Conventional Nuclear (AKA Nuclear Fission) a thread for discussion of the pros / cons.

  • For relatively small turbines, stone and quartz have effectively infinite durability. We have stone structures that have stood for a thousand years in Europe. Due to its large footprint, it would work best if the tower had another functional use as a building, rather like the old wind mills of Europe.


    This website sings the praises of concrete as a wind turbine tower material.


    I accept most of their conclusion, but I think they overstate the matter. Using steel has not limited tower height to 80m. We already have steel towers about triple that. But concrete is a much cheaper and energy efficient material, within its limitations. High strength concretes are now routinely used with compressive strength of 100MPa. That is is 40% of the yield strength of low alloy structural carbon steel. For a material that has about 2% of the energy cost of steel on a volume basis. This is why concrete is such a ubiquitous material in the built world.


    Hybrid approaches probably offer the best options. Hexagonal cross section towers could have steel prestressed cables running through ducts in the concrete. This allows the tower to resist flexural loads using easily replaceable steel components. This avoids having to use fat Cross section towers that would otherwise be needed to absorb all forces compressively. Concrete has close to zero tensile strength. Loading concrete with embedded steel reinforcement is a good way of limiting its life to no more than a few decades. Prestressing cables are components that can be replaced when they reach the end of their fatigue life.

  • The problems with both PV and wind are outages, However reliable, there are weather conditions with low wind for days on end, and PV of course has limitations.

    Nuclear power has exactly the same outage problem -- only much worse! Nuclear plants often shut down abruptly in a SCRAM because of relatively minor problems. Plumbing problems are most common. Pipes are often clogged. In California, one shut down because a storm at sea stirred up seaweed that clogged the cooling water inlet pipe. These SCRAM events are seldom dangerous. They are usually resolved in a day or two, as I recall. (https://www.nrc.gov/reactors/o…ps-experience/scrams.html) However, they abruptly remove 1000 MW of power from the grid. You must have an alternative source of power available at a moment's notice, or there will be outages. Nuclear power plants going offline was the main cause of the Texas outages in 2021.


    Individual wind turbines also fail, but that only removes 1 or 2 MW from the grid, not 1000 MW. So, wind farms are more reliable and they require less backup than nuclear power plants. Furthermore, the main cause of wind power going off -- or decreasing -- is weather. Lack of wind, or too much wind. This can now be predicted about a week in advance with confidence. So, you know there will be a problem, and you can arrange to have some other source of electricity on line. For example, you might delay maintenance to a natural gas plant, knowing there will be little wind next week. Or, if you know there will be a lot of wind, you might schedule maintenance.


    Or, you need to have alternative forms of power available to fill the gaps. That might be conventional nuclear.

    Conventional nuclear cannot be used to fill in the gaps. That calls for a dispatchable generator of some sort. Nuclear power cannot be "dispatched" (turned on at moment's notice). It takes a day or two to turn on a nuclear plant, or turn it off. Furthermore, nuclear plants are terrifically expensive, so they have to run full time as baseline generators. Leaving one off for a day can mean you lose millions of dollars for the interest payments. The uranium fuel is relatively cheap compared to coal or natural gas, so it makes sense to run the plants day and night for as long as you can, until they have to be refueled, or undergo maintenance.


    Uranium fuel is cheap, but wind and sunlight cost nothing, so a nuclear plant that costs about as much as a wind turbine per kilowatt of capacity ends up being more expensive over the life of the system. Nuclear plants also need more maintenance than wind or solar, and they are much more expensive to decommission. The Vogtle nuclear plant in Georgia that costs three times more per kilowatt than the most expensive wind system ever made (in the north sea) is an economic nightmare that will never again be constructed.


    Coal is also unsuitable for dispatchable energy. Again, because the plant itself is so expensive, it has to be used for baseline generation. Also, you cannot have coal mines, miners, and railroad trains full of coal sitting on the sidelines, delivering fuel only when it is needed at irregular intervals. The mines and railroads will go bankrupt, as many of them done in recent years. Dispatchable sources nowadays include natural gas, hydroelectric, batteries, and 1 MW to 5 MW standby Diesel generators. (Those are the ones I have read about or visited. There may be others.) The Diesel generators are the cheapest per kilowatt of capacity, but the fuel is the most expensive, so they are best for occasional standby use. A tractor trailer sized 2 MW Diesel generator is fully automatic. There are no employees babysitting such generators. Leaving one turned off most of the time is not as expensive as sidelining a train full of coal.

  • Jed Rothwell, all power plants of all kinds experience component failures that cause them to trip offload. The fact that we see 4-5 trips every month in a US fleet of 100 PWRs and BWRs, does not seem to be strong evidence of poor reliability in light water reactors. Many of these faults will be corrected within hours. Some SCRAMS are actually planned events. And the important thing is they are not correlated. One trip does not lead to another, because they are caused by independent failures. This is a very different issue to the seasonal and daily intermittency associated with renewable energy sources. The problem here is regional fluctuations in the availability of the energy source. It effects all generators of that type simultaneously.


    Incidentally, you are aware of the large batteries that are installed between large windfarms and solar power plants and their grid connections? Many non-engineers think these are there for 'storage', I.e. to buffer intermittent energy generation. Their true function is a bit more complex. Wind turbines in a farm are not independently connected to the grid. Power electronics is used to synchronise individual turbines onto a common wave form that aligns with the grid sine wave. A single malfunctioning turbine can distort that waveform and result in frequency shifts that cause cascade failures leading to the entire farm dropping off grid. Individual turbines can trip off the busbar to prevent this from happening. The bigger the individual turbines, the larger the wave form distortion that a single point failure can cause and the greater the probability of tripping the whole farm off grid. The batteries are there to prevent frequency surges that would crash the entire grid and allow sufficient time for back up plants to activate. Those back up plants are usually gas turbines.


    The instability problems associated with trying to keep hundreds of individual wind turbines synchronised to a single grid connection, is one the things prompting a rethink in how these units are designed. In many ways it makes more sense fitting individual turbines with hydraulic pumps and connecting the hydraulic main to a single generator on the ground. A certain amount of storage is then provided by a flywheel on the central generating shaft.


    "Coal is also unsuitable for dispatchable energy. Again, because the plant itself is so expensive, it has to be used for baseline generation. Also, you cannot have coal mines, miners, and railroad trains full of coal sitting on the sidelines, delivering fuel only when it is needed at irregular intervals."


    Capital cost is not the primary reason why coal plants are unsuitable as back up power plants, though poor utilisation will damage their economics. Also, months worth of fuel is routinely stored in coal heaps ready to load into mills. Coal deliveries respond to long-term demand trends. Boilers, steam drums, pipework and turbines are thermally thick steel components. They require lengthy thermal soak time before a unit can be brought on load. That consumes fuel and boilers often have to be started using oil and gas. Even so, repeated thermal cycling between hot and cold conditions gradually knackers them. It pushes maintenance costs through the roof. It is a problem for any thermal power plant being used as back up, though gas turbines suffer the least.


    Nuclear power plants can shed load without tripping. It takes many hours to bring the plant back online from a cold start, but they can in principle operate at half load. The bigger problem is that reducing load means reducing reactivity with control rods. That distorts the flux profile of the core leading to uneven burn up in the fuel. You end up having the to refuel at about the same interval regardless of power history.

  • all power plants of all kinds experience component failures that cause them to trip offload. The fact that we see 4-5 trips every month in a US fleet of 100 PWRs and BWRs, does not seem to be strong evidence of poor reliability in light water reactors. Many of these faults will be corrected within hours. Some SCRAMS are actually planned events. And the important thing is they are not correlated. One trip does not lead to another, because they are caused by independent failures. This is a very different issue to the seasonal and daily intermittency associated with renewable energy sources.

    It is very different because:

    1. A nuke going offline can be catastrophic, as in Texas. Too much power is lost in an instant. That never happens with wind turbines.
    2. Intermittency and interruptions with wind and solar can be predicted a week ahead of time, so they can be prepared for. Most nuke SCRAM incidents are unplanned.
    1. Nuclear power plants can shed load without tripping. It takes many hours to bring the plant back online from a cold start, but they can in principle operate at half load.

    Yes, they can be run at half load, but that costs tremendous amounts of money. They are only profitable run at full power 24/7.

  • Also, months worth of fuel is routinely stored in coal heaps ready to load into mills. Coal deliveries respond to long-term demand trends.

    I meant that if you set up mines and railroads to deliver coal for continuous, 24/7 operation, you cannot dial down those deliveries to operate 3 days a week. You would have people, mining equipment and railroads sitting idle. That is what has happened with coal companies, which is why they are going bankrupt. A natural gas pipeline takes fewer people to operate, and it goes to several different customers (power plants or gas companies), so it can handle interruptions and variations more economically.

  • Coal is also unsuitable for dispatchable energy. Again, because the plant itself is so expensive, it has to be used for baseline generation.

    Coal is the cheapest energy source if you can dig it out just upfront at teh surface:


    But lignite is the dirtiest from of coal with a high P/S and mineral content. The energy cost from such a site are between 4-5 Cents kwh...

  • And no one here besides me has even mentioned the development of LTFR. This is the Conventional Nuclear Fission we should be all focusing into.

    This may be a good idea. It may be a sweet idea, as engineers say. I cannot judge. But I think the time for this has come and gone, just as it has for pebble bed reactors. The thing is, any fission reactor is inherently dangerous. It has long-lived radioactive materials. Wind and solar have two gigantic advantages over any fission reactor: 1. They are not inherently dangerous. 2. They are here, now, and getting cheaper and better every day.


    I have said this before, but it bears repeating. One of the most important keys to successful, profitable technology is getting there first. The winner is not necessarily the best, the cheapest, the optimum, or the most elegant design. It is whatever technology first starts to sell like hotcakes. That is why the PC became the standard in the 1980s, and why Microsoft Windows is still a derivative of the PC standard. The Mac was a better computer architecture, but the PC survives and even dominates many markets just because it got there first. This is called contingency and incumbency. See p. 63:


    https://lenr-canr.org/acrobat/RothwellJcoldfusiona.pdf


    The standard shift transmission with a clutch plate was a kludge. Ridiculous, inefficient, difficult to use, and the clutch plate quickly wore out. It was needed because you cannot stop an internal combustion engine (ICE). It stalls. You have to gradually transmit the power to wheels when the car starts up, without stopping the motor. If we invented ICE today, I expect we would come up with a better method, like the automatic shift. But the standard shift was used for more than a century, and it will probably last until the end of ICE technology a decade or two from now. It stuck around mainly because it worked and it got here first.


    Once a product begins to gain momentum over others, and it becomes the standard, it is very difficult for other products to catch up, even if they have important advantages. The price of the dominant product falls rapidly. It becomes a commodity. Technicians train in installation and maintenance, and they don't have time to learn a competing technology. Peripherals are developed. Regulations and infrastructure are built around it. So, even though a new nuclear reactor would have advantages over wind and solar, I doubt it could compete.


    The advantages of contingency and incumbency do not last forever. Eventually something much better comes along, and the old technology is finally laid to rest. Standard shift cars are hardly sold these days. All ICE cars will soon go out of production. Electric cars are better in many ways, and they will soon be cheaper, which is the most important advantage a product can have. Microsoft Windows may last decades longer. I cannot guess how long. It will remain backward compatible, because Microsoft does not want its customers thinking, "as long as my old software doesn't work, I might as well look at the Macs or some other platform." But, eventually, I am sure that some far superior operating system will arrive. It will not be backward compatible. It will be completely different. I suppose it will be based on massively parallel processing, with thousands of CPUs on one large chip. Or -- who knows? -- on laptop quantum computers. It will have much better AI, such as the ability to take dictation and output text, and to understand natural language.


    Sooner or later something much better than wind and solar will come along. I hope it is cold fusion, and it comes soon. But at this moment in history, wind and solar are the best ways to produce electricity. And electricity is rapidly becoming the best way to power automotive transportation (cars and trucks).

  • I agree with just about everything you say except i believe hydrogen is the future. The Infrastructure for electric is in its infancy. Natural gas lines are already in place and as you say, the first to the finish line isn't always the best choice

  • I am not buying a new car, I thought I could wait until the Tesla becomes more affordable in the second-hand car market. Guess I will have a long wait, but meanwhile we can join a car-sharing scheme, since most of the time they are not used but sit around collecting rust! Or maybe wait until a LENR-powered vehicle is eventually made!

  • The Infrastructure for electric is in its infancy.

    I think it is well developed. In any case, as I explained before, it has more than enough capacity to charge electric cars, as long as that is usually done at night. As I said, that takes about as much electricity per car as running a clothes dryer for two hours. At night the grid can easily support every house doing that.

    Natural gas lines are already in place

    There is a book about hydrogen fuel, "Tomorrow's Energy" (https://www.amazon.com/Tomorro…/dp/B08BT3T22V/ref=sr_1_1). It discusses pipelines. A hydrogen pipeline in Germany has been in use for decades. I think since the 1920s. It is safe. However, ordinary pipelines for natural gas cannot be used for hydrogen. The hydrogen leaks too much. I think the book -- and other sources -- say pipelines might be retrofitted with new internal liners and valves, but that would cost a lot of money. (It has been a while since I read the book, so I don't recall the details.) Charging electric cars is much cheaper. No new infrastructure needed.


    An NREL study in 1992 concluded that electric cars use less energy overall than hydrogen vehicles. See Table A3:


    https://www.lenr-canr.org/acrobat/NRELenergyover.pdf

  • There’s a number of startups working in the so called “molten salt” reactor concept. Here just one example from Copenhague. They have a long headstart over cold Fusion considering the technology was tested to the MW scale more than 6 decades ago.

    OUR TECHNOLOGY | Seaborg
    www.seaborg.com

    I certainly Hope to see LENR helping humans to blossom, and I'm here to help it happen.

  • I don't claim much expertise with this stuff, but from a cursory google you would needs to review several 100 papers 9or else find a well-focussed review) to know what work has been done.


    Now - you are going further than filed anisotropy due to discrete neutrons and protons, and asking what is the additional anisotropy due to the fact that the fundamental constituents on nuclei are quarks.


    Here is a good lay-person's intro to the interior parton model of the proton, and the deep inelastic scattering data that provides experimental evidence for this

  • The Toyota "Mirai" car is powered with hydrogen fuel cells. If Toyota and others had begun intensive development of that technology back when electric cars and batteries were still on the back burner, it might have ended up better than batteries. But that did not happen. As I said above, batteries got here first, which is a nearly unbeatable advantage in business. A competing technology that arrives later will only win out if it has massive advantages over the existing dominant technology. Hydrogen cars do have advantages, especially in range, but they are not large. I do not think the advantages are big enough to make hydrogen cars economically viable.


    If electric cars still had a maximum range of 100 miles, the Mirai 400-mile range would be a huge advantage. But most electric cars now get between 200 and 300 miles, so 400 miles is no longer a killer advantage. If you need a long range electric car, the premium you pay for that is not high. The Leaf SV model has a 150 mile range and costs $28,800. The S model with a 226 mile range is $32,400. If you need the range, the $3,600 premium will be worth it to you.


    You can see examples of giant advantages versus marginal competitive advantages in many products, such as laptop computer screen resolution, or nowadays, desktop computer CPU speed. Speed used to matter a lot but nowadays most users are not willing pay a premium for it. (But I did! I have an i9-10900.)


    "Mirai" means "future," which is a melancholy name, because I think this vehicle has no future. A group of engineers put their best years into this, but their work was in vain.


    I do not think hydrogen has a future in automotive transportation. It might be used as an energy storage and transport medium. Suppose there was a massive array of solar panels in the U.S. southwest. (https://www.nrel.gov/gis/asset…ghi-2018-usa-scale-01.jpg) The population is low there. The electricity might be stored during the day as hydrogen. It might be sent to population centers in hydrogen pipelines. It would cost a lot to retrofit most natural gas pipelines to carry hydrogen, but retrofitting a few of them, or building some new ones, would not cost as much. Nowadays, I believe the plan would be to store solar energy in batteries, and send it to populated areas by conventional high voltage power lines. Hydrogen might work better. I wouldn't know.


    Note that in many markets, such as Atlanta or Hiroshima, it makes no sense to store solar electricity in batteries or anywhere else. Peak demand is caused by air conditioning. Air conditioning use is highest when the sun is brightest. So, solar peaks exactly when you need it most. You should use it all at that moment. If solar was 30% of all electricity, perhaps it would make sense to store it, but if it is only ~5% in Atlanta, it should be used immediately.