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Power Technology

MIT Designs Tsunami Proof Floating Nuclear Reactor 218

Posted by samzenpus
from the riding-the-waves dept.
First time accepted submitter Amtrak (2430376) writes "MIT has created designs for a nuclear plant that would avoid the downfall of the Fukushima Daiichi plant. The new design calls for the nuclear plant to be placed on a floating platform modeled after the platforms used for offshore oil drilling. A floating platform several miles offshore, moored in about 100 meters of water, would be unaffected by the motions of a tsunami; earthquakes would have no direct effect at all. Meanwhile, the biggest issue that faces most nuclear plants under emergency conditions — overheating and potential meltdown, as happened at Fukushima, Chernobyl, and Three Mile Island — would be virtually impossible at sea."
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MIT Designs Tsunami Proof Floating Nuclear Reactor

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  • by The123king (2395060) on Thursday April 17, 2014 @07:09PM (#46783819)
    They power nuclear subs, nuclear icebreakers etc. Stick a transformer on it and connect it to the grid, Bingo, floating nuclear power plant.
    • Those are tiny next to land based nuke plants.

    • by CrimsonAvenger (580665) on Thursday April 17, 2014 @07:13PM (#46783853)

      They power nuclear subs, nuclear icebreakers etc. Stick a transformer on it and connect it to the grid, Bingo, floating nuclear power plant.

      More to it than that. The overwhelming majority of the power for a nuclear sub/icebreaker/etc is used to make the props go roundy-roundy.

      Only a very small part of that power goes to drive the generators (note that nuclear powered ships/subs HAVE been used to provide emergency power to shore installations, by the by).

      And since the generators are sized for the amount of power needed by the boat/ship, you can't just push more steam through them to get more power.

    • by Darinbob (1142669)

      Those also sink. As do oil drilling platforms. Sure the tsunami or earthquake won't destroy them but that doesn't necessarily make them safer than if they were on land.

      • Subs are designed to sink.

        Its part of their mission.

        There was a british nuclear sub involved in the search for MH370
        I don't know if its still on the case, given that no more pings have been heard, and they expect the batteries of the black boxes to have run out by now. A nuclear attack sub has good passive sonar, great for detecting other sound, but not useful at looking at the ocean bottom for wreakage.

        • by necro81 (917438)

          Subs are designed to sink.

          Its part of their mission.

          Don't be a dolt. Submarines are designed to dive, not sink. Sinking is, more or less, a one-way trip, whereas diving is reversible. If subs sink, they and their entire crew are lost.

          Since you've never been in a submarine (your post makes that obvious), I'll bet you've at least seen a movie or two with a submarine in it. When it's time for the boat to go under the water, the captain says "Diving Stations!" "Make ready to dive!" or simply "Dive

  • WHAT COULD GO WRONG? (Score:5, Informative)

    by Jeremiah Cornelius (137) on Thursday April 17, 2014 @07:11PM (#46783827) Homepage Journal

    It's perfect! Unsinkable? Unthinkable!
    No Homer will ever be allowed, and all the regulators will be objective and unbowed!

    • No Homers but we can still have one.

      Can't wait for nuclear sharknado to come out

    • by icebike (68054)

      It's perfect! Unsinkable? Unthinkable!
      No Homer will ever be allowed, and all the regulators will be objective and unbowed!

      Plus its SO much easier to deal with disasters at sea [al.com] and we have such a good track record in doing so.

    • Since when is sarcasm informative?
  • by muecksteiner (102093) on Thursday April 17, 2014 @07:16PM (#46783867)

    Compare the relative frequency of major hurricanes/typhoons to that of major earthquakes. Add to that the various potential problems that any floating structure has (springing a leak and sinking comes to mind here).

    Then, consider that in Japan, the nuclear plant closest to the quake epicentre actually survived unscathed. Because the people designing it did not stick with the minimum legal specs for the seawall height like the geniuses at Fukushima had, but did some research on their own. And simply made the seawall much higher.

    Conventional plants are not that bad, if they are designed by competent people. If you put them on barges, though, as these dudes are proposing, you are just adding to the potential failure modes, while not avoiding any that are impossible to handle. Not a good thing.

    • The single largest contributor to nuclear reactor safety, or more precisely the lack thereof is that the overwhelming majority of the ones currently in operation were built decades ago from designs dating back 50+ years. The engineers of my grandparent's generation did wonderful work for their time, their understanding and their available technology. But to continue to rely upon BWRs [wikipedia.org], especially ones built so long ago is the folly and the reason nuclear power gets the reputation it does.
      • by AmiMoJo (196126) *

        No current designs being manufactured address the problems that affected Fukushima. Okay, you have a limited amount of passive cooling, but eventually you still need power. Worse still the passive coming is only rated for earthquakes orders of magnitude smaller than the Tohoku one. Confusion on the ground can still lead to the same kinds of mistake, like closing the wrong valve or not venting hydrogen properly.

    • by OneAhead (1495535) on Thursday April 17, 2014 @07:58PM (#46784159)

      Because the people designing it did not stick with the minimum legal specs for the seawall height like the geniuses at Fukushima had, but did some research on their own. And simply made the seawall much higher.

      Yeah, and then once the water came over the seawall, the inevitable mayhem was exacerbated by:
      * A lot of the electrical equipment needed to get the pumps up-and-running again being under the waterline and not sealed, so flooded and water-damaged
      * The backup generators being placed in a vulnerable position
      * The containment being an obsolete design, based on engineering principles that have long been discredited (but hey, there are many of those still up and running in the USA)
      * Common "bugfixes" to mitigate some of the known weaknesses of the design (valves and stuff) not being implemented
      * The spent fuel pools not being very well contained, and pretty full (endemic in the industry)

      Hindsight is 20/20, but my point is, the industry can be made a whole lot safer just with some simple fixes, not to even mention newer designs that have passive cooling capabilities. If it would not have been dismissing its critics for decades, something this accident would never have been this bad, and the industry's future would not be threatened by public outrage. In line with what parent said, Fukushima Daiichi comes close to a "man-made disaster".

      Conventional plants are not that bad, if they are designed by competent people. If you put them on barges, though, as these dudes are proposing, you are just adding to the potential failure modes, while not avoiding any that are impossible to handle. Not a good thing.

      To be honest, TFA is a lot better thought-out than a nuclear-plant-on-a-barge, but even so, it remains a monstrosity that gives me the creeps just looking at the CGI.

      • > Fukushima Daiichi comes close to a "man-made disaster".

        Not close, entirely. Every one of those reactors could have been safely shut down except for man-made decisions that added to the problems.

        Reactor 1, for instance, would almost certainly not have melted down if the isolation condenser had been turned on and left on through the entire event. But the operators started second guessing themselves, and turned it off thinking it was out of water. Not that running out of water was a bad thing, you see the

        • The bigger problem is that ALL REACTORS ARE RUN BY HUMANS and the track record for their response to major disasters is not great. Sometimes people do the right thing, in fact most of the time, but many opportunities exist for disaster, and a statistically significant amount of the time responses fail. Furthermore there will always be greedy and unmotivated operators cutting costs like TEPCO. I have no reason to believe that Entergy for instance (a major US operator of nuclear power plants) is any better th

      • I actually like the concept a lot. But I agree that there is some potential for fallout here:

        Having a replacement for Fukushima is one thing, but a world of these going wrong could be a real problem. A majority of the world's oxygen comes from phytoplankton in the ocean: killing them in mass via radioactive leaks might actually create a credible climate disaster.

        Not likely that all of the world's reactors would start spilling simultaneously, but the only thing about this that gives me pause. Otherwise, t

  • by hamburger lady (218108) on Thursday April 17, 2014 @07:20PM (#46783903)

    then a huge rogue wave hits it. aw shiiiiiiiiiiit

  • While it might be moored out at sea, it would have to be built in a much different way to avoid the possible dangers from a hurricane tipping it over or making it unstable.

  • She was unsinkable - right up until she sank. So when this platform gets floated off its mooring by a tsunami or whatever, how will we be sure it doesn't sustain damage sufficient to cause it to sink?

    Of course, it might save a couple hundred square miles of land from being contaminated - but contaminating thousands of square miles of ocean doesn't seem preferable to me.

    • Or more to the point, what happens if it breaks its moorings and floats up onto a beach? It's easy to pump out oil from a grounded supertanker. Removing a nuclear reactor is a whole new kettle of fish
    • Solution: sink it in advance of nature doing the job. i.e. SSNs without the propulsive and weapons systems.
    • We can make unsinkable objects. The problems with the Titanic were mostly because the designers were incapable of modeling the behavior correctly because they had no computers and human calculations powering a finite element method is expensive to say the least. It had been done for at least one project, the Afsluitdijk in the Netherlands, but against extreme cost.
      Nowadays we have computers that can model such a problem with an accuracy those designers could only dream of.
      Also, we learned that watertight bu

  • How about we build nuclear reactors underground? The thing may get buried, but even that should help to contain rather than spread the contamination.

    Just spitballing here. Feel free to flame away and tell me all the reasons why this can't ever be made to work. IANANE.

    • Re: (Score:3, Informative)

      by Anonymous Coward

      subsurface water carries the contamination away, contaminating water supplies forever and at an ever increasing distance. yucca mountain was one of the rare places where that was not true.

      • by mmell (832646)
        Damnit, you're right. Oh well.
        • by MrKaos (858439)

          Damnit, you're right. Oh well.

          No, the AC is wrong. Yucca mountain has ground water issues that affect the storage of the material. CSIRO research showed that groundwater issues are mitigated by granite storage which can capture the isotope in its structure. DOE itself called for 'defence in depth' and it's own report judged Yucca to be unsuitable as groundwater penetrated the facility in as little as 50 years.

    • by Chas (5144)

      How about we build nuclear reactors underground? The thing may get buried, but even that should help to contain rather than spread the contamination.

      Just spitballing here. Feel free to flame away and tell me all the reasons why this can't ever be made to work. IANANE.

      It's not that crazy. A lot of the new small reactor designs call for burying them.

    • by MrKaos (858439)

      How about we build nuclear reactors underground? The thing may get buried, but even that should help to contain rather than spread the contamination.

      Just spitballing here. Feel free to flame away and tell me all the reasons why this can't ever be made to work. IANANE.

      This was one of the main recommendations (amongst 30 or so) from a Nuclear industry panel (Westinghouse, General Electric, Bechtel, Sargent & Lundy, Northern States Power and Commonwealth Edison) commissioned by the NRC. These should have been included in standardised Nuclear power station designs like the AP-1000, however they made the plants more expensive.

    • by rossdee (243626)

      How about we use the nuclear reactor that is already undergound (in the center of the earth.) That natural reactor has kept the mGM molten for more than 6 bi;;ion years, we are not going top run out of that energy any time soon.

  • NIMBO! (Score:4, Funny)

    by mythosaz (572040) on Thursday April 17, 2014 @07:34PM (#46784007)

    Not in my back ocean!

  • It was said that it's impossible for land based Nuclear reactors to melt down, so "virtually impossible" can't be impossible enough.
    • and we can one so bad it an China Syndrome

    • Who told you that lie? Several reactors have suffered a melt down / loss of primary containment event where fuel slumped to the bottom of the pressure vessel and burned through. TMI is an example of such an event. This was always a possibility in Generation II PWR and BWR designs. It's one of the reasons we need to be building Generation III+ replacements.
  • with modern design.
    What about the issue of getting the electricity to shore.
    Remember, when these reactors were design. plate tectonics was new.

  • Couple problems (Score:5, Informative)

    by Solandri (704621) on Thursday April 17, 2014 @08:18PM (#46784285)
    Mind you, I am pro-nuclear.

    Meanwhile, the biggest issue that faces most nuclear plants under emergency conditions â" overheating and potential meltdown, as happened at Fukushima, Chernobyl, and Three Mile Island â" would be virtually impossible at sea."

    Simply being at sea doesn't prevent the cooling problem. Remember, Fukushima was right on the ocean. The problem is that the cooling system has to have at least two loops. An internal loop of coolant (usually water, though salt has also been used) actually travels inside the reactor. Consequently it picks up some residual radioactivity from being exposed to all those neutrons flying around. You cannot just use this single loop for cooling, or else you're releasing this radioactive coolant into the environment.

    A second external loop of coolant cools the internal loop via a heat exchanger. This external loop picks up nowhere near as much radioactivity, and the coolant (water) is safe to dump back into the environment.

    If it were just one loop, you could come up with a clever design using thermal expansion to make the water flow through it to provide passive cooling in the event of a pump failure. But with two loops (and the inner loop being closed), you're pretty much reliant on active pumping to remove heat from the reactor core. The problem at Fukushima was that power to these pumps failed, and backup generators designed specifically to supply power in that scenario were flooded and their fuel source contaminated.

    I don't see how putting the plant on a floating platform helps in this scenario, unless you're willing to open up the primary cooling loop to the environment and just dump water straight into the reactor (with the resulting steam carrying both heat and radioactivity out). Which was pretty much what they ended up doing at Fukushima. If they'd done it before the cladding on the fuel rods melted, we'd only be dealing with a small amount of radioactive water (deuterium, tritium, etc) being released into the environment as steam, instead of fission byproducts being directly released. So I don't see how being by vs on the ocean makes any difference for this scenario.

    Maybe you could design the steel containment sphere to act as a heat sink, allowing sufficient cooling when submerged? But the containment's primary job is to contain what happens inside. That's why it's a sphere - it encloses the largest volume for the least amount of material and surface area, and its mechanical behavior under stress are very easy to predict. This is precisely the opposite of what you want from a heat sink. You want the most surface area for a given enclosed volume. Which makes me suspect that the steel containment could only operate as a heat sink if you're willing to compromise its protective strength somewhat.

    The other problem I see is that putting it out at sea hinders accessibility. Meaning more mundane events like a fire, which are trivial to handle on land, become much more problematic at sea.

    • There was a drawing visible in the video for about 10-15 seconds. Mind you, it's not a lot to go on... The reactor itself was shown below the water level. The design appeared to be similar to designs I've seen which use passive convection cooling. In addition to that, the outer containment was labeled as "flooded with sea water" or something to that effect. To your other point, the shape of the outer containment was a cylinder. The appearance was similar to some Generation III+ designs that flood the
  • Everything I need to know about energy logistics I learned from Sim City 2000.

    You put the plants / reactors away from the city, out in the water, so that pollution doesn't bother folks and if there's an explosion, nothing else catches on fire. The cost of maintaining the power lines is far less than additional rebuilding costs after a disaster strikes and the plant blows. I guess next they'll discover it's fucking egregiously foolish to zone schools and residential next to industrial plants. [wikipedia.org] In this case

  • Considering how badly infested stationary ocean objects can become with various types of sea life, and how much maintenance it takes to keep a small sailboat from corroding and suffering general mechanical failures due to both of the above, I wonder at the amount of maintenance required to keep one of these in operation.

  • What could possibly go wrong?

    http://www.cnn.com/2014/01/24/... [cnn.com]

    Rat-infested nuclear Cherynobyl.

  • So what about Tsunamis? What if a giant rock or snowball from outerspace hits it at upwards of 17000 miles per hour?

    Better not worry too much, just chill out to some smooth, rolling basslines from the 1970s [youtube.com], man.

    I think it's going ro be a long, long time...

    • Yeah.... about that. It won't matter much where the reactor is located if "a giant rock or snowball from outerspace hits..." and creates a tsunami. You think Fukushima was bad, wait till the giant tsunami you speak of inundates coastlines across three or four continents.
      • by phayes (202222)

        Indeed. There hasn't been a single death attributable to the Fukashima meltdown, and thousands were killed by the Tsunami, yet somehow some people still think that the reactor is the big problem...

  • by gweihir (88907) on Thursday April 17, 2014 @09:03PM (#46784541)

    Like, say, placing the emergency generators on the hills right next to it, nothing bad would have happened. Of if they had spend the extra $100.000 that would have cost for hydrogen valves, the buildings would not have exploded.

    The problem is not that nuclear cannot be made safe. The problem is that the people doing nuclear cannot make it safe. And as these are also the people doing waste storage, this will remain a serious issue for the next, say, 1 million years or so. The combination of greed and stupidity found in nuclear planners is absolutely staggering.

    • There was enough money involved to attract management with plenty of political skill to get the good jobs but no background on what they are attempting to manage. That has led to a cycle of needing a unmistakable disaster with each generation of management or they forget their responsibilities. TMI was the perfect one since it was an obvious fuckup with little consequence, but it was too long ago for anyone other than engineers, technicians and other non-horse judges to take seriously. Chenobyl gets writ
    • by gnupun (752725)
      Well, hindsight is 20/20. Can you can guarantee that the design of the next reactor using smart and cautious engineers won't blow up or cause damage? No! There's also the problem of dumping nuclear waste. I think the harm caused by coal is less than that caused by a nuclear reactor incident and the risk of maintaining a reactor is totally not worth it.
  • The Integral Fast Reactor (IFR) design (state of the art 1986) shuts down safely in the event of a sudden, complete power failure. It uses nuclear waste as fuel, reprocessing until there is orders of magnitude less long life nuclear waste than with a light water reactor, the design they propose to float. IFR is an inherently safer design that largely solves our nuclear waste problem. Why are we dreaming of ways to build more light water reactors?
    • by dbIII (701233)
      What happened to the IFR is a very good example of the US nuclear industry eating it's own children and why you are not going to get anything as good as it without buying it from India or cleaning up government corruption.
  • ... by Korean shipbuilder ...... Hmm. On second though .....

  • "would be virtually impossible at sea."

    Ah, use of those famous last words I see......

  • Another option to not run out of water is to just have the thing downhill from a large permanent lake.
    Putting something out at sea and sacrificing containment for the sake of reliable cooling water seems to be ignoring that there is more than one possible mode of failure. It also means that the thing can never be mothballed but instead needs to be actively dismantled at the end of it's life - not a trivial task when there would be a great deal of radiation involved in many parts being demolished.
    However wh
  • One of the biggest expenses I hear about when someone is building a new nuclear reactor is the zillion lawsuits that spring up. I imagine a fair amount of these could be avoided if the physical structure was built in a different country from the one adding the fissile material. Or, even in the same country, people would be less likely to try to stop construction because if it's a good reactor and people stopped you from using it, you could probably sell it to someone else who is willing to use it. I imag
  • Chernobyl would not have been prevented by putting the reactor in water. It was the only accident which had a "nuclear power excursion" as the reason. TMI and Fukushima were a failure of the classical cooling.

    In Chernobyl the operators ignored the normal precautions. They operated the fuel in a state where xenon (see http://hyperphysics.phy-astr.g... [gsu.edu]) was present. Due to this the system was far away from the assumed stable oprtion point assumed in the controls.

    The power which you would have needed to dissi

  • Back in the 1970s, General Electric created a company called Offshore Power Systems that was intended to build floating nuclear plants. I knew some of the people who worked there.

    No such plants were ever built, though, and OPS is long gone.

  • Using seawater in the secondary cooling loop makes maintaining the cooling system a nightmare because seawater's rather corrosive.

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