4 ms·

Delivering 4GW in a single project would certainly set it apart. Perhaps the sweet spot for nuclear is not the traditional 1GW level. Although that would crea

by 7952 6y ago

Delivering 4GW in a single project would certainly set it apart. Perhaps the sweet spot for nuclear is not the traditional 1GW level. Although that would create a very large single point of failure that would need peakers/batteries/pumped hydro to backup on failure. An interesting project would be to stick a 5GW reactor in the middle of the North Sea and run export cables to all the surrounding countries. Build near an old oil well for hydrogen storage and include a thermal hydrogen generator.

baybal2 6y ago
Yes, a 4GW reactor is certainly not for any country to build for above reasons (shut down a double digit of your generation every time you refuel.) Even moderately industrialised countries will think twice, but it is indeed very logical for top 10 economies. The biggest problem will be building a containment building this big. A dilemma it is. Containment building can't do anything about reactor explosion. Either steam explosion from Chernobil like event, or hydrogen explosion is not survivable by containment building of any reactor in service. And containment building for a reactor this big will be even less useful. This means abandoning them, and going for Chernobil like no containment building construction.
- fuoqi 6y ago
  >hydrogen explosion is not survivable by containment building of any reactor in service Or you can simply include specialized hydrogen burners like in the modern VVER reactors, which have complied with the post-Fukushima requirements even before the event has happened. Also a Chernobyl-like event is simply impossible on PWR reactors.
  - baybal2 6y ago
    > simply impossible on PWR reactors. Easily possible. I'll give you a few scenarios I came up within just minutes. Loss of coolant -> drop in reactivity -> overheat of core -> core melts, and falls into puddle of remaining water at the bottom of the reactor -> instant reactivity boost -> boom Loss of coolant -> drop in reactivity -> overheat of core -> coolant comes back -> water spayed onto hot fuel -> steam flash -> steam-cladding reaction -> boom
    - fuoqi 6y ago
      I can reply to you with only one thing: please, learn more about modern reactor designs and their safety systems, don't embarrass yourself. Also learn why the Chernobyl event was so nasty and why its impact is significantly bigger compared to Fukushima (hint: graphite moderation).
      - baybal2 6y ago
        Now, do us a favour, and tell us how that is not possible. You are embarrassing yourself here with lack of manners, and constant attacks. Behave yourself.
        fuoqi 6y ago
        It's unproductive to discuss such matters with a total layman who didn't bother to do even a basic research, but ok, I will play along. Let's start from the simplest thing: a Chernobyl-like event is impossible on PWR because they do not use graphite moderators. Simple, right? I could've finished on this, but let me educated you a bit more. Modern reactors have the following safety systems in place (it's not a full list): - Hydrogen burners (recombiners) mentioned in my previous comment, which significantly reduce amount of hydrogen inside containment. - Systems for fast automatic Boron injection. - Heat sink systems designed to work without electricity. - Passive cooling systems, which are significantly more reliable than the isolation condenser used on Fukushima-1. - A way of supplying additional coolant externally. - Core catchers which lead corium from the containment building. If you know Russian you can read for example this paper [0] from Gidropress (Rosatom subsidiary) to learn more about how modern nuclear reactors handle severe accidents associated with a total loss of electricity. It's about older VVER-1000 reactors, which are a bit less advanced than the newer VVER-1200 and TOI designs, but it should be a good starting point. [0]: http://www.gidropress.podolsk.ru/files/proceedings/mntk2019/documents/mntk2019-037.pdf http://www.gidropress.podolsk.ru/files/proceedings/mntk2019/...
        baybal2 6y ago
        > It's unproductive to discuss such matters with a total layman who didn't bother to do even a basic research, but ok, I will play along. I will play along too. It will be very surprising to me if you are an actual industry insider. You have not addressed the loss of coolant. > Let's start from the simplest thing: a Chernobyl-like event is impossible on PWR because they do not use graphite moderators. Simple, right? I could've finished on this, but let me educated you a bit more. Modern reactors have the following safety systems in place (it's not a full list): Power excursion is very well possible on PWRs during rapid coolant/pressure loss, especially with very fresh, or very old fuel. Positive scram is possible on PWRs too under condition when rods/poison rapidly reduce coolant temperatures. Boron injection will not work if your coolant went supercritical. Catalytic hydrogen recombiners can help with gradual hydrogen release, but would be of no use if you are hit with sudden release. Passive heat sinks will not do anything if you reactor already lost big part of its coolant. Etc, etc.
  - deleted 6y ago
    [deleted]
- phicoh 6y ago
  What do you do with this power if solar and wind are cheaper? I.e. in a free market, what if buyers prefer wind and solar energy? Do you dump the energy at a loss, go bankrupt leaving investors and banks to write off the cost? Why would anyone take that risk? Is there anyone willing to build such a powerplant at fixed cost? (i.e. after x billion euro you either get the plant or your money back) Obviously, the situation will change if hit the wall with wind and solar. But there are no reliable predictions if or when we would hit a wall.
  - baybal2 6y ago
    > What do you do with this power if solar and wind are cheaper? > Do you dump the energy at a loss Yes, if you dump energy at loss is still not a total loss, and you still make money if you above water longer than you aren't. The point of making the reactor that powerful is exactly to get more profit even at super low rates.
    - phicoh 6y ago
      That seems unlikely. If, for example, you run at a loss 50% for the time, then you need to have extra expensive rates during the other 50% of the time. Based on typical construction costs of nuclear power plants, those high rates are extremely attractive for competition from wind and solar. Which will reduce the amount of power that can be sold at premium rates, which requires even higher rates to compensate, etc. Basically, in a free market, nuclear power is competing with power from batteries, hydrogen, and other ways of storing electricity. This is an extremely unattractive market for nuclear.
petre 6y ago
No, the solution is building multiple sub 100 MW (NuScale Power and others) and a few sub 500 MW SMRs for major cities (think post VVER 440 designs and Rolls Royce SMRs). Gen VI+ has passive safety requirements that would render a multi GW plant too big and too expensive. Think huge tanks of water, double containment, passive circulation, gravitational safety features and minimal disruption of fisheries and habitats. We need smaller and more modular NPPs with reactor vessels built on an assembly line and QCed, good safety guarantees, minimal staff, minimal operational costs and the ability to regulate the energy output in a wider range.
- baybal2 6y ago
  Building smaller reactors in not as solution to nuclear's cost for many reasons I wrote above. Economics of small reactors is unsound. A cult like group pushing "small modular reactors" pushes a very likely deliberately miscalculated pricing estimates for them.
  - 7952 6y ago
    Some of the designs seem to have high civil engineering costs. Digging big holes is not exactly a cheap thing to do.

by 7952 6y ago

baybal2 6y ago

Yes, a 4GW reactor is certainly not for any country to build for above reasons (shut down a double digit of your generation every time you refuel.) Even moderately industrialised countries will think twice, but it is indeed very logical for top 10 economies. The biggest problem will be building a containment building this big. A dilemma it is. Containment building can't do anything about reactor explosion. Either steam explosion from Chernobil like event, or hydrogen explosion is not survivable by containment building of any reactor in service. And containment building for a reactor this big will be even less useful. This means abandoning them, and going for Chernobil like no containment building construction.

fuoqi 6y ago
>hydrogen explosion is not survivable by containment building of any reactor in service Or you can simply include specialized hydrogen burners like in the modern VVER reactors, which have complied with the post-Fukushima requirements even before the event has happened. Also a Chernobyl-like event is simply impossible on PWR reactors.
- baybal2 6y ago
  > simply impossible on PWR reactors. Easily possible. I'll give you a few scenarios I came up within just minutes. Loss of coolant -> drop in reactivity -> overheat of core -> core melts, and falls into puddle of remaining water at the bottom of the reactor -> instant reactivity boost -> boom Loss of coolant -> drop in reactivity -> overheat of core -> coolant comes back -> water spayed onto hot fuel -> steam flash -> steam-cladding reaction -> boom
  - fuoqi 6y ago
    I can reply to you with only one thing: please, learn more about modern reactor designs and their safety systems, don't embarrass yourself. Also learn why the Chernobyl event was so nasty and why its impact is significantly bigger compared to Fukushima (hint: graphite moderation).
    - baybal2 6y ago
      Now, do us a favour, and tell us how that is not possible. You are embarrassing yourself here with lack of manners, and constant attacks. Behave yourself.
      - fuoqi 6y ago
        It's unproductive to discuss such matters with a total layman who didn't bother to do even a basic research, but ok, I will play along. Let's start from the simplest thing: a Chernobyl-like event is impossible on PWR because they do not use graphite moderators. Simple, right? I could've finished on this, but let me educated you a bit more. Modern reactors have the following safety systems in place (it's not a full list): - Hydrogen burners (recombiners) mentioned in my previous comment, which significantly reduce amount of hydrogen inside containment. - Systems for fast automatic Boron injection. - Heat sink systems designed to work without electricity. - Passive cooling systems, which are significantly more reliable than the isolation condenser used on Fukushima-1. - A way of supplying additional coolant externally. - Core catchers which lead corium from the containment building. If you know Russian you can read for example this paper [0] from Gidropress (Rosatom subsidiary) to learn more about how modern nuclear reactors handle severe accidents associated with a total loss of electricity. It's about older VVER-1000 reactors, which are a bit less advanced than the newer VVER-1200 and TOI designs, but it should be a good starting point. [0]: http://www.gidropress.podolsk.ru/files/proceedings/mntk2019/documents/mntk2019-037.pdf http://www.gidropress.podolsk.ru/files/proceedings/mntk2019/...
        baybal2 6y ago
        > It's unproductive to discuss such matters with a total layman who didn't bother to do even a basic research, but ok, I will play along. I will play along too. It will be very surprising to me if you are an actual industry insider. You have not addressed the loss of coolant. > Let's start from the simplest thing: a Chernobyl-like event is impossible on PWR because they do not use graphite moderators. Simple, right? I could've finished on this, but let me educated you a bit more. Modern reactors have the following safety systems in place (it's not a full list): Power excursion is very well possible on PWRs during rapid coolant/pressure loss, especially with very fresh, or very old fuel. Positive scram is possible on PWRs too under condition when rods/poison rapidly reduce coolant temperatures. Boron injection will not work if your coolant went supercritical. Catalytic hydrogen recombiners can help with gradual hydrogen release, but would be of no use if you are hit with sudden release. Passive heat sinks will not do anything if you reactor already lost big part of its coolant. Etc, etc.
- deleted 6y ago
  [deleted]
phicoh 6y ago
What do you do with this power if solar and wind are cheaper? I.e. in a free market, what if buyers prefer wind and solar energy? Do you dump the energy at a loss, go bankrupt leaving investors and banks to write off the cost? Why would anyone take that risk? Is there anyone willing to build such a powerplant at fixed cost? (i.e. after x billion euro you either get the plant or your money back) Obviously, the situation will change if hit the wall with wind and solar. But there are no reliable predictions if or when we would hit a wall.
- baybal2 6y ago
  > What do you do with this power if solar and wind are cheaper? > Do you dump the energy at a loss Yes, if you dump energy at loss is still not a total loss, and you still make money if you above water longer than you aren't. The point of making the reactor that powerful is exactly to get more profit even at super low rates.
  - phicoh 6y ago
    That seems unlikely. If, for example, you run at a loss 50% for the time, then you need to have extra expensive rates during the other 50% of the time. Based on typical construction costs of nuclear power plants, those high rates are extremely attractive for competition from wind and solar. Which will reduce the amount of power that can be sold at premium rates, which requires even higher rates to compensate, etc. Basically, in a free market, nuclear power is competing with power from batteries, hydrogen, and other ways of storing electricity. This is an extremely unattractive market for nuclear.

petre 6y ago

No, the solution is building multiple sub 100 MW (NuScale Power and others) and a few sub 500 MW SMRs for major cities (think post VVER 440 designs and Rolls Royce SMRs). Gen VI+ has passive safety requirements that would render a multi GW plant too big and too expensive. Think huge tanks of water, double containment, passive circulation, gravitational safety features and minimal disruption of fisheries and habitats. We need smaller and more modular NPPs with reactor vessels built on an assembly line and QCed, good safety guarantees, minimal staff, minimal operational costs and the ability to regulate the energy output in a wider range.

baybal2 6y ago
Building smaller reactors in not as solution to nuclear's cost for many reasons I wrote above. Economics of small reactors is unsound. A cult like group pushing "small modular reactors" pushes a very likely deliberately miscalculated pricing estimates for them.
- 7952 6y ago
  Some of the designs seem to have high civil engineering costs. Digging big holes is not exactly a cheap thing to do.