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Fukushima Radiation Levels High, But Leak Plugged

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  • by elrous0 (869638) * on Wednesday April 06, 2011 @12:05PM (#35734100)

    Helpful radiation chart [xkcd.com] for those of us who don't have a clue whether 100 millisieverts is a tiny dose or enough to create a Godzilla monster.

    In short, it's definitely into the "You might want to step-up your planned schedule on those cancer screenings" territory.

    • by bluefoxlucid (723572) on Wednesday April 06, 2011 @12:09PM (#35734158) Journal
      100 millisieverts per...? A millisievert is a specific amount. If you are getting 100mS/sec you are probably in serious trouble; 100mS/day, you want to leave. Also WHERE outside the buildings? Just outside the door levels are high; 200 meters away, levels are dropping off by inverse cube law.
      • by elrous0 (869638) *

        I assumed they meant per hour.

        • Look! We fixed one of the any problems! Suceess!

          "United States government engineers sent to help with the crisis in Japan are warning that the troubled nuclear plant there is facing a wide array of fresh threats that could persist indefinitely, [nytimes.com] and that in some cases are expected to increase as a result of the very measures being taken to keep the plant stable, according to a confidential assessment prepared by the Nuclear Regulatory Commission."

          • They fixed th most concerning problem. There not calling the reactor fixed, nor are they saying there is no concern.

            • They fixed the uncontrolled spill of a couple of liters per minute into the ocean so they can keep on with the controlled spill of a couple of thousand tons? Wait, they didn't fix the uncontrolled spill, they plugged on hole, temporarily at best. They don't know the flow path, they don't know where it comes from and where else it is going. If that sells at good news, the spinmeisters are getting a bonus this year.
        • by radtea (464814)

          I assumed they meant per hour.

          Why?

          Seriously, I am reasonably expert on radiation safety (I've worked as a medical physicist and spent a good deal of my professional career around radiation sources of one kind or another) and I have no clue what anyone could possibly mean when they say "rates exceed 100 mSv". It's like saying, "the spacecraft was traveling in excess of 30 km when it impacted." If it was impact on the Moon that might mean "30 km/s", if it was impact on Earth it might mean "30 km/hr".

          The only thing such statements certai

      • by ukemike (956477)
        It is also worth considering that sieverts are a calculated unit. There is a not a direct conversion from becquerels to sieverts. Sieverts are a measure of dose equivalent.

        [wikipedia]
        The dose equivalent is a measure of biological effect for whole body irradiation. The dose equivalent is equal to the product of the absorbed dose and the Quality Factor.
        The Quality Factor (Q) depends on the type of radiation:
        X-ray, Gamma ray, or beta radiation: Q = 1
        alpha particles: Q = 20
        neutrons of unknown energy
        • and of course alpha radiation from outside your body is hahahaha my t-shirt is a hazard suit. So, really want to avoid inhaling dust here.
      • by blueg3 (192743)

        Inverse square law, no?

      • by Jake73 (306340)

        My car is really fast. It goes over 500 meters!!!

    • by MyLongNickName (822545) on Wednesday April 06, 2011 @12:16PM (#35734252) Journal

      Hi,

      I am glad I have Slashdot posters here who can help me determine the risk of radiation leaks from Japan. I take such advice as seriously as I do the sex tips I frequently see posted on Slashdot.

    • The key to the chart

      "(However, keep in mind that I am not a radiation expert, and this chart is intended for general public informational use only.)"

      So, yes, please make your judgements based on a web comic.

      • by geekoid (135745)

        OTOH, it's pretty accurate and he provides all the references.
        So if you are concerned, read the references. I learned about this crap years ago ni the ilitary. I did have to learn to convert from my historic mothod(rems/rads) to the SI method.

        • The main point to remember, however, is that it is referenced to whole body radiation exposure. I don't agree with the style of presentation, which I find somewhat confusing, but the most important problem is that your exposure is getting significantly up when you ingest or inhale particulate radioactive matter.
      • Re: (Score:2, Informative)

        by maxume (22995)

        It isn't a comic though, it is a chart prepared in the style of a particular web comic.

        (Your entire context is sort of strange to me, very few laypeople are going to have enough understanding of the sources and dynamics of the contaminants to "judge" the situation, and the very limited surveys and information available would make it very difficult for them to be precise, not to mention the fact that the situation is not stable (they do seem to be gaining more control though, which is at least better than th

    • by ozbird (127571)
      On the bright side, radiation levels in Australia have fallen since banana prices jumped to $18/kg. (Cyclones, floods, whatever.)
      • by elrous0 (869638) *

        radiation levels in Australia have fallen

        Oh man, I wish I had known this before I invested heavily in dune buggies and shoulderpads.

  • Units (Score:5, Insightful)

    by Colonel Korn (1258968) on Wednesday April 06, 2011 @12:08PM (#35734142)

    100 millisieverts? Per hour? Per day? Per century? Thanks, Slashdot, for giving us a useless number.

    • by jd (1658)

      Per Library of Congress*. That's the default on Slashdot, when no other units are given.

      *Yes, you were expecting time rather than bytes, so remember to cast the type before assignment.

      • I assumed the Library of Congress unit of time referred to the time it would take a million monkeys on a million typewriters to replicate it by chance, the LoCUoT.

        What's the sense of adopting a standard unit if we can only use it for a single type of measurement? I've already modified my oven dial to the Library of Congress unit of energy, the LoCUoE.

    • by gatkinso (15975)

      Per picosecond.

    • Re:Units (Score:5, Funny)

      by M. Baranczak (726671) on Wednesday April 06, 2011 @12:24PM (#35734350)

      Per furlong.

    • 100 millisieverts? Per hour? Per day? Per century? Thanks, Slashdot, for giving us a useless number.

      I assumed it meant that the meter had recorded a *cumulative* amount of 100 mSv before it fizzled out. I have a counter on my desk that I've had running since this disaster occurred. In that time, it's accumulated 0.013 mSv with the background here.

    • Per fortnight.
  • by Animats (122034) on Wednesday April 06, 2011 @12:26PM (#35734378) Homepage

    The leak that was stopped was from a drain pit to the ocean. The reactor itself is still leaking highly radioactive water. They're running out of places to put it.and are frantically building tanks and ponds.

    • by c0lo (1497653)

      The leak that was stopped was from a drain pit to the ocean. The reactor itself is still leaking highly radioactive water. They're running out of places to put it.and are frantically building tanks and ponds.

      This and... did they actually managed to stop the water leaking into the soil? Or is just a case of "out of the media sight, out of mind"?

  • 100 mS is no joke (Score:3, Insightful)

    by ShooterNeo (555040) on Wednesday April 06, 2011 @12:34PM (#35734490)

    So according to the chart, if you hang around an area with 100 mS per hour for an hour, you'll receive a dose likely to cause cancer. Hang around for 4 hours, and you get radiation poisoning. That's not a lot of time - it takes days of labor to do anything major. Probably takes 30 minutes just to walk around part of the plant looking for radiation leaks. This must be why it took so long to plug that water leak - no one could hang around the leak for more than brief intervals.

    Heck, even refueling a diesel pump - which is just increasing the amount of highly radioactive water you have to dispose of somehow - is going to take 20 minutes at a minimum, right?

    I'm sure the workers are doing what they can - sprinting through the hot areas, working in shifts, using automation when they can - but the larger the contaminated area gets and the more fission products leak the worse the problem becomes. If you cannot even enter the building the reactor is in, how can you fix anything? They can't just send in robots and spray concrete willy nilly - if the reactor cores fully melt down and form critical masses at the bottom of the reactor vessel, gigawatts of heat will be produces and burn through any containment.

        They need to have active pumps flushing water through the reactor vessels and out to the cooling tower and back again. This is the only method that won't create more and more radioactive water that has to be disposed of. (because right now they are just pumping water in and it leaks out of the reactor vessel and pools somewhere)

    But to do that, somehow has to enter the building, install new pumps, fix breaks in the wiring, fix holes in the pipes, install sensors, power it up, and so forth. That's many hours of labor, and beyond the dexterity of what robots can do.

    http://xkcd.com/radiation/ [xkcd.com]

    • by khallow (566160)

      I'm sure the workers are doing what they can - sprinting through the hot areas, working in shifts, using automation when they can - but the larger the contaminated area gets and the more fission products leak the worse the problem becomes. If you cannot even enter the building the reactor is in, how can you fix anything? They can't just send in robots and spray concrete willy nilly - if the reactor cores fully melt down and form critical masses at the bottom of the reactor vessel, gigawatts of heat will be produces and burn through any containment.

      Keep in mind that everything is decaying over time and there's still some isotopes in the few day range which are still decaying. Much of this will remain hot for centuries, but merely waiting does ease the problem. They can also clean up the problem (vacuum, wash, whatever, the radioactive contamination, vitrify it or otherwise stabilize it, and bury it).

      And they're beyond issues of criticality. What fuel has melted is now both diluted (since it mixed up with metal, concrete, etc) and "poisoned" by elem

    • Re:100 mS is no joke (Score:4, Informative)

      by pushing-robot (1037830) on Wednesday April 06, 2011 @01:02PM (#35734966)

      So according to the chart, if you hang around an area with 100 mS per hour for an hour, you'll receive a dose likely to cause cancer.

      No. To use the inevitable car analogy:

      A scientist says: "Car accidents can happen to anyone who is in an automobile. However, studies have shown that car crashes are an insignificant cause of death for those who drive less than 1000 miles per year.

      An editor summarizes: "Minimum one-year driving linked to increased car crash risk: 1000 miles".

      You read: "If you drive 1000 miles you'll probably die".

      • Radiation poisoning happens at 400 mS. Your analogy fails. 100 mS is the minimum level at which we KNOW cancer rates go up significantly. They probably rise at lower radiation doses as well.

        • "significantly" in the statistical sense that we can find any correlation between radiation and increased cancer occurrence, not the laymen's sense of "greatly". Also keep in mind that's a YEARLY dose linked with cancer and I think we're talking about an hourly dose of 100 mSv there so you are certainly correct that it is quite a serious amount indeed.
    • If you hang around an area with 100 mS per hour for an hour, you'll receive a dose likely to cause cancer.

      Well, you'll receive a dose that has been statistically shown to increase your chances of getting cancer, which is not quite the same thing as likely.

      There was a handful of articles floating around last week that the plant company was looking to hire semi-skilled 'Jumpers' to do the kinds of jobs you're talking about. They'll pay you a ridiculous amount of money ($2500-5000) to get trained in on a simple task like refueling a generator or patching a damaged cable, then you jump in, get the work done as fas

      • What a way to make a living. And it's a nice chunk of change...IF you don't end up being the 1/100 or 1/1000 that develops some kind of nasty cancer early and dies slowly and horribly...or is forced to spend hundreds of k on medical bills.

        • except that something like 1/5 of the population dies of cancer anyway. So, getting 100mSv increases your chance from 200/1000 to 205/1000 (based on increase in risk .05%/rem, which is debatable). However, most studies show the increase in cancer rates cannot be distinguished from background until dose exceeds somewhere between 10 and 20 rem (100 - 200 mSv).
    • by Rashkae (59673)

      No, not a dose likely to cause cancer. A dose that has a measurable effect on increasing your lifelong chances of getting cancer. The base chance of a random person, with no extra-ordinary risk factors, getting cancer is somewhere around 46%. It's assumed that any exposure to radiation increases this, but with radiation doses less than 100mSv, the increase chance of getting cancer is so small it can't be measured/detected. (and I'm pretty sure, though don't remember exactly, that the first level of incr

    • by sl3xd (111641)

      So according to the chart, if you hang around an area with 100 mS per hour for an hour, you'll receive a dose likely to cause cancer. Hang around for 4 hours, and you get radiation poisoning.

      Not quite. There's a difference between an increased chance of cancer (something like a 5% increased chance of getting cancer in the next 30 years) and being "likely to cause cancer". Similarly, 400 mSv marks the beginning of some symptoms of radiation poisoning - itchy skin being the primary symptom.

      As exposure moves

    • by blueg3 (192743)

      It's not "likely", it's "measurably likely". As in, there is a small but measurable increase in the probability that you will one day get cancer.

      100 mSv/hr is not a trivial amount of radiation. It's not Godzilla or Chernobyl, but it's substantial. As you point out, a few hours at 100 mSv/hr will cause radiation poisoning, and a few more hours will kill you.

  • by v1 (525388) on Wednesday April 06, 2011 @12:44PM (#35734620) Homepage Journal

    "We have repeatedly asked the government and Tepco to stop further radiation leaks into the ocean. But the government and Tepco ignored us and dumped radioactive water into the sea, which is utterly outrageous," said the letter from Japan's largest fishermen's labour group. "What they have done is unforgivable. It could really destroy our business."

    (emphasis mine)

    They are being totally selfish and turning a blind eye to what the government has been trying to tell them. They have many millions more gallons of water than they can store. Some of it has to be dumped. They could dump some less contaminated water from the storage pond to make room for much more dangerous water that has to be removed from the reactors, OR they could stop using the pond and just dump that highly radioactive water from the reactors straight into the ocean, which would be much worse for the fishing industry over the next several years. No one else has a better idea, unless these fishermen care to stop by with some buckets?

    They're upset at what's happening, and are lashing out and treating it like they're the deliberate targets of a random malicious decision. It's the best option available at this time. I don't even know if a technology exists to remove radiation from water, I'm assuming it either doesn't exist or is too slow to be practical otherwise they wouldn't be using storage ponds in the first place.

    • by ibpooks (127372)

      I don't even know if a technology exists to remove radiation from water, I'm assuming it either doesn't exist or is too slow to be practical otherwise they wouldn't be using storage ponds in the first place.

      The technology does exist to remove the radioactive particles from the water, but the water treatment plant at Fukushima is offline as a result of the damage and lack of electricity. The only option at this point is to store as much contaminated water as possible until the treatment plant can be reactivated. Furthermore, if the primary contaminant is Iodine-131, they simply need to quarantine the water long enough for the Iodine to decay at which point the water can be safely discharged into the sea witho

    • by timeOday (582209)
      Perhaps what they're really doing with these statements is pulling a number in the queue of people lining up for compensation of financial damages. It will be argued that this was a preventable outcome of the tsunami. For example, the reactors might have been placed on higher ground.

      I can see their point. If elevated radiation is detected in their catch, nobody will touch it with a ten foot pole. They will have no livelihood, and that is a terrifying prospect for anybody.

  • When I look up and see the Moon, I see a large amount of energy that soon could be within Humanities reach.
    • When I look up and see the Moon, I see a large amount of energy that soon could be within Humanities reach.

      That's the sun. Daylight. An interesting concept. You might try it some time.

      • I think he's referring to the abundance of helium-3 in the lunar regolith, which could be used for nuclear fusion.
    • Yep, we'll have fusion power in 50 years. Just like they said 50 years ago.

  • by rickb928 (945187) on Wednesday April 06, 2011 @01:20PM (#35735200) Homepage Journal

    Even if they get the hydrogen under control, the amount of water, the damage to the secondary containment, the likely damage to primary containment, the contamination of the site, it's not just that Fukushima Daiichi will never operate again. Daiichi will be entombed and left to decay for at least a decade, probably longer, much longer. All six reactors are lost, 5&6 are just not going to be operated because it is too hot to work there 8 hours a day.

    While they wait for decay to lower levels enough for machines to clean things up, there will be continuing groundwater and soil contamination. They will have to build a new seawall and interceptor wells to limit (not prevent) contamination of the local sea. The local population won't be allowed within 12km, and they won't WANT to be within 20km or more. Agriculture will likely be ruined, having to wait for years to once again export their products. It's the Cesium isotopes that will cause the worst problems, and cause the lasting effects, and they are not able to contain this yet. Hopefully #3 won't blow a Plutonium cloud that, even if it were minimal, would poison the area for the forseeable future. There is no assurance that this will not happen.

    This is already inevitable, and there will be no real discussion, because TEPCO cannot admit to the inevitable outcome yet. To do so is to admit defeat, lose all face, and watch them become a single-yen stock.

    And somehow Japan needs to replace the generating capacity. Quickly.

    Overall this situation is redefining 'worst-case'. It may have been simpler to have a couple of core melts and just pour concrete and sand over the whole damned thing. Now we've gotten broken containment, multiple vectors, and inadequate resources. Oh, and the Japanese way of self-reliance to the point of failure. Works for the residents and their migration, doesn't work for engineering problems.

    • by blueg3 (192743)

      Overall this situation is redefining 'worst-case'. It may have been simpler to have a couple of core melts and just pour concrete and sand over the whole damned thing. Now we've gotten broken containment, multiple vectors, and inadequate resources. Oh, and the Japanese way of self-reliance to the point of failure. Works for the residents and their migration, doesn't work for engineering problems./quote.

      No, there's still quite a ways to go before you get near "worst case". One bad scenario is failing to cool the fuel to the point that it combusts, putting ash heavy with radioactive material into the air. (Also bad is an explosive failure of the primary containment, but that's very unlikely these days.) Uncontained radioactive materials at the reactor site and in the ocean is one thing. Radioactive materials in the ground water is worse. Radioactive materials in the atmosphere in large quantities is very bad.

  • The bad news (Score:5, Interesting)

    by westlake (615356) on Wednesday April 06, 2011 @01:48PM (#35735574)

    Workers are pumping nitrogen into one of the reactors at Japan's damaged nuclear plant in an attempt to prevent an explosion caused by dangerously overheated fuel rods.

    Officials at TEPCO, which operates the Fukushima plant, said a dangerous hydrogen buildup is taking place at its number-one reactor. Japan's NHK television quoted officials saying hydrogen is accumulating inside the reactor's containment vessel - an indication that the reactor's core has been damaged.

    Crisis at Japan Nuclear Plant Shifts to New Blast Risk [voanews.com]

    Chemistry 201: Why Is Fukushima So Gassy? [nytimes.com]

    But there are reasons...that Fukushima is particularly vulnerable.

    One is its recent use of seawater to cool the reactors's fuel rods and cores. In addition to the oxygen in water molecules, cold seawater can hold a great deal of dissolved oxygen gas. But warm water cannot; so as the seawater was heated in the reactor, the dissolved oxygen emerged and gathered in the empty space above the water.

    (Ordinary reactor cooling water has had the oxygen removed from it by plant operators to reduce the possibility of rust.)

    In addition, gamma radiation from the nuclear fuel in the reactor would continuously produce small amounts of hydrogen and oxygen by breaking up water molecules --- and the normal method of recombining these elements into water at such plants in a controlled fashion is no longer available.

    Plants of the Fukushima variety usually have catalytic converters that accomplish that at the point where steam has run through the turbine and is condensed back into water for another trip through the reactor. But that path has been closed since the plant lost power at the moment of the March 11 earthquake.

    Hydrogen can also emerge from the zirconium metal used as fuel cladding. One of the lessons of the Three Mile Island accident in 1979 near Harrisburg, Pa., is that when the cladding comes into contact with steam rather than water, it goes through a reaction that is akin to rusting; it picks up oxygen from the water molecule and gives off hydrogen.

    This only happens at high temperatures, but uncertainty reigns at the moment about temperatures in the Fukushima reactor cores. With some cooling channels blocked, they are likely to have hot spots.

    By design, boiling water reactors like these have far more zirconium metal in them than pressurized water reactors do. They boil water directly in the core, covering the fuel assemblies with a water/steam mixture rather than keeping them immersed in water. The water has to be directed to each individual fuel assembly and therefore each sits in its own zirconium box.

    All of that zirconium is available for an oxidation reaction with steam in which the metal absorbs oxygen from water and turns to a powdery rust, releasing hydrogen.

  • Radiation monitors designed for people working at a site that has chronic exposure risk, maybe. Personal radiation monitors for acute exposure can handle well above 100 mSv/hr. Radiation monitors in general can measure above 100 Sv/hr, 3 orders of magnitude higher than what they're talking about. It's not that the levels of radiation are "immeasurable", as the article incorrectly states. It's just that they apparently don't have equipment on hand sufficient to measure it.

  • by Marrow (195242) on Wednesday April 06, 2011 @02:13PM (#35735924)

    And connects to a drain at the bottom of a pit underneath a nuclear reactor. And this is to help when they wax the floors? This is to clean up after barbecues? This drain is used when the have the weekly trim everyones hair day underneath the reactors? Considering these buildings are supposed to be nearly hermetically sealed, why the snot do the plans call for a pipe that goes out the the friggin ocean?

    • by DrJimbo (594231)

      Considering these buildings [the reactor buildings] are supposed to be nearly hermetically sealed, why the snot do the plans call for a pipe that goes out [to] the friggin ocean?

      Your mistake was believing the bullshit some people have been spouting that the reactor buildings were a third layer of containment after the ziroconium clad fuel rods and the containment vessel. Here is excerpt from an article from earlier in the crisis called Containment vessel failure unlikely [japantimes.co.jp]:

      The containment vessel is the last line of defense for containing lethal radioactive materials, and significant damage would pose grave safety concerns.

      Drains and tunnels actually make sense. When a reactor is functioning properly, almost all of the radioactivity is contained within the zirconium clad fuel rods. The water circulating around the rods that acts

  • by Dasher42 (514179) on Wednesday April 06, 2011 @03:14PM (#35736696)

    What I don't see enough discussion about is the bioaccumulative effect.

    For catch-up: fat-soluble toxins can accumulate in the bodies of organisms such that at every step of the food chain, the concentration is multiplied. It's not just a single species accreting the toxin, but what happens when its predators are eating from this concentrated source. Any links up the food chain up to the apex predator are going to have a multiplied effect, which is why a seemingly insignificant amount of mercury pollution versus the ocean's volume has made tuna consumption a point of caution.

    We are seeing radiation levels that could be a bit of a concern and the Fukushima situation is still not under control. And are some of the compounds it's emitting bioaccumulative? Yes, Cesium 137 for example, and that has a half-life of 30 years. And the first thing you should do is move your consumption as far down the food chain as possible. Even if you don't plan to go vegan, learn Indian cooking or a low-meat cuisine, because the less animal product you're consuming, the better.

    Sources:
    http://www.ncbi.nlm.nih.gov/pubmed/11482657 [nih.gov]
    http://www.marietta.edu/~biol/102/2bioma95.html [marietta.edu]
    http://science.jrank.org/pages/854/Bioaccumulation.html [jrank.org]
    http://www.businessinsider.com/san-francisco-rainwater-radiation-181-times-above-us-drinking-water-standard-2011-4 [businessinsider.com]

    • by sl3xd (111641)

      Bioaccumulation doesn't really apply - radioactive isotopes aren't fat-soluble toxins.

      Radioactive isotopes are water-soluble - often highly so.

      Of the main contenders from a nuclear plant:

      Iodine: Is excreted via urine (like any other mineral). Not a real candidate for any meaningful analog of bioaccumulation, as its half life is so short. It still causes damage while in the body, but it'll generally only be the first or second ingester that is affected; after that, Iodine will have broken down.

      Cesium: A

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