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Post by eclipse on Jun 25, 2014 20:31:45 GMT 9.5
For some reason I thought we'd only have to wait 200 or 300 years, but this is 100 times worse. I enjoyed the video at the link below. The wonky spider webs and beetle markings were interesting. But, unfortunately, no Godzilla's rise from the ashes to punish the 'evildoers'. content.time.com/time/health/article/0,8599,2067562,00.html
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Post by Roger Clifton on Jun 26, 2014 8:55:54 GMT 9.5
For some reason I thought we'd only have to wait 200 or 300 years You have been misled. There is no power produced at Chernobyl these days. That chap is director of a monument to excessive fear. The more horrible he makes it sound, the more money he gets to play with. Here is what CyrilR has to say about it: bravenewclimate.proboards.com/post/3951
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Post by eclipse on Jun 26, 2014 15:24:04 GMT 9.5
Yeah, Pandora's Promise showed people living in the zone quite happily it seemed. The rads were not too high according to his little yellow doover. The movie never explained what those numbers actually meant? Never went into what a lethal dose is, what a harmful dose is, and ... what a 'dose' is in the first place. But it was interesting to see airlines and high beaches being worse than some parts of the Chernobyl exclusion zone! That, to a lay person like myself, was fascinating!
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Post by David B. Benson on Jun 27, 2014 8:42:42 GMT 9.5
en.wikipedia.org/wiki/Absorbed_doseThe quantity absorbed dose is of fundamental importance in radiological protection for calculating radiation dose. However, absorbed dose is a physical quantity and used unmodified is not an adequate indicator of the likely health effects in humans.The graphic is quite helpful.
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Post by eclipse on Jun 27, 2014 11:55:13 GMT 9.5
OK, wow, I never knew Sievert's were not an actual unit of measure, but were rather a calculated unit of estimated damage. I guess it must reflect the movies I've watched, but I always preferred 'Rads', especially after that Martin Sheen and Emilio Estevez movie. So if 1 banana is 1/10th of a micro sievert, I'm trying to guess what their device used in Pandora's Promise. Was it Sieverts? I think I need to go back and watch it again. How much would one of those measuring doovers cost? If cheap enough, it might be fun to take around and freak people out with how much radiation they're absorbing. A good educational tool as well!
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Post by David B. Benson on Jun 28, 2014 8:57:40 GMT 9.5
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Post by eclipse on Jun 28, 2014 17:54:56 GMT 9.5
Ha! $32 bucks! That's it, I'm going to show the guys at work just how radioactive that trendy granite area is. (And by extension, just how unremarkable being bathed in low grade rads really is).
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Post by cyrilr on Jul 2, 2014 19:16:27 GMT 9.5
The 20000 year or hundred thousand year or whatever other variations there are, these are just uninformed or deliberate scaremongering. The fact is that virtually all (>99% today if I recall correctly) of the contamination around Chernobyl is from Cs-137, and yes that has a half life of 30 years, actually slighly shorter due to environmental diffusion (erosion, covering up with sediment, dust and other natural processes). The longer half life stuff, almost all of that is actually still in the reactor building. It isn't mobile, even without a sarcophagus or containment, because it isn't volatile. This longer half life stuff like 20000 years doesn't even contribute a major dose in the actual reactor building itself, that is almost all from shorter lived fission products like Cs137 and Sr90 etc. So it is not fair to use the 20000 year number because this contributes a negligible amount to the dose you'd get. But it is reasonable to state that the reactor building and generally the plant site itself would not be a safe shelter even in 200 years time assuming it is not decomissioned. But that's not important because it is a tiny restricted area. The surrounding countryside is perfectly safe to live in today, not 200 years from now, today, so it is needlessly condemned. The scale of the radiophobia is almost unbelievable, here is a decent reference for more reading on it: www.21stcenturysciencetech.com/Articles_2010/Summer_2010/Observations_Chernobyl.pdfAccording to the LNT model with 'collective dose', roughly 1 million people a year are being killed from the feeble natural background radiation around us. That's absurd, the reason why this number is calculated is due to a very silly calculation method that just lumps all invidual doses together and then divides by the lethal dose. For example if you drink 365 glasses of beer in one day you'll almost certainly die. So, the LNT model says if a group of 1000 people each drinks one glass of beer a day, all of them will be dead by the end of the year. I'm not joking, that's what this ridiculous model actually states! We all know the real number is zero deaths since no one will be killed by a one glass of beer a day consumption, not in a year, not in 10 years.
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Post by jagdish on Jul 3, 2014 16:26:38 GMT 9.5
Radioactivity is an energy like heat. It is bad only over a level. We all have 150-250g of potassium in our bodies which is radioactive. Residents of Ramsar in Iran and Kerala coast in India live in a high natural radiation without any ill effects. That could be taken as the level of harmless radiation. We could keep Chernobyl as a nature reserve and study it publicly to assure the world. Same could be done for some of nuclear testing sites in the US and Central Asia.
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Post by eclipse on Jul 5, 2014 12:13:46 GMT 9.5
Would robots be able to drive in and cut up the 'dried' lava flow in Chernobyl and then reprocess it all for fuel? Why are they going to spend billions building a huge sarcophagus over the thing? Even the term feels like something ancient Egyptian Pharaohs would have commissioned!
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Post by cyrilr on Jul 8, 2014 21:15:23 GMT 9.5
Just came across this excellent read on Chernobyl: users.physics.harvard.edu/~wilson/freshman_seminar/Radiation/publications/chernobyl,%2010%20years%20after_health%20consequences.pdf It has data on dose rates of the restricted area. Between 70 and 400 mSv in 70 years which is 1.1 to 5.7 mSv per year. This is a typical background radiation level!! So by the Chernobyl evacuation and condemnation standard, pretty much all of Europe should be condemned and evacuated based on natural background radiation levels! All of Scandinavia is worse than the highest value of the restricted area around Chernobyl! Pretty shocking.
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Post by Roger Clifton on Jul 11, 2014 15:35:20 GMT 9.5
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Post by cyrilr on Jul 12, 2014 17:56:36 GMT 9.5
An update on this that I posted on another forum: Peak background radiation today in the region appears to be 25 microR/h, that's 2.2 mSv/y. The red area. Since this only measures gamma radiation it accurately describes the cesium contamination dose rate. Well actually no, about half that peak dose appears to be natural, so likely we're talking about roughly a 1 mSv/year peak from Chernobyl contamination in the worst affected areas today. 2.2 mSv/year is below the average natural background radiation of the world, due primarily to ubiquitous radon. chornobyl.in.ua/en/radiation-background-ukraine.htmlSo, for talking points, you can say that the worst contaminated areas are considerably less radioactive than all of Scandinavia. Oddly enough there is no plan yet to evacuate and condemn Sweden, Finland and Switzerland, as their natural background radiation is worse than the worst areas around Chernobyl.
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Post by eclipse on Jul 13, 2014 10:55:32 GMT 9.5
Awesome post! I love it when someone breaks down the technical measurements into real world examples written in simple English. I've facebooked and blogged this post.
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Post by eclipse on Jul 14, 2014 20:19:52 GMT 9.5
Now I'm being asked if anyone is seriously recommending that people move back in. The poster is not questioning whether or not the air contains equivalent background radiation, but whether people should move back and start digging: digging to build houses and lay foundations and do plumbing and even a little backyard farming and chooks. Digging. Moving stuff around. Won't that stir it all up again?
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Post by cyrilr on Jul 15, 2014 0:03:09 GMT 9.5
Now I'm being asked if anyone is seriously recommending that people move back in. The poster is not questioning whether or not the air contains equivalent background radiation, but whether people should move back and start digging: digging to build houses and lay foundations and do plumbing and even a little backyard farming and chooks. Digging. Moving stuff around. Won't that stir it all up again? Don't see why not. Cs-137 is troublesome because the most likely daughter product decays with a hard gamma. Stirring it up makes little difference. Say, a few mm of soil on it (sediment since 1986) makes little difference in the gamma dose. Cs137 doesn't bioaccumulate, biological half life is 2-3 months only, so its for all intents and purposes an external dose and it comes from gamma rays (from barium direct gammas and secondary Bremsstralung). The actual beta ray itself doesn't get through shoes and clothes (in fact a short distance of air stops it) though it will increase if you stir buried Cs137. Still, even a 10x increase in dose rate from stirring would not be any risk to health. According to researcher Jerry Cuttler, there's a sort of turning point in health effects above 2 rad/day. www.nuclearsafety.gc.ca/eng/pdfs/Presentations/Guest-Speakers/2013/20130625-Cuttler-CNSC-Fukushima-and-beneficial-effects-low-radiation.pdfThe worst areas near Chernobyl are below 0.005 rad/day above background. Finland background at 0.02 rad/day.
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Post by eclipse on Jul 18, 2014 21:17:32 GMT 9.5
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Post by eclipse on Jul 21, 2014 19:45:52 GMT 9.5
Can someone help me convert mrem's to Sieverts and tell me if this article says we can move back into Chernobyl or Fukushima?... or what fraction (in English) we're looking at now? Are they still two or five or five hundred times too radioactive for the EPA (not the guys here who still might feel the EPA is being radically over-cautious).
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Post by cyrilr on Jul 22, 2014 0:36:57 GMT 9.5
Can someone help me convert mrem's to Sieverts and tell me if this article says we can move back into Chernobyl or Fukushima?... or what fraction (in English) we're looking at now? Are they still two or five or five hundred times too radioactive for the EPA (not the guys here who still might feel the EPA is being radically over-cautious). 100 rem = 1 sievert. So, the new proposed standard of 500 to 5000 mrem/year would be 5 to 50 mSv/year. Still too low, 50 mSv/year is under 0.14 mSv/day. I encourage everyone to think about dose per day units. There is no point in considering any toxin on a per year basis, how much beer do you take per year, that's not very relevant, unless you want to scare people, how much do you take per day is what affects your health. (think about taking one glass a day for a year or taking nothing all year and then 365 glasses on Christmas!). And use scientific units like Gray and Sievert. Rem is pointless, and just makes everything 100x larger and scary. Micro is completely scaremongering inflation of figures, use millisieverts. The link from Dr. Jerry Cuttler shows a threshold dose used in the 1930s that is very safe. It is 2 mSv/day. We know this to be a safe dose from actual exposed human, dog, and fruit fly populations. Not some silly theoretical LNT model, but real experiments, some Basically everywhere in the Ukraine is lower than that and thus habitable. However there are some patches of forest close to the Chernobyl reactor and of course the reactor itself which are above 2 mSv/day. The Red Forest is the worst affected area with spikes of 20 mSv/day though most of it is much less. 20 mSv/day of Cs-137 and Sr-90(which is what the contamination in the red forest is for >>99%) would take about 100 years to get down to the safe level of 2 mSv/day, though most of the forest would be safe in less than 50 years. Just about everywhere else is still being needlessly condemned. Good read on the nuclear radiophobia: nuclearradiophobia.blogspot.nl/2011/07/nuclear-power-and-radiophobia.html
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Post by eclipse on Jul 22, 2014 18:06:40 GMT 9.5
OK thanks Cyril, and I totally hear you on the mSv/day! (When are Americans going to switch to that mSv/day, and while they're at it, fix their English and go metric as well? )
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Post by cyrilr on Jul 22, 2014 23:24:32 GMT 9.5
It is an artifact of the false notion that radiation and cancer are linearly and cumulatively linked. Grossly throwing in all DNA enzyme repair and cell protection mechanisms, even ignoring high school and college level biology, doesn't bother the LNT folks in the slightest. If you believe no dose is safe and you can add x dose per person in y sized population to get xy "collective dose", then yes, dose per year - actually dose per lifetime - makes sense.
If, however, you're living in the real world, then you will notice that everything else has limits per day or per hour. A box of aspirin, a bottle of beer... all have prescriptions of don't take more than x amount per hour or per day. And no self respecting, scientific health organisation would divide the amount of alchol produced per year by the lethal dose to calculate a death toll of alcohol worldwide!
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Post by Roger Clifton on Jul 24, 2014 9:16:13 GMT 9.5
threshold dose used in the 1930s ... 2 mSv/day. Basically everywhere in the Ukraine [and Belarus?] is lower than that and thus habitable. However there are some ... Forest ...20 mSv/day So rangers - and poachers - who spend only 2.4 hours a day in forest areas of 20 mSv/day would thus be safe. Early after the evacuations from Fukushima, an area up to 20 mSv per year, not per day, was re-designated as safe to work in but not to reside, that is for only half a day at a time. When a similar area was designated as safe for children to return to school but not reside, public outcry reversed the decision. The appropriate duration for a meaningful "accumulated dose" would seem to be a day, judging by radiologists' advice to radiotherapy patients. According to the Wikipedia entry on using radiation to kill cancers: "The total dose is fractionated (spread out over time) for several important reasons. Fractionation allows normal cells time to recover, while tumor cells are generally less efficient in repair between fractions." and "typical fractionation schedule for adults is 1.8 to 2 Gy per day, five days a week." As the dose is photons, that means 1800 to 2000 mSv each day in the locality of the tumour is needed to kill it, a thousand times the 1930's guideline. Considering that the daily dose to the tumour is in thousands of millisieverts while the surrounding tissue recovers each day from hundreds of mSv, it appears that a day is about the time it takes to repair even heavy radiation damage. However, replenishing the body's fighting reserves must take longer, as the same article indicates: "and you may need extra sleep or rest breaks over the next few days".
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Post by colinF on Jul 24, 2014 9:43:45 GMT 9.5
It is interesting you should discuss Chernobyl, but not mention a UN report into the disaster. That report found that hysterical doctors in Poland, Norway, Sweden and other countries caused more "deaths" by recommending unnecessary abortions than deaths caused by the disaster itself - well so far. This is not all that accurate, btw, as it does not include the longer term effects, that is if they are being measured at all. I also suggest that it is really unlikely that any incidence of cancer can be proven directly connected with the disaster, so we will never get an accurate picture at all - no matter what assumptions we make in analysis.
It is simple, our bodies can tolerate background radiation. Long term variations to that will cause health problems that not necessarily reveal themselves as being connected to background radiation. Consider the incidence of melanoma in Australia, it is four times higher than it is in the rest of the world (http://www.skincancer.gov.au/internet/skincancer/publishing.nsf/content/fact-2) The chart above clearly shows why.
So why do we do things that can create increase in the amount of background radiation?
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Post by cyrilr on Jul 24, 2014 23:38:25 GMT 9.5
threshold dose used in the 1930s ... 2 mSv/day. Basically everywhere in the Ukraine [and Belarus?] is lower than that and thus habitable. However there are some ... Forest ...20 mSv/day So rangers - and poachers - who spend only 2.4 hours in forest areas of 20 mSv/day would thus be safe. Early after the evacuations from Fukushima, an area up to 20 mSv per year, not per day, was re-designated as safe to work in but not to reside, that is for only half a day at a time. When a similar area (of limit 20? mSv/a) was designated as safe for children to return to school but not reside, public outcry reversed the decision. The appropriate duration for a meaningful "accumulated dose" would seem to be a day, judging by radiologists' advice to radiotherapy patients. According to the Wikipedia entry on using radiation to kill cancers: "The total dose is fractionated (spread out over time) for several important reasons. Fractionation allows normal cells time to recover, while tumor cells are generally less efficient in repair between fractions." and "typical fractionation schedule for adults is 1.8 to 2 Gy per day, five days a week." As the dose is photons, that means 1800 to 2000 mSv each day in the locality of the tumour is needed to kill it, a thousand times the 1930's guideline. Considering that the daily dose to the tumour is in thousands of millisieverts while the surrounding tissue recovers each day from hundreds of mSv, it appears that a day is about the time it takes to repair even heavy radiation damage. However, replenishing the body's fighting reserves must take longer, as the same article indicates: "and you may need extra sleep or rest breaks over the next few days". We should be careful not to take this example too far. 1000 mSv in say a few minutes, once a day, isn't a chronic dose at all. The 2 mSv/day is for constant, chronic radiation. And 1000 mSv is also much larger in total dose, even if 1% ends up in healthy tissue you get 10 mSv/day which is well into the bad health effects area if chronic (primarily reduced life expectancy though oddly enough not much more due to cancer). The 2 mSv/day chronic radiation appears a fairly hard limit, insofar as that is possible with radiation effects on biology in current scientific understanding. For instance dogs irradiated continuously with 3 mSv/day showed a few percent reduction in life expectancy. That's a significant bad health effect. It's hard to use the prompt exposure of gamma ray treatment patients because most of them are old or have other illnesses and thus have reduced life expectancy. Definately if you recover from a fatal cancer, with or without radiation therapy, that is not something you shrug off with a single good night sleep!
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Post by Roger Clifton on Jul 25, 2014 8:15:46 GMT 9.5
The 2 mSv/day is for constant, chronic radiation. ... appears a fairly hard limit That sure is hefty irradiation. It's ten times more than is received by the long-term residents of the most irradiated areas (76 mSv/a) in Kerala, India, so it does fall into the category of a unnaturally high dose rate. Could it be that the limit was set for patients taking several weeks of radium/radon therapy in the 1930s? Your reference to the statistics on dogs impacted by chronic 3 mSv/day is telling evidence that 2 mSv/day is a "hard limit" for chronic exposure. That value is close to Wade Allison's "relatively safe" recommendation for 100 mSv per month. However, as a particle physicist, his experience was a world with occasional high acute doses punctuating a normal low chronic dose rate environment. Victims of such radiation accidents receive prompt assistance, such as drugs, whereas a high chronic dose rate is relentless, a burden regardless of our other ailments coming and going. All too often we fail to make the distinction between "chronic" (constant, long-term) and "acute" (intense, brief).
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Post by eclipse on Jul 25, 2014 17:03:41 GMT 9.5
So Roger, you're not convinced that 2 mSv/day is safe?
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Post by cyrilr on Jul 25, 2014 17:48:09 GMT 9.5
The 2 mSv/day is for constant, chronic radiation. ... appears a fairly hard limit That sure is hefty irradiation. It's ten times more than is received by the long-term residents of the most irradiated areas (76 mSv/a) in Kerala, India, so it does fall into the category of a unnaturally high dose rate. Could it be that the limit was set for patients taking several weeks of radium/radon therapy in the 1930s? Your reference to the statistics on dogs impacted by chronic 3 mSv/day is telling evidence that 2 mSv/day is a "hard limit" for chronic exposure. That value is close to Wade Allison's "relatively safe" recommendation for 100 mSv per month. However, as a particle physicist, his experience was a world with occasional high acute doses punctuating a normal low chronic dose rate environment. Victims of such radiation accidents receive prompt assistance, such as drugs, whereas a high chronic dose rate is relentless, a burden regardless of our other ailments coming and going. All too often we fail to make the distinction between "chronic" (constant, long-term) and "acute" (intense, brief). Hefty, well compared to what? To background, yes, there are a few places that are 2 mSv/day, extremely rare though (some hot spots near Ramsar, Iran get that high but most of the area is below 1 mSv/day). But, that's not the most relevant comparison because natural background radiation causes very little DNA damage. Eating food and drink, just regular diet (no excessive alcohol, saturated fats etc.) gives you slightly more damage/oxidative stress than 2 mSv/day. So, compared to other sources of DNA damage, even the highest background radiation levels are lower than combined other "natural" sources of DNA damage. Yes, consider the following. If you drink 365 glasses of beer in one day, you will be deadly sick and must have your stomach pumped out in a hospital. With high quality medical assistance, you might survive, even if you do there are serious damages to DNA and organs. So I'd still rather take 1 glass a day for a year than 365 glasses on one day of the year, even though the dose is the same. There is some discussion on whether truely chronic (constant, relentless) or pulsed (say once a day a 2 mSv dose, administered in one second), is better for DNA repair response. There is some speculation that a too low dose rate per second (constant, background radiation) will not stimulate the required repair mechanisms as much as a higher daily or weekly dose for a given total dose. We need more data on this because most human data isn't relevant.
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Post by eclipse on Nov 19, 2014 8:43:25 GMT 9.5
Speaking of nuclear pollution, a friend just put me onto this article. How bad is Hanford really? www.thedailybeast.com/articles/2013/02/24/at-the-hanford-nuclear-reservation-a-steady-drip-of-toxic-trouble.html1. WHAT'S IN THE CASKETS?I mean, even the wiki doesn't spell out what is actually in those caskets, and what has leaked. I went to footnote 4 en.wikipedia.org/wiki/Hanford_Site#cite_note-Ecology-4 and it took me to web.archive.org/web/20080624232748/http://www.ecy.wa.gov/features/hanford/hanfordfacts.html which says: Yeah, thanks. So what is the 30 million gallons of waste again? Tritium? We're just not told. The next problem? Then the fact file says "67 of the single shell tanks have leaked about 1 million gallons of highly radioactive waste into the ground. This waste is traveling through groundwater toward the Columbia River." But the wiki says its a BILLION gallons. So the wiki needs sabotage checking as well, if anyone loves a wiki-fight: here's your red flag! Anyway, in the meantime I am of course pointing out that Hanford was one of the 30 Manhattan Project sites and this is not about nuclear power but bombs, and probably says a bit about our learning curve with how to handle radioactive stuff in the first place! 2. HOW TO CLEAN IT UPThe piece says: Ouch. That's a lot of money: more even than the original Manhattan Project in today's terms. ($26bn in 2014 terms). Is vitrifying this stuff necessary? Could they chemically separate out any useful stuff to put in an IFR / LFTR? How much of this stuff would be untouchable? Rather than just seeing the $70 billion as a complete write-off, could there be an economic case for recovering at least some of that money in an associated onsite breeder of some type? If so, how would you imagine designing the 'flow'. (See this SCIAM article about 'flow' through the chemical separation process). www.scientificamerican.com/article/hanford-nuclear-cleanup-problems/3. DANGER?How dangerous is the Hanford area anyway?
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Post by eclipse on Dec 5, 2014 16:26:03 GMT 9.5
Another meme doing the rounds on Facebook. What does 10E6 mean? It's red. It MUST be bad! (Gotta love all the INFORMATION in this fear-meme!)
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Post by eclipse on Dec 10, 2014 16:12:14 GMT 9.5
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