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Nuclear Reactor Simulator

dalton-nrs.manchester.ac.uk

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Re: Nuclear Reactor Simulator

#111

Post by Retric »

jtriangle wrote: post #106
Retric wrote: post #103

Earlier quoted context omitted.

Yes, thus the term base load power. However, while a 1GW nuclear power plant is only ~6,000$ an hour in fuel costs that still adds up. So, curtailing nuclear in favor of solar/wind with zero fuel costs is still a net gain assuming it’s not going to cause other issues. Further the massive ramp off of these sources is becoming a serious issue for the nuclear industry.

Solar/wind don't have fuel costs, but they do have maintenance costs, and they tend to get replaced fairly often relative to nuclear installations, and while none of the above lasts forever. Like a modern wind turbine is rated at 20 years, but most installations are operating at half that in favor of installing larger turbines instead of using existing turbines that produce less power. Gridscale solar is much in the…

> so you need base load

First base load isn’t a benefit it’s a downside. The ideal generation has low fixed cost per kWh and flexible generation right now that’s hydro where you get a limited number of kWh per month but have a lot of flexibility when in the month you’re producing power. Natural gas turbines fill the same niche at higher cost per kWh which opens the door for “base load” generation as long as it’s cheap enough.

What’s really scaring nuclear is battery backed solar as ~5 year construction timelines + 50 year lifespan means they need to complete not just with todays low prices but solar and battery prices from 5 and 55 years from now. Battery backed solar is lower risk and similar ROI today, but projecting forward things keep getting worse for nuclear.

> Gridscale solar is much in the same situation, where, the panels themselves are rated for 25-ish years, but, are replaced early in favor of something newer and more productive.

That never really happens for grid scale installations. Land costs are seriously negligible unlike roof space which is more limited.

1 acre of solar farm in a decent location for solar generates ~500,000 kWh per year. Ex: https://en.wikipedia.org/wiki/Springbok_Solar_Farm At even extreme land costs of say 1,000$/acre per year you’re only adding 0.02c/kWh as in 2 / 100th of 1 cent per kWh.

Old solar farms are almost pure profit. There’s literally 30 year old solar panels still in operation and little reason to replace them any time soon. Sure, old panels are lower efficiency but not low enough to really matter here.

Re: Nuclear Reactor Simulator

#112

Post by synecdoche »

jtriangle wrote: post #104
omneity wrote: post #99

Earlier quoted context omitted.

Do you mean PID controllers?

Programable Industrial Controllers. That can include PID, or it can be far smarter or dumber. The idea behind them is, you have purpose built, redundant, single purpose controllers for everything, so, swapping one out is no big deal, and doesn't require any knowhow. You load the config, plug it in, done. Usually they're very simple, doing jobs like "read this sensor(s) every X miliseconds, make adjustments to this ou…

A cursory search for Programable Industrial Controller gave me no hits apart from PLCs. Those would typically contain PID controllers. Could a link be provided to a PIC as meant here?

Re: Nuclear Reactor Simulator

#113

Post by nine_k »

topherclay wrote: post #108
jtriangle wrote: post #80

Earlier quoted context omitted.

I think the idea is that this is sped up significantly. Also, in real life, there's not a human twisting the dials for "more steam" or "more reactor", that's undoubtedly handled with PIC controllers and software. Humans are just keeping an eye on things and running checklists when the software doesn't respond properly.

Why are you telling him what you think the idea is when he is the one who wrote it?

Verifying that your idea is understood by the audience the way you had planned is important for almost any author.

Re: Nuclear Reactor Simulator

#115

Post by cyberax »

ok_dad wrote: post #55
tiffanyg wrote: post #54

Earlier quoted context omitted.

Thank you so much for sharing that! Beautiful / elegant and simple! It's been decades since I looked at any of the details involved in any of the various types of reactors that have been designed. When I did, in the past, I hadn't even encountered concepts like "control theory" or spent any time with the subject matter of "systems engineering" or even "chemical engineering". I.e., areas where you start thinking about…

The Chernobyl disaster was partly because the design was graphite moderated, which does not have the safety that water does since it’s not self regulating due to the GPs explanation about that above. When the reactor started to go supercritical, it was reinforced by the moderator working better to create more neutrons, the opposite of what you’d want.

It's a tad more complicated. Light water is both a good neutron moderator _and_ a good neutron absorber.

If you vaporize the water, thus reducing its density, it reduces both the neutron absorption, and it reduces the moderation efficiency. But crucially, the moderating efficiency matters much more in regular reactors, so the overall reactor power will drop.

In a graphite-moderated reactor, water's moderating efficiency might not matter much. So if you vaporize the water, there's going to be less neutron absorption, but there's still going to be plenty of graphite moderator to help neutrons to slow down. So the reactor power will _increase_ unless compensated by other means, and this can result in a self-reinforcing loop (see: Chernobyl).

BTW, the neutron absorption is the reason it's very hard (though not impossible) to make water-cooled breeder reactors that produce more nuclear fuel than they consume.

After the Chernobyl disaster, several remaining RBMK reactors were made safer by enlarging the cooling channels. This increased the amount of water present in the core, thus increasing the dependency on water's moderating effect, greatly reducing the positive void coefficient. It couldn't be completely eliminated, but it was reduced to a level where it can't result in prompt criticality anymore.

Re: Nuclear Reactor Simulator

#116

Post by cyberax »

ok_dad wrote: post #55
tiffanyg wrote: post #54

Earlier quoted context omitted.

Thank you so much for sharing that! Beautiful / elegant and simple! It's been decades since I looked at any of the details involved in any of the various types of reactors that have been designed. When I did, in the past, I hadn't even encountered concepts like "control theory" or spent any time with the subject matter of "systems engineering" or even "chemical engineering". I.e., areas where you start thinking about…

The Chernobyl disaster was partly because the design was graphite moderated, which does not have the safety that water does since it’s not self regulating due to the GPs explanation about that above. When the reactor started to go supercritical, it was reinforced by the moderator working better to create more neutrons, the opposite of what you’d want.

> supercritical

All reactors are technically supercritical. Chernobyl reactor became _prompt_ _critical_.

Normally, a small amount (just around 0.2%) of fission neutrons are emitted within a 1-3 seconds after a fission event. They are called "delayed neutrons", and this small percent of delayed neutrons is what pushes a reactor over the criticality threshold.

Since these neutrons are delayed, it gives enough time for control systems and natural feedback mechanisms to keep the reaction rate steady.

If you push your reactor past the delayed neutrons so that there are enough of prompt neutrons to sustain the criticality, you're screwed. The reaction rate can double within microseconds, far too fast for anything macroscopic to react. So within less than a millisecond your reactor can overheat, until the nuclear fuel becomes too hot to fission because its atoms move too fast (usually somewhere around 1000C).

And then it'll be followed by some extreme thermodynamics and chemistry: steam explosion, water-zirconium reaction, graphite moderator fire, etc.

Here's a research reactor that does prompt criticality excursions in controlled conditions: https://www.youtube.com/watch?v=pa0Fmcv83nw (with a countdown!)

Re: Nuclear Reactor Simulator

#117

Post by Y_Y »

synecdoche wrote: post #112
jtriangle wrote: post #104

Earlier quoted context omitted.

Programable Industrial Controllers. That can include PID, or it can be far smarter or dumber. The idea behind them is, you have purpose built, redundant, single purpose controllers for everything, so, swapping one out is no big deal, and doesn't require any knowhow. You load the config, plug it in, done. Usually they're very simple, doing jobs like "read this sensor(s) every X miliseconds, make adjustments to this ou…

A cursory search for Programable Industrial Controller gave me no hits apart from PLCs. Those would typically contain PID controllers. Could a link be provided to a PIC as meant here?

Did you google it without quotes?

https://www.google.com/search?q=%22Programable+Industrial+Co...

In am effort to relate to their userbase big G has made their search engine just search for whatever the fuck instead of what it was asked for, sometimes some combination of quotion marks and verbatim mode will trick it into being useful.

Re: Nuclear Reactor Simulator

#118

Post by Duanemclemore »

MadnessASAP wrote: post #28
cratermoon wrote: post #13

The very first nuclear plant simulator I ever played with was a primitive text-based program, running on a DEC 11/780. To win the game you had to average a certain number of MWh over each turn (days). It seemed easy, just turn it on and let it run, but there was a catch. The game simulated normal fatigue, meaning that the longer it ran, the more likely something would go wrong. Also, the higher power you ran, the fas…

Might it have been Oakflat Nuclear Power Plant Simulator[1] you're thinking of? I'm not aware of a version that ran on the DEC but it might very well have existed and it sounds quite similar. I can certainly credit it for developing my unhealthy fascination with nuclear power. Also perhaps my unhealthy tendency to push buttons and see what happens! [1] https://www.mobygames.com/game/62490/the-oakflat-nuclear-pow...

I never realized this was the one I had on both C64 and DOS! When I played C64 I was too young (4-5yo) to actually play it. And the DOS version came on one of those disks comprised of half freeware games, half bootleg games. (Back when you could still buy those at legit retailers). Anyway that's germane because I seem to remember that once the reactor powered up it would immediately meltdown. I realized at the time - I think this was the developer's copy protection. Which struck me as much more entertaining and clever than just not working if it was a bootleg copy.

Re: Nuclear Reactor Simulator

#119

Post by preisschild »

Ericson2314 wrote: post #64
niekze wrote: post #41

Former US Navy submarine nuclear reactor operator here. Adjusting the steam output was kind of strange. On a submarine, the steam used to propel the submarine dwarfs all the other steam loads. As a result, there's a throttleman who controls that. Even though this simulation is simplified, it's not too bad. It does hide some of the really interesting aspects of a water cooled/moderated nuclear reactor. The most intere…

I know land vs sea is different, but after decades of nuclear submarines working beautifully it's just so sad to me we don't have abundant SMRs by now.

Large nuclear reactors have better economics (per energy produced) than small reactors due to economy of scale benefits.

But SMRs can still be useful for small towns, remote communities, district heating, process heat for nearby industry and so on.

Re: Nuclear Reactor Simulator

#120

Post by azan_ »

einpoklum wrote: post #72
benjojo12 wrote: post #43

Earlier quoted context omitted.

I am one of the programmers that worked on this port back in 2013, I can assure you that we (the programmers) also wanted to make a scenario where the plant would explode, however given it was designed to promote nuclear technology to school children (generally speaking), the people funding the project were not so keen to have nuclear technology shown off in that way!

> however given it was designed to promote nuclear technology to school children ... and that was not a problem for you ethically?

What ethical problem would you have here?
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