Possibilities for Small Modular Nuclear Reactors?

[Diogenes]

I believe these Ideas have been discussed here before, but some people might not be familiar with them.


http://www.theoildrum.com/node/6751

[WizWom]

The Koreans have run with this idea; they plan to provide electricity to their outlying islands with small (~20 MWe) nuclear plants, since they have problems with consistent links between those islands and the mainland.

There are other places such plants would be very useful: Micronesia, the outback wilds of other nations, and, of course, ships and trains if they can be made hardy enough for transportation safety.

For instance, a modern locomotive might be 2000 HP; that's actually about 26 MWe - currently they generate that with a diesel generator system, and then use the electricity.

[Enginerd]

I believe these Ideas have been discussed here before, but some people might not be familiar with them.

Renewable energy such as solar, wind, and biodiesel do not seem to be sufficiently available. Burning oil, gas, and coal not only make a mess, but they also tend to finance despots (both corporate and political). The world clearly needs some type of nuclear power.

I would love to have a (working positive net Q) Polywell power plant in every town, village, and city. If that proves impossible, I would love to see a bunch of smaller thorium reactors dotting the world. But if the political and economic willpower to develop thorium is lacking, small uranium based pebble bed reactors, such as the one being built for Galena, Alaska, or the Hyperion HPM, seem pretty sensible.

The enormous light water reactors of years past dump their heat into convenient large rivers. In the very arid area I live, fresh water is becoming increasingly valuable and scarce. Smaller, high-temperature reactors, of whatever sort, using heat rejection to air, are going to be much more successful than conventional reactors that use water cooling. Which is why projects such as this one proposed to be built in the middle of the desert are IMHO a bad idea.

[93143]

For instance, a modern locomotive might be 2000 HP; that's actually about 26 MWe

You might want to check your numbers - 2000 hp is just shy of 1.5 MW...

[MSimon]

The problem with nukes is that you need very highly trained operators to avoid criticality accidents. Get that one solved and nukes will proliferate.

[WizWom]

For instance, a modern locomotive might be 2000 HP; that's actually about 26 MWe

You might want to check your numbers - 2000 hp is just shy of 1.5 MW...

I went backward; 1346 HP/MWe - teach me to post when I'm tired.

20MWe would be 26,000 HP; we don't NEED that much power on land.

Now, your typical jet airplane uses ~100,000 HP; that would be ~80MWe - which would be very cool to get with no refueling for years.

[WizWom]

The problem with nukes is that you need very highly trained operators to avoid criticality accidents. Get that one solved and nukes will proliferate.

Sub-critical accelerator driven. But that has the technical challenge of working out how to make a compact accelerator.

[Helius]

The problem with nukes is that you need very highly trained operators to avoid criticality accidents. Get that one solved and nukes will proliferate.

Or innocuous failure states.

We could start by removing the requirement that a hot reactor requires to run ant 160 BAR, and remove much Fission product on the fly or on a regular basis to prevent longer term decay heat generation.

During "Round One", AKA Generation ZERO through Generation III, It seems that use of natural safety features was more of an afterthought. An example being the positive reactivity coefficient of Chernobyl.

We'll get there, Once we're done with Windmills, solar panels, and algal Biomass, all being promoted by the Fossil Fuel companies, in order to keep the primacy of their core business.

[Enginerd]

The problem with nukes is that you need very highly trained operators to avoid criticality accidents. Get that one solved and nukes will proliferate.

Isn't the exactly the reason why small, unpressurized liquid sodium reactors such as the Toshiba 4S are being built -- to avoid all that tedious worry that something will go wrong when you have Homer Simpson at the controls?

[MSimon]

During "Round One", AKA Generation ZERO through Generation III, It seems that use of natural safety features was more of an afterthought. An example being the positive reactivity coefficient of Chernobyl.

US reactors have always been built with negative reactivity/temperature coefficient. At least for the PWRs.

[pennywise]

Another big problem of small-scale nuclear plants is their economical (non)competitiveness.

I'm sure you've all heard that comparison about shoemakers. A small manufacturer makes 500 pairs a week. Then you come and say "What would a pair for me cost?"
And ther we have another, big one, that makes 1 million per week. Your question is the same. Now is there anyone here willing to convince me, that a pair of shoes, made by bigger manufacturer won't be considerably cheaper?

We can draw the same paralell to power plants. In order to acquire cheap energy which would make our standard of living better, we must build units as big as technology and energy markets allow it (but not bigger).

AFAIK Westinghouse had to design 1GVA version of their nuclear plant, because 600MVA didn't sell. Not competitive enough.

[pennywise]

I'm sure small scale fission reactors will prove appropriate in distant places where power grid expand would be difficult and too expensive. While that kind of application might hold for them, they will not be able to replace standar big units.

As far as Polywell is concerned I guess it will be far more competitive than anything else, so no worries there.

[WizWom]

AFAIK Westinghouse had to design 1GVA version of their nuclear plant, because 600MVA didn't sell. Not competitive enough.

No, they have been going to larger and larger cores in order to save on the number of operators.

But the early plants were ~100-300 MW, and many countries are installing plants of this size still, even though they have demand the larger plants - because the smaller plants are cheaper to build.

For what its worth, in another thread there was mention of the PRISM setup, which is only 311MWe.

See http://www.world-nuclear.org/info/inf08.html

[Aero]

I'm sure small scale fission reactors will prove appropriate in distant places where power grid expand would be difficult and too expensive. While that kind of application might hold for them, they will not be able to replace standar big units.

As far as Polywell is concerned I guess it will be far more competitive than anything else, so no worries there.

Distant places or consumers of huge amounts of power. Aluminum refining comes to mind, as do petroleum refineries. Refineries currently use about seven percent of feedstock on site for energy and if that 7% of feedstock would pay for the life cycle cost of the nuclear power plant, it only makes sense to use one. Who can do the financial analysis?

[Helius]

Another big problem of small-scale nuclear plants is their economical (non)competitiveness.

I'm sure you've all heard that comparison about shoemakers. A small manufacturer makes 500 pairs a week. Then you come and say "What would a pair for me cost?"
And ther we have another, big one, that makes 1 million per week. Your question is the same. Now is there anyone here willing to convince me, that a pair of shoes, made by bigger manufacturer won't be considerably cheaper?

We can draw the same paralell to power plants. In order to acquire cheap energy which would make our standard of living better, we must build units as big as technology and energy markets allow it (but not bigger).

AFAIK Westinghouse had to design 1GVA version of their nuclear plant, because 600MVA didn't sell. Not competitive enough.

Your analogy breaks down, if the "shoe" was the power plant. As it stood in the past, each power plant was a "one of a kind"; whereas the new modular plants will be the standardized mass market product, the "shoe" in your analogy, where many identical products are produced.

I wonder if 3rd world poor will get the labor contracts for modular plants as they do now for shoes? Naaa. Prolly not.