wearing protective clothing like you.”
  • On The Pointy Guy) As a symbol of the discontent that elicits such a situation, there was an “incident” on 28 August has a live camera from TEPCO, which is mounted inside the block 1, sent pictures of a “mysterious” staff, who has placed himself in front of the lens and has said anything, while he pointed his finger at the camera. Murakami explains that after the conference on 30th August, during which expressed Yasuhiro Sonoda, responsible parliamentarians of the Cabinet, the wish that he would like to share the thoughts of “this person”, what he thinks, the guy who pretends to be that person and the real conditions on the website the bulletin board system of “2channel” has been disclosed. He has hit the nail on the head when he said that “for the people who work there, the working conditions are unfair and illegal. We have no insurance, we are poorly paid and we even have a contract. ”
  • Murakami confirmed, “that what he wrote on the Internet, the truth. Even when I worked before the accident in March as a temporary worker in Fukushima Daiichi have, you have promised me 15,000 yen a day and I’ve got nothing. “He continues,” when I asked at the sitting of the subcontractor, why do not they pay me what they owe me, they said, ‘You work for a subcontractor? So they have no right to make such a request.” I turned also to workers of TEPCO, which have responded harshly to me, I consider myself strictly to the rules of the line and that’s all. “I wait one more month and if they do not pay me, I’ll sue the subcontractor. “Murakami is confirmed by the descriptions, which are made on the internet about the poor accommodation,” even when it has cooled a bit in early September, break every day at least 10 workers due to fatigue together. I want them to rapidly improve the living conditions.”
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  • Osamu Sato (pseudonym), an approximately forty years old, is also working for a subcontractor of TEPCO. He has the explanations that have been recently released by TEPCO denied and replied that “there is no reason to mention that the situation had stabilized, etc., that’s not true.” “TEPCO announced that the situation is fine, although on the grounds of the things that are very much behind schedule, much more numerous than those that run well. This is the extreme main obstacle drive more radioactivity in the key zones.
  • On 1 August, measurements show in addition to an exhaust pipe between reactor 1 and 2 incredibly high readings, which can hardly believe it: 10,000 millisievert/hour! (Such a dose to take once meant certain death). From there it always escape greatly increased radiation doses. It has begun, and from there to discover little by little other zones, where the values are higher than 100 millisievert, zones which are provided with a cone that bears “forbidden access” the inscription, in the vicinity of such zones can not be work.
  • Even many experienced workers from the nuclear industry have refused to work in Fukushima, she said, “This is suicide,” because they know the effects of elevated radioactivity. To compensate for this, we hired more and more people without experience, instead of being useful to increase the chaos.” Whether you begin the process of establishing a decontamination system or whether the reactor buildings with a lack of protection surrounds, at the end are nothing more than the emergency measures.
  • You will not find a real solution that allows to separate the molten fuel rods, which are the cause of the diffusion of radioactive material when the technician can not approach the fast reactor core. In any case, it is an operation “almost impossible”, said the analysis by Masashi Goto, Toshiba developed for the nuclear reactor cores. “In the blocks 1, 2 and 3, there is a strong possibility that has emerged during the melting of nuclear fuel not only from the pressure vessel, but also from the protective sheath. At the moment nobody is able to determine, is melted in the extent and to what extent the core. I can not imagine how people can work there or at another location, where the danger has reached a point that nobody has ever experienced. “
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TEPCO redefines "cold shutdown" - Only bottom of pressure vessel has to be under 100 de... - 0 views

enenews.com/s-celcius-reactor-core-coolant

shared by D'coda Dcoda on 05 Sep 11 - No Cached
  • Plugging reactors no longer stated goal for Tepco, Japan Times, July 20, 2011: [...] A cold shutdown is usually defined as bringing the temperature of the reactor-core coolants to below 100 degrees. But this has been redefined as bringing the temperature at the bottom of the pressure vessels to below 100 degrees and reducing the release of radioactive materials from the reactors [...]
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Quake risk to reactors greater than thought - USA - [02Sept11] - 0 views

news.yahoo.com/greater-thought-071301249.html

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  • WASHINGTON (AP) — The risk that an earthquake would cause a severe accident at a U.S. nuclear plant is greater than previously thought, 24 times as high in one case, according to an AP analysis of preliminary government data. The nation's nuclear regulator believes a quarter of America's reactors may need modifications to make them safer.The threat came into sharp focus last week, when shaking from the largest earthquake to hit Virginia in 117 years appeared to exceed what the North Anna nuclear power plant northwest of Richmond was built to sustain.
  • The two North Anna reactors are among 27 in the eastern and central U.S. that a preliminary Nuclear Regulatory Commission review has said may need upgrades. That's because those plants are more likely to get hit with an earthquake larger than the one their design was based on. Just how many nuclear power plants are more vulnerable won't be determined until all operators recalculate their own seismic risk based on new assessments by geologists, something the agency plans to request later this year. The NRC on Thursday issued a draft of that request for public comment.
  • The NRC and the industry say reactors are safe as they are, for now. The average risk to U.S. reactors of core damage from a quake remains low, at one accident every 500 years, according to the AP analysis of NRC data.The overall risk at a typical reactor among the 27 remains very slight. If the NRC's numbers prove correct, that would mean no more than one core accident from an earthquake in about 30,000 years at the typical reactor among the 27 with increased risk.
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  • The review, launched well before the East Coast quake and the Japan nuclear disaster in March, marks the first complete update to seismic risk in years for the nation's 104 existing reactors, despite research showing greater hazards
  • But emails obtained in a more than 11,000-page records request by The Associated Press show that NRC experts were worried privately this year that plants needed stronger safeguards to account for the higher risk assessments.
  • The nuclear industry says last week's quake proved reactors are robust. When the rumbling knocked out off-site power to the North Anna plant in Mineral, Va., the reactors shut down and cooled successfully, and the plant's four locomotive-sized diesel generators turned on. The quake also shifted about two dozen spent fuel containers, but Dominion Virginia Power said Thursday that all were intact.Still, based on the AP analysis of NRC data, the plant is 38 percent more likely to suffer core damage from a rare, massive earthquake than it appeared in an analysis 20 years ago.
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Worst Nuclear Disasters - Civilian [15Apr11] - 0 views

www.epicdisasters.com/...rst_nuclear_disasters_civilian

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  • The top civilian nuclear disasters, ranked by International Nuclear and Radiological Event Scale. Worst Civilian Nuclear Disasters 1. Chernobyl, Soviet Union (now Ukraine) April 26, 1986 INES Rating: 7 (major impact on people and environment)
  • The worst nuclear disaster of all time resulted from a test of the reactor’s systems. A power surge while the safety systems were shut down resulted in the dreaded nuclear meltdown. Fuel elements ruptured and a violent explosion rocked the facility. Fuel rods meted and the graphite covering the reactor burned. Authorities reported that 56 have died as a direct result of the disaster—47 plant workers and nine children who died of thyroid disease. However, given the Soviet Union’s tendency to cover up unfavorable information, that number likely is low.  International Atomic Energy Agency reports estimate that the death toll may ultimately be as high as 4,000. The World Health Organization claims that it’s as high as 9,000. In addition to the deaths, 200,000 people had to be permanently relocated after the disaster. The area remains unsuitable for human habitation. 2. Fukushima, Japan March 11, 2011 INES Rating: 7 (major impact on people and environment) Following a 9.0 magnitude earthquake and tsunami, Japan’s Fukushima nuclear power facility suffered a series of ongoing equipment failures accompanied by the release of nuclear material into the air. The death toll for this currently is at two but is expected to rise and as of April 2011, the crisis still ongoing. A 12 mile evacuation area has been established around the plant.
  • 3. Kyshtym, Soviet Union Sept. 29, 1957 INES Rating: 6 (serious impact on people and environment) Poor construction is blamed for the September 1957 failure of this nuclear plant. Although there was no meltdown or nuclear explosion, a radioactive cloud escaped from the plant and spread for hundreds of miles. Soviet reports say that 10,000 people were evacuated, and 200 deaths were cause by cancer.
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  • 4. Winscale Fire, Great Britain Oct. 10, 1957 INES Rating: 5 (accident with wider consequences) The uranium core of Britain’s first nuclear facility had been on fire for two days before maintenance workers noticed the rising temperatures. By that time, a radioactive cloud had already spread across the UK and Europe. Plant operators delayed further efforts in fighting the fire, fearing that pouring water on it would cause an explosion. Instead, they tried cooling fan and carbon dioxide. Finally, they applied water and on Oct. 12, the fire was out. British officials, worried about the political ramifications of this incident, suppressed information. One report, however, says that in the long run, as many as 240 may have died from accident related cancers. 5.
  • Three Mile Island, Pennsylvania, US March 28, 1979 INES Rating: 5 (accident with wider consequences) Failure of a pressure valve resulted in an overheating of the plant’s core and the release of 13 million curies of radioactive gases. A full meltdown was avoided when the plant’s designers and operators were able to stabilize the situation before contaminated water reached the fuel rods. A full investigation by the US Nuclear Regulatory Commission suggests that there were no deaths or injuries resulting from the incident.
  • 6. Golania, Brazil Sept, 1987 INES Rating: 5 (accident with wider consequences) Scavengers at an abandoned radiotherapy institute found a billiard ball sized capsule of radioactive cesium chloride, opened it and then sold it to a junkyard dealer. The deadly material was not identified for more than two year, during which time it had been handled by hundreds, including some who used the glittery blue material for face paint. Of the 130,000 tested, 250 were discovered to be contaminated and 20 required treatment for radiation sickness. Four died, including the two who originally found the capsule, the wife of the junkyard owner and a small girl who used the powder as face paint. 7. Lucens, Switzerland January 1, 1969 INES Rating: 5 (accident with wider consequences) When the coolant on a test reactor facility in a cave in Switzerland failed during startup, the system suffered a partial core meltdown and contaminated the cavern with radioactivity. The facility was sealed and later decontaminated. No known deaths or injuries.
  • 8. Chalk River, Canada INES Rating: 5 (accident with wider consequences) May 24, 1958 Inadequate cooling lead to a fuel rod fire, contaminating the plant and surrounding labs. 9. Tokaimura,Japan Sept. 30, 1999 INES Rating: 4 (accident with local consequences) The nuclear plant near Tokai had not been used for three years when a group of unqualified workers attempted to put more highly enriched uranium in a precipitation tank than was permitted. A critical reaction occurred and two of the workers eventually died of radiation exposure. Fifty six plant workers and 21 others also received high doses of radiation. Residents within a thousand feet of the plant were evacuated.
  • 10. National Reactor Testing Station, Idaho Falls, Idaho January 3, 1961 INES Rating: 4 (accident with local consequences) Improper withdrawal of a control rod led to a steam explosion and partial meltdown at this Army facility. Three operators were killed in what is the only known US nuclear facility accident with casualties. In addition to these, there have been a number of deadly medical radiotherapy accidents, many of which killed more people than the more commonly feared nuclear plant accidents: 17 fatalities – Instituto Oncologico Nacional of Panama, August 2000 -March 2001. patients receiving treatment for prostate cancer and cancer of the cervix receive lethal doses of radiation.[7][8] 13 fatalities – Radiotherapy accident in Costa Rica, 1996. 114 patients received an overdose of radiation from a Cobalt-60 source that was being used for radiotherapy.[9]
  • 11 fatalities – Radiotherapy accident in Zaragoza, Spain, December 1990. Cancer patients receiving radiotherapy; 27 patients were injured.[10] 10 fatalities – Columbus radiotherapy accident, 1974–1976, 88 injuries from Cobalt-60 source. 7 fatalities – Houston radiotherapy accident, 1980.Alamos National Laboratory.[18] 1 fatality – Malfunction INES level 4 at RA2 in Buenos Aires, Argentina, operator Osvaldo Rogulich dies days later.
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Impacts of the Fukushima Nuclear Power Plants on Marine Radioactivity - Environmental S... - 0 views

pubs.acs.org/...es202816c

shared by D'coda Dcoda on 09 Dec 11 - No Cached
  • The impacts on the ocean of releases of radionuclides from the Fukushima Dai-ichi nuclear power plants remain unclear. However, information has been made public regarding the concentrations of radioactive isotopes of iodine and cesium in ocean water near the discharge point. These data allow us to draw some basic conclusions about the relative levels of radionuclides released which can be compared to prior ocean studies and be used to address dose consequences as discussed by Garnier-Laplace et al. in this journal.(1) The data show peak ocean discharges in early April, one month after the earthquake and a factor of 1000 decrease in the month following. Interestingly, the concentrations through the end of July remain higher than expected implying continued releases from the reactors or other contaminated sources, such as groundwater or coastal sediments. By July, levels of 137Cs are still more than 10 000 times higher than levels measured in 2010 in the coastal waters off Japan. Although some radionuclides are significantly elevated, dose calculations suggest minimal impact on marine biota or humans due to direct exposure in surrounding ocean waters, though considerations for biological uptake and consumption of seafood are discussed and further study is warranted.
  • there was no large explosive release of core reactor material, so most of the isotopes reported to have spread thus far via atmospheric fallout are primarily the radioactive gases plus fission products such as cesium, which are volatilized at the high temperatures in the reactor core, or during explosions and fires. However, some nonvolatile activation products and fuel rod materials may have been released when the corrosive brines and acidic waters used to cool the reactors interacted with the ruptured fuel rods, carrying radioactive materials into the ground and ocean. The full magnitude of the release has not been well documented, nor is there data on many of the possible isotopes released, but we do have significant information on the concentration of several isotopes of Cs and I in the ocean near the release point which have been publically available since shortly after the accident started.
  • We present a comparison of selected data made publicly available from a Japanese company and agencies and compare these to prior published radionuclide concentrations in the oceans. The primary sources included TEPCO (Tokyo Electric Power Company), which reported data in regular press releases(3) and are compiled here (Supporting Information Table S1). These TEPCO data were obtained by initially sampling 500 mL surface ocean water from shore and direct counting on high-purity germanium gamma detectors for 15 min at laboratories at the Fukushima Dai-ni NPPs. They reported initially results for 131I (t1/2 = 8.02 days), 134Cs (t1/2 = 2.065 years) and 137Cs (t1/2 = 30.07 years). Data from MEXT (Ministry of Education, Culture, Sports, Science and Technology—Japan) were also released on a public Web site(4) and are based on similar direct counting methods. In general MEXT data were obtained by sampling 2000 mL seawater and direct counting on high-purity germanium gamma detectors for 1 h in a 2 L Marinelli beaker at laboratories in the Japan Atomic Energy Agency. The detection limit of 137Cs measurements are about 20 000 Bq m–3 for TEPCO data and 10 000 Bq m–3 for MEXT data, respectively. These measurements were conducted based on a guideline described by MEXT.(5) Both sources are considered reliable given the common activity ratios and prior studies and expertise evident by several Japanese groups involved in making these measurements. The purpose of these early monitoring activities was out of concern for immediate health effects, and thus were often reported relative to statutory limits adopted by Japanese authorities, and thus not in concentration units (reported as scaling factors above “normal”). Here we convert values from both sources to radionuclide activity units common to prior ocean studies of fallout in the ocean (Bq m–3) for ease of comparison to previously published data.
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  • We focus on the most complete time-series records from the north and south discharge channels at the Dai-ichi NPPs, and two sites to the south that were not considered sources, namely the north Discharge channels at the Dai-ni NPPs about 10 km to the south and Iwasawa beach which is 16 km south of the Dai-ichi NPPs (Figure 1). The levels at the discharge point are exceedingly high, with a peak 137Cs 68 million Bq m–3 on April 6 (Figure 2). What are significant are not just the elevated concentrations, but the timing of peak release approximately one month after to the earthquake. This delayed release is presumably due to the complicated pattern of discharge of seawater and fresh water used to cool the reactors and spent fuel rods, interactions with groundwater, and intentional and unintentional releases of mixed radioactive material from the reactor facility.
  • the concentrations of Cs in sediments and biota near the NPPs may be quite large, and will continue to remain so for at least 30–100 years due to the longer half-life of 137Cs which is still detected in marine and lake sediments from 1960s fallout sources.
  • If the source at Fukushima had stopped abruptly and ocean mixing processes continued at the same rates, one would have expected that the 137Cs activities would have decreased an additional factor of 1000 from May to June but that was not observed. The break in slope in early May implies that a steady, albeit lower, source of 137Cs continues to discharge to the oceans at least through the end of July at this site. With reports of highly contaminated cooling waters at the NPPs and complete melt through of at least one of the reactors, this is not surprising. As we have no reason to expect a change in mixing rates of the ocean which would also impact this dilution rate, this change in slope of 137Cs in early May is clear evidence that the Dai-ichi NPPs remain a significant source of contamination to the coastal waters off Japan. There is currently no data that allow us to distinguish between several possible sources of continued releases, but these most likely include some combination of direct releases from the reactors or storage tanks, or indirect releases from groundwater beneath the reactors or coastal sediments, both of which are likely contaminated from the period of maximum releases
  • It is prudent to point out though what is meant by “significant” to both ocean waters and marine biota. With respect to prior concentrations in the waters off Japan, all of these values are elevated many orders of magnitude. 137Cs has been tracked quite extensively off Japan since the peak weapons testing fallout years in the early 1960s.(13) Levels in the region east of Japan have decreased from a few 10s of Bq m–3 in 1960 to 1.5 Bq m–3 on average in 2010 (Figure 2; second x-axis). The decrease in 137Cs over this 50 year record reflects both radioactive decay of 137Cs with a 30 year half-life and continued mixing in the global ocean of 137Cs to depth. These data are characteristic of other global water masses.(14) Typical ocean surface 137Cs activities range from <1 Bq m–3 in surface waters in the Southern Hemisphere, which are lower due to lower weapons testing inputs south of the equator, to >10–100 Bq m–3 in the Irish Sea, North Sea, Black Sea, and Baltic Seas, which are elevated due to local sources from the intentional discharges at the nuclear fuel reprocessing facilities at Sellafield in the UK and Cape de la Hague in France, as well as residual 137Cs from Chernobyl in the Baltic and Black Seas. Clearly then on this scale of significance, levels of 137Cs 30 km off Japan were some 3–4 orders of magnitude higher than existed prior to the NPP accidents at Fukushima.
  • Finally though, while the Dai-ichi NPP releases must be considered “significant” relative to prior sources off Japan, we should not assume that dose effects on humans or marine biota are necessarily harmful or even will be measurable. Garnier-Laplace et al.(1) report a dose reconstruction signal for the most impacted areas to wildlife on land and in the ocean. Like this study, they are relying on reported activities to calculate forest biota concentrations,
  • D'coda Dcoda on 09 Dec 11
     
    From Wood's Hole, note that calculations are based on reports from TEPCO & other Japanese agencies. Quite a bit more to read on the site.
D'coda Dcoda

"Now They Tell Us" Series: TEPCO Admits Reactor 1 Corium May Be 65 Centimeters into the... - 0 views

ex-skf.blogspot.com/...ll-us-series-tepco-admits.html

shared by D'coda Dcoda on 01 Dec 11 - No Cached
  • There you go! It took TEPCO only 8 and a half months to say what many people have been saying at least for 8 months.The corium has long escaped the Reactor Pressure Vessel AND the Containment Vessel of Reactor 1 (that much TEPCO has actually admitted, but..), and has eaten into the concrete pedestal to about 65-centimeter deep.For Reactors 2 and 3, TEPCO thinks (hopes, wishes...) that a good chunk of the corium dropped from the RPV onto the CV. No mention whether the corium there is eating into the concrete or not.From NHK News (11/30/2011; quick translation, subject to revision):
  • Significant amount of melted fuel in the Containment Vessel
  • It has been discovered by TEPCO's analysis that the significant amount of Reactor 1's melted fuel pierced through the steel Reactor Pressure Vessel and dropped onto the Containment Vessel, then melted the concrete at the bottom of the CV. It is estimated that the melted fuel may have eaten into the concrete to maximum 65 centimeters deep.
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  • Using different methods, TEPCO and various other research institutions have been analyzing the state of the melted fuel based on the reactor temperatures and the amount of water being poured into the reactors, and the results were announced on November 30 at a workshop held by the national government.
  • In Reactors 1 thorugh 3 of Fukushima I Nuclear Power Plant, core meltdowns have occurred, and it is considered that part of the melted fuel has dropped from the RPVs to the CVs. However, the details are not yet known even after more than 8 months since the accident started.
  • For Reactors 2 and 3, TEPCO also estimates that part of the fuel has dropped to the Containment Vessels, showing how severe the accident has been.
  • TEPCO's result shows that, in the most severe case, all of the fuel would have melted, of which a significant portion pierced through the bottom of the Reactor Pressure Vessel and dropped onto the Containment Vessel.
  • There is a concrete platform [pedestal] at the bottom of the Containment Vessel, which is then covered with steel plates
  • When the melted fuel drops to the bottom of the Containment Vessel, a core-concrete reaction takes place at a high temperature, melting the concrete. In the worst case, in Reactor 1, the melted fuel could reach 65 centimeters deep into the concrete.
  • At the thinnest part of the concrete, it is only 37 centimeters to the outer steel plate of the Containment Vessels. This is a very severe accident.
  • TEPCO also estimates that in the worst cases for Reactors 2 and 3, 57% and 63% of the fuel have melted, respectively, and part of the fuel dropped onto the Containment Vessels.
D'coda Dcoda

Yomiuri: Meltdowns were advancing while being kept hidden from public for months - Gov'... - 0 views

enenews.com/t-very-cautious-about-meltdown

shared by D'coda Dcoda on 16 Dec 11 - No Cached
  • [On March 12]  “It’s a core meltdown. We believe the fuel has started to melt [in the No. 1 reactor],” Koichiro Nakamura of the Nuclear and Industrial Safety Agency said at a press conference at 2 p.m. [On March 14] Nakamura did an about-face only two days after his initial statement: – “We can’t say for certain whether there’s been a meltdown” According to research results announced by TEPCO in May: – Most of the fuel at the No. 1 reactor had melted by the morning of March 12 – This means Nakamura’s initial explanation was correct
  • Finally admitted on June 7 there had been a meltdown Nov. 30 [Tepco said of Unit 1]: – “Almost all of the (68 tons of) nuclear fuel melted, fell through a pressure vessel and eroded the concrete bottom of the containment vessel by up to 65 centimeters” Therefore, a meltdown had advanced in the reactor core and this fact was hidden from the public for about three months
  • Explaining why the agency’s information had undergone such a change, Terasaka said: “After the Prime Minister’s Office’s instruction, we became very cautious about using the term ‘meltdown.’ We felt our statements should not exceed what the Prime Minister’s Office said at press conferences.”
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