Nuclear-powered Royal Navy submarine in near-miss with ferry ITV News 21 Jan 19, A nuclear-powered Royal Navy submarine was involved in a near-miss with a large passenger ferry, it has emerged.
An investigation has been launched into the previously unreported incident, which occurred in the Irish Sea on November 6.
The ferry was Stena Superfast VII, which operates between Northern Ireland and Scotland.
It has a capacity for 1,300 passengers and 660 cars.
The submarine was submerged at the depth needed to extend its periscope above the surface of the water.
The Royal Navy would not confirm which of its 10 submarines was involved. They are all nuclear-powered but only four carry Trident nuclear missiles……… https://www.itv.com/news/2019-01-21/royal-navy-submarine-in-near-miss-with-ferry/
January 22, 2019
Posted by Christina Macpherson |
safety, UK |
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Historic nuclear accident dashed Swiss atomic dreams https://www.swissinfo.ch/eng/radioactive_historic-nuclear-accident-dashed-swiss-atomic-dreams/44696398 JAN 21, 2019
Fifty years ago today, a nuclear meltdown occurred in Switzerland’s first experimental nuclear power station. Built in an underground chamber in Lucens in the western part of the country, it was the site of the worst nuclear accident in Swiss history.
The plant was opened in 1962, with the aim of not only producing energy, but also allowing Switzerland to develop a reactor bearing the “Made in Switzerland” label and enabling experiments with nuclear energy.
But these plans were pushed aside when disaster struck in the plant’s reactor cavity on January 21, 1969. A pressure tube burst which created a power surge leading to the reactor malfunctioning and an explosion. Luckily, a member of staff who was scheduled to be working on the reactor at the time was found safe and sound elsewhere. The plant’s underground design also prevented people and the environment from being harmed.
The accident’s severity registered at 5 out of a possible 7. The concentration of leaked cooling gas that was behind the door of the reactor cavity was lethal. It wasn’t even possible to measure the radioactivity because it was above the maximum level on the measuring instruments.
But the reactor cavern was not completely sealed: the radioactivity spread to the control room 100 metres away. In the machine cavern closest to the reactor, a team involved in shutting down the turbine had been exposed to radiation. A witness report said that since the decontamination showers had been out of order, the workers had to shower in a temporary facility without hot water.
The government ordered an inquiry into the incident and a report was eventually published ten years later. The Swiss Association for Atomic Energy found there had been no major negligence on the part of the plant’s managers. The cause of the incident was corrosion in a pressure tube, brought about by humidity.
January 22, 2019
Posted by Christina Macpherson |
history, incidents, Switzerland |
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China’s Guangdong to have 26 nuclear reactors, Indigenous Hualong reactors to be built at new megaplant in Huizhou, By ASIA TIMES STAFF JANUARY 17, 2019 China’s southern Guangdong province is on a spree constructing nuclear power plants, with the latest addition to the province’s nuclear plant cluster in the city of Huizhou, 90 kilometers northeast of Hong Kong…..
The 120 billion yuan (US$17.74 billion) megaproject, to be run by the state-owned China General Nuclear Power Corp (CGN), will bring the total number of nuclear reactors in Guangdong, a manufacturing powerhouse and China’s largest provincial economy, to 26.
CGN’s ultimate plan is to boost that number to 46, spanning 11 plants, to power Guangdong’s booming economy, whose gross domestic product in 2018 is tipped to hit the 10-trillion-yuan mark and surpass South Korea and Canada.
The new reactors in Huizhou, already given the go-ahead by China’s environmental watchdog, will be built around China’s indigenous, third generation Hualong (China Dragon) pressurized water nuclear reactor ……..
The first Hualong reactor went live in Fujian province in 2017.
Still, concerns are being raised about the safety of so many nuclear plants, including Daya Bay, Ling’ao, Taishan, Lufeng, Yangjiang and Huizhou, within a radius of about 100 km from Hong Kong and Macau.
Guangdong’s aggressive plans to harness nuclear energy have long stoked fears about safe operations and the disposal of spent fuel rods.
CGN has sought to allay misgivings by promising more transparent consultation, reactor management and notification of incidents, but the company has given scant information about the Huizhou plant, the built-in safety infrastructure and contingency plans.
The company told Xinhua that the National Nuclear Safety Administration would conduct a further assessment of the plant’s design and safety facilities and decide the start of its construction. http://www.atimes.com/article/chinas-guangdong-to-have-26-nuclear-reactors/
January 19, 2019
Posted by Christina Macpherson |
China, safety |
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Russia’s Rosatom wins two bids for accident management at Fukushima NPP http://tass.com/world/1039631, January 12, 2019, MOSCOW, Russia’s state nuclear corporation Rosatom has been engaged in the nuclear control plan at Japan’s stricken Fukushima nuclear power plant and has already won two bids in that project, Rosatom CEO Alexei Likhachev said in a televised interview with Rossiya’24 news channel on Saturday.
“We have been engaged by Japan to implement the nuclear accident management plan at the Fukushima NPP. We have won two tenders and are getting ahead,” he said.
In September 2017, Rosatom’s First Deputy CEO Kirill Komarov said that Rosatom offered help to Japanese counterparts in handling the crippled Fukushima NPP.
The nuclear disaster at the Fukushima-1 power plant in March 2011 was triggered by an earthquake-induced tsunami that knocked out vital reactor cooling systems. This resulted in three nuclear meltdowns, hydrogen explosions and a massive release of radioactive waste, which contaminated the surrounding area. Clean-up operations continue at the power plant and adjacent territories. According to the current action plan, full decommissioning of the station may take place only around 2040.
January 14, 2019
Posted by Christina Macpherson |
Fukushima continuing, Russia, safety |
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Nuclear Regulatory Commission ex-Chairman Gregory Jaczko is adamantly opposed to the idea of keeping existing nuclear reactors running as a way to offset climate change, because each reactor is like a time bomb ready to explode if the cooling is cut off by a total station blackout, by equipment failure, by major pipe breaks, or by acts of warfare, sabotage, or terrorism. The societal dislocation caused by the spread of radioactive material over wide areas, affecting drinking water, food and habitation for decades or centuries, is as bad as the ravages of climate change for the communities so affected.As Chairman of the US Nuclear Regulatory Commission at the time of the Fukushima disaster, Jaczko has a unique insight into the factors that make nuclear power plants dangerous even after so-called “safe” shutdown. The Ex-NRC regulator argues against nuclear energy as a tactic to fight climate change 4 knows, too, that the arguments levied against renewables are ultimately incorrect, as technology to store energy and to rechannel it is growing by leaps and bounds. Investing tens or hundreds of billions of dollars into maintaining old nuclear reactors, which are becoming increasingly dangerous as they age, is simply stealing money away from investments in the renewable revolution that is our best hope for a sustainable energy future.
Ex-NRC regulator argues against nuclear energy as a tactic to fight climate change 1 Background: by Dr Gordon Edwards, http://www.ccnr.org/Jaczko_nixes_nukes_2019.pdf January 11, 2019 Commercial nuclear power plants are water-cooled. They are fuelled by ceramic uranium fuel pellets stacked inside long narrow rods made of zirconium metal. A number of these rods are bound together into a fuel assembly — in Canada such an assembly is called a fuel bundle.
Heat is produced by splitting uranium atoms. That heat is transported by the liquid water coolant which flows past the zirconium tubes containing the fuel. The heat is used to produce steam that will turn the blades of a steam turbine to generate electricity.
As the uranium fuel undergoes nuclear fission (splitting uranium atoms), hundreds of varieties of intensely radioactive byproducts build up inside the fuel. These are (1) broken fragments of uranium atoms, called “fission products”; (2) heavier-than-uranium elements, including plutonium, called “transuranic actinides”. These byproducts are millions of times more radioactive than the original fuel.
Loss of Cooling During a severe nuclear accident, the cooling is lost. Even if the reactor has been safely shut down just beforehand, and the fission process has been totally arrested, the temperature of the fuel will still soar to destructive levels without adequate cooling.
The problem is that radioactivity cannot be shut off. The radioactive byproducts created during nuclear fission remain in the fuel, and they continue to generate heat. In the case of a 1000 megawatt reactor, immediately following shutdown, over 200 megawatts of heat continue to be generated by the ongoing atomic disintegrations of the radioactive waste byproducts. After one hour this drops to about 30 megawatts of heat, which is still a tremendous rate of thermal energy release.
If the coolant is no longer circulating — perhaps because of a station blackout, as at Fukushima, or due to a large pipe break followed by a failure of emergency cooling — that “residual heat” or “decay heat” will not be removed from the core of the reactor.
Make no mistake, even 30 megawatts is a lot of heat — unless it is rapidly removed, that heat is more than enough to melt the fuel and surrounding structural materials of a nuclear reactor at a temperature of 2800 degrees C (5000 degrees F). That’s more than twice the melting point of steel. It’s the beginning of a partial or total core meltdown.
Hydrogen Gas Buildup At about 1800 degrees C (3300 degrees F), long before the fuel melts, the solid zirconium “cladding” surrounding the fuel starts to melt. Any failure of the zirconium cladding allows the escape, under high pressure, of dozens of radioactive waste byproducts that were previously trapped inside the fuel. The superheated steam that now fills the reactor vessel is suddenly infused with a multitude of radioactive gases, vapours, aerosols and ashes, all ready to be expelled into the atmosphere if there is any failure of containment.
At an even lower temperature, 700-800 degrees C, steam reacts chemically with the zirconium metal. Recall that water molecules are combinations of hydrogen and oxygen atoms (H2O). The blistering hot zirconium metal strips the oxygen out of the steam, forming zirconium oxide, while releasing all the left-over hydrogen. Hydrogen gas mixes with the steam-filled radioactively contaminated air to form an explosive mixture. Any spark will detonate the hydrogen in a devastating blast, more powerful than a natural gas explosion.
Such hydrogen gas explosions almost always accompany a nuclear meltdown. There were several such explosions during the partial meltdown of the NRX reactor at Chalk River, Ontario, in 1952; during the Three Mile Island partial meltdown in Pennsylvania in1979; and during the triple meltdown at Fukushima Dai-ichi in Japan in 2011. Such explosions will often damage the containment envelope of the nuclear reactor, spewing highly radioactive materials into the outer atmosphere.
Radioactive Exposures People, animals and plants are irradiated from above by “skyshine” from gamma-radiation-emitting gases passing overhead. Metallic radioactive vapours such as cesium-137, iodine-131 and strontium-90 will condense on vegetation, soil, buildings, skin, clothing, and surfaces of all kinds, leaving a lasting legacy of radioactive contamination, irradiating living things by “groundshine”. And these radioactive materials gradually work their way into the food chain, sometimes re-concentrating along the way, yielding contaminated crops, meat, fish, water, milk, mushrooms, berries, and much else besides. Ingesting or inhaling such materials will lead to the internal irradiation of people and animals by radioactive materials that lodge in the lungs, the bones, the blood, or the soft organs of the body.
For example, radioactive iodine condenses on pastureland, and the concentration of radioactive iodine in the grass becomes about 100 times greater than in the air above the pasture. The concentration of radioactive iodine in cow’s milk is about 100-1000 times greater than it is in the grass they eat. Then, when a young child drinks the cow’s milk, the concentration of radioactive iodine in the child’s thyroid gland is about 7-10 times greater than it is in the contaminated milk. So, a child’s thyroid can be exposed to radioactive iodine levels that are several orders of magnitude greater than that found in the contaminated air that they might breathe.
Radioactive cesium accumulates in meat and fish, often making them unsuitable for human consumption. Even today, hunters in Germany and the Czech Republic are compensated by their respective governments if they kill a wild boar, because they cannot eat the meat due to radioactive cesium contamination from the Chernobyl accident 33 years ago. In Japan, wild boars in the Fukushima forested areas have levels of radioactive cesium in their bodies that are 10 to 150 times greater than the maximum permissible levels for human consumption. Boars love mushrooms, and fungi are especially adept at concentrating radioactivity.
Nuclear Regulatory Commission ex-Chairman Gregory Jaczko is adamantly opposed to the idea of keeping existing nuclear reactors running as a way to offset climate change, because each reactor is like a time bomb ready to explode if the cooling is cut off by a total station blackout, by equipment failure, by major pipe breaks, or by acts of warfare, sabotage, or terrorism. The societal dislocation caused by the spread of radioactive material over wide areas, affecting drinking water, food and habitation for decades or centuries, is as bad as the ravages of climate change for the communities so affected.
As Chairman of the US Nuclear Regulatory Commission at the time of the Fukushima disaster, Jaczko has a unique insight into the factors that make nuclear power plants dangerous even after so-called “safe” shutdown. The Ex-NRC regulator argues against nuclear energy as a tactic to fight climate change 4 knows, too, that the arguments levied against renewables are ultimately incorrect, as technology to store energy and to rechannel it is growing by leaps and bounds. Investing tens or hundreds of billions of dollars into maintaining old nuclear reactors, which are becoming increasingly dangerous as they age, is simply stealing money away from investments in the renewable revolution that is our best hope for a sustainable energy future.
January 12, 2019
Posted by Christina Macpherson |
radiation, Reference, safety |
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