11 ms·

Japan nuclear body says radioactive water at Fukushima an 'emergency'

93 points by yapcguy 13y ago

mpyne 13y ago
More details would be nice. As the article notes, tritium itself is almost innocuous (its decay is via a weak beta particle emission, about the only way it could hurt you is if you ingested a lot of it). Either way the problem with radioactive materials relates to the concentration in solution of radioactive materials more than the binary "radioactiveness" of the material. After all the human body itself is 'radioactive' if only from the K-40 and C-14 that are present. Without knowing the concentration of radioactive contaminants like Co-60 and radiocesium that might leak into the sea it's hard to know how much of an 'emergency' we'd be looking at. All we'd know for sure is that TEPCO is incompetent... but then what else is new?
- ChuckMcM 13y ago
  It would be hugely better to actually have details. Water, aka H2O, doesn't activate so it is not radioactive, it can however carry radioactive isotopes in solution. Is the groundwater flowing from the neighbouring area? (implied) then the it is carrying cesium from the environment away (good thing if you want to move back into the neighbourhood) is it picking up new contaminants from a broken reactor vessel? I wonder if anyone has a better source for data here.
  - khuey 13y ago
    Water can be radioactive if some of those hydrogen atoms are really tritium.
  - akiselev 13y ago
    > Water, aka H2O, doesn't activate so it is not radioactive, it can however carry radioactive isotopes in solution. What? Tritium is an unstable hydrogen isotope that is radioactive, no matter what molecule it is found in. Combine that with acid-base chemistry which revolves around the disassociation of hydrogen from water and that tritium can end up as a beta emitter anywhere in the body, including in actual strands of DNA [1]. What radioactive isotopes the water carries as a solute is irrelevant to the presence of tritium in the molecules. [1] http://www.ncbi.nlm.nih.gov/pubmed/11130944 http://www.ncbi.nlm.nih.gov/pubmed/11130944
    - ChuckMcM 13y ago
      Ah yes, there is that. And in fact a bit of searching turns up this is probably what Reuters was reporting [http://www.japantimes.co.jp/news/2013/08/03/national/huge-leak-of-tritium-feared-in-fukushima/#.Uf_p4Ndj3mE http://www.japantimes.co.jp/news/2013/08/03/national/huge-le...] I had originally dismissed Tritium as a candidate for the contamination because its nominally only in the reactor water and the Reuter's article talked about 'groundwater' (which is the name nominally given to water that accumulates in aquifers as a result of soil percolation). Apparently TEPCO is losing control of the reactor coolant water which is a different thing. That said, Tritium [1] isn't a particularly "bad" agent as it decays into Helium3 (great for fusion reactors if you've got one :-) and then floats away. [1] http://en.wikipedia.org/wiki/Tritium http://en.wikipedia.org/wiki/Tritium
  - mpyne 13y ago
    Water can activate (much more so than you think in fact, though I can't discuss further maybe someone with a civilian background in nuclear physics can fill in). Certainly the long-term danger is more from what the water will carry in solution than from the water itself though.
    - ChuckMcM 13y ago
      It is too bad you can't say more about this, one of the fun things I got to do a couple of years ago was to stare into the pool of the Reed Research reactor running at power and look at the awesome Cerenkov radiation (that eerie blue glow, it looked exactly like this : http://en.wikipedia.org/wiki/File:Cerenkov_Effect.jpg http://en.wikipedia.org/wiki/File:Cerenkov_Effect.jpg [yes that is the actual reactor, no I didn't take this picture :-)])
    - VLM 13y ago
      "though I can't discuss further maybe someone with a civilian background in nuclear physics can fill in" Oh spare us the cloak and dagger. I don't think oxygen radioactivation has been classified for about 80 years now. There's even a pretty good wikipedia page at http://en.wikipedia.org/wiki/Isotopes_of_oxygen http://en.wikipedia.org/wiki/Isotopes_of_oxygen The "natural" stable isotope O-16 needs to get triple neutron activated before you get an unstable isotope O-19 and the half life of that is like a minute. So its about half a million minutes per year, and its been about two years, so thats about a million half lives later... I think all the O-19 is long gone. I do agree 100% that the "stuff" dissolved in the water is about a zillion times more important than the oxygen itself. Its so mainstream there's some interesting radio oxygen dating work done using the Dole Effect, which also has a wiki page. TLDR is photosynthesis preferentially concentrates certain O isotopes so you can make all kinds of assumptions about glaciation and where plants are growing (ocean or land) given some 16O:18O ratios. http://en.wikipedia.org/wiki/Dole_effect http://en.wikipedia.org/wiki/Dole_effect There's even a cool wikipedia article with a UTF-8 name. http://en.wikipedia.org/wiki/%CE%9418O http://en.wikipedia.org/wiki/%CE%9418O Which brings you to the greater topic of isotope geochemistry http://en.wikipedia.org/wiki/Isotope_geochemistry http://en.wikipedia.org/wiki/Isotope_geochemistry I'm sure there is at least some cloak and dagger stuff that can't be discussed but there's a simply huge amount of open literature about oxygen radioactivity. I would suspect there's more open lit stuff about isotopic geochemistry than cloak and dagger stuff.
- jlgreco 13y ago
  > its decay is via a weak beta particle emission, about the only way it could hurt you is if you ingested a lot of it Well, it is water contamination they're talking about. People have the tendency to ingest large amounts of water. Of course, as you say, knowing the concentration is vital to understanding the risk posed. You could drink gallons of water laced with a gamma emitter if the concentration were low enough (well, not gallons. You'd get water intoxication ;).
  - mpyne 13y ago
    Well I don't think people ingest large amounts of seawater. :) Perhaps fish and other seafood (assuming that the tritium concentrates in the seawater around Japan and doesn't get dispered into the wider Pacific). But then the tritium would be mostly "fixed" within the flesh of the fish and end up being mostly self-shielding. Perhaps the ATP w/ tritium and similar products get carried into cells but by that point we're talking about nothing worse than the day-to-day problems of life under the sun, eating bananas, breathing the sweet sweet scent of brick-induced radon, etc.
- nknighthb 13y ago
  I'm not sure that Reuters didn't misunderstand something. The tritium mention seems oddly out of place. A lot more than tritium has leaked from this plant, and I would be surprised if the water they're leaking now is contaminated solely with tritium. Also, I think with regard to tritium spilling into the sea, they're probably less concerned about a direct effect on people than on the fish swimming around in it.
- mzs 13y ago
  Back in '07 the Canadian Nuclear Safety Commission couldn't get a limit from Japan: http://nuclearsafety.gc.ca/eng/readingroom/healthstudies/tritium/ http://nuclearsafety.gc.ca/eng/readingroom/healthstudies/tri...
- yk 13y ago
  But Tritium can be quite ugly if it gets into the body, since it can replace hydrogen. (And can therefore accumulate in the body.) This depends on the molecules tritium is attached to. And on a further note, I believe that websites which need JS to scroll text are malicious.
  - VLM 13y ago
    Ah its not so bad. If you have to take something radioactive, thats the one element I'd take because I'd pee most of it out in about a week. The phrase no one on HN has mentioned yet is "biological half life". There's a pretty decent wikipedia article at http://en.wikipedia.org/wiki/Biological_half-life http://en.wikipedia.org/wiki/Biological_half-life Whats important is the ratio of biological half life to radiological half life. Superficially it sounds like you're WAY better off with contaminated water, with a bio half life of about a week, than plutonium around 100 years, a difference of about 4 ords of magnitude. However the half life of 3H is in the 10s of years range and non-RTG Pu is about 20K years range or about 3 ords of magnitude lower activity. So the net effect is it hangs around 4 ords of magnitude longer, but specific activity is 3 ords of magnitude lower, so given X number of atoms, Pu is only about 10 times worse for you than 3H. All bets off for the Pu RTG isotope that is so short half life it self-melts pretty easy, or that one Pu isotope thats mostly harmless but its decay product is icky (I think 241pu to 241Am where the 241Pu if it wouldn't decay is mostly harmless but the 241Am is icky)
    - mpyne 13y ago
      Plus when we're talking about transuranics we have to account for the chemical toxicity which is normally much more dangerous than the radiation itself. Great point bringing up biological half-life by the way, especially as that helps explain why some isotopes are considered more dangerous than others for what may seem to be counterintuitive reasons.
    - yk 13y ago
      Well, the question is where is the tritium. If it comes in the form of heavy water, then the biological half life is indeed short. But tritium can substitute essentially any hydrogen, and so it can also come in the form of amino acids, which have a good chance to end up in the nucleus of a cell. So especially for tritium, it can essentially end up in anything where organic chemistry is involved, which is to say everywhere. However, the general problem I have with articles about the dangers of radioactivity is, that they almost never contain enough information to actually judge how dangerous it is. It is usually easy to get a factor of 100 or more variation in the dangers of radioactivity, based on the exact contamination scenario, the precise isotope abundances etc. So even Pu is not always very bad, since PuO is almost insoluble in water, which can be used for nice party tricks [1]: [...] to eat as much plutonium as any prominent nuclear critic will eat or drink caffeine. My offers were such as to give me a risk equivalent to that faced by an American soldier in World War II, according to my calculations of plutonium toxicity which followed all generally accepted procedures. [1] http://www.phyast.pitt.edu/~blc/book/chapter13.html http://www.phyast.pitt.edu/~blc/book/chapter13.html
brianbreslin 13y ago
Has anyone done tests to see how the radioactive water and other contaminants have affected the pacific as a whole? how about the fish stock near japan? http://www.grida.no/images/series/vg-climate/large/32.jpg http://www.grida.no/images/series/vg-climate/large/32.jpg
- akiselev 13y ago
  It's extremely difficult to do such a study because the entire system is just so complex and there's no way to control for many of the variables. There have, however, been limited studies about bioaccumulation of tritium in phytoplankton and how it can move up the food chain [1]. As another poster said, tritium decays by beta radiation which isn't necessarily harmful but if it accumulates in the food chain, it might be dangerous (just like heavy metals and fish, for example). Tritium's half life is about 12 years so its not inconceivable. It's a different environment but you can probably draw some conclusions about the impact/spread of radioactive particles by looking at Chernobyl. Edit: [1] http://www.ncbi.nlm.nih.gov/pubmed/22863967 http://www.ncbi.nlm.nih.gov/pubmed/22863967
- toomuchtodo 13y ago
  Does this mean we have to start equipping undersea seismic sensors and surface buoys with geiger counters? :(
  - Bjoern 13y ago
    The dilution of the radioactive content by the ocean is probably high. Overall the risk is low for significant contamination due to the overall ocean volume. The issues are so-called hot-spots which cause certain fish to be extremely radioactive and streams causing concentrations of radioactive materials highly contaminating only certain regions and fish. That being said, there are so many pollutants in the oceans that I'm confused why people are not more outraged about ocean pollution. Vice Documentary about garbage streams. e.g. https://www.youtube.com/watch?v=D41rO7mL6zM https://www.youtube.com/watch?v=D41rO7mL6zM Finally, its certainly not acceptable to have on-going ocean pollution, which is probably happening in Fukushima Daiichi.
- 13y ago
marze 13y ago
Anyone can correct me if I'm wrong, but I believe for two years Tepco has been dumping about 150 tons of water a day on the melted cores at the bottom of the reactor buildings (or wherever they are), and pumping 100 tons of it out to filter and reuse. Obviously, 50 tons/days has disappeared every day for 2+ years. Since that water came in contact with the melted cores is extremely radioactive (not just tritium). Measurements of the water filling the lower levels of turbine buildings supports this thinking (something like 1 Seivert/hr). Since TEPCO has not allowed any independent measurements of the ocean within kilometers of the site, nor independent ground water measurements, and the independent ocean measurements taken at large distance from the site do not show a decrease in contamination vs. time, it appears likely they've been leaking substantial amounts of cesium and other radionuclides into the ocean for >2 years. If so, an impressive coverup. The math is simple, water in minus water out, and where did the missing water go.
- VLM 13y ago
  Hmm we'll lets run this thru the engineering filter and see how much is reasonable. Well, something that can't run forever, stops, and its been close enough to forever that you can assume we're evaporating away 50 tons/day. Where else could it be going? But is that a reasonable evap rate from an engineering perspective? 50 tons is about 50K kilograms. Takes about a KWH to boil away a kilo of water so we're looking at about 50K KWH or 50 MWH per day. Now there's about 25 hours in a day so thats about 2 MW continuous boiling away water, or at least on long term average. A big reactor runs in the GW range but decay heat starts around 10% and slowly drops over time. Actually a couple years in, most should be gone although the long tail is pretty long. So it was dumping out tens of MW continuously and now maybe much less. So we're looking at a couple MW generated, vs a couple MW to make that much water vapor. Seems reasonable. So I'm willing to believe from an engineering estimate, aside from solar heating and whatever, that 50 tons of water simply evaporates away. We can argue volumetric, if a ton is about 1K kilos and 1 L water is about 1 Kg, that would strongly imply a ton of water is about a 1K liters or about one cubic meter. I suppose we could have gotten to this same point by talking about mL vs cubic centimeters vs grams. Anyway you're claiming a cube of water a meter on a side, stacked 50 tall each day, for a couple years. I say that most of that has to have evaporated away otherwise you'd have 50 meters deep of water covering the entire site after a thousand or so days.
api 13y ago
Fukushima converted me away from being a supporter of nuclear, or at least conventional nuclear. Maybe something like LFTR or WAMSR could re-open the debate in my mind, but the debate for conventional solid-phase reactor cores is pretty much closed. Not because I buy into all the fear mongering about radiation, but for a much simpler reason: it showed that conventional nuclear is not cost-effective vs. the alternatives and is not scalable. In any system, accidents will happen. Worst case accidents will happen. The frequency may be low, but Fukushima shows that one singular bad accident can completely obliterate the economic rationale for nuclear power in a given country. Fukushima is going to be a billions-a-year money pit for Japan for at least the next decade and a half. Given those costs plus the fact that nuclear without accidents is not substantially cheaper than alternatives, it just seems more rational to invest the money and R&D effort required to solve the energy storage and distribution problems associated with solar and wind energy. In the end, provided we can back them up and distribute the power efficiently, there is actually more energy available from the sun and the wind than there is from any actionable real-world plan for scaling nuclear that I've ever seen. Renewables also have many other benefits including: - Very low risk... basically no more dangerous than any other construction or manufacturing. - No fuel, so little to no real sustainability concerns. This means that once we make them work they will work forever and we won't have to worry about energy anymore. - Small incremental investment cost. Wind and solar can be deployed in small increments, and it's exponentially easier to raise small increments of money than large ones. - Less politically centralized. Nuclear demands centralized regulation and huge centralized financial control, and nuke plants are central points of failure for the entire industrial system built around them. Were we to rely on them exclusively they would become easy "off switches." Renewables by contrast open up the potential for a "PC revolution" in energy. It just seems like a no brainer for me. Nuclear is a boondoggle, at least for most uses.
- nazgulnarsil 13y ago
  We have spent decades and hundreds of billions chasing a particularly poor form of nuclear because of the US and Russian military industrial complexes. Dismissing nuclear because of horrible past decisions seems unwise.
  - 13y ago
carsonreinke 13y ago
`Tepco's "sense of crisis is weak"`, ultimately the problem.
- Bjoern 13y ago
  The infamous Atomic Village problem, particularly Tepco's corruption is quite well known and paradoxically accepted by the society. https://www.youtube.com/watch?v=pGsYdDpUSzg https://www.youtube.com/watch?v=pGsYdDpUSzg (turn on captions)
LolWolf 13y ago
But what was leaked is really not all that much. Recall that 1Bq is a disintegration per second, and, although a few trillion is quite a bit, this is over a massive volume. Now, there's nothing stated in terms of how much leaked into water sources, so, there's little judgment that can be made. But I believe it's little to truly worry about.

93 points by yapcguy 13y ago

mpyne 13y ago

More details would be nice. As the article notes, tritium itself is almost innocuous (its decay is via a weak beta particle emission, about the only way it could hurt you is if you ingested a lot of it). Either way the problem with radioactive materials relates to the concentration in solution of radioactive materials more than the binary "radioactiveness" of the material. After all the human body itself is 'radioactive' if only from the K-40 and C-14 that are present. Without knowing the concentration of radioactive contaminants like Co-60 and radiocesium that might leak into the sea it's hard to know how much of an 'emergency' we'd be looking at. All we'd know for sure is that TEPCO is incompetent... but then what else is new?

ChuckMcM 13y ago
It would be hugely better to actually have details. Water, aka H2O, doesn't activate so it is not radioactive, it can however carry radioactive isotopes in solution. Is the groundwater flowing from the neighbouring area? (implied) then the it is carrying cesium from the environment away (good thing if you want to move back into the neighbourhood) is it picking up new contaminants from a broken reactor vessel? I wonder if anyone has a better source for data here.
- khuey 13y ago
  Water can be radioactive if some of those hydrogen atoms are really tritium.
- akiselev 13y ago
  > Water, aka H2O, doesn't activate so it is not radioactive, it can however carry radioactive isotopes in solution. What? Tritium is an unstable hydrogen isotope that is radioactive, no matter what molecule it is found in. Combine that with acid-base chemistry which revolves around the disassociation of hydrogen from water and that tritium can end up as a beta emitter anywhere in the body, including in actual strands of DNA [1]. What radioactive isotopes the water carries as a solute is irrelevant to the presence of tritium in the molecules. [1] http://www.ncbi.nlm.nih.gov/pubmed/11130944 http://www.ncbi.nlm.nih.gov/pubmed/11130944
  - ChuckMcM 13y ago
    Ah yes, there is that. And in fact a bit of searching turns up this is probably what Reuters was reporting [http://www.japantimes.co.jp/news/2013/08/03/national/huge-leak-of-tritium-feared-in-fukushima/#.Uf_p4Ndj3mE http://www.japantimes.co.jp/news/2013/08/03/national/huge-le...] I had originally dismissed Tritium as a candidate for the contamination because its nominally only in the reactor water and the Reuter's article talked about 'groundwater' (which is the name nominally given to water that accumulates in aquifers as a result of soil percolation). Apparently TEPCO is losing control of the reactor coolant water which is a different thing. That said, Tritium [1] isn't a particularly "bad" agent as it decays into Helium3 (great for fusion reactors if you've got one :-) and then floats away. [1] http://en.wikipedia.org/wiki/Tritium http://en.wikipedia.org/wiki/Tritium
- mpyne 13y ago
  Water can activate (much more so than you think in fact, though I can't discuss further maybe someone with a civilian background in nuclear physics can fill in). Certainly the long-term danger is more from what the water will carry in solution than from the water itself though.
  - ChuckMcM 13y ago
    It is too bad you can't say more about this, one of the fun things I got to do a couple of years ago was to stare into the pool of the Reed Research reactor running at power and look at the awesome Cerenkov radiation (that eerie blue glow, it looked exactly like this : http://en.wikipedia.org/wiki/File:Cerenkov_Effect.jpg http://en.wikipedia.org/wiki/File:Cerenkov_Effect.jpg [yes that is the actual reactor, no I didn't take this picture :-)])
  - VLM 13y ago
    "though I can't discuss further maybe someone with a civilian background in nuclear physics can fill in" Oh spare us the cloak and dagger. I don't think oxygen radioactivation has been classified for about 80 years now. There's even a pretty good wikipedia page at http://en.wikipedia.org/wiki/Isotopes_of_oxygen http://en.wikipedia.org/wiki/Isotopes_of_oxygen The "natural" stable isotope O-16 needs to get triple neutron activated before you get an unstable isotope O-19 and the half life of that is like a minute. So its about half a million minutes per year, and its been about two years, so thats about a million half lives later... I think all the O-19 is long gone. I do agree 100% that the "stuff" dissolved in the water is about a zillion times more important than the oxygen itself. Its so mainstream there's some interesting radio oxygen dating work done using the Dole Effect, which also has a wiki page. TLDR is photosynthesis preferentially concentrates certain O isotopes so you can make all kinds of assumptions about glaciation and where plants are growing (ocean or land) given some 16O:18O ratios. http://en.wikipedia.org/wiki/Dole_effect http://en.wikipedia.org/wiki/Dole_effect There's even a cool wikipedia article with a UTF-8 name. http://en.wikipedia.org/wiki/%CE%9418O http://en.wikipedia.org/wiki/%CE%9418O Which brings you to the greater topic of isotope geochemistry http://en.wikipedia.org/wiki/Isotope_geochemistry http://en.wikipedia.org/wiki/Isotope_geochemistry I'm sure there is at least some cloak and dagger stuff that can't be discussed but there's a simply huge amount of open literature about oxygen radioactivity. I would suspect there's more open lit stuff about isotopic geochemistry than cloak and dagger stuff.
jlgreco 13y ago
> its decay is via a weak beta particle emission, about the only way it could hurt you is if you ingested a lot of it Well, it is water contamination they're talking about. People have the tendency to ingest large amounts of water. Of course, as you say, knowing the concentration is vital to understanding the risk posed. You could drink gallons of water laced with a gamma emitter if the concentration were low enough (well, not gallons. You'd get water intoxication ;).
- mpyne 13y ago
  Well I don't think people ingest large amounts of seawater. :) Perhaps fish and other seafood (assuming that the tritium concentrates in the seawater around Japan and doesn't get dispered into the wider Pacific). But then the tritium would be mostly "fixed" within the flesh of the fish and end up being mostly self-shielding. Perhaps the ATP w/ tritium and similar products get carried into cells but by that point we're talking about nothing worse than the day-to-day problems of life under the sun, eating bananas, breathing the sweet sweet scent of brick-induced radon, etc.
nknighthb 13y ago
I'm not sure that Reuters didn't misunderstand something. The tritium mention seems oddly out of place. A lot more than tritium has leaked from this plant, and I would be surprised if the water they're leaking now is contaminated solely with tritium. Also, I think with regard to tritium spilling into the sea, they're probably less concerned about a direct effect on people than on the fish swimming around in it.
mzs 13y ago
Back in '07 the Canadian Nuclear Safety Commission couldn't get a limit from Japan: http://nuclearsafety.gc.ca/eng/readingroom/healthstudies/tritium/ http://nuclearsafety.gc.ca/eng/readingroom/healthstudies/tri...
yk 13y ago
But Tritium can be quite ugly if it gets into the body, since it can replace hydrogen. (And can therefore accumulate in the body.) This depends on the molecules tritium is attached to. And on a further note, I believe that websites which need JS to scroll text are malicious.
- VLM 13y ago
  Ah its not so bad. If you have to take something radioactive, thats the one element I'd take because I'd pee most of it out in about a week. The phrase no one on HN has mentioned yet is "biological half life". There's a pretty decent wikipedia article at http://en.wikipedia.org/wiki/Biological_half-life http://en.wikipedia.org/wiki/Biological_half-life Whats important is the ratio of biological half life to radiological half life. Superficially it sounds like you're WAY better off with contaminated water, with a bio half life of about a week, than plutonium around 100 years, a difference of about 4 ords of magnitude. However the half life of 3H is in the 10s of years range and non-RTG Pu is about 20K years range or about 3 ords of magnitude lower activity. So the net effect is it hangs around 4 ords of magnitude longer, but specific activity is 3 ords of magnitude lower, so given X number of atoms, Pu is only about 10 times worse for you than 3H. All bets off for the Pu RTG isotope that is so short half life it self-melts pretty easy, or that one Pu isotope thats mostly harmless but its decay product is icky (I think 241pu to 241Am where the 241Pu if it wouldn't decay is mostly harmless but the 241Am is icky)
  - mpyne 13y ago
    Plus when we're talking about transuranics we have to account for the chemical toxicity which is normally much more dangerous than the radiation itself. Great point bringing up biological half-life by the way, especially as that helps explain why some isotopes are considered more dangerous than others for what may seem to be counterintuitive reasons.
  - yk 13y ago
    Well, the question is where is the tritium. If it comes in the form of heavy water, then the biological half life is indeed short. But tritium can substitute essentially any hydrogen, and so it can also come in the form of amino acids, which have a good chance to end up in the nucleus of a cell. So especially for tritium, it can essentially end up in anything where organic chemistry is involved, which is to say everywhere. However, the general problem I have with articles about the dangers of radioactivity is, that they almost never contain enough information to actually judge how dangerous it is. It is usually easy to get a factor of 100 or more variation in the dangers of radioactivity, based on the exact contamination scenario, the precise isotope abundances etc. So even Pu is not always very bad, since PuO is almost insoluble in water, which can be used for nice party tricks [1]: [...] to eat as much plutonium as any prominent nuclear critic will eat or drink caffeine. My offers were such as to give me a risk equivalent to that faced by an American soldier in World War II, according to my calculations of plutonium toxicity which followed all generally accepted procedures. [1] http://www.phyast.pitt.edu/~blc/book/chapter13.html http://www.phyast.pitt.edu/~blc/book/chapter13.html

brianbreslin 13y ago

Has anyone done tests to see how the radioactive water and other contaminants have affected the pacific as a whole? how about the fish stock near japan? http://www.grida.no/images/series/vg-climate/large/32.jpg http://www.grida.no/images/series/vg-climate/large/32.jpg

akiselev 13y ago
It's extremely difficult to do such a study because the entire system is just so complex and there's no way to control for many of the variables. There have, however, been limited studies about bioaccumulation of tritium in phytoplankton and how it can move up the food chain [1]. As another poster said, tritium decays by beta radiation which isn't necessarily harmful but if it accumulates in the food chain, it might be dangerous (just like heavy metals and fish, for example). Tritium's half life is about 12 years so its not inconceivable. It's a different environment but you can probably draw some conclusions about the impact/spread of radioactive particles by looking at Chernobyl. Edit: [1] http://www.ncbi.nlm.nih.gov/pubmed/22863967 http://www.ncbi.nlm.nih.gov/pubmed/22863967
toomuchtodo 13y ago
Does this mean we have to start equipping undersea seismic sensors and surface buoys with geiger counters? :(
- Bjoern 13y ago
  The dilution of the radioactive content by the ocean is probably high. Overall the risk is low for significant contamination due to the overall ocean volume. The issues are so-called hot-spots which cause certain fish to be extremely radioactive and streams causing concentrations of radioactive materials highly contaminating only certain regions and fish. That being said, there are so many pollutants in the oceans that I'm confused why people are not more outraged about ocean pollution. Vice Documentary about garbage streams. e.g. https://www.youtube.com/watch?v=D41rO7mL6zM https://www.youtube.com/watch?v=D41rO7mL6zM Finally, its certainly not acceptable to have on-going ocean pollution, which is probably happening in Fukushima Daiichi.
13y ago

marze 13y ago

Anyone can correct me if I'm wrong, but I believe for two years Tepco has been dumping about 150 tons of water a day on the melted cores at the bottom of the reactor buildings (or wherever they are), and pumping 100 tons of it out to filter and reuse. Obviously, 50 tons/days has disappeared every day for 2+ years. Since that water came in contact with the melted cores is extremely radioactive (not just tritium). Measurements of the water filling the lower levels of turbine buildings supports this thinking (something like 1 Seivert/hr). Since TEPCO has not allowed any independent measurements of the ocean within kilometers of the site, nor independent ground water measurements, and the independent ocean measurements taken at large distance from the site do not show a decrease in contamination vs. time, it appears likely they've been leaking substantial amounts of cesium and other radionuclides into the ocean for >2 years. If so, an impressive coverup. The math is simple, water in minus water out, and where did the missing water go.

VLM 13y ago
Hmm we'll lets run this thru the engineering filter and see how much is reasonable. Well, something that can't run forever, stops, and its been close enough to forever that you can assume we're evaporating away 50 tons/day. Where else could it be going? But is that a reasonable evap rate from an engineering perspective? 50 tons is about 50K kilograms. Takes about a KWH to boil away a kilo of water so we're looking at about 50K KWH or 50 MWH per day. Now there's about 25 hours in a day so thats about 2 MW continuous boiling away water, or at least on long term average. A big reactor runs in the GW range but decay heat starts around 10% and slowly drops over time. Actually a couple years in, most should be gone although the long tail is pretty long. So it was dumping out tens of MW continuously and now maybe much less. So we're looking at a couple MW generated, vs a couple MW to make that much water vapor. Seems reasonable. So I'm willing to believe from an engineering estimate, aside from solar heating and whatever, that 50 tons of water simply evaporates away. We can argue volumetric, if a ton is about 1K kilos and 1 L water is about 1 Kg, that would strongly imply a ton of water is about a 1K liters or about one cubic meter. I suppose we could have gotten to this same point by talking about mL vs cubic centimeters vs grams. Anyway you're claiming a cube of water a meter on a side, stacked 50 tall each day, for a couple years. I say that most of that has to have evaporated away otherwise you'd have 50 meters deep of water covering the entire site after a thousand or so days.

api 13y ago

Fukushima converted me away from being a supporter of nuclear, or at least conventional nuclear. Maybe something like LFTR or WAMSR could re-open the debate in my mind, but the debate for conventional solid-phase reactor cores is pretty much closed. Not because I buy into all the fear mongering about radiation, but for a much simpler reason: it showed that conventional nuclear is not cost-effective vs. the alternatives and is not scalable. In any system, accidents will happen. Worst case accidents will happen. The frequency may be low, but Fukushima shows that one singular bad accident can completely obliterate the economic rationale for nuclear power in a given country. Fukushima is going to be a billions-a-year money pit for Japan for at least the next decade and a half. Given those costs plus the fact that nuclear without accidents is not substantially cheaper than alternatives, it just seems more rational to invest the money and R&D effort required to solve the energy storage and distribution problems associated with solar and wind energy. In the end, provided we can back them up and distribute the power efficiently, there is actually more energy available from the sun and the wind than there is from any actionable real-world plan for scaling nuclear that I've ever seen. Renewables also have many other benefits including: - Very low risk... basically no more dangerous than any other construction or manufacturing. - No fuel, so little to no real sustainability concerns. This means that once we make them work they will work forever and we won't have to worry about energy anymore. - Small incremental investment cost. Wind and solar can be deployed in small increments, and it's exponentially easier to raise small increments of money than large ones. - Less politically centralized. Nuclear demands centralized regulation and huge centralized financial control, and nuke plants are central points of failure for the entire industrial system built around them. Were we to rely on them exclusively they would become easy "off switches." Renewables by contrast open up the potential for a "PC revolution" in energy. It just seems like a no brainer for me. Nuclear is a boondoggle, at least for most uses.

nazgulnarsil 13y ago
We have spent decades and hundreds of billions chasing a particularly poor form of nuclear because of the US and Russian military industrial complexes. Dismissing nuclear because of horrible past decisions seems unwise.
- 13y ago

carsonreinke 13y ago

`Tepco's "sense of crisis is weak"`, ultimately the problem.

Bjoern 13y ago
The infamous Atomic Village problem, particularly Tepco's corruption is quite well known and paradoxically accepted by the society. https://www.youtube.com/watch?v=pGsYdDpUSzg https://www.youtube.com/watch?v=pGsYdDpUSzg (turn on captions)

LolWolf 13y ago

But what was leaked is really not all that much. Recall that 1Bq is a disintegration per second, and, although a few trillion is quite a bit, this is over a massive volume. Now, there's nothing stated in terms of how much leaked into water sources, so, there's little judgment that can be made. But I believe it's little to truly worry about.