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Power Science

In Nuclear Power, Size Matters 230

PerlJedi writes "Most nations with nuclear power capabilities have been re-assessing the risk/benefit of nuclear power reactors following the Fukushima plant melt down, a newly released study suggests the U.S. should expand its nuclear power production using 'Small Modular Reactors'. 'The reports assessed the economic feasibility [PDF] of classical, gigawatt-scale reactors and the possible new generation of modular reactors. The latter would have a generating capacity of 600 megawatts or less, would be factory-built as modular components, and then shipped to their desired location for assembly.'"
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In Nuclear Power, Size Matters

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  • by denis-The-menace ( 471988 ) on Wednesday December 14, 2011 @02:14PM (#38372728)

    Should be using Thorium instead.

  • So you're going to increase the number of sites? I thought Not-In-My-Backyard was the reason we didn't just build more big nuclear reactors. You can make the designs as safe as you want -- hell, look at molten salt thorium reactors and the CANDU design. The problem is that the people living anywhere near it are going to be dead set against it. And Fukushima didn't help that image.

    Also I didn't see anything about this increasing the number of attack sites for anyone who wants to hit one of these things or steal it. That would be an increased risk factor, as well, right?

    From an engineering and economic perspective these things are probably great ideas. But what state or township is going to approve a nuclear power plant -- even a small modular one -- given unfortunate recent events?
  • by Trepidity ( 597 ) <delirium-slashdo ... h.org minus city> on Wednesday December 14, 2011 @02:15PM (#38372756)

    One thing favoring the big plants is that neighbors' opinion about nuclear power, at least in the U.S., often follows a pattern where initially putting one in is very unpopular, but once one is put in, as it brings jobs, seems to be safe, and unlike traditional industry doesn't pollute or produce bad odors, local popularity goes up. In fact when you poll people living near a major nuclear plant about the possibility of putting in a new unit, results are usually quite positive. So from a political perspective at least, that favors putting in a bunch of power generation in the same place: it's not worth going through the trouble of convincing the local population in each place only to generate 600 megawatts there.

    For these to work, I think we'd need a more widespread change where the default attitude towards being near a nuclear generating facility is positive or at least neutral. Then you could just scatter then around without much worry.

  • Re:Olds (Score:5, Interesting)

    by ColdWetDog ( 752185 ) on Wednesday December 14, 2011 @02:19PM (#38372814) Homepage

    A friend of mine was interning for a company that did a lot of work with these about 10-11 years ago. He was saying they were the big thing, back then. Lower risk, easy to setup/install, cheap due to mass production. Of course, he was stating they they wouldn't go above 100MW., which is a bit of a difference.

    Anyway, I'm surprised it's taken this long for them to see the feasibility in the idea. It really does make a lot of sense.

    And Toshiba has been trying to get it's small, modular 4S [wikipedia.org] reactors sited in nowhere Alaska for decades and hasn't been able to do it. Not gonna happen.

    The only way for this to work is, as mentioned in TFA, have the US government buy a bunch and test them out. Seems actually a fairly reasonable idea - the military has need of off grid power in odd places, has built in technical and security forces that should allow for safe evaluation of the reactors, has the money to do this. So, if this has been true for at least a decade, what's the problem? Whatcouldpossiblygowrong?

  • Toshiba 4S (Score:5, Interesting)

    by scorp1us ( 235526 ) on Wednesday December 14, 2011 @02:19PM (#38372824) Journal

    The Toshiba 4S [wikipedia.org] seems like it would make an ideal neighborhood reactor. Plus, I love the design. Rather than using control rods to stop the reaction, the reflector enables the reaction. By controlling the radioactivity of the core you ensure it can never get too critical. And the reflecting band even if it gets jammed only enables a small part of the core to overheat.

    And it's small enough to be self-contained.

  • by vlm ( 69642 ) on Wednesday December 14, 2011 @02:54PM (#38373418)

    Whoops also forgot another reason why Th sucks, its harder to make fuel rods. Hotter manufacturing temps. So they end up being more expensive and/or less reliable than U, which is supposedly the opposite of what the system is supposed to produce. So the theoretical 3rd world operator finds it easier and safer and cheaper to use U rods.

    Th is a second class fuel. The best thing to burn in your steam locomotive is anthracite, if you can still get it. Next worse is bituminous. If you're really scraping the bottom of the barrel and gotta do what ya gotta do, you harvest irish peat and burn that in your steamie. But trying to convince people peat is just as good as anthracite, or peat is cheaper, or peat should really be your first choice, or I read an article about peat and figure it might be fun to try, thats just not gonna work. Stick to the U and Pu designs until the world runs out of U in 20000 years or so. After that, you gotta do what you gotta do, and whip out the Th designs.

  • by Animats ( 122034 ) on Wednesday December 14, 2011 @03:00PM (#38373516) Homepage

    The point of the actual paper has nothing to do with reactor design. It's that the financing of a 1GW plant creates too much economic risk for utilities. They point out that 70% of utilities with large nuclear plants at some point faced a bond rating downgrade.

    A production line with steady production improves costs more than "modularity". That's how France did nuclear power - a lot of plants, built in the 1980s, all the same, with common components. There's a scale issue with how big an object you can move to the site - if the thing will fit on a road or rail car, it can be built and tested in a factory. There's a big discontinuity in delivered price when something gets too big to move and essentially gets built on site. The paper doesn't address that issue when talking about "modularity".

    (This is even an issue with wind turbines. The upper limit on size comes from how big an object you can truck to the site. Ocean units can be bigger because they're brought in on barges.)

  • by denis-The-menace ( 471988 ) on Wednesday December 14, 2011 @03:27PM (#38373936)

    Watch the video first. (at least first 10 seconds of it)

    1. With LFTR you have next to no waste.
    From what I remember, there are 2 radioactive leftovers and both are valuable.
    -molybdenum-99 (Medical usage)
    -Plutonium-238 (Space probes)(VERY valuable)

    2. Uranium has an [Expensive] established fuel chain. You can only get fuel pellets from ONE supplier: the one who built the reactor. And no, they don't have sales.

    3. Advantage of thorium vs uranium:
    -No enrichment
    -No 10000 year radio-active waste
    -No high-pressure water cooling schemes that need power to work and backups up the wazoo.
    -Others mentioned in the video

  • by Anonymous Coward on Wednesday December 14, 2011 @07:13PM (#38377312)

    That's an engineer looking for a complicated solution. The right answer is dig a hole beneath the local water table or below sea/lake/river level, and install a one way valve. Local water table is 500 feet below? Don't build the plant there, build it somewhere within 50 feet of the water table, or lake/sea/river level..

    Nope, digging a hole to the water table to store anything hazardous is about the worst idea I have ever heard. I think I'll stick with solutions designed by engineers, thanks. A reservoir of water on higher ground, with gravity feed, to a pool that is designed with eventual cleanup and - very importantly - de-comissioning considered from the outset.

    If you want to know how bad it is to dig a pit below the water table and chuck radioisotopes into it, do some reading on Dounreay in Scotland. Still, not to worry, they should have it sorted it out in another 300 years.

    The truth is that pools often are bad news, because stuff gets chucked into them as an alternate to proper safe long term storage. This happened at Fukushima and is basically a problem all over the world. The most hazardous building in Western Europe? B30 at Sellafield in the UK, which contains a huge fuel pool full of all kinds of crap (they aren't sure exactly what is in there -- but it is thought there is a about 1500kgs of plutonium sludge amongst the rods in various states of decay). The second worst building is right next door. These pools are open-air, and you can see both of these pools if you go to google maps and have a mooch around the Sellafield site.

They are relatively good but absolutely terrible. -- Alan Kay, commenting on Apollos

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