Tag Archives: waste

Alice’s Restaurant and Nuclear Waste

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It’s not uncommon for scientists to get inspiration from popular music. I’d already written about how the song ‘City of New Orleans’ inspires my view of the economics of trains, I’d now like to talk about dealing with nuclear waste, and how the song Alice’s Restaurant affects my outlook.

As I see it, nuclear power is the elephant in the room in terms of clean energy. A piece of uranium the size of a pencil eraser produces as much usable energy as three rail cars of coal. There is no air pollution and the land use is far less than for solar or wind power. The one major problem was what to do with the left over eraser-worth of waste. Here’s the song, it’s 18 1/2 minutes long. The key insight appeared in the sixth stanza: “…at the bottom of the cliff there was another pile of garbage. And we decided that one big pile Is better than two little piles…”

The best way to get rid of nuclear waste would be (as I’ve blogged) to use a fast nuclear reactor to turn the worst components into more energy and less-dangerous elements. Unfortunately doing this requires reprocessing, and reprocessing was banned by Jimmy Carter, one of my least favorite presidents. The alternative is to store the nuclear waste indefinitely, waiting for someone to come up with a solution, like allowing it to be buried in Yucca Mountain, the US burial site that was approved, but that Obama decided should not be used. What then? We have nuclear waste scattered around the country, waiting. I was brought in as part of a think-tank, to decide what to do with it, and came to agree with several others, and with Arlo Guthrie, that one big pile [of waste] Is better than two little piles. Even if we can’t bury it, it would be better to put the waste in fewer places (other countries bury their waste, BTW).

That was many years ago, but even the shipping of waste has been held up as being political. Part of the problem is that nuclear waste gives off hydrogen — the radiation knocks hydrogen atoms off of water, paper, etc. and you need to keep the hydrogen levels low to be able to transport the waste safely. As it turns out we are one a few companies that makes hydrogen removal pellets and catalysts. Our products have found customers running tourist submarines (lead batteries also give off hydrogen) and customers making sealed electronics, and we are waiting for the nuclear shipping industry to open up. In recent months, I’ve been working on improving our products so they work better at low temperature. Perhaps I’ll write about that later, but here’s where you’d go to buy our current products.

Robert Buxbaum, July 4, 2021. I’ve done a few hydrogen-related posts in a row now. In part that’s because I’d noticed that I went a year or two talking history and politics, and barely talking about H2. I know a lot about hydrogen — that’s my business– as for history or politics, who knows.

Recycle nuclear waste

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In a world obsessed with stopping global warming by reducing US carbon emissions, you’d think there would be a strong cry for nuclear power, one of the few reliable sources of large-scale power that does not discharge CO2. But nuclear power produces dangerous waste, and I have a suggestion: let’s recycle the waste so it’s less dangerous and so there is less of it. Used nuclear fuel rods, in particular. We burn perhaps 5% of the uranium, and produce a waste that is full of energy. Currently these, semi-used rods are stored in very expensive garbage dumps waiting for us to do something. Let’s recycle.

I’ve called nuclear power the elephant in the room for clean energy. Nuclear fuel produces about 25% of America’s electricity, providing reliable baseline generation along with polluting alternatives: coal and natural gas, and less-reliable renewables like solar and wind. Nuclear power does not emit CO2, and it’s available whether or not the sun shines or the wind blows. Nuclear power uses far less land area than solar or wind too, and it provides critical power for our navy aircraft carriers and submarines. Short of eliminating our navy, we will have to keep using nuclear.

Although there are very little nuclear waste per energy delivered, the waste that there is, is hard to manage. Used nuclear fuel rods in particular. For one thing, the used rods are hot, physically. They give off heat, and need to be cooled. At first they give off so much heat that the rods must be stored under water. But rod-heat decays fractally. After ten years or so, rods can be stored in naturally cooled concrete; it’s still a headache, but a smaller one The other problem with the waste rods is that they contain about 1.2% plutonium, a material that can be used for atomic bombs. A major reason that you can’d just dump the waste into the ocean or into a salt mine is the fear that someone will dig it up and extract the plutonium for an a- bomb. The extraction is easy compared to enriching uranium to bomb-grade, and the bombs work at least as well. Plutonium made this way was used for the bomb that destroyed Nagasaki.

The original plan for US nuclear power had been that we would extract the plutonium, and burn it up by recycling it to the nuclear reactor. We’d planned to burry the rest, as the rest is far less dangerous and far less, long-term radioactive. We actually did some plutonium recycling of this sort but in the 1970s a disgruntled worker named Silkwood stole plutonium and recycling was shut down in the US. After that, political paralysis set in and we’ve come to just let the waste sit in more-or-less guarded locations. There was a thought to burry everything in a guarded location (Yucca Mountain, Nevada) but the locals were opposed. So the waste sits waiting to leak out or be stolen. I’d like to return to recycling, but not necessarily of pure plutonium as we did before Silkwood: there is no guarantee that there won’t be other plutonium thieves.

Instead of removing the plutonium for recycling, I’d like to suggest that we remove about 40% of the uranium in the rod, and all of the “ash”, this is all of the lighter atom elements created from the split uranium atoms. This ash is about 5% of the total. The resultant rods would have about 2% plutonium, 97.5% enriched uranium (about 1% enriched at this stage) plus about 0.5% higher transuranics. This composition would be a far less dangerous than purified plutonium. It would be less hot and it would not be possible to use it directly for atom bombs. It would still be fissionable, though, at the same energy content as fresh rods.

There is an uncommonly large amount of power available in nuclear fuel

Several countries recycle by removing the ash. Because no uranium is removed, the material they get has about half the usable life of a fresh rod. After one recycle, there is not much more they could do. If we remove uranium material is a lot more easily used, and more easily recycled again. If we keep removing ash and uranium, we could get many, many recycles. The result is a lot less uranium mining, and more power per rod, and fewer rods to store under guard.

The plutonium of multiply recycled rods is also less-usable for fission bombs. With each recycle, the rods build up a non-fisionabl isotope of plutonium: Pu 240. This isotope is not readily separated from the fissionable isotope, Pu 239, making multiply used rods relatively useless for fission bombs.

Among the countries that do some nuclear waste recycling are Canada, France, Russia, China, and Germany. Not a bad assortment. I would be happy to see us join them.

Robert Buxbaum September 9, 2019

My steam-operated, high pressure pump

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Here’s a miniature version of a duplex pump that we made 2-3 years ago at REB Research as a way to pump fuel into hydrogen generators for use with fuel cells. The design is from the 1800s. It was used on tank locomotives and steamboats to pump water into the boiler using only the pressure in the boiler itself. This seems like magic, but isn’t. There is no rotation, but linear motion in a steam piston of larger diameter pushes a liquid pump piston with a smaller diameter. Each piston travels the same distance, but there is more volume in the steam cylinder. The work from the steam piston is greater: W = ∫PdV; energy is conserved, and the liquid is pumped to higher pressure than the driving steam (neat!).

The following is a still photo. Click on the YouTube link to see the steam pump in action. It has over 4000 views!

Mini duplex pump. Provides high pressure water from steam power. Amini version of a classic of the 1800s Coffee cup and pen shown for scale.

Mini duplex pump. Provides high pressure water from steam power. A mini version of a classic of the 1800s Coffee cup and pen shown for scale.

You can get the bronze casting and the plans for this pump from Stanley co (England). Any talented machinist should be able to do the rest. I hired an Amish craftsman in Ohio. Maurice Perlman did the final fit work in our shop.

Our standard line of hydrogen generators still use electricity to pump the methanol-water. Even our latest generators are meant for nom-mobile applications where electricity is awfully convenient and cheap. This pump was intended for a future customer who would need to generate hydrogen to make electricity for remote and mobile applications. Even our non-mobile hydrogen is a better way to power cars than batteries, but making it mobile has advantages. Another advance would be to heat the reactors by burning the waste gas (I’ve been working on that too, and have filed a patent). Sometimes you have to build things ahead of finding a customer — and this pump was awfully cool.

Nuclear Power: the elephant of clean energy

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As someone who heads a hydrogen energy company, REB Research, I regularly have to tip toe about nuclear power, a rather large elephant among the clean energy options. While hydrogen energy looks better than battery energy in terms of cost and energy density, neither are really energy sources; they are ways to transport energy or store it. Among non-fossil sources (sources where you don’t pollute the air massively) there is solar and wind: basically non-reliable, low density, high cost and quite polluting when you include the damage done making the devices.

Compared to these, I’m happy to report that the methanol used to make hydrogen in our membrane reactors can come from trees (anti-polluting), even tree farming isn’t all that energy dense. And then there’s uranium: plentiful, cheap and incredibly energy dense. I try to ignore how energy dense uranium is, but the cartoon below shows how hard that is to do sometimes. Nuclear power is reliable too, and energy dense; a small plant will produce between 500 and 1000 MW of power; your home uses perhaps 2 kW. You need logarithmic graph paper just to compare nuclear power to most anything else (including hydrogen):

log_scale

A tiny amount of uranium-oxide, the size of a pencil will provide as much power as hundreds of train cars full of coal. After transportation, the coal sells for about $80/ton; the sells for about $25/lb: far cheaper than the train loads of coal (there are 100-110 tons of coal to a train-car load). What’s more, while essentially all of the coal in a train car ends up in the air after it’s burnt, the waste uranium generally does not go into the air we breathe. The coal fumes are toxic, containing carcinogens, carbon monoxide, mercury, vanadium and arsenic; they are often radioactive too. All this is avoided with nuclear power unless there is a bad accident, and bad accidents are far rarer with nuclear power than, for example, with natural gas. Since Germany started shutting nuclear plants and replacing them with coal, it appears they are making all of Europe sicker).

It is true that the cost to build a nuclear plant is higher than to build a coal or gas plant, but it does not have to be: it wasn’t that way in the early days of nuclear power, nor is this true of military reactors that power our (USA) submarines and major warships. Commercial nuclear reactors cost a lot largely because of the time-cost for neighborhood approval (and they don’t always get approval). Batteries used for battery power get no safety review generally though there were two battery explosions on the Dreamliner alone, and natural gas has been known to level towns. Nuclear reactors can blow up too, as Chernobyl showed (and to a lesser extent Fukushima), but almost any design is better than Chernobyl.

The biggest worry people have with nuclear, and the biggest objection it seems to me, is escaped radiation. In a future post, I plan to go into the reality of the risk in more detail, but the worry is far worse than the reality, or far worse than the reality of other dangers (we all die of something eventually). The predicted death rate from the three-mile island accident is basically nil; Fukushima has provided little health damage (not that it’s a big comfort). Further, bizarre as this seems the thyroid cancer rate in Belarus in the wind-path of the Chernobyl plant is actually slightly lower than in the US (7 per 100,000 in Belarus compared to over 9 per 100,000 in the USA). This is clearly a statistical fluke; it’s caused, I believe, by the tendency for Russians to die of other things before they can get thyroid cancer, but it suggests that the health risks of even the worst nuclear accidents are not as bad as you might think. (BTW, Our company makes hydrogen extractors that make accidents less likely)

The biggest real radiation worry (in my opinion) is where to put the waste. Ever since President Carter closed off the option of reprocessing used fuel for re-use there has been no way to permanently get rid of waste. Further, ever since President Obama closed the Yucca Mountain burial repository there have been no satisfactory place to put the radioactive waste. Having waste sitting around above ground all over the US is a really bad option because the stuff is quite toxic. Just as the energy content of nuclear fuel is higher than most fuels, the energy content of the waste is higher. Burying it deep below a mountain in an area were no-one is likely to live seems like a good solution: sort of like putting the uranium back where it came from. And reprocessing for re-use seems like an even better solution since this gets rid of the waste permanently.

I should mention that nuclear power-derived electricity is a wonderful way to generate electricity or hydrogen for clean transportation. Further, the heat of hot springs comes from nuclear power. The healing waters that people flock to for their health is laced with isotopes (and it’s still healthy). For now, though I’ll stay in the hydrogen generator business and will ignore the clean elephant in the room. Fortunately there’s hardly any elephant poop, only lots and lots of coal and solar poop.