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Thread: Is Nuclear Power Worth the Risk?

  1. #21
    tWebber Leonhard's Avatar
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    Quote Originally Posted by Cow Poke View Post
    So, first, Merry Christmas.
    Merry Christmas

    Second - having been in the gas compression business, we would often have two to four large compression units (gas fired, gas compressing) ganged together, each compressor unit capable of handling the load, for redundancy and ease of maintenance.

    So, would smaller reactors be safer or easier to operate, and ganged together to produce power, are we unnecessarily increasing risk, etc?

    Or are larger reactors necessarily more efficient....?
    That is a question that's been asked a lot by many technicians. Planning a nuclear power plant is difficult for political reasons. So once you finally do get approval it makes sense to build an enormous power plant.

    But almost all nuclear power plants consists of multiple reactor cores. Chernobyl, infamous as it is, consisted of four reactors, 5 and 6 were under construction at the time. Fukushima had six. Chernobyl had a core explosion followed by a meltdown in Reactor Unit 4, and after the area was cleaned up Unit 1, 2 and 3 kept running until 2006 when they were finally turned off.

    Many people have argued that we shouldn't build massive nuclear power plants, but instead build smaller modular reactors. Say a little power unit somewhere at 100-300MW that could power a city block. Some of the new designs only need to be refueled every twenty years, and it also provides hot water to the local community.

    But that requires a significantly friendlier environment for approving nuclear power. Right now the massive amount of planning required, means it only really makes sense to go big when you build a power plant like that.

    Nuclear fuel is so energy dense, especially for breeder reactors, that it just doesn't make sense to talk about efficiency. I'd rather have a nuclear powerplant that was half as efficient, but cost twenty percent less to build, than have one that squeezed out ever last joule.

    The advantage of smaller nuclear reactors if that we can build components for them on an assembly line, standardize everything, which makes everything safer and more reliable in principle*.



    * Always with the caveat risk that your production line might introduce a common error into a hundred units sitting out there. For this reason many nuclear power plants were built using multiple suppliers as a rule.

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  3. #22
    tWebber Leonhard's Avatar
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    Quote Originally Posted by Teallaura View Post
    Fukushima is the high end of the potential disaster scale. Chernobyl is thus far the other.
    Chernobyl released more than twenty times of the radioactive materials as Fukushima, and that was directly into the air. The majority of Fukushima's release was a leaky valve into the ocean which was later closed. Most of Fukushima's outlet was diluted into the pacific ocean.

    To this day people in east Germany have to check wild life with dosimeters before determining if they're edible, still some hot spots out there that game end up grassing on.

    The biggest danger with nuclear is complacency. The second is political change. Not in the developed world but in unstable developing countries.
    I think there's a lot of concern to be had about the older 2nd generation reactors built in the seventies. They're old, wonky, and its good that Germany is shutting down theirs. Their mistake wasn't to shut them down, but deciding not to build new ones.

    I think the first is part of the political fallout, if not causally related, of Three Mile Island. We were assured of the complete safety of nuclear and finding out differently the hard way made nuclear power a pariah for decades. That history can't be repeated.
    The ironic thing is that Three Mile Island is an example of how well that power plant managed to contain a meltdown. There was a small release of radioactive gas, elevating the radiation in the nearby area for a couple of weeks, but after that things rapidly subsided. The destroyed reactor was successfully decommissioned as well, which is a story no one hears about. The release is orders of magnitude less than either Fukushima or Chernobyl.

    Those are the challenges, not objections.

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    tWebber Leonhard's Avatar
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    Quote Originally Posted by Cow Poke View Post
    Second - having been in the gas compression business, we would often have two to four large compression units (gas fired, gas compressing) ganged together, each compressor unit capable of handling the load, for redundancy and ease of maintenance.
    I forgot to mention that in almost all US power plants, they do this with all the important equipment, like the coolant pumps. They use multiple pumps, each one alone sufficient to do all the pumping needed, and each pump must come from a different supplier to avoid common flaws.

  5. Amen Cow Poke amen'd this post.
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    tWebber demi-conservative's Avatar
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    Russia has just started to power a state with its first floating nuclear reactor. Greenpeace is mad.

    Quote Originally Posted by Leonhard View Post
    Its not as bad as you think, most countries in general can be considered as acting in good faith. Denmark easily got international approval, so did Sweden. The reason Denmark doesn't have nuclear power is because we actively chose not to.
    You would rank among the highly trusted nations.
    . Bloomberg, by comparison, may be the candidate that most of the Founders hoped would arise: a wealthy patrician, much like them, who would use his vast resources and influence to defeat what he views as disruptive elements in the nation’s political system.

  7. #25
    tWebber TheLurch's Avatar
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    I have thoughts on nuclear power, which shouldn't surprise you, since i seem to have thoughts on most things.

    Current nuclear plants make a major contribution to limiting climate change, and should be kept operational for as long as they can be operated safely. The US is, unfortunately, shutting a number of them because the current price of electricity does not include any cost of carbon emissions, meaning they cannot be operated economically against competition like renewables and natural gas, both of which are substantially cheaper.

    Operating them safely will always remain a challenge. Safety is expensive, and they're being operated by for-profit companies, meaning that a strong regulatory organization is necessary to manage that tension. We've had that in the US, though other countries haven't been so lucky (Japan provides a classic example of industry capture of a regulatory agency). That's an ongoing, societal-level challenge.

    Building new ones has turned out to be an almost impossible challenge. As far as I'm able to determine, no plants have been completed on time and/or budget in decades in a western-style democracy (South Korea being a possible exception), with cost overruns that are typically on the scale of 1.5-2x the original cost. Given that original cost was enormous, and a number of projects have been cancelled outright, no private entity is willing to finance the construction, meaning that any new plants will have to essentially be a government-funded project. There are also challenges with maintaining the expertise needed to build these things, given that new projects happen so rarely.

    There are designs that are intended to be cheaper and easier to build, but most of those are still in the experimental stage, and will require decades before they're ready for general use. There will also be a time lag as companies learn to operate them (nuclear plants in the US started out with capacity factors worse than current wind farms; it took decades to learn to operate them at 90+% availability). Essentially, any new tech is giving renewables + storage an additional 30 years to improve in cost and use cases. Given existing trajectories, that's a very difficult challenge to overcome.

    Reprocessing of fuel is essentially a non-contributor. Only two countries (France and Japan) have ever attempted this, and they've shut the efforts down. Since they were government projects, profitability wasn't an issue, but all indications are that it was far to expensive to continue, which suggests it will never work as a private industry.


    The sum total of my thoughts is that i'd really like nuclear to be doing more for us. It could play a major role in hastening the necessary phase out of fossil fuels. But i simply don't see a path for the economics to work out, which means that even maintaining the status quo will require major government interventions into the market. And i don't see any party or constituency with the political strength to make that happen in most countries.
    "Any sufficiently advanced stupidity is indistinguishable from trolling."

  8. #26
    See, the Thing is... Cow Poke's Avatar
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    Quote Originally Posted by TheLurch View Post
    I have thoughts on nuclear power, which shouldn't surprise you, since i seem to have thoughts on most things.

    Current nuclear plants make a major contribution to limiting climate change, and should be kept operational for as long as they can be operated safely. The US is, unfortunately, shutting a number of them because the current price of electricity does not include any cost of carbon emissions, meaning they cannot be operated economically against competition like renewables and natural gas, both of which are substantially cheaper.

    Operating them safely will always remain a challenge. Safety is expensive, and they're being operated by for-profit companies, meaning that a strong regulatory organization is necessary to manage that tension. We've had that in the US, though other countries haven't been so lucky (Japan provides a classic example of industry capture of a regulatory agency). That's an ongoing, societal-level challenge.

    Building new ones has turned out to be an almost impossible challenge. As far as I'm able to determine, no plants have been completed on time and/or budget in decades in a western-style democracy (South Korea being a possible exception), with cost overruns that are typically on the scale of 1.5-2x the original cost. Given that original cost was enormous, and a number of projects have been cancelled outright, no private entity is willing to finance the construction, meaning that any new plants will have to essentially be a government-funded project. There are also challenges with maintaining the expertise needed to build these things, given that new projects happen so rarely.

    There are designs that are intended to be cheaper and easier to build, but most of those are still in the experimental stage, and will require decades before they're ready for general use. There will also be a time lag as companies learn to operate them (nuclear plants in the US started out with capacity factors worse than current wind farms; it took decades to learn to operate them at 90+% availability). Essentially, any new tech is giving renewables + storage an additional 30 years to improve in cost and use cases. Given existing trajectories, that's a very difficult challenge to overcome.

    Reprocessing of fuel is essentially a non-contributor. Only two countries (France and Japan) have ever attempted this, and they've shut the efforts down. Since they were government projects, profitability wasn't an issue, but all indications are that it was far to expensive to continue, which suggests it will never work as a private industry.


    The sum total of my thoughts is that i'd really like nuclear to be doing more for us. It could play a major role in hastening the necessary phase out of fossil fuels. But i simply don't see a path for the economics to work out, which means that even maintaining the status quo will require major government interventions into the market. And i don't see any party or constituency with the political strength to make that happen in most countries.
    OK, thanks for your thoughts.

    What are the output ranges of the reactors on USS Aircraft Carriers? Since an aircraft carrier is, in essence, a small city (5,000-6,000 people plus heavy equipment, shops, propulsion, etc)... aren't those reactors of older design, and are they as safe as the military would have you believe? I ask that because, if there ever were a major accident, would it be possible for them to hide it? Could we count on "incident reporting" to be forthright?
    "Neighbor, how long has it been since you’ve had a big, thick, steaming bowl of Wolf Brand Chili?”

  9. #27
    tWebber Leonhard's Avatar
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    Quote Originally Posted by TheLurch View Post
    I have thoughts on nuclear power, which shouldn't surprise you, since i seem to have thoughts on most things.
    Current nuclear plants make a major contribution to limiting climate change, and should be kept operational for as long as they can be operated safely. The US is, unfortunately, shutting a number of them because the current price of electricity does not include any cost of carbon emissions, meaning they cannot be operated economically against competition like renewables and natural gas, both of which are substantially cheaper.

    Operating them safely will always remain a challenge. Safety is expensive, and they're being operated by for-profit companies, meaning that a strong regulatory organization is necessary to manage that tension. We've had that in the US, though other countries haven't been so lucky (Japan provides a classic example of industry capture of a regulatory agency). That's an ongoing, societal-level challenge.

    Building new ones has turned out to be an almost impossible challenge. As far as I'm able to determine, no plants have been completed on time and/or budget in decades in a western-style democracy (South Korea being a possible exception), with cost overruns that are typically on the scale of 1.5-2x the original cost. Given that original cost was enormous, and a number of projects have been cancelled outright, no private entity is willing to finance the construction, meaning that any new plants will have to essentially be a government-funded project. There are also challenges with maintaining the expertise needed to build these things, given that new projects happen so rarely.

    There are designs that are intended to be cheaper and easier to build, but most of those are still in the experimental stage, and will require decades before they're ready for general use. There will also be a time lag as companies learn to operate them (nuclear plants in the US started out with capacity factors worse than current wind farms; it took decades to learn to operate them at 90+% availability). Essentially, any new tech is giving renewables + storage an additional 30 years to improve in cost and use cases. Given existing trajectories, that's a very difficult challenge to overcome.

    Reprocessing of fuel is essentially a non-contributor. Only two countries (France and Japan) have ever attempted this, and they've shut the efforts down. Since they were government projects, profitability wasn't an issue, but all indications are that it was far to expensive to continue, which suggests it will never work as a private industry.


    The sum total of my thoughts is that i'd really like nuclear to be doing more for us. It could play a major role in hastening the necessary phase out of fossil fuels. But i simply don't see a path for the economics to work out, which means that even maintaining the status quo will require major government interventions into the market. And i don't see any party or constituency with the political strength to make that happen in most countries.
    At least not as the technology is now, where the reactors themselves are used to generate high-pressure steam. This requires absolutely enormous pressure vessels and containment structures, which double and triple the costs. I've seen better designs where the reactor is used to heat melted salt or sodium. Those designs have been languishing since the fifties, usually shut down for political reasons, though research into molten salt reactors has always been simmering.

    In that case, you remove any pressure in the reactor system, and you typically gain the ability to passively cool the reactor with airflow in case of an emergency, meaning you gain walk-alway safety. We could then do away with the need for the containment structure, and then the size of the reactor radically decreases.

    But as you say these designs are years, a decade or more, away from actually being built. Right now we're left with the pressured reactor designs from the seventies, that cost as much as 12-15000$/kW installed capacity.

    Add on top of that the unfriendly political environment for reactors and waste disposal, and it's just hard to build and test these things.

    It's not like the fifties where engineers could build a reactor out in the desert of Arizona and have it undergo a criticality excursion just to see what happened when a reactor output suddenly exceeded its design parameters by a factor of a thousand.


  10. #28
    tWebber Leonhard's Avatar
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    Quote Originally Posted by Cow Poke View Post
    What are the output ranges of the reactors on USS Aircraft Carriers? Since an aircraft carrier is, in essence, a small city (5,000-6,000 people plus heavy equipment, shops, propulsion, etc)... aren't those reactors of older design, and are they as safe as the military would have you believe? I ask that because, if there ever were a major accident, would it be possible for them to hide it? Could we count on "incident reporting" to be forthright?
    All modern reactors are pretty much safe, though those naval reactors are definitely 'handle with care'. They have to run for many years without refueling so they use highly enriched uranium, lined with some sort of neutron absorber to reign in all the excess reactivity. Over the years the neutron radiation wears down the absorbers, which causes the reactivity to rise about at the same rate as the reactivity of the fuel itself is lessened from being spent.

    There's been at least one criticality excursion on a soviet submarine in a drydock, when they accidentally lifted the control rods of the reactor core out too far, causing the uranium fuel to suddenly flare up and spew itself out across the dry dock.

    They're impressively compact, but its not the design I'd be looking for in reactors. My favorite is actually the Moltex design.

    This video gives a good look at how a modern day molten salt reactor could look like. In particular the 3:00 to 5:00 mark gives a sobering outlook on the prospect on nuclear power, and the economic hurdles it needs to clear if it has to move from being a niche thing, to a dominant player in the energy market.


  11. Amen Cow Poke amen'd this post.

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