tag:blogger.com,1999:blog-14307486.post684332569231114299..comments2024-03-28T11:24:13.222+00:00Comments on theatre of noise: Fukushima Nuclear Power Station information (following earthquake)robinhttp://www.blogger.com/profile/08743788064455642852noreply@blogger.comBlogger15125tag:blogger.com,1999:blog-14307486.post-89787141922703233562011-03-15T03:33:39.871+00:002011-03-15T03:33:39.871+00:00Yet another explosion (the third) and radiation le...Yet another explosion (the third) and radiation levels up dramatically, peaking at 8217 µSv per hour and steadily putting out a third of that. This is many times higher than the previous amount. <br /><br />It is obvious now that there is a partial meltdown at Fukushima Dai-ichi and that containment has also, at least in part, failed. I am very sad for the people evacuated from the region, who might now never return home.robinhttps://www.blogger.com/profile/08743788064455642852noreply@blogger.comtag:blogger.com,1999:blog-14307486.post-54494840640536867582011-03-14T12:07:15.512+00:002011-03-14T12:07:15.512+00:00I believe this will be the last update I will writ...I believe this will be the last update I will write on events as they unfold. Instead I will concentrate on explanatory articles if the need continues.<br /><br />BBC and other media report mediating water in Reactor 2 is now low, indicating it may be next in line for serious cooling problems. Airborne radiation has been detected 60 miles away from the plants. The US Navy offshore have also detected unusual radiation amounts. And the seawater flushed through the reactors will also inevitably carry radiation into the ocean.<br /><br /><b>Though not catastrophic in themselves, this series of accidents has and will continue to increase the local, regional and global radiation levels. In this way it is just like all other activities (bomb tests, waste disposal, etc.) related to the nuclear industry. The Fukushima incidents should be seen as indicative of the true damage we do to the environment every single day through nuclear power. The vast amounts of money invested in such technologies and installations should be diverted to less poisonous energy sources.</b>robinhttps://www.blogger.com/profile/08743788064455642852noreply@blogger.comtag:blogger.com,1999:blog-14307486.post-59413361387869440192011-03-14T02:52:06.268+00:002011-03-14T02:52:06.268+00:00This story is not going to let me sleep!
A new ex...This story is not going to let me sleep!<br /><br />A new explosion, this time at Reactor 3, has taken place, at 02:21 14 March local time. Some reports say two explosions. Initial word is that these are hydrogen blasts as before at Reactor 1. TEPCO states the core is not damaged by these. How they would know is beyond me.robinhttps://www.blogger.com/profile/08743788064455642852noreply@blogger.comtag:blogger.com,1999:blog-14307486.post-77731483758163550192011-03-14T02:07:40.269+00:002011-03-14T02:07:40.269+00:00Source for above from Nikkei.Source for above from <a href="http://e.nikkei.com/e/fr/tnks/Nni20110312D12JFF03.htm" rel="nofollow">Nikkei</a>.robinhttps://www.blogger.com/profile/08743788064455642852noreply@blogger.comtag:blogger.com,1999:blog-14307486.post-74466470851547347882011-03-14T02:05:30.555+00:002011-03-14T02:05:30.555+00:00Cs-137 and I-131 have been released from the plant...Cs-137 and I-131 have been released from the plant. This is a sure sign that a nuclear meltdown has in fact occurred to some degree... though please read above to realise that is not the end of the world.<br /><br />It is however a great deal more than many websites will tell you. In my research I am discovering that the pro-nuke lobby controls large amounts of the internet reporting that takes place on blogs and supposedly independent websites. that is not surprising since many owe their jobs to the nuclear industry, which has a very deep purse indeed.<br /><br />The following sites are definitely propaganda machines. Read their info with care:<br />http://www.world-nuclear-news.org<br />http://bravenewclimate.com<br />http://ansnuclearcafe.org<br />http://morgsatlarge.wordpress.comrobinhttps://www.blogger.com/profile/08743788064455642852noreply@blogger.comtag:blogger.com,1999:blog-14307486.post-34885913375440616342011-03-14T01:33:50.759+00:002011-03-14T01:33:50.759+00:00Here is a detailed document on the Boiling Water t...Here is a <a href="http://www.ansn-jp.org/jneslibrary/npp2.pdf" rel="nofollow">detailed document</a> on the Boiling Water type reactors. Fukushima Dai-ichi Reactor 1 is the oldest and crudest type. In fact it was scheduled to be de-activated permanently later this very month!robinhttps://www.blogger.com/profile/08743788064455642852noreply@blogger.comtag:blogger.com,1999:blog-14307486.post-38069092491571864472011-03-14T00:45:28.749+00:002011-03-14T00:45:28.749+00:00Corrections:
Strontium-90 is abbreviated Sr-90
Ces...Corrections:<br />Strontium-90 is abbreviated Sr-90<br />Cesium-137 is of course Cs-137robinhttps://www.blogger.com/profile/08743788064455642852noreply@blogger.comtag:blogger.com,1999:blog-14307486.post-41981448703648197262011-03-14T00:19:10.595+00:002011-03-14T00:19:10.595+00:00How do we measure radiation amounts? The sievert (...How do we measure radiation amounts? The sievert (Sv) measures the actual biological toxicity of radiation, which varies depending on the organ affected and the type of radiation. Because it attempts to take these into account, it is said to measure "dose equivalent". Practical amounts are measured in millisievert (mSv), of which there are a thousand in an Sv, and microsievert (µSv), of which there are a million in an Sv. As a baseline reference, the natural background radiation varies at different places on the Earth, but averages about 2.4 mSv per year, or .27 µSv per hour.<br /><br />How much radiation is safe? According to the US Nuclear Regulatory Commission, the <a href="http://www.nrc.gov/reading-rm/basic-ref/glossary/annual-limit-on-intake-ali.html" rel="nofollow">Annual Limit on Intake</a> (ALI) is set at 50 mSv per year, roughly 20 times the background radiation. <a href="http://www.mcgill.ca/ehs/radiation/manual/3/" rel="nofollow">Canada</a> follows the International Commission on Radiological Protection (ICRP) and limits Nuclear Energy Workers to 100 mSv over 5 years. General members of the public are limited to 1 mSv per year, which is actually below the background radiation level!<br /><br />Routine or special procedure medical X-rays add significantly to your radiation intake. These vary widely from 5 µSV for a dental X-ray to 7 mSv for a chest CT and 15 mSV for a CT of the abdomen and pelvis. Thus you can get several times your usual annual radiation intake in one visit to the doctor. However, these amounts are still considered insignificant in relationship to the 1 in 5 chance we have of dying from cancer. (Reference: <a href="http://www.radiologyinfo.org/en/safety/index.cfm?pg=sfty_xray" rel="nofollow">Radiology Info</a>.)<br /><br />How does this compare to the radiation emitted from Fukushima following the earthquake? Kyodo <a href="http://english.kyodonews.jp/news/2011/03/77392.html" rel="nofollow">reported</a> that Fukushima Dai-ichi peaked at 1,557 µSv per hour at 13:52 13 March, but this rate went down to 184 µSv/h about 50 minutes later. If one took in the maximum rate for one hour this would be equivalent to a spinal X-ray, said to increase your risk of a fatal cancer by a chance of 1 in 100,000 to 1 in 10,000.<br /><br />From this we can say with some certainty that acceptable radiation limits are placed very conservatively by the regulatory bodies. The fact that these might be exceeded in this accident even by large factors should not necessarily be a cause for concern, <i>so long as the time-frames of exposure are short</i>.robinhttps://www.blogger.com/profile/08743788064455642852noreply@blogger.comtag:blogger.com,1999:blog-14307486.post-47565971004881302532011-03-13T18:56:00.968+00:002011-03-13T18:56:00.968+00:00*higher doses*higher dosesrobinhttps://www.blogger.com/profile/08743788064455642852noreply@blogger.comtag:blogger.com,1999:blog-14307486.post-29244985893371370932011-03-13T18:36:17.262+00:002011-03-13T18:36:17.262+00:00So what are these dangerous by-products? Three are...So what are these dangerous by-products? Three are most important.<br /><br />Iodine-131 is quickly concentrated in the thyroid, where it causes cancers or functional problems (depending on dose -- higher does can strangely be less dangerous than low doses). A common preventative measure is to take potassium iodide in an attempt to fill all the possible receptors with "good iodine" before the radioactive variation can infiltrate. This explains the Iodine pills being distributed in Japan. With a half-life of 8 days the threat from I-131 is short-term but very real.<br /><br />Cesium-137 is absorbed by plants and then moves through the food-chain (when cattle eat grass, for example) to humans. With a half-life of 29 years this is a long-term problem that can be alleviated by removing contaminated soil and other methods. We are particularly vulnerable since 100% of C-137 is absorbed through our gastro-intestinal tract (whereas other isotopes are generally not absorbed or might be only minimally). C-137 is the primary long-term contaminant from the Chernobyl disaster.<br /><br />Strontium-90, with a half-life of 28.8 years, binds in our bodies in place of Calcium. One famous study found that babies born after 1963, when large-scale atomic testing became the norm, had 50 times the level of S-90 in their teeth. Even twice the amount has been shown to greatly increase early death by cancer.robinhttps://www.blogger.com/profile/08743788064455642852noreply@blogger.comtag:blogger.com,1999:blog-14307486.post-13196848910578074012011-03-13T18:24:45.051+00:002011-03-13T18:24:45.051+00:00Uranium 235 is the fissile material in nuclear rea...Uranium 235 is the fissile material in nuclear reactors. When bombarded with a neutron, each nucleus creates two more neutrons (thus leading to a chain reaction if some are not otherwise captured) and four possible radioactive by-products. These will decay in turn, either into stable atoms or further radioactive atoms. The half-life is the amount of time that must pass for half the amount of the original material to decay. After ten half-lives the substance is generally considered "safe". Half-lives vary from fractions of seconds to hundreds of thousands of years; nuclear "waste" is a long-term, some would say insoluble, problem.<br /><br />Normally the heavy waste material is contained in the fuel rods.But in the event of a reactor core breach, various elements can be let loose into the general environment, with various ill effects. These occur for several reasons. First, high-energy waves can instantly destroy cells they come into contact with. With lymphocytes reduced, one is vulnerable to normal infections. Nerve cells do not regenerate and their loss can be significant. And so on. Even in smaller doses, cancers and other long-term problems are increased significantly.<br /><br />The most dangerous isotopes are those which appear to our body like a benign substance that we need. The isotope binds to receptors in place of that useful substance. When the unstable isotope decays, it does so in close proximity to healthy cells and so causes the most damage. We are relatively protected from decays in the environment around us, but entirely vulnerable when these happen within our body.robinhttps://www.blogger.com/profile/08743788064455642852noreply@blogger.comtag:blogger.com,1999:blog-14307486.post-76647714616440020512011-03-13T17:36:25.381+00:002011-03-13T17:36:25.381+00:00Note that I am making certain simplifications. For...Note that I am making certain simplifications. For one, the water around the core does not, in normal operation, convert to steam. It is kept under pressure and so stays liquid, but gets very hot. This super-hot water then heats a second circuit of water that <i>is</i> allowed to vaporise. If the water around the core vaporises it can no longer act as a medium to inhibit neutron flow. This is a potentially disastrous eventuality which may have happened at Reactor 1, though not before the control rods were in place.robinhttps://www.blogger.com/profile/08743788064455642852noreply@blogger.comtag:blogger.com,1999:blog-14307486.post-16475027420217892382011-03-13T17:21:56.596+00:002011-03-13T17:21:56.596+00:00The whole purpose of a nuclear reactor is to susta...The whole purpose of a nuclear reactor is to sustain nuclear fission in a controlled reaction. A large enough density of radioactive material needs to be brought together to commence fission but not so much that an uncontrolled chain reaction occurs. The core of the reactor is composed of rods of enriched uranium in a grid, with control rods available in another grid that offsets this. All around is water, which heats very quickly due to the radiation. In normal operation this water is pumped through rapidly and the resulting steam is used to generate power.<br /><br />To shut down the reactor, the control rods are fully inserted to dampen the nuclear reaction. The fissionable material then needs time to cool off, and this is aided by continuing the flows of cool water. In the case of Fukushima the first process went without hitch but the second process has been threatened by power loss and possible structural damage.<br /><br />Radiation is always a product of a nuclear reaction, but that term covers a wide range of products created by the nuclei. This is why it is meaningless to talk of "radiation leaks" without pinpointing what product one is talking about. There are two main categories: electromagnetic and particulate. Electromagnetic radiation (gamma ray, X-ray) is the same form as a radio wave, only with much higher energy. Particle radiation (alpha particles, beta particles, neutrons) are called ionising radiation since they are capable of producing ions when they pass through other matter. <br /><br />"Nuclear meltdown" is a term that produces a lot of emotional reactions. But scientists use this to describe any occasion when the reactor core overheats to the point of damaging the reactor apparatus itself. Of course this is highly undesirable, but does not necessarily mean a "disaster" in the China Syndrome sense. (Except to the owner of the power plant, since the reactor would likely be a write-off.)<br /><br />So the key questions become:<br />1. How much and of which type is the radiation that has escaped from the reactors?<br />2. What is the possibility of a meltdown (if one has not occurred) and what is the severity of the meltdown (once it has)?<br /><br />And furthermore:<br />3. Are the correct steps being taken to ensure public safety in light of 1. and 2.?robinhttps://www.blogger.com/profile/08743788064455642852noreply@blogger.comtag:blogger.com,1999:blog-14307486.post-80368192082822599412011-03-13T17:21:03.397+00:002011-03-13T17:21:03.397+00:00This comment has been removed by the author.robinhttps://www.blogger.com/profile/08743788064455642852noreply@blogger.comtag:blogger.com,1999:blog-14307486.post-40159477672620304662011-03-13T14:16:27.388+00:002011-03-13T14:16:27.388+00:00Every technology creates also the corresponding ac...Every technology creates also the corresponding accident scenario. In the case of nuclear power these are horrible indeed. Hype does not help further understanding, but instead only polarises opinion further. Rational analysis should convince anyone of the need for safer energy alternatives.robinhttps://www.blogger.com/profile/08743788064455642852noreply@blogger.com