The Rise of Small Nuclear Plants

ColdWetDog writes "The Oil Drum (one of the best sites to discuss the technical details of the Macondo Blowout) is typically focused on ramifications of petroleum use, and in particular the Peak Oil theory. They run short guest articles from time to time on various aspects of energy use and policies. Today they have an interesting article on small nuclear reactors with a refreshing amount of technical detail concerning their construction, use, and fueling. The author's major thesis: 'Pick up almost any book about nuclear energy and you will find that the prevailing wisdom is that nuclear plants must be very large in order to be competitive. This assumption is widely accepted, but, if its roots are understood, it can be effectively challenged. Recently, however, a growing body of plant designers, utility companies, government agencies, and financial players are recognizing that smaller plants can take advantage of greater opportunities to apply lessons learned, take advantage of the engineering and tooling savings possible with higher numbers of units, and better meet customer needs in terms of capacity additions and financing. The resulting systems are a welcome addition to the nuclear power plant menu, which has previously been limited to one size — extra large.'"

Comments

Re:The Navy?

[Chris Burke]

I would assume the nuclear plants found on submarines and large warships both provide a lot of energy and are not in the category of 'extra large.'

Nor are they in the category of "economical", which is what was meant by "the prevailing wisdom is that nuclear plants must be very large in order to be competitive." Economically competitive, you see. Something the Navy cares about far less than, well, basically every other factor that goes into the design of a naval nuclear power plant.

Macondo blowout?

[Hatta]

Let's call it what it is. The BP disaster.

Re:This is good.

[JackCroww]

I recently was part of a discussion about energy here in the US and this was my brother's contribution:

It's quite simple, actually. The United States has not built a nuclear power plant since the seventies. Almost all of the plants we built then, and all of the plants that are still online, are pressurized light water (PLW) designs. This means that that coolant in the reactor, which also moderates the nuclear reaction, is ordinary water under great pressure (typically at least twice the industrial norm of 600 lb/in^2 steam). A PLW reactor produces as much plutonium 239 as it consumes uranium 235. We erroneously call Pu-239 nuclear waste, and the governments since the Clinton Administration have been looking to find a place to bury it for a quarter of a million years.

However, until the Clinton administration, your government was busy designing a better reactor. The program was called integral fast reactor, or IFR. IFR was a metal-moderated reactor. The coolant was liquid metal, sodium or lead. These elements don't moderate the neutrons, they fly unhindered through the pile. That means they can fission Pu-239. In fact, they can fission anything higher than uranium on the periodic table. That's not all a fast reactor can do, though. It can also turn anything on the other (left) half of the bottom row of the periodic table into fissionable material. That's what "fast" means in the name. The reactor produces its own fuel from thorium or uranium in its natural state! Just the uranium that has been mined to date, which we use for cannon shells once we've taken the U-235 out of it, is sufficient for 300-400 years of the US energy needs. The known reserves are good for 50,000 years or so. Uranium is more plentiful in the earth's crust than gold or tin, and there is three times as much thorium as uranium. Energy forever.

What does "integral" mean? It means that the fuel is recycled on-site. The fuel in the IFR is in metallic, rather than ceramic form. It is simply re-smelted periodically (not the whole load, just a few rods' worth), and the slag is the only waste. The balance of the fuel plus a tiny bit of uranium or thorium in its natural state, is recast into pellets and returned to the reactor. The volume of the nuclear waste is reduced by several orders of magnitude. The nature of the waste is only the light elements that are the products of the fission reaction. They have either extremely short half lives, measured in seconds to months, or such long half lives that they are essentially stable. They are also mainly low-energy beta emitters, instead of neutron and gamma emitters. While this waste is hellishly radioactive at first, it will be less radioactive than uranium ore in less than 300 years, and reactors might produce a couple hundredweight in a fifty year lifespan, instead of thousands of tons of spent fuel rods as a PLW reactor would.

Additional benefits of the IFR design? The fuel is in metallic form, suspended in liquid metal. It gets no hotter than the coolant, and thus cannot have a catastrophic loss of coolant, or "blow down", which is what happens if there is a leak in the primary circuit of a LWR. The fuel in a LWR is in ceramic form, and gets much hotter than the coolant (which is in turn much hotter than liquid sodium). If it were not continuously cooled, it would destroy its container and melt, hence the term "melt down." If that happens to enough fuel elements in a reactor, the fuel gathers at the bottom of the vessel and continues to react, until it melts through the bottom of vessel, or the "china syndrome." None of these is possible with the IFR design. As it gets warmer, the fuel assemblies expand and move away from each other, slowing or stopping the reaction. The IFR, in fact, was tested for this. They turned off the control system. The reactor heated slightly, and stopped working. The cut off the heat exchanger (simulating what happens if the heat exchanger or a turbine goes bad at a LWR plant)--same thing. The reactor heated slightly and shut itself down,

Re:This is good.

[Urza9814]

Saying nuclear won't fulfill our needs because of "peak Uranium" is at best stupid, at worst a lie to try to stop development of nuclear power. We likely have enough fuel (Uranium, Thorium, Plutonium, etc) for _thousands of years_ at our current energy consumption. That's the electrical grid, cars, everything. If we can just make everything run on electricity and build the best reactors our scientists can design, we would be fine for hundreds of years at a _minimum_. And I think it's safe to assume we'd be switched over to fusion by then :)

The problem is not the technology, it's not the resources, it's the regulations and the industry. We aren't building new plants because power companies aren't willing to invest large sums of money. Because regulations make it hard for them to _acquire_ large amounts of money (limits on how much profit utilities can take in.) We can't build breeder reactors because, for an extremely short period of time, they produce enriched uranium. Without breeder reactors, we can't take care of the waste problem because it lasts freakin' forever (without breeder reactors) and nobody wants it stored or transported anywhere within a thousand miles of them.

If you got a bunch of engineers and said "figure out how to solve our energy problem", they could throw together a nuclear power system that could power the world into the next millennium - and it would be cheap, it would be clean, and it would be safe. It's only restrictions like "you can't create highly radioactive products, even for a few seconds, you can't build anything big, you can't build anywhere near populated areas, and you can't use the word 'radioactive' or 'nuclear'" that causes problems.

Re:This is good.

[Firethorn]

I'd recommend looking at this post.

First, the nuclear power industry pretty much has the best safety record going. Per dollar of product produced, it kills the least amount of people. Let's see, in the past decade it's killed, what, 3 people (the 3 Japanese workers in a reprocessing plant that got stupid by using a steel bucket instead of the multi-million machine intended for the purpose). Just this year, in the USA, for oil and natural gas we have the Deepwater horizon, which killed 11. China regularly loses hundreds each year, we lost 25 in the explosion at Massey this year. 34 miners lost their lives the year before in various incidents.

Second - Let's look at Yankee Rowe - third commerical nuclear reactor. Shut down early due to concerns that the reactor vessel might be becoming brittle.
Cost: $36M in 1960, $209M in 2k dollars
Decommission: $450M($567M), worst case. $320M($403M) is the 'basis average'.
During it's life, Yankee Rowe produced 34 Billion kwh, achieving a sub-performing 74% capacity factor - most of the newer reactors still in service are well over 90%.
So, going by an average 3 cents a kwh, that's $1.02B in electricity produced. That leaves $244M for operations and profit during it's time. So not very expensive, though not as good as would be hoped. If you go by the worst case decommission costs. Basis average would be a lot better, as would it have been if the reactor had lasted it's expected lifetime.

Third - You have got to be kidding me. 19.4% in 2007

Fourth - So nuclear power needs loan guarantees to proceed. Wind and Solar power need cash subsidies, often in excess of half their cost! Heck, your 'clean coal' got more subsidies than nuclear - $29.81/MWh for 'clean coal', Solar $24.34 and wind around $23.37, nuclear got only $1.59/MWh

In total dollars:
Refined Coal: $2,156M
Solar: $14M
Wind: $724M
Nuclear: $1,267M

The biggest problem with coal is air pollution. There is technology available to reduce pollution to negligible levels, but nobody wants to use it because it's "too expensive". Instead of flushing a few Billion down the toilet with nuclear power, we could put that money into clean coal technology.

Still have the problems with fly ash and such, so it's still not 'clean', and at that point your 'clean coal' is more expensive to install than nuclear, as well as more expensive to operate.

Thorium Power

[hydromike2]

The future of energy is in thorium. It a) cant be weaponized, b) is cleaner, c) does not need to be throttled up like uranium. They are developing these plants in other parts of the world such as india.