Japan’s Nuclear Problem

Pouring seawater in means these power stations are done! That, of course, is the least of anyone’s concern.

Seawater. That was the scare word for me. Reuters reported

Tokyo Electric Power (TEPCO) workers on Sunday were pouring seawater into two reactor cores at the coastal Fukushima Daiichi power plant and were considering using seawater on a third. Authorities have been forced to vent radioactive steam into the air to relieve pressure in the plant and reactors at the company’s nearby Daini plant are also troubled.

Pouring seawater in means these power stations are done! That, of course, is the least of anyone’s concern.

“I am not aware of anyone using seawater to cool a reactor core before. They must be desperate to find water and the seawater was the only thing nearby,” said Richard Meserve, former chairman of the U.S. Nuclear Regulatory Commission

Nuclear power is enticing. When it works well it works really well. Electricity produced at nuclear power plants normally comes with little environmental impact. Here’s the icing on the cake: The Department of Energy says after all costs are taken into account nuclear generation costs half as much per kilowatt hour than conventional fossil fuel plants! That’s a big deal.

Of course when nukes go bad the downside is catastrophic. The devastation Japan has already seen might be just the beginning.

Nuclear power production is similar to conventional power production: steam powers turbines. The heat that produces the steam comes from nuclear fission.

Here’s the rub. The fission must be kept under control otherwise the nuclear fuel will get very hot. We’re talking thousands of degrees hot!

If left uncontrolled temperatures can rise high enough to melt the radioactive fuel rods and breech the reactor vessel and containment structure. That would release uranium and it’s byproducts into the environment.

After Chernobyl the Russians were forced to permanently evacuate a sizable radius around the power plant. That’s already happened at least temporarily in Japan.

Using seawater to try and cool the reactor has been described by one expert as a “Hail Mary pass.” Hail Mary passes usually don’t work.

16 thoughts on “Japan’s Nuclear Problem”

  1. Seems they have decided to use seawater in the hopes they can delay a meltdown long enough so they can fix any damage inside the reactor as well as getting the cooling mechanisms fixed. Which in theory should work if the process is not too far along already, the thing with seawater is that its highly corrosive so eventually the seawater will just add to the problem…it’s a quick fix at best but it’s better than nothing…

  2. It’s unfortunate that generators failed and heard that Reactor #3 is more dangerous than #1 because it is a MOX (Mixed oxide) reactor. It has a greater chance of melting down.

  3. I found this yesterday and it was (pardon the pun) illuminating:
    “An article written by someone who actually knows something about nuclear plants:”


    Comparisons to Chernobyl aren’t good since it’s apparently better designed. And, according to this, the vented “radioactive” steam was only radioactive for seconds or minutes due to the isotopes involved. I’m not a nuclear physicist, but ts article has been picked up and re-posted several times now, by people who know more about this that I do.

  4. Nuclear power is a good thing but one must question the wisdom of building such plants on a coastal area in a region prone to both earthquakes and resulting tsunamis.

  5. It looked like there were “breakwaters” installed in front of the plants offshore to protect the plants from high waves. Maybe if they had installed higher breakwaters, say 30 foot, they could have prevented the damage to the plants. Higher breakerwaters and maybe a “seawall”or two. So much money spent on plants and not much to prevent a huge wave from causing a disaster.

  6. I wonder if the fuel rods can be pulled by some mechanical means, or whether the whole thing is damaged beyond that point. This is not pretty. I hope we don’t get to see whether the term “China Syndrome” is accurate.

  7. OMG Goeff,

    They just said at 11:53 am on Foxnews.com that they had another failure of the seawater messure and can no longer rule out a meltdown ! -Dave

  8. This is really Scary now. I thought I heard someone, (Though I can’t place a name or website that I heard it from) that if the Containment Houseing around the cores do not hold that it would go into the Atmostshere and prevailing winds could carry it close to the west coast here. We need to pray for the people of japan, this could be a disatrrous event for life and limb for them above what they already have endured. They really need a break.

    1. Relax, the situation in Japan is serious, but as serious as the hysterically hyperventilating talking heads would like you to think… First let me preface this by saying I am not an expert in nuclear power, so this is going to be a quick and dirty explanation of what’s going on Japan.

      1) The reactors at Fukushima Daiichi are shutdown, meaning the control rods are in place shutting off the nuclear reaction.

      That doesn’t mean the reactor immediately goes cold there is still something called “decay heat” which comes from traces of other radioactive isotopes that has to dissipate. It typically takes a week or more for happen. Which from all reports is what the Japanese are dealing with, the problem here that is that the earthquake and tsunami apparently knocked out both the primary and secondary cooling systems so the operators aren’t able to keep enough water circulating through core to keep it from overheating while the decay heat dissipates.

      2) None of this amounts to “another Chernobyl.” First the reactors in question are completely different designs. The Russian reactor used graphite instead of water to “moderate” the neutrons, which is what makes nuclear reaction possible. Second the Chernobyl reactor had no containment structure so when the graphite caught fire and burned for four days there was nothing to contain the radioactive smoke that spread across a wide area.

      3) Don’t let the talk a “meltdown” unnerve you… This isn’t widely known but, the core did melt down at Three Mile Island and remained contained within the reactor vessel. In order for oft mention “China Syndrome” to occur the molten mass of the melted core would burn its way trough the reactor vessel — roughly 8-10 inches of steel and through the secondary containment pad roughly 10-30 feet of concrete. I won’t say it’s impossible, but it’s unlikely.

      Assuming they can restore the cooling system and enough water circulating through the core this will turn out to be more media hype than actually disaster.

      I’d strongly recommend reading through this: http://bit.ly/dECfPm thread at Blackfive — Pay close attention to the comments from “Subsunk” and “grtflmark” and William Tucker’s op-ed “Japan Does Not Face Another Chernobyl” in today’s Wall Street Journal: http://on.wsj.com/fr47la

  9. Geoff, with this latest development, is there a potential risk for the United States…especially, West Coast,or Hawaii? Just wondering and you are so knowledgeable. Thanks

    1. Not at all, the situation in Japan is indeed serious and you’re right to be concerned. The situation on the ground quite as out of control as some news reports make it out to be.

      Here’s the latest update from the Nuclear Energy Institute:


      Radiation readings at the Fukushima Daiichi site boundary were measured today at a lower level, between 2 and 3 millirem per hour.


      Fukushima Daiichi
      The reactors at the Fukushima Daiichi plant are in stable condition and are being cooled with seawater, but workers at the plant continue efforts to add cooling water to fuel pools at reactors 3 and 4.

      The status of the reactors at the site is as follows:

      Reactor 1’s primary containment is believed to be intact and the reactor is in a stable condition. Seawater injection into the reactor is continuing.

      Reactor 2 is in stable condition with seawater injection continuing. The reactor’s primary containment may not have been breached, Tokyo Electric Power Co. and World Association of Nuclear Operators officials said on Thursday.

      Access problems at the site have delayed connection of a temporary cable to restore off-site electricity. The connection will provide power to the control rod drive pump, instrumentation, batteries and the control room. Power has not been available at the site since the earthquake on March 11.

      Reactor 3 is in stable condition with seawater injection continuing. The primary containment is believed to be intact. Pressure in the containment has fluctuated due to venting of the reactor containment structure.

      TEPCO officials say that although one side of the concrete wall of the reactor 4 fuel pool structure has collapsed, the steel liner of the pool remains intact, based on aerial photos of the reactor taken on March 17. The pool still has water providing some cooling for the fuel; however, helicopters dropped water on the reactor four times during the morning (Japan time) on March 17. Water also was sprayed at reactor 4 using high-pressure water cannons.

      Reactors 5 and 6 were both shut down before the quake occurred. Primary and secondary containments are intact at both reactors. Temperature instruments in the spent fuel pools at reactors 5 and 6 are operational, and temperatures are being maintained at about 62 degrees Celsius. TEPCO is continuing efforts to restore power at reactor 5.

      Fukushima Daini
      All four reactors at the Fukushima Daini plant have reached cold shutdown conditions with normal cooling being maintained using residual heat removal systems.

      They’re not out of the woods, but the contrary to some news reports the sky isn’t falling.

      1. Bah… that should read The situation on the ground is not quite as out of control as some news reports make it out to be.

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