Nuclear Power Pros and Cons

Picking up something from a thread in Hell,
Simon Toad wrote: »
My title was "Mad Scientist", my avatar (created by babybear) accompanied that.

My doctorate was in nuclear physics, since then I've moved around through a variety of environmental applications of nuclear techniques.

I have been stubbornly anti-nuclear power since Chernobyl, and my opinions were reinforced by Fukushima. Its an issue in Australia that comes up seasonally, as an alternative to coal power. I have always thought that we should rely on renewables to replace coal. We have no nuclear power plants, just a research reactor in Sydney.

Given your commitment to peace and the environment (stronger than mine in both cases I think), you might be a good person for me to talk to about whether my stubborn opposition is the right response. If you feel like shooting an article suitable for non-scientists across on the topic, I'd be grateful.
There's a lot of material available, but most articles are horrendously biased one way or the other - the more balanced material tends to be less accessible for the non-expert. I don't actually have a go-to list of articles that are both suitable for the non-expert and sensibly balanced. The lack of balance out there does make it fertile ground for our students, exams (previous years) and assessed coursework (this year and probably next) always have a question for them to outline the science on one aspect of nuclear power and express their opinions for or against, and several of them always come out with something related to that for their critical studies (this year it was radioactive materials from fusion power that seemed to be the popular question). Perhaps I should get myself a blog to put out my own views, though that's going to be called biased by everyone else (and, quite justifiably too) - in lieu of that, a new thread to simply discuss things.

For the record, I'm conditionally in favour of nuclear power being part of a low-carbon power generation mix. As we de-carbonise transport, and also remove gas and oil from cooking and heating, the demand for electricity will increase significantly so there needs to be new generating capacity. It's the conditions that are the important part.

1. We need to start with efficiency, such that we reduce demand where practicable.
2. Practical means of renewable generation should be prioritised - that means a mix of generating types (if it's heavily biased towards wind, for example, you suffer from potential shortfall if there's a nationwide calm period)
3. There will be a requirement for base-load constant generating capacity. If this can't be met by small scale hydro (large scale hydro with massive dams have problems of their own), tidal or other predictable near constant renewables, then that's the generating capacity space for nuclear.
4. The choice of nuclear technology should be biased towards safety and waste management rather than cost.
4a. water cooled reactors overheat if the coolant isn't pumped around during shutdown (which requires power when the reactor isn't generating, and hence is a demand on the rest of the grid)
4b. gas cooled reactors should have pumps running in shutdown (which take a lot less power than pumping water) but pump failure doesn't lead to overheating and meltdown
4c. gas cooled reactors don't scale up to very large size as easily as water cooled, so the more economic designs are all big, water cooled designs - I would consider these the highest risk option in relation to safety
4d. safety extends across the whole fuel cycle - from mining uranium through to long term waste storage; in terms of environmental impact and human health, uranium mining is often forgotten, and waste storage suffers from chronic procrastination.
5. we have a legacy of nuclear waste to be managed, new reactors will add to that from first spent fuel coming out approx. 3 years after startup. To build new reactors, we need to have at least a means of safely processing that new waste - ideally, be making progress in dealing with the legacy.
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Comments

  • This is something I'd really like to know more about but there is a problem due to the highly technical nature of the subject, and the way populations fears can be exploited, or even correctly raised. There's nothing wrong with fear. But it's the science-politics-industry relationship which is so difficult to handle.

    So can I ask a less technical question. Does anyone know how this is playing out in France, which is SFAIK the most nuclear reliant advanced democracy? When Merkel shut it all down in Germany, was there any impact in France? Way is it that a nation so apparently averse to vaccines, can live so happily with nuclear power? Or is there really a lot of anti-nuclear feeling there?
  • Last night 60 Minutes talked with Bill Gates whose people are working on a new nuclear reactor. Most current reactors depend on radioactive rods heating water and water reactors can be quite unstable. The design his people are working on uses more of a pod for the fissionable material and they will be heating liquid sodium which is quite stable. Thus, the reactors can be smaller and nearly automatic. Apparently, they have been approved to build a test reactor using the new model.
  • Liquid sodium was the coolant for Japanese fast breeder reactors if I remember rightly? I think the advantage is the fairly high thermal conductivity of the sodium - I'd take a lot of convincing that liquid sodium was "more stable" than water.
  • Anteater wrote: »
    So can I ask a less technical question. Does anyone know how this is playing out in France, which is SFAIK the most nuclear reliant advanced democracy?
    Maybe @Eutychus has better on the ground information, but the French plan at present is to reduce reliance on nuclear, to about 50% of generating capacity - presumably with renewables making up the rest.

  • Liquid sodium was the coolant for Japanese fast breeder reactors if I remember rightly? I think the advantage is the fairly high thermal conductivity of the sodium - I'd take a lot of convincing that liquid sodium was "more stable" than water.
    Liquid sodium was the coolant of choice for all the fast breeder prototypes - in France, UK and elsewhere as well as in Japan. So, there's a significant body of experience with the material, but the people who actually did that work are at or past retirement age (certainly the senior people at the time). Which means the practical experience will need to be relearnt, even if some of it has been recorded on paper that personal experience is far better.

    The advantages on paper are high thermal conductivity and low neutron capture cross sections (so you don't lose neutrons that could otherwise keep the reaction going, and you don't get so many radioactive activation products in your coolant). The biggest problems associated with liquid metal coolants are to do with the engineering of pipes to carry the stuff, the experimental fast breeders all suffered from coolant leaking from pipes. Liquid metals do need reactors that run hotter than a conventional water or gas cooled reactor, which also means needing fuel encapsulation that won't melt at these higher temperatures.
  • Thanks for starting this thread Alan. I will read with interest.
  • MaryLouiseMaryLouise Purgatory Host, 8th Day Host
    Coming in from a lay (ignorant) perspective -- right now, many of us living in or around Cape Town are worried about the ageing Koeberg nuclear power station on the West Coast of the Cape.

    Information received last month from the Electricity Supply Commission (ESKOM) in response to requests for information under the Promotion of Access to Information Act (PAIA) legislation, revealed that 40 years of exposure to sea air had damaged the concrete of the containment buildings at Koeberg and, at one stage, the concrete containment dome was found to have cracked around the entire 110m circumference.

    The provided 31-page report, which refers to repairs done up until 2018, has 11 pages entirely blacked out and various other sections, photos and tables redacted. The South African public needs more transparency from Eskom, as the proposed 20-year extension of Koeberg’s lifespan and additional nuclear builds are being debated.

    Is there a fixed 'lifespan' for old nuclear power stations and are most stations just closed down at a certain point?
  • Martin54Martin54 Shipmate
    edited February 16
    Definitive Alan, gold standard.
    Picking up something from a thread in Hell,
    Simon Toad wrote: »
    My title was "Mad Scientist", my avatar (created by babybear) accompanied that.

    My doctorate was in nuclear physics, since then I've moved around through a variety of environmental applications of nuclear techniques.

    I have been stubbornly anti-nuclear power since Chernobyl, and my opinions were reinforced by Fukushima. Its an issue in Australia that comes up seasonally, as an alternative to coal power. I have always thought that we should rely on renewables to replace coal. We have no nuclear power plants, just a research reactor in Sydney.

    Given your commitment to peace and the environment (stronger than mine in both cases I think), you might be a good person for me to talk to about whether my stubborn opposition is the right response. If you feel like shooting an article suitable for non-scientists across on the topic, I'd be grateful.
    There's a lot of material available, but most articles are horrendously biased one way or the other - the more balanced material tends to be less accessible for the non-expert. I don't actually have a go-to list of articles that are both suitable for the non-expert and sensibly balanced. The lack of balance out there does make it fertile ground for our students, exams (previous years) and assessed coursework (this year and probably next) always have a question for them to outline the science on one aspect of nuclear power and express their opinions for or against, and several of them always come out with something related to that for their critical studies (this year it was radioactive materials from fusion power that seemed to be the popular question). Perhaps I should get myself a blog to put out my own views, though that's going to be called biased by everyone else (and, quite justifiably too) - in lieu of that, a new thread to simply discuss things.

    For the record, I'm conditionally in favour of nuclear power being part of a low-carbon power generation mix. As we de-carbonise transport, and also remove gas and oil from cooking and heating, the demand for electricity will increase significantly so there needs to be new generating capacity. It's the conditions that are the important part.

    1. We need to start with efficiency, such that we reduce demand where practicable.
    2. Practical means of renewable generation should be prioritised - that means a mix of generating types (if it's heavily biased towards wind, for example, you suffer from potential shortfall if there's a nationwide calm period)
    3. There will be a requirement for base-load constant generating capacity. If this can't be met by small scale hydro (large scale hydro with massive dams have problems of their own), tidal or other predictable near constant renewables, then that's the generating capacity space for nuclear.
    4. The choice of nuclear technology should be biased towards safety and waste management rather than cost.
    4a. water cooled reactors overheat if the coolant isn't pumped around during shutdown (which requires power when the reactor isn't generating, and hence is a demand on the rest of the grid)
    4b. gas cooled reactors should have pumps running in shutdown (which take a lot less power than pumping water) but pump failure doesn't lead to overheating and meltdown
    4c. gas cooled reactors don't scale up to very large size as easily as water cooled, so the more economic designs are all big, water cooled designs - I would consider these the highest risk option in relation to safety
    4d. safety extends across the whole fuel cycle - from mining uranium through to long term waste storage; in terms of environmental impact and human health, uranium mining is often forgotten, and waste storage suffers from chronic procrastination.
    5. we have a legacy of nuclear waste to be managed, new reactors will add to that from first spent fuel coming out approx. 3 years after startup. To build new reactors, we need to have at least a means of safely processing that new waste - ideally, be making progress in dealing with the legacy.

    So

    1. can only happen at the margin, in a world of rising demand for the remainder of the century. 4c's predicate is counter to efficiency. Can we compare risks please? The risks of inefficiency in the doughnut are no less real. And we're just talking about the risk of water over gas cooled reactors. The risk of non-nuclear far outweighs nuclear. Fossil is beyond the pale but renewables come with vast opportunity costs and inefficiencies. Risk. 4d. & 5 are non-negotiable, as in aviation, manufacturing and construction where risk has tumbled; it is unacceptable, despite and because of insane Grenfell and even Boeing 737 MAX systemic profit motivated step backs; we learn from our mistakes. 5. is about political fear of constituent fear. The risk of vitrification and rational storage and the benefits of waste as resource, like all of this, need to be fully, transparently, globally addressed, at UN level.

    Scotland could lead in this Alan.
  • MooMoo Kerygmania Host
    Alan, what do you think of thorium reactors?
  • MaryLouise wrote: »
    Is there a fixed 'lifespan' for old nuclear power stations and are most stations just closed down at a certain point?
    Power stations would have been built with a design life. But, also the performance of many materials in the reactor would have been unknown in advance (they'd have all been tested in high flux environments, but performance over 30 years would still be an extrapolation from a few months) and in general engineers would have been cautious so these components are still OK at the end of design life allowing them to be operated for a bit longer. At least in the UK, such lifetime extensions come with requirements for ongoing inspection at a higher frequency than design to identify material problems, and if there are problems further extensions would be prevented. Most UK reactors are now beyond design life (the Sizewell B PWR being the exception).

    It sounds like the cracks in the outer containment at Koeberg falls into the category of not exceeding design life (I don't know the design life of that reactor, but 40y would have been at the longer end of design life at the time). This would be secondary containment, but would still be part of the safety systems of the plant - it would be designed to contain any radioactive materials released from the primary system in the event of a minor accident (in water reactors there would be pressure release valves against overpressurisation of the coolant, allowing controlled release of pressure without risking pipes bursting - the released water vapour will be radioactive and should be contained in the building - several accidents have occurred when these valves do their job then fail to close releasing more water than the containment systems can handle, Three Mile Island was the worst of these). If the cracks extend all the way through the wall then that obviously compromises that safety feature, if they are structural such that the dome is in danger of collapse then that's a very serious state which will almost certainly need the reactor shut down so that the building can be made safe (even after removing the fuel from the reactor that building would need to be made safe because there'll be a lot of radioactive material still there which won't do well to tonnes of concrete falling on it). If the cracks are superficial then it may not be a safety issue - but, it would need someone with more expertise than me on the site actually inspecting it to make such a decision. When you get what we would call a freedom of information (FOI) request and the document is mostly redacted that probably makes most people more worried than whatever was redacted would do.
  • Moo wrote: »
    Alan, what do you think of thorium reactors?
    Thorium reactors suffer some of the disadvantages of uranium reactors - you still have highly active fission products to deal with, and water cooled reactors would still need active pumping in shut down. They have an advantage that thorium is more abundant, and mining presents a lower radiological hazard (the radon isotope in the Th decay chain has a much shorter half life and so doesn't accumulate in the mine to the extent of the radon from 238U). Also, the abundant isotope of Th (232Th) is the one you want for a reactor, whereas the abundant U isotope (238U) is non-fissile - though breeds to make 239Pu which is, so you need to mine a lot less to get the same power. Most of the very long lived radionuclides that require storage for millennia are produced from activation of 238U, so would be absent in a thorium reactor - though there are some fission products which also have very long half lives so you still need a very long term storage option, just for smaller volumes of material. The Th cycle still needs a uranium or plutonium fuelled reactor to initiate the production of the fissile material, and because the reactor is a breeder some reprocessing to extract the 233U and thorium from waste components. The claim that thorium reactors don't produce weapons grade material is partly true, the 233U could be extracted to make a bomb but there would also be 232U present which would make such a device quite unstable (as in, it could literally blow up in your face - which conventional state armed forces wouldn't like, though whether terrorists prepared to die would worry if a bomb detonates as they assemble it in a populated area is a different question), separation of 232U and 233U is very challenging but probably not impossible (though, getting 239Pu from a conventional uranium reactor is much easier).
  • My take-away so far is that nuclear power has a role in generating base load power as part of a mix of renewable energy generating sources, but only if other renewable technologies are unavailable.

    I'm wondering how you ( @Alan Cresswell ) would balance the risks and costs, environmentally in particular, of the nuclear option as against:

    1. existing coal power stations with or without a viable carbon capture technology;

    2. building new coal power stations specifically to fill the niche you identify for nuclear, both with and without carbon capture technology.

    Carbon capture is being pushed hard here by the conservatives, which is a worry for me, and the debate we hear in the media about it is inconclusive, as far as I can make out. One radio host, Philip Adams (an octogenarian lefty who is pretty good on most things) calls carbon capture technology bulldust. Yet there are expensive pilot programmes ongoing.
  • MaryLouiseMaryLouise Purgatory Host, 8th Day Host

    Thanks @Alan Cresswell , not reassuring but it helps me get a clearer idea of what might be happening.
  • I've done a bit more looking around the 'net. Koeberg came online in 1984 with a 40 year design life (until 2024), and is a pair of 970MWe PWRs built with seismic protection to 0.3g equivalent to protection against a magnitude 7 earthquake (post Fukushima testing showed that the system would withstand 0.5g - so on that front very well built). The operators are seeking a 20y extension (to 2044). It supplies about half the electricity for the Western Cape, so if it's closed there would be severe power shortages.

    The concerns about the concrete relate to salt ingress into the wall corroding the reinforcement bars - these then expanded causing surface cracks. The operator claims these have been fully repaired (though it looks like just replacement of the concrete rather than repair to the reinforcement bars, which would be a major undertaking), and that measures to prevent further salt ingress are planned (presumably part of their safety case for the operation life time extension). The documents obtained by local activists under Promotion of Access to Information Act legislation were heavily redacted, for what the operators claimed was sensitive technical information. The nuclear industry (everywhere) has a history and culture of secrecy, but also needs to be open and transparent if they want to win and maintain public trust - information on the extent and costs of repair work may have some commercial sensitivity, but ISTM that the gains from public trust through transparency would trump commercial sensitivity. Hiding things like that makes it look like there's something to hide - eg: the damage repaired was more serious than reported, or there was corruption in awarding contracts to do the repairs (and, where there's financial corruption there's always a suspicion about the quality of work done).

    World Nuclear News is an industry publication, and some may consider them unreliable because of that, but I've found them quite good at reporting facts (you can take their conclusions with a pinch of salt if you like). WNN report on the Koeberg containment building.
  • Simon Toad wrote: »
    My take-away so far is that nuclear power has a role in generating base load power as part of a mix of renewable energy generating sources, but only if other renewable technologies are unavailable.

    I'm wondering how you ( @Alan Cresswell ) would balance the risks and costs, environmentally in particular, of the nuclear option as against:

    1. existing coal power stations with or without a viable carbon capture technology;

    2. building new coal power stations specifically to fill the niche you identify for nuclear, both with and without carbon capture technology.

    Carbon capture is being pushed hard here by the conservatives, which is a worry for me, and the debate we hear in the media about it is inconclusive, as far as I can make out. One radio host, Philip Adams (an octogenarian lefty who is pretty good on most things) calls carbon capture technology bulldust. Yet there are expensive pilot programmes ongoing.

    Alan will correct me. Nuclear vs. coal is a no brainer. Carbon capture is about as practicable as nuclear fusion. A staggering waste of energy=£
  • Simon Toad wrote: »
    I'm wondering how you ( @Alan Cresswell ) would balance the risks and costs, environmentally in particular, of the nuclear option as against:

    1. existing coal power stations with or without a viable carbon capture technology;

    2. building new coal power stations specifically to fill the niche you identify for nuclear, both with and without carbon capture technology.
    Burning coal, IMO, is the dirtiest form of power generation, and should be phased out of the generating mix as soon as possible (Scotland has been coal free since 2016, the UK as a whole is very nearly coal-free). Mining of coal results in very significant local environmental degradation. The CO2 production per MWh of power is by far the worst of all fossil fuels, and the combustion products contain a mix of toxins including sulphur compounds, heavy metals, particulates (the particular issues depend on the source of the coal), modern power stations scrub most of these out before the smoke goes up the chimney but that still leaves waste materials to be handled and takes energy which further reduces the net output of the power plant. That waste, and the ash left in the bottom of the furnace, also contains significant quantities of radioactive materials, in some cases approaching low level waste levels. Coal fired power stations have released more radioactive materials into the environment than nuclear power.

    Carbon capture is an expensive technical fix to problems caused by a different technology which will have limited value (and, again takes energy further reducing the net output of the power plant). Nature came up with a very effective means of carbon capture and storage, it's called coal, and we're never going to compete with that. The best option is to not try, and leave the coal in the ground. Then, for carbon capture go with reinstating active peat bogs and reforestation.
  • DafydDafyd Shipmate
    I know people who do carbon capture research. On the whole, I think they would agree that it's suboptimal from an environmental point of view and that coal mining is a dirty industry, but they doubt leaving coal in the ground across the world is politically feasible.

    Running coal plants with carbon capture, while less efficient, is still economic.

    In a mixed-fuel economy, the advantage of fossil fuels is that they're flexible in response to sudden changes in demand. You can't ask the wind to blow faster when a quarter of the population all put their kettles on at once, and around a nuclear plant you want to make no sudden movements, but you can more or less dump another lot of coal in the furnace whenever you need to. (My source would no doubt claim that all the above is an oversimplification and the matter is complex, in the way people supervising other people's doctorates do.)
  • But that fast top electricity is what the hydroelectric plant at Dinorwig does - a quick boost to the grid by opening the dam, creation of electricity by the water at the high lake driving the turbines as it falls to the lower lake. Use of low cost electricity overnight from power stations that cannot be turned on or off so quickly to pump the water back up again.
  • MaryLouiseMaryLouise Purgatory Host, 8th Day Host
    I've done a bit more looking around the 'net. Koeberg came online in 1984 with a 40 year design life (until 2024), and is a pair of 970MWe PWRs built with seismic protection to 0.3g equivalent to protection against a magnitude 7 earthquake (post Fukushima testing showed that the system would withstand 0.5g - so on that front very well built). The operators are seeking a 20y extension (to 2044). It supplies about half the electricity for the Western Cape, so if it's closed there would be severe power shortages.
    ...
    World Nuclear News is an industry publication, and some may consider them unreliable because of that, but I've found them quite good at reporting facts (you can take their conclusions with a pinch of salt if you like). WNN report on the Koeberg containment building.

    Thanks for this @Alan Cresswell -- yes, nuclear power is a major source of supply here in the Western Cape, the more so given our unstable power grid and frequent electricity black-outs. There is considerable opposition from not just environmental groups but civic groups worrying that the refurbishment of Koeberg might push up the cost of already exorbitant electricity prices for consumers. And Eskom secretiveness and lack of response meant that when three earthquakes struck the Western Cape last year many civic groups demanded access to a 2017 study by the National Nuclear Regulator, which assessed the seismic risk at the Koeberg site.

  • Dafyd wrote: »
    I know people who do carbon capture research. On the whole, I think they would agree that it's suboptimal from an environmental point of view and that coal mining is a dirty industry, but they doubt leaving coal in the ground across the world is politically feasible.

    Running coal plants with carbon capture, while less efficient, is still economic.

    In a mixed-fuel economy, the advantage of fossil fuels is that they're flexible in response to sudden changes in demand. You can't ask the wind to blow faster when a quarter of the population all put their kettles on at once, and around a nuclear plant you want to make no sudden movements, but you can more or less dump another lot of coal in the furnace whenever you need to. (My source would no doubt claim that all the above is an oversimplification and the matter is complex, in the way people supervising other people's doctorates do.)

    Last I heard coal plants are not a good choice for fast-response supply. You need gas, hydro, surplus wind or some form of storage for that (time to full production for pumped storage is measured in seconds).
  • Last I heard coal plants are not a good choice for fast-response supply. You need gas, hydro, surplus wind or some form of storage for that (time to full production for pumped storage is measured in seconds).

    You're right that coal is usually base load, and gas is more often used for peaking, but I think there are modern coal plants that are more dynamic than traditional ones.
  • DafydDafyd Shipmate
    You want I think to put carbon capture on gas as well as on coal.
  • Gee DGee D Shipmate
    The CO2 production per MWh of power is by far the worst of all fossil fuels, and the combustion products contain a mix of toxins including sulphur compounds, heavy metals, particulates (the particular issues depend on the source of the coal), modern power stations scrub most of these out before the smoke goes up the chimney but that still leaves waste materials to be handled and takes energy which further reduces the net output of the power plant. That waste, and the ash left in the bottom of the furnace, also contains significant quantities of radioactive materials, in some cases approaching low level waste levels. Coal fired power stations have released more radioactive materials into the environment than nuclear power.

    Carbon capture is an expensive technical fix to problems caused by a different technology which will have limited value (and, again takes energy further reducing the net output of the power plant). Nature came up with a very effective means of carbon capture and storage, it's called coal, and we're never going to compete with that. The best option is to not try, and leave the coal in the ground. Then, for carbon capture go with reinstating active peat bogs and reforestation.

    IIRC, over 75% of the electricity generated in NSW is in coal fired stations, with a few per cent more from oil. The balance is hydro with some wind and solar generation. There is no way politically at the moment to introduce nuclear power. That would be to send your party almost instantly to the opposition benches and condemn it to remain there. I can't see there being any change in that.
  • Globally, almost 40% of electricity is generated from coal. So, it's not going to be easy to phase out and replace with alternative, cleaner generating capacity. Even if a nation (or state) decided to build nuclear to replace coal it would still be at least 10y before that capacity came on line - so in addition to the political problems there's a technological/regulatory issue with build time. Whereas, renewables can be installed far more quickly.
  • Am I correct in thinking that there is a lot of projected new Chinese and Russian nuclear build in the developing world?
  • There are about 50 reactors currently under construction. China has the biggest programme, about 15 reactors under construction, but I'm not sure if there are any Chinese reactors being built outside China. There are about 10 Russian reactors are being built in Russia, Turkey, Belarus, Slovakia, Bangladesh, Iran and India. Also some French reactors (including the pair at Hinkley Point in the UK), US reactors (2 at Vogtle being the first new reactors in the US since Three Mile Island) and some I'd need to explore more to find out which nation designed them. Of the nations currently building nuclear reactors, Bangladesh would be the only one that would normally be considered "developing world". Another 50 ish are planned (as in, reached the point where there's a site identified, and/or the type of reactors to build is defined - as opposed to places where some politician is saying "it would be good if we had some nuclear reactors")

    There's a list of countries with nuclear programmes which appears to only show the more developed plans in each nation. Note that some nations (eg: Namibia) are listed because they have a uranium mining industry, rather than plans to build nuclear reactors.
  • Globally, almost 40% of electricity is generated from coal. So, it's not going to be easy to phase out and replace with alternative, cleaner generating capacity. Even if a nation (or state) decided to build nuclear to replace coal it would still be at least 10y before that capacity came on line - so in addition to the political problems there's a technological/regulatory issue with build time. Whereas, renewables can be installed far more quickly.

    That's their biggest selling point, regardless of the risks, costs, inefficiency. Alongside nuclear backbone.
  • Surely the bottom line is this:

    Broadly people recognise that it is unsustainable to keep using methods of power generation that pollute, whether in producing the means of generation, in the actual generating process, or afterwards as the result of power generation.

    Nuclear power fails on all three grounds.
  • Gee D wrote: »
    The CO2 production per MWh of power is by far the worst of all fossil fuels, and the combustion products contain a mix of toxins including sulphur compounds, heavy metals, particulates (the particular issues depend on the source of the coal), modern power stations scrub most of these out before the smoke goes up the chimney but that still leaves waste materials to be handled and takes energy which further reduces the net output of the power plant. That waste, and the ash left in the bottom of the furnace, also contains significant quantities of radioactive materials, in some cases approaching low level waste levels. Coal fired power stations have released more radioactive materials into the environment than nuclear power.

    Carbon capture is an expensive technical fix to problems caused by a different technology which will have limited value (and, again takes energy further reducing the net output of the power plant). Nature came up with a very effective means of carbon capture and storage, it's called coal, and we're never going to compete with that. The best option is to not try, and leave the coal in the ground. Then, for carbon capture go with reinstating active peat bogs and reforestation.

    IIRC, over 75% of the electricity generated in NSW is in coal fired stations, with a few per cent more from oil. The balance is hydro with some wind and solar generation. There is no way politically at the moment to introduce nuclear power. That would be to send your party almost instantly to the opposition benches and condemn it to remain there. I can't see there being any change in that.

    I think your political judgement is probably right Gee D. I was surprised a decade ago when my brother (an ALP member at the time) didn't want to exclude it definitively. I think there is more support than I thought (I thought there was zero support back then). But it is just perfect for a scare campaign.

    I thought the Greens' policy made an interesting point about power plants being a terrorist target.

    I also remind myself especially that Alan's support is highly conditional, a very significant distinction being that it is a last gasp option if renewables are not available for the niche position he identifies for nuclear.
  • Surely the bottom line is this:

    Broadly people recognise that it is unsustainable to keep using methods of power generation that pollute, whether in producing the means of generation, in the actual generating process, or afterwards as the result of power generation.

    Nuclear power fails on all three grounds.

    So do all others more so.
  • Bill_NobleBill_Noble Shipmate
    edited February 20
    Fusion reactors are still some way off (unless someone can do a Tony Stark Arc Reactor).

    The present hopeful device is called a Stellarator, where the electromagnets which form the walls of the chamber are shaped to twist the superheated gas (plasma) into a ribbon shape instead of the more traditional donut. Keeping the plasma stable while getting it hot enough for atomic nuclei to fuse together is the challenge.

    TMI: https://physicsworld.com/a/new-mechanism-could-reduce-plasma-turbulence-in-stellarators/
  • ITER is likely to be the first fusion reactor to generate more energy than it takes to heat the plasma. But, at present, this will be for testing various components of the system and there's no plans to extract electricity from that energy. Current schedule is for first plasma at the end of 2025, but I suspect covid has delayed that a bit, and it was probably optimistic in the first place.
  • Dave WDave W Shipmate
    When I fantasize about fusion reactors, I prefer Commonwealth Fusion Systems.
  • ITER is likely to be the first fusion reactor to generate more energy than it takes to heat the plasma. But, at present, this will be for testing various components of the system and there's no plans to extract electricity from that energy. Current schedule is for first plasma at the end of 2025, but I suspect covid has delayed that a bit, and it was probably optimistic in the first place.

    That's a bit close isn't it Alan? The breakthrough is always a couple of decades away isn't it? This is one of the biggest rip offs ever perpetrated by @Arethosemyfeet's proper science practitioners, if not the biggest. Rationally it can't work, but never let that stop a scientist! Because empirically there is a 'finite' probability that it can technofix everything. Again, follow the money.
  • Yes, first sustained fusion reaction within 10y. Of course, there'll need to be some time to examine the data and learn from that, putting those lessons into the design of the next step which will be the first to supply electricity to the grid. So, the old "fusion generated electricity within 50y" may now be "within 20y" ... but, that's still too long to be a significant part of solving the current climate emergency and the need to radically de-carbonise.
  • Martin54 wrote: »
    ITER is likely to be the first fusion reactor to generate more energy than it takes to heat the plasma. But, at present, this will be for testing various components of the system and there's no plans to extract electricity from that energy. Current schedule is for first plasma at the end of 2025, but I suspect covid has delayed that a bit, and it was probably optimistic in the first place.

    That's a bit close isn't it Alan? The breakthrough is always a couple of decades away isn't it? This is one of the biggest rip offs ever perpetrated by @Arethosemyfeet's proper science practitioners, if not the biggest. Rationally it can't work, but never let that stop a scientist! Because empirically there is a 'finite' probability that it can technofix everything. Again, follow the money.

    It's in that fuzzy boundary between investment and gambling. Energy from fusion is such a shiny, valuable bauble that almost any feasible amount of time, money and effort could be justified if one could be sure of achieving it. And I think it's eminently achievable, as the issues are technological now rather than scientific. This separates it from something like sapient AI, where we're not even sure it can be done, nevermind how to do it. In some ways even FTL travel is more feasible than strong AI, as we can theorise ways FTL could work even if they require unobtanium to be realised.
  • They're all in the same pile of rainbow unicorn shit. What makes you think it's 'eminently achievable' now that there's a really cool mathematical model with a twist in it? The trouble with fusion is it's just one more mountain path rise away, whereas with AI and FTL especially, we know we've peaked. Only taxpayers - far worse led than shareholders - are dumb enough to finance fusion.
  • So @Arethosemyfeet, I should have addressed you in the above.
  • Bugger. So[rry].
  • Fusion power has been 10 years away for my whole life. I expect my children will be able to say the same.
  • Most of my life it's been 30 years away ... but, if I live the rest of my life with it 10 years away I wouldn't be surprised (disappointed, but not surprised).

    If the issues of radioactive waste from fusion are sorted before they get the first reactor running would be even more surprising. I suspect that the same procrastination of dealing with that for fission reactors will be applied to fusion waste.
  • 30 years is politically unsustainable spending a billion a year of taxpayers' money on it, nothing as bad as the CAP of course (now down to only 37% of the £200bn budget from 73%), whereas 10 is keeping a bunch of techies happy in a Keynesian, bootstrap sort of way, getting non-stick frying pans as spin off boons to humanity. Some smart populist politician is going to target it soon enough.

    It . will . never . happen . . .

    Remember @Alan Cresswell there are no technofixes ; )
  • It will happen, and so will strong AI (unfortunately). No FTL though I'm afraid.

    So says the Turquoise Crystal Ball.
  • I think FTL is more likely than a general AI (despite having written repeatedly about the latter), in the sense that there may be ways of accessing dimensions where c is different and/or space is closer together. A general AI has to contend with things that aren't simply engineering solutions (no matter how boggling the engineering might be).
  • Martin54 wrote: »
    30 years is politically unsustainable spending a billion a year of taxpayers' money on it, nothing as bad as the CAP of course (now down to only 37% of the £200bn budget from 73%), whereas 10 is keeping a bunch of techies happy in a Keynesian, bootstrap sort of way, getting non-stick frying pans as spin off boons to humanity. Some smart populist politician is going to target it soon enough.

    It . will . never . happen . . .

    Remember @Alan Cresswell there are no technofixes ; )

    If it helps, 35 nations are sharing ITER development costs. However, right now Hinckley Point C’s £22 billion bill is all ours to pay back. Along with furlough borrowing etc.
  • Doc Tor wrote: »
    I think FTL is more likely than a general AI (despite having written repeatedly about the latter), in the sense that there may be ways of accessing dimensions where c is different and/or space is closer together. A general AI has to contend with things that aren't simply engineering solutions (no matter how boggling the engineering might be).

    But there is already a 40 watt meatware engineering solution to intelligence. I feel it must therefore be possible to do it with silicon, which is much more betterer.
  • Bill_Noble wrote: »
    Martin54 wrote: »
    30 years is politically unsustainable spending a billion a year of taxpayers' money on it, nothing as bad as the CAP of course (now down to only 37% of the £200bn budget from 73%), whereas 10 is keeping a bunch of techies happy in a Keynesian, bootstrap sort of way, getting non-stick frying pans as spin off boons to humanity. Some smart populist politician is going to target it soon enough.

    It . will . never . happen . . .

    Remember @Alan Cresswell there are no technofixes ; )

    If it helps, 35 nations are sharing ITER development costs. However, right now Hinckley Point C’s £22 billion bill is all ours to pay back. Along with furlough borrowing etc.

    Well, Hinkley is going to go straight on our electricity bills, no "paying back" as such. We'll need to pay the (minimal) cost of servicing the furlough debt but we've no need to rush repaying the principal.
  • DafydDafyd Shipmate
    edited February 22
    I should suspect that any method of achieving FTL that involves different possible worlds will have a hidden catch (e.g. the time it takes to switch possible worlds and back increases in proportion to the time the journey was reduced by) which means it ends up sublight overall.

    AIUI any effective form of FTL could be used to build a time machine; travelling backwards in time can be used to violate the Second Law of Thermodynamics; the Second Law of Thermodynamics wishes you luck with that.
  • Dafyd wrote: »
    I should suspect that any method of achieving FTL that involves different possible worlds will have a hidden catch (e.g. the time it takes to switch possible worlds and back increases in proportion to the time the journey was reduced by) which means it ends up sublight overall.

    AIUI any effective form of FTL could be used to build a time machine; travelling backwards in time can be used to violate the Second Law of Thermodynamics; the Second Law of Thermodynamics wishes you luck with that.

    I don't think we understand time well enough to make that assertion. I accept that it may end up being theoretically possible but practically not, but causality may well end up a casualty.
  • Backwards in what?
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