Japan: New meltdown fears at second reactor; how much radiation has been released in Fukushima crisis?


A spokesperson for the Japanese government says authorities are presuming that "possible meltdowns are under way at two nuclear reactors" at this hour.

Chief Cabinet Secretary Yukio Edano told reporters there is a "possibility" of a meltdown at the plant's No. 1 reactor, adding, "It is inside the reactor. We can't see." He then added that authorities are also "assuming the possibility of a meltdown" at the facility's No. 3 reactor.
A third reactor at the Fukushima #1 power plant in Japan has lost its emergency cooling functionality. Now, six total reactors have failed at two Fukushima nuclear power plants since the earthquake and tsunami hit.

BBC News overview here.

Mainichi News reports that at least 15 people have been hospitalized for radiation exposure. At the time of this blog post, NHK television is reporting a slightly higher count: 133 evacuees have been tested for radiation exposure, 19 of them have confirmed contaminated. First responders are also distributing Iodine tablets to potentially affected populations.

Japan's Kyodo news agency reports that radiation levels have risen above the legal safety limit around the No. 1 Fukushima plant, and the matter is now considered an "emergency situation."

Asahi Shimbun reports that Japan's central government has declared a state of emergency at the No. 2 Fukushima nuclear power plant, which sits about 8 km south of the No. 1 Fukushima plant where the previous explosion occurred.

A state of emergency had been declared for the No. 1 plant the previous day. Residents within 10 kilometers of the No. 1 plant were told to evacuate. Traces of radioactive cesium were confirmed around the plant in an inspection.

But how much? And how far out does the risk of radioactive contamination reach?

William Broad writes in the New York Times:
The different radioactive materials being reported at the nuclear accidents in Japan range from relatively benign to extremely worrisome. The central problem in assessing the degree of danger is that the amounts of various radioactive releases into the environment are now unknown, as are the winds and other atmospheric factors that determine how radioactivity will disperse around the stricken plants.

But the situation is not good, and as more data becomes available, the news isn't improving.

Here's an updated NYT overview on efforts to prevent a greater crisis at the Fukushima plants, now that a second reactor has failed.

In just the past few hours, Tokyo Electric Power Company (TEPCO, the company that operates the nuclear plants in question) has started releasing air from a reactor container vessel at the plant's No.3 reactor.

In this AP article, some possible next-step scenarios if these current efforts to cool down the reactors fail:

If the reactor core became exposed to the external environment, officials would likely began pouring cement and sand over the entire facility, as was done at the 1986 Chernobyl nuclear accident in the Ukraine, Peter Bradford, a former commissioner of the U.S. Nuclear Regulatory Commission, said in a briefing for reporters.

At that point, Bradford added, "many first responders would die."

Don't miss Boing Boing science editor Maggie Koerth-Baker's "explainer" on how nuclear power plants work: "Nuclear energy 101: Inside the "black box" of power plants".


  1. uh… “A third reactor at the Fukushima #1 power plant in Japan has lost its emergency cooling functionality.” vs TFA: “The utility supplier notified the government early Sunday morning that the No. 3 reactor at the No. 1 Fukushima plant had lost the ability to cool the reactor core… The disaster raised fears over radioactive leaks from the plants after cooling systems there were hampered, most seriously at the No. 1 reactor.”

    I didn’t see mention of any reactor other than #1 having a cooling issue, the #3 reactor seems to be the *second* reactor to lose cooling at the Fukushima #1 power plant.

    1. TFA:

      “Another nuclear reactor at the Fukushima No. 1 facility in Japan has lost its emergency cooling capacity, according to the Associated Press, bringing to three the number of reactors at that facility to fall prey to Friday’s magnitude 8.9 earthquake and tsunami. Added to failure of three reactors at Fukushima No. 2, the count is now six overall.”

      LA Times synopsis of most recent AP reports.

      1. AIUI:

        6 reactors have lost cooling capabilities so far
        2 reactors have begun venting (radioactive) steam as a result of excessive temperatures

        All are worrisome, but the latter much more so than the former, as shutdowns had been initiated at all reactors and so in theory would eventually cool down on their own. The need to vent steam indicates the rate of slowdown of reaction isn’t keeping up with the accumulation of heat, which would be the real problem. If the reaction in a reactor is slowing down quickly enough that heat doesn’t build too much, the lack of active cooling shouldn’t be a major issue.

        Again, that’s all as I understand the news reports and other sources (including Maggie’s very informative article). I’m not a nuclear scientist. :p

    1. Non-sensationalized maybe. Unbiased? Obviously not.
      This incident is horrible, terrible, sad, scary, all sorts of things.
      But it definitely also is sensational.

      My senses tell me so.

    1. The NEST team isn’t for this type of nuclear emergency. They are for events involving terrorist weapons, improvised or otherwise, on U.S. territory. Or do I misunderstand you, and you believe these aren’t really reactors but rather terrorist weapons, and that the FBI has jurisdiction in Japan so therefore could call for a NEST team?

      You might read the following document to clear up your misunderstandings.


  2. ironically at least one of the reactors was scheduled to be shut down this month.(according to wikipedia). What I’d like to know is what happens to the seawater that they’re using to cool these reactors. Does it turn into steam? does it go back to the ocean? into the ground? I’m assuming it becomes radioactive but just how radioactive?

  3. Maybe it’s just my inner evil overlord talking, but why aren’t nuclear plants dug into mountains or at least buried underground? Obviously, there’s the cost issue, but even if they just put an artificial hill over it, it’d make the whole thing a lot harder for radioactivity to get out of.

  4. Good thing nuke plants are immune to earthquakes. Just place them far enough inland and you then solve the tsunami problem too. For some great quotes on how safe nuclear energy is try reading this.

    1. FTA: “100 times .01 is still less than smoking a pack of cigarettes every day.”
      Yes, 100 times .01 is 1.0 What does that have to do with anything? We’re having a 2000.0 ,or so, issue.
      Do you nuke fans live in an alternate reality?

  5. It’s all about decay heat removal. That is the one term no one is using. Nuclear fission, or the splitting of uranium atoms in this case, produes lighter, more often then not, unstable isotopes of every day elements. These elements undergo various beta minus, alpha, and beta plus decays, giving off heat in the process. A reactor will continue to generate heat long after it is shut down, with the fissioning at a minimum but a large percentage of decay heat produced at some fraction of the highest power reached of its total power output. I work on reactors daily, and the levels of radiation here are low, such that you probably get more exposure handling fertilizer all day then you would standing next to the reactor containment. But really, it is Decay Heat of the fission products and everyone is trying to get Decay Heat removal methods working, and seawater is definitely a last resort. The water used in a reactor plant has to be of certain pH, conductivity, certain concentrations of certain compounds, etc. It is very pure water, and to add seawater, with all the ions and stuff in seawater, it is the worse kind of water to put into a plant, built with exotic metals and materials that are rarely seen outside of these applications. I would be worried that the ions in the seawater will be activated, producing more contaminated water. But no, this water should not be dumped back out in to the ocean. If anything, stuff like this is dumped >50 nautical miles out, “Dilution is the solution.”

  6. I’m getting increasingly frustrated with all this talk of “radioactivity” escaping. That’s an abstract noun… I’d much rather be told which radioisotopes have escaped, because this makes an enourmous difference to how serious this is, how long things will remain contaminated and what is actually happening in the reactor.

    I’m especially confused about them giving doses of iodine. This is usually done to avoid radioiodine collecting in the body, by making sure the body has more than enough iodine already. As far as I can see, the vented steam should not contain radioiodine, since it’s supposed to be composed exclusively of the products of neutron-activated water. I-131 is a uranium fission product. If these people really need iodine supplements, they’ve been exposed to material from the fuel rods.

    I hope it’s just somebody’s knee-jerk “iodine treats radiation” response.

  7. a 8.9 is like 1000x stronger than a 7.9 (correct me if i’m wrong) so here’s the headline you’ll never see

    “reactor survives quake 1100x above its design limit”

      1. NO, No, no! Don’t just throw around numbers unless you know what you’re doing. The moment magnitude scale and the Richter scale are base-10 logarithmic scales. The correct answer is that 8.9 is 31.6x stronger than 7.9. The formula to use is:


        If there was a 2.0 difference in magnitude, than there would be a 1,000x difference.


  8. Things are definitely bad, but not a disaster. I’m really getting sick and tired of nimrod reporters calling it another Chernobyl – BECAUSE IT AIN’T. I know nuclear scientists, my father was a nuclear engineer, I’ve spent a lot of time with amateur fusion experimenters, and they know a bit about the subject.

    It is fundamentally impossible for a Chernobyl-level event to happen. Chernobyl had *no* containment whatsoever, and a design that would get hotter if the cooling system failed. Even though the Fukushima #1 reactor is 40 years old, it has the containment to keep it from turning into the Soviet catastrophe. There will be venting of radioisotopes – there is no avoidance of that, at this stage. Every day after shutdown, however, the cores will get cooler and cooler, and the danger level of a full core melt goes down.

    Look, people – if they were going to go Chernobyl, they would have already! The introduction of seawater means they’re writing off any further use of the reactor, since there is no way in hell you can get a reactor vessel recertified after doing that. Too much corrosion. Worst case scenario now is that the cores melt and settle in the bottom of the containment vessel. You then put a concrete cap on it and clean it up in 40 years when the radiation has gone down to just above background – like the Windscale fire – http://en.wikipedia.org/wiki/Windscale_fire – which is just about completely decontaminated. 50 years later.

    The biggest problem with nuclear power is the fear of cancer – “OMG a leak will kill everyone with cancer!!!”. Although a real concern, short of a truly idiotic series of events, the risk of a massive release of radioactive material into the environment is minute. And everyone who works with nukes work with an abundance of caution. Is it nasty? Yes. Maybe we should be more aware of the dangers of living our highly electrified life, and the toxic industrial waste we have to generate to keep our houses brightly lit and perfectly climate controlled.

    P. S. – every coal plant in the country emits more radioactive material in its smokestack than nukes do. But don’t let that get in the way of the fearmongering.

  9. #
    1125: Worrying news, this: The operators of the damaged Fukushima nuclear plant say it’s possible that cooling water at one of the reactors has evaporated, Reuters reports. The company says it can’t rule out the possibility that the nuclear fuel rods in Number 2 reactor were now exposed and could be at risk of meltdown.

    BBC live

    time stamp 20:38 Japan time

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