Nuclear Reactors Final

I am getting bored of this topic, and I want to get to wind-solar-hydro so I can finish up with the energy technology stuff and write varied stuff. So I am going to compress it a lot. If anyone wants to see it expanded, let me know and I will take care of it later.

This post is about breeder reactors, thorium reactors, preventing nuclear proliferation, how the electricity costs stack up to other power plants, and why nuclear power is so expensive.

Nuclear power is expensive because the up-front costs are massive. The cleanest and most efficient coal fired power plants might cost a billion dollars to build. It might take 5 years to build it. Nuclear power plants seem to cost about $8 billion to build with all the safety features they use to prevent nuclear meltdowns (seriously, the new tech is very safe, and it shows in the cost). And they seem to take 8-15 years to build, depending on how much Greenpeace or pretty much every other group tries to stop construction via litigation. In other words, they take out an $8B loan and accrue interest for 8-15 years before they can start paying it back. Stuff costs a lot. Why do it? Cause nuclear waste can be contained, unlike the NOx and CO2 from natural gas and coal plants. Also, South Korea thinks it can build a nuclear plant a nuclear power plant in a short amount of time for only $5 billion. United Arab Emirates decided this was a good idea, and is buying four South Korean nuclear reactors to desalinate water.

Schematic of the South Korean nuclear power plant to be built in the United Arab Emirates, from link above.

The US Energy Administration Administration agrees that nuclear power is now less expensive than it used to be. I have ripped a table straight off their web page that shows it (see, I really am getting lazy in this post).

Table 1. Estimated levelized cost of new generation resources, 2018 
U.S. average levelized costs (2011 $/megawatthour) for plants entering service in 2018
Plant type Capacity factor (%) Levelized capital cost Fixed O&M Variable O&M (including fuel) Transmission investment Total system levelized cost
Dispatchable Technologies
Conventional Coal 85 65.7 4.1 29.2 1.2 100.1
Advanced Coal 85 84.4 6.8 30.7 1.2 123.0
Advanced Coal with CCS 85 88.4 8.8 37.2 1.2 135.5
Natural Gas-fired
Conventional Combined Cycle 87 15.8 1.7 48.4 1.2 67.1
Advanced Combined Cycle 87 17.4 2.0 45.0 1.2 65.6
Advanced CC with CCS 87 34.0 4.1 54.1 1.2 93.4
Conventional Combustion Turbine 30 44.2 2.7 80.0 3.4 130.3
Advanced Combustion Turbine 30 30.4 2.6 68.2 3.4 104.6
Advanced Nuclear 90 83.4 11.6 12.3 1.1 108.4
Geothermal 92 76.2 12.0 0.0 1.4 89.6
Biomass 83 53.2 14.3 42.3 1.2 111.0
Non-Dispatchable Technologies
Wind 34 70.3 13.1 0.0 3.2 86.6
Wind-Offshore 37 193.4 22.4 0.0 5.7 221.5
Solar PV1 25 130.4 9.9 0.0 4.0 144.3
Solar Thermal 20 214.2 41.4 0.0 5.9 261.5
Hydro2 52 78.1 4.1 6.1 2.0 90.3

 

Note that last column is $ per megawatt hour. It is the bottom line cost of producing power from that plant. First, what is dispatchable vs non-dispatchable? Dispatchable means you get it whenever you want it. You can ramp it up or down however you please. Non-dispatchable means that you depend on external factors, like the fickle winds of.. well.. winds?

Tangent! Winds are really just redistribution of energy from the equator to the poles. The sun shines more at the equator, heating it up, and then energy likes to move from areas of high energy to areas of low energy, so it does it using wind. And sometimes hurricanes. So really, wind power is just really inefficient solar power. You know what else is really inefficient (and slow) solar power? Hydrocarbons and coal. Cause they are really just buried plant and algae matter and such. That is tens to hundreds of millions of years old. So, coal and oil are really just really old, slow, and dirty solar power. Tangent done!

Tangent picture? This shows how the equator heats more than the rest of the earth. These extra heat has to redistribute to be more even. Hurricanes start near the equator cause of the heat there, then move away from it. from: http://oceanworld.tamu.edu/resources/oceanography-book/oceansandclimate.htm

Nuclear power is almost as cheap as coal power, and cheaper than clean coal (note, clean coal still produces a ton of CO _2 and NO _X )! What gives? How is nuclear so inexpensive? Well, we haven't built a nuclear power plant in the US in years. We don't know what it will actually cost. Those are just estimates. Also, people are quite scared of nuclear power. The cost of building nuclear power rises when you have environmentalists and NIMBY folks suing the pants off nuclear power developers. But let's make one thing clear: if the new generation of nuclear power plants are as inexpensive as they are supposed to be, the power is less expensive that all other power plants other than natural gas (note: the US does not have capacity to build more hydro power), and less expensive than even that if you account for NO X produced by and methane leaks associated with natural gas power (methane production and transport will always have leaks, and it is 23x as powerful a greenhouse agent as CO2).

Let's look at a few more things on the chart above. Remember when I said natural gas got cheap? Look at how cheap it is to produce power from natural gas on the chart above. Think anyone is building nuclear, solar, or offshore wind when you can build and deploy reliable natural gas power? Somehow, the answer to this is yes. Yes, people are building all these things, despite being expensive. Which is kind of cool.

Before moving away from costs, look at the variable costs. The variable costs are high for everything except renewables and nuclear. Why is this? Cause renewables and nuclear don't really use fuel. Yes, a nuclear plant uses fuel, but it costs almost nothing relative to the labor and the capital costs. All the cost of these is upfront CAPEX (capital expense), and then you get free power.

Finally, lets take a really close look at the variable costs. This link is pretty sweet for those of you interested. It contains variable costs for each power source. You can see that fuel is the bulk of cost of fossil steam plants, but less than a quarter of the total cost of nuclear, and nuclear fuel is 1/4 the price per energy unit than even dirt cheap natural gas.

Enough about costs! Onto breeder reactors!

In the first post I mentioned that one part of nuclear reactions is to give off neutrons. Sometimes instead of a neutron splitting an atom, the atom absorbs it. U-235 is the uranium we use in nuclear reactors. U-238 doesn't produce as much heat, cause it doesn't like to decay as fast, so it isn't viable nuclear fuel. Or is it?! U-238 is like a catcher in baseball. Except it catches neutrons. And then it incorporates them into its nucleus to become U-239. In other words, it really isn't like a catcher in baseball.

The breeder reaction series. From: http://nuclearpowertraining.tpub.com/h1019v1/css/h1019v1_76.htm

What's special about U-239? It decays rapidly through a special type of decay to become neptunium-239 and eventually plutonium 239! This process can extract up to 100x the energy from nuclear fuel. You know what's magic about that? Less nuclear waste produced. Also, you produce a ton of nuclear fuel this way. You can also use thorium-232, which then becomes uranium-233 after absorbing a neutron, which can in turn be used for nuclear fuel. Thorium is very cheap and very abundant. So the plutonium and uranium that is magically created through awesomely manipulating nuclear forces is then used in nuclear thermal reactors to produce power.

Nuclear proliferation!

Having a nuclear power plant does not mean you can make nuclear bombs. Nuclear bombs required U-235 enriched to a very high level. What exactly is enrichment? Natural uranium is less than a few percent U-235, the rest is U-238. The uranium comes as a solid, and is processed by making it dance with a bunch of flourine. UF _6 is produced, which is gasified uranium. The U-238 is slightly heavier than U-235, so it very very slowly settles to the "bottom" if you spin it very fast in centrifuges. Once you have enriched it to somewhere between 5 and 8%, U-235, it is good to go into a reactor and make energy. To make a bomb, you have to enrich it to around 90%. Enriching it further gets exponentionally more difficult. Getting from 50% to 70% is much more difficult than getting it from 10% to 50%. So making bombs is hard.

What about plutonium? Seems like any fool can make plutonium. And in fact, they can! All you have to do it get some U-235, wrap it in U-238, and you have make a breeder reactor in your back yard! This seriously happened. Someone made a breeder reactor in their garage at 17. And this wasn't one of those kids that comes from a brilliant family with a ton of money that goes to work in a world famous lab and 'discovers' a new technique under the watchful eye of one of the most brilliant researchers in the world. This was your every day kid who was just really interested in something.

Except that building a nuclear weapon from plutonium is even more difficult than from uranium. Cause when you make the plutonium, you always get a large amount of another plutonium isotope. The other isotope loves to go critical much earlier than Pu-239. Remember what happens to a potentially critical nuclear reaction when the fuel gets split up? No? Remember what happened to Chernobyl when a small gas explosion spread the core out everywhere? It completely shuts down the critical reaction. In other words, plutonium loves to accidentally blow up to early and just spread itself around without going critical. Not much of a weapon there. How do we have plutonium bombs then? Really smart people made special triggering mechanisms to make this happen. How do they do this? I dunno. If I did, I wouldn't be out in public writing a blog, I'd be doing super secret awesome research somewhere.

Turns out that only the US and a handful of other countries have figured this one out. So while any old fool can make a breeder reactor, the combined science of most nations is not good enough to figure out how to do it.

One last thing. If nuclear power is so difficult, how did so many countries get it? Well, US and Russia developed it. The US gave it to China at some point to balance some power issues with the Soviet Union. The US gave it to several other allies as well. The Soviet union gave it out some, too. China then distributed to crazies like North Korea years later, and Pakistan and India were given it through similar pathways. In other words, it is still pretty difficult to develop.

Hey, I just covered 4 whole things in one post, and managed to get more terrible jokes in. Awesome.

Aww darn, I forgot to include the small amount of original research I did on this topic. Next article

Thanks for reading

-Jason

One thought on “Nuclear Reactors Final

  1. Pingback: Wind Power | Jason Munster's Energy and Environment Blog

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