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Japan Power News

Safety Measures Fail To Stop Fukushima Plant Leaks 157

AmiMoJo writes "The operator of the Fukushima Daiichi plant has been developing countermeasures to deal with repeated leaks from tanks of contaminated water. But despite the measures, 100 tons of radioactive water leaked on Wednesday and Thursday. 'The leaked water was among the most severely contaminated that Tepco has reported in the aftermath of the March 2011 disaster at the Fukushima Daiichi plant, when damage caused by an earthquake and a tsunami led to meltdowns in three of the plant’s reactors. Each liter of the water contained, on average, 230 million becquerels of particles giving off beta radiation, the company said. About half of the particles were likely to be strontium 90, which is readily taken up by the human body in the same way that calcium is, and can cause bone cancer and leukemia.' The estimated volume of the leaked radioactive materials caused Japan's nuclear regulator to rank the leak a level-3 serious accident. The international scale of nuclear and radiological events ranges from zero to 7."
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Safety Measures Fail To Stop Fukushima Plant Leaks

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  • Re:Solution: (Score:3, Informative)

    by MightyYar ( 622222 ) on Friday February 21, 2014 @03:04PM (#46305315)

    Indeed, the total spill is about the same size as a large-ish residential pool. The ocean will never know.

  • by nojayuk ( 567177 ) on Friday February 21, 2014 @03:44PM (#46305601)

    "Google Cherynobyl? To this very day it is so radioactive you can't get within 50 to 100 miles of it?"

    After the accident/explosion/fire etc. in 1986 the Ukrainian authorities continued to operate the three other undamaged reactors at Chernobyl (they needed the electricity supplies). After a few years folks started running tourist trips to visit the area including the evacuated towns surrounding the damaged reactor. Thousands of workers have been working on the reactor building for decades attempting to entomb it or at least cover it up so it doesn't leak quite as much residual radioactivity as it does even today.

    Sure in a Hollywood disaster movie script the Chernobyl site is so radioactive you can't get within 50 to 100 miles of it. However this is real life which is kinda different.

    Ah, I just realised you're trolling, aren't you? Silly me.

  • by iggymanz ( 596061 ) on Friday February 21, 2014 @03:52PM (#46305657)

    nonsense, the leaking isotopes will decay in decades not centuries.

    Fukushimi diachi is a local problem, never mind hysteria over non-events like the detected level of one extra xenon atom per cubic meter in the USA, that's nothing. less than nothing.

    Chernobyl was just bad engineering meets bad management, other plants in the world can't do what that one did. And Fukushima diachi hasn't caused widespread damage like Chernobyl did.

  • Re:Solution: (Score:5, Informative)

    by hey! ( 33014 ) on Friday February 21, 2014 @04:12PM (#46305785) Homepage Journal

    Well, dilution *is* a reasonable approach to disposing of this waste, but what we have here appears to be an ongoing leak from a point source into tidal waters, which is not at all the way you'd design a project to dilute the waste.

    There are several big differences between letting the stuff leak and a proper attempt to diffuse the waste over a large area of the ocean. First of all the leak is a point source discharging into an intertidal zone. My wife is a physical oceanographer who helped site a major sewage outfall, so I remember some of the concerns. Stuff that is discharged right near the shore doesn't diffuse nicely out to deep water, it gets transported along the shore with the same currents that deposit sand from rivers along the coast.

    This means that the S90 may well get deposited in sediments. The concentration of S90 probably won't be enough to be a direct concern to humans, but because strontium is an analog to calcium, it can bioaccumulate [wikipedia.org]. This means the somewhat incomplete process of dilution gets undone when critters like benthic worms on the bottom of the food chain consume the S90, and are in turn consumed by ground fish and so on up the food chain. At each trophic level [wikipedia.org] the S90 is concentrated a little more.

    I agree that the amount here reported is probably not a serious threat to human and environmental health, but the problem is that this process is ongoing. It is possible that what is going on doesn't present any threat to human or environmental health, but we can't be sure. By the time we figure it out it will be too late to do anything (or anything affordable) about it if it is a problem.

    In a nutshell: dilution could work, but there's a significant chance that just letting the stuff leak into the sea won't do the job. This stuff needs to be contained or otherwise dealt with *now*.

  • by Ckwop ( 707653 ) <Simon.Johnson@gmail.com> on Friday February 21, 2014 @04:43PM (#46306065) Homepage

    Fukushima is a serious nuclear disaster. It's a very situation that we should all be concerned about. But this should not lead to any pause in our appetite for nuclear energy.

    What people often fail to appreciate is that even coal fired powerstations release quite large amounts of radioactive material in to atmosphere. Coal fired powerstations burn about a million times as much material as a nuclear powerstation per joule of energy produced. Some of that material is radioactive. That stuff isn't been sealed in a container in burrried in a mountain, it's being blown up chimney stacks along with the rest of the rather unpleasant stuff.

    Don't believe me? Reflect on this passage taken from this (PDF) document [ohio-state.edu]:

    The EPA found slightly higher average coal concentrations than used by McBride et al. of 1.3 ppm and 3.2 ppm, respectively. Gabbard (A. Gabbard, “Coal combustion: nuclear resource or danger?,” ORNL Review 26, http://www.ornl.gov/ORNLReview... [ornl.gov] 34/text/colmain.html.) finds that American releases from each typical 1 GWe coal plant in 1982 were 4.7 tonnes of uranium and 11.6 tonnes of thorium, for a total national release of 727 tonnes of uranium and 1788 tonnes of thorium. The total release of radioactivity from coal-fired fossil fuel was 97.3 TBq (9.73 x 1013 Bq) that year. This compares to the total release of 0.63 TBq (6.3 x 1011 Bq) from the notorious TMI accident, 155 times smaller.

    So far, there has not been a single confirmed death due to Fukushima accident. In comparison, there were 20 deaths in the US just mining for coal in 2013. This is not to mention all the deaths being caused by cancers and other health problems being caused by breathing polluted air.

    If we're ever going to get on top of this climate change challenge, nuclear must be leading the charge. Nuclear is a safe, non-polluting technology. Modern designs are fail-safe in every sense of the word. The newer designs can even cope with a loss of external power (like Fukushima experienced) yet still stay safe.

    This is the 21st century. The technology is mature, sensible and safe. Really, we should be looking to retire every coal fired plant as a matter of urgency, if only to reduce the amount of radioactive contamination of the atmosphere!!

  • by Anonymous Coward on Friday February 21, 2014 @05:45PM (#46306629)

    Considering your smoke detectors have about 37,000 Bq of radioactive material in them, the amount of radioactive material released is equal to the same number becquerels as 10,270 smoke detectors.

    Chernobyl's release of Strontium 90 was estimated at 200 PetaBecquerels. That is 200 * 10^15 power. Or 536 million times as much as that was recently leaked at Fukushima.

    But hey, 380 million is a scary sounding number, so it works well for propaganda purposes.

  • by dfenstrate ( 202098 ) <dfenstrate AT gmail DOT com> on Friday February 21, 2014 @06:18PM (#46306901)
    There's no reason to think the melted core will get that far down, or even burn through the concrete floor, or even leave the reactor vessel in any sort of coherent form. Chernobyl's overheated core just spread through the lower parts of the structure (look for the 'elephant's foot' picture), Three Mile island's core was scraped off the inside of the reactor vessel, having only blued the metal.

    'Corium' is basically molten ceramic (The fuel is a uranium-oxide matrix.) It has such poor heat conducting properties that during normal operations, it could be 3000F in the center of a pellet, and 650F on the surface of the cladding- 3/16" away from the center.

  • by symbolset ( 646467 ) * on Friday February 21, 2014 @06:37PM (#46307081) Journal
    That's 380 million per liter times 100,000 liters. Considering how much of this stuff they have on the site the total must be quite horrific.
  • by Guppy ( 12314 ) on Saturday February 22, 2014 @10:41AM (#46310757)

    You are not comparing like with like. The potassium in a banana is mostly passed through the body harmlessly, as only enough to maintain the normal level is absorbed.

    Mostly correct. Instead of only absorbing "only enough to maintain the normal level", what you will actually get is absorption of a bit more than enough to maintain the normal level, coupled with increased elimination (mostly via urine) to maintain that normal level. Either way there is no difference -- there is no long-term storage of Potassium in the body, it is all present as the soluble, highly-mobile aqueous ion. So any increased level of from a radioactive source will relatively rapidly come back down to equilibrium levels of radioactivity, once you return to your intake from your regular Potassium sources.

    Anyway, the ratio of radioactive Potassium (to non-radioactive Potassium) in your body will be equal to the average level of radioactive Potassium in Bananas (and other dietary sources, mostly plant-derived materials); the Potassium-40 isotope to non-radioactive isotopes is mostly at equilibrium concentration in the environment. For a 70kg human this means approximately 160g of total Potassium in the body, with 0.0187 grams of 40K, producing 4,900 disintegrations per second (becquerels) [wikipedia.org].

    The strontium in this water is absorbed by the body like calcium, accumulating in the bones where it will sit for years or decades slowly irradiating you, which is why is causes cancer and leukaemia.

    Partially correct. Like Potassium, Calcium is regulated at a "normal" level, and the body will reduce absorption (from the gut), and increase elimination (mostly through urine) to eliminate excess. Accumulation happens if there is a deficit, or with active deposition of osseous material. However, due to constant turn-over of bone Calcium, at any given time a small amount of material is simultaneously being both absorbed and released from long-term storage. So this means a small amount of the ingested material will go into long-term storage, even when your body is not actively increasing Calcium stores.

    However, note that while Potassium-40 and non-radioactive Potassium are chemically identical (well, almost identical -- some tiny kinetic effects may be present, negligible), Calcium and Strontium are not. They are grossly handled the same by the body, but there may be some differences in absorption / retention / excretion rates between the two substances -- so the radioactive Strontium will not be a straightforward constant fraction of the Calcium pool as it moves around in the body.

    I'm disappointed. I expect more than this level of scientific illiteracy from +4 Slashdot comments.

    I'm not disappointed; I never had any expectations to begin with :)

I find you lack of faith in the forth dithturbing. - Darse ("Darth") Vader