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Thursday, November 17, 2011

Radioactive water at Fukushima Daiichi - new video

TEPCO has released the fourth, and final, video in its series covering the handling of contaminated water at Fukushima Daiichi. This series has been of particular interest to this writer; after the gravity of the entire accident scenario had become clear (or clear enough) one of the first real races against time was that involved with finding enough storage capacity for the water that was being used to cool the three damaged reactors, since it clearly was leaking out of the reactors and not only entering the reactor buildings but the turbine buildings and even outside pipeways ("trenches" in TEPCO's parlance.) From that point on, a number of simultaneous plans were launched to secure storage and to process this water and for quite some time it seemed as if the company were only a step or less ahead of the water buildup.

Quite the opposite is now the case, and in fact, even with the early growing pains that the water cleanup systems had, TEPCO appears to have mastered the situation. I have hammered this following point to death, but it bears repeating: While many accident scenarios have been played out and simulated in the past, even to the point of core damage and melt, none has done anything to educate the industry on the realities of a major accident like Fukushima Daiichi has. TEPCO and NISA are literally writing accident handling procedure as they're inventing it, and are implementing it immediately with only brief, but clear, analysis .. because time is of the essence. It is certain that much hindsight has been used by outside critics in regards to TEPCO's handling of both the accident and its releases to the press in the writing of critical pieces, but this again is hindsight after all and it's hard to imagine a better onsite and offsite performance by any other company.

General George S. Patton wrote something to the effect that "a workable solution applied vigorously is vastly superior to a perfect solution applied too late," and TEPCO has taken this kind of thinking to heart by taking the best possible solution for each problem that it could have soon, while also looking a bit down the road. This is exactly why, having two different purification systems, TEPCO continues to work on making the earlier, more complicated one work while it operates the second, slightly better (simpler) design which arrived on site much later. (TEPCO, as shown in the video, intends to install pumps between two of the Kurion system skids to avoid having to change the pumps that fail frequently on the second skid; these pumps are adjacent to the cesium adsorption tanks which have a high rad level at their surfaces, making pump changeout workers become rad sponges. The new pumps will get around this problem, and probably be better pumps.)

All that considered, please watch this video more than once. It goes by quickly enough that the real complexity of the onsite water transfer and storage job might come off too lightly; consider the size of this site, and look at the overhead plan showing just how much area the tank system is taking up and how widespread it is. This would be a very important thing to consider, at least briefly, for any nuclear plant site --- in other words, if this kind of thing ever did happen on site, would there be enough space for tankage of a magnitude in correct proportion to the number of plants at that given site? If there are enough acres, are they level? Much in this video makes one stop and think on the second viewing.


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7:25 PM Eastern Thursday November 17, 2011
ATOMIC POWER REVIEW

8 comments:

  1. This is a very informative video.
    It is worth viewing this after going through the reports and videos TEPCO has posted Nov 17 summarizing the efforts to control this disaster.
    http://www.tepco.co.jp/en/press/corp-com/release/11111701-e.html
    Overall, the documentation shows a very large effort on many fronts to try to bring this situation under control. TEPCO is indeed pioneering the practice of nuclear disaster recovery, with substantial progress made. Hopefully the horrendous cost will encourage a more clearer appreciation of the value of a belt and suspenders safety mentality.

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  2. > would there be enough space for tankage ...?

    And if so, would it be simpler to plan ahead by using that for solar panels and battery banks, and thermal concentrators and molten salt storage -- equipping each plant with for a solar flare grid-failure with a backup power source for plant cooling that would remain available to cover months-long outages?

    As cheap as solar is getting, every nuclear plant could be equipped to be capable of stand-alone months-long safe operation.

    Could be done before the next major solar flare.

    Cheaply. And if there's no flare? Extra power.

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  3. Someone on the ANS Social Media list was recently discussing the output from stored energy in molten salt and it was something ridiculously low, so that the power required to pump the molten salt would be as much as the salt had in it in the first place. The real deal is to get the EDG or gas turbine standby power equipment in as safe a position as possible, with guaranteed fuel and cooling.. and ensure that portable power generation is available no matter what within about an hour and a half or two hours.

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  4. > guaranteed fuel and cooling.. and ensure
    > that portable power generation is available
    > no matter what

    How well would guarantees and assurances work in this event? Not likely at all.
    http://ieet.org/index.php/IEET/more/brin20110416

    A cite for your source on the economics of using molten salt would be welcome; have you looked at
    what's published? http://www.osti.gov/bridge/product.biblio.jsp?osti_id=1022291#

    Not defending any single power source; just saying, as you point out, the need for acreage for handling waste water is now better understood, and the same acreage would could also support power sources above (PV) and below (mass storage) along with the water you've pointed out should be available before it will be needed.

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  5. @Hank... Geez, here we go again... YES, I've looked at what's published... a member of the ANS with a degree in nuclear engineering pointed out during a discussion that the storage capacity of molten salt in BTU/lb mass is not a sufficient storage capacity if you need to pump it to remove the heat from it... especially if you use very large masses. You might get plant support from it, but it's not like hydro plants that pump water up high to storage and then use water turbines to power the grid. Of course the molten salt proponents disagree, but since none of these is ever likely to be built we won't have to be let down by it.

    As to your statement about guarantees and assurances in the case of EMP pulse attack... You're getting a bit far out there.

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  6. > none ... is ever likely to be built

    Several have been in operation for some years, and more are being built:

    "Andasol 1 began in July 2006 and the plant became operational in March 2009. The construction of the second power plant began in February 2007 and started its test run in mid-2009 ...."
    http://www.power-technology.com/projects/andasolsolarpower/


    http://blogs.kqed.org/climatewatch/2011/11/29/solar-energy-what-to-do-when-the-sun-sets/
    and venture capital comments on molten solar at
    http://www.brightsourceenergy.com/technology


    >EMP pulse ... far out
    The EMP attack is cold war stuff, agreed.
    Solar flare isn't fiction; the sun is known to behave as described:
    http://news.nationalgeographic.com/news/2011/03/110302-solar-flares-sun-storms-earth-danger-carrington-event-science/

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  7. Re what's built,
    http://scholar.google.com/scholar?start=10&q=andasol+molten+salt+operation

    for example, now:
    http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=6035949

    Proceedings of the IEEE
    Volume: PP Issue: 99
    Molten-Salt Power Towers: Newly Commercial Concentrating Solar Storage
    DOI: 10.1109/JPROC.2011.2163739
    06 October 2011
    Abstract

    Molten-salt storage is already commercially available for concentrating solar power (CSP) plants, allowing solar power to be produced on demand and to “backup” variable renewable sources such as wind and photovoltaics. The first CSP plants to operate commercially with molten-salt storage utilized parabolic trough concentrators, for example, the Andasol-1 plant. A new type of storage plant has now reached commercial status, with the 19.9-MW $_{rm e}$ Torresol Gemasolar power tower, featuring 15 h of molten-salt storage, having come online in Spain in May 2011. Advantages of the power tower storage system include the elimination of heat transfer oil and associated heat exchangers, a lower salt requirement, higher steam cycle efficiency, better compatibility with air cooling, improved winter performance, and simplified piping schemes. Near-term advances in molten-salt power tower technology include planned up-scaling, with SolarReserve due to begin constructing a 110-MW $_{rm e}$ plant in Nevada by August 2011. Other advances include improvements to the thermal properties of molten salts and the development of storage solutions in a single tank. With these developments at hand, CSP will continue to provide dispatchable solar power, with the capacity to provide energy storage for 100% renewable electricity grids in sun-belt countries."

    Just sayin' -- none of us should rely on something claimed by some guy on a website who says something we intuitively think must be true (or not).

    Look this stuff up. What anyone knew or believed in the past isn't likely accurate _now_.

    Google Scholar isn't a bad alternative to memory.
    It's usually more up to date than what some guy remembers and posts.

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  8. @hank: Thanks for wasting a half hour of my life that I cannot get back. Now, can you possibly tell me which nuclear project in the United States is being built either A. Using molten salt as a coolant, thus having it available (theoretically) as a heat storage source or B. With a molten salt storage capacity for backup? If this technology is so mature, why is no one using it?

    I can answer that, but you'll spend another six weeks "looking things up" on Google instead of consulting engineers actually working in the field here in the United States, and then I'll lose another half hour. So let's stick to backup power technology for nuclear plants that is workable, available, and will be approved by the NRC and the owner-operators.

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