April 8th, 2011

#2655: Just recycle it

Spent nuclear fuel is not actually "spent" in the sense that it's forever unusuable for use in a nuclear reactor.

All right: when you've got a pound of coal or a gallon of gasoline, and you burn that, it's spent; it's gone. All of its latent chemical energy has been converted into other forms and its entropy has irreversibly increased.

When you've got a pound of nuclear fuel, however....

We stop using nuclear fuel after a certain amount of time only because of the buildup of certain isotopes which are quite literally called "poisons", because they poison the chain reaction that makes heat to boil water to make steam to drive the turbines that turn generators, thus liberating countless kajillions of electrons to do our bidding. But for these poisons, these fuel rods could stay in the reactor ad infinitum.

In a sane world, the fuel elements could be chemically processed to remove these poisons, and put back into service. The poisons would still have to be stored, but they'd take up very little space compared with entire fuel assemblies.

But we're not allowed to do that.

No: in the United States--up until about 2006--there was an Executive Order (from Jimmy Carter) and a federal law, both of which prohibited the reprocessing of spent nuclear fuel. The theory goes that if you reprocess spent nuclear fuel, one of the things you end up with is plutonium, which can be used to make bombs, yada-yada, what if terrorists got ahold of it, blah blah blah, etcetera.

Trust me: you don't want to get near plutonium that's come from a commercial light water reactor. The plutonium used to make bombs comes from breeder reactors, and it comes from uranium that's been in the reactor less than about 30 days. Pu-239 is relatively docile stuff, being primarily an alpha emitter; but when you leave fuel in the reactor longer than about a month, you start getting an increasing concentration of Pu-240, which is a beta emitter with a shorter half-life than Pu-239. Besides that, it's got some other characteristics which make it rather undesirable for making bombs. Okay, Wikipedia!
Plutonium-240 has a high rate of spontaneous fission, raising the neutron flux of any sample it is in. The presence of plutonium-240 limits a sample's usability for weapons or reactor fuel, and determines its grade.
Pu-240 emits neutrons, and neutrons are bad for you.

You wouldn't need a search warrant to find nuclear terrorists who stole Pu-240; they'd glow in the dark. They also wouldn't move much, being dead and all.

So the illegality of reprocessing spent nuclear fuel is based on a false premise (that reprocessing spent fuel from commercial light water reactors causes "nuclear proliferation") and Bush wisely rescinded Carter's stupid EO; and the GOP-led Congress repealed the law that made processing illegal.

2006 was too late. Carter's edict was issued in 1978, as I recall; 28 years later the industrial capacity for reprocessing spent fuel has long since been extinct. We'd have to build new plants to do it.

But in this country, chock-full of eco-nazis and NIMBYs? Heh. Just try to build a plant for reprocessing spent fuel. I'm going to stand over here, where there's a good view, so I can point and laugh.

Nuclear power represents the cleanest, safest, and cheapest source of energy when we are allowed to use it correctly. The problem is, we've never been able to do that. The guys selling fossil fuels are partly to blame, because they knew that nuclear power would make paupers of them and hired lobbyists to make sure that never happened; but they're not the only guilty parties. The eco-nazis hate nuclear power because it also represents a way for humans to have clean, cheap electricity--and "too much industry" is a major bugaboo for eco-nazis, regardless of how clean it might be.

Argh.

* * *

Iran's building nuclear bombs. You can tell me I'm wrong but there's no way in hell I'm going to believe that Iran wants nuclear power "for peaceful purposes" solely because the Iranian government says so.

* * *

Doug Powers on AP editing the story to remove Obama's "trade in your gas-guzzler if you can't afford gasoline!" bullshit.

* * *

Midwest Chick posts about a recent Illinois Supreme Court case.

Short form: guy from Indiana who has a concealed-carry permit accidentally brought a gun into Illinois. There is some disagreement on whether or not the gun was unloaded, but it was in a closed armrest compartment in his car.

The guy was charged with a felony for having a gun without a FOID card, and also was charged for not having the gun in a suitable case. He was found guilty of both charges at the circuit and appellate level.

Here's the thing:

The FOID card statute specifically says that if you come from out-of-state and are licensed to own a gun there, you may bring your gun into Illinois as long as it's in a proper case. The guy was charged under a different statute; so you have two laws with differing rules: one law says that you're fine as long as you're legal in your home state; the other says you're committing a felony unless you have a FOID card (which, unless I'm mistaken, can only be issued to Illinois residents anyway).

The nice thing is, the ISC reversed the verdicts. The "FOID card" thing was just stupid; and the "case" issue was dealt with because the gun was in an enclosure and not immediately accessible. And apparently the center console (between the front seats) would be just as legal as one between the back seats, according to the decision.

This is, at least, a step in the right direction. Maybe someday Illinois can join the rest of the country in allowing people to exercise their civil rights.

* * *

Yesterday, I woke up in a way that I have only ever awakened once before.

Consciousness returned slowly to me. A dream ended, and I could feel bits of my brain "switch on" as I woke up. Finally, after a few moments of this graceful power-on procedure, I was fully awake.

Usually I wake up in the middle of a dream. The waking process is abrupt and unpleasant, and it leaves me feeling cruddy. This time it was just like falling asleep, only in reverse.

Why isn't it like that more often? I mean, I get that there are things like alarm clocks and retards with stupid-loud stereo systems, but the laws of probability seem to indicate that it would happen more often than twice in 44 years. WTF.

I'd bet that's how people who can wake up easily always wake up.

* * *

After a nap (from 11-ish until 4) I had a shower, and then went and got a McSkillet.

I needed that shower. I don't remember the last time I had one. The last shower I remember was Saturday night, and I admit (with a certain amount of dread) that it's possible that was the last time I bathed.

Shit.

Well--when you're living alone and unemployed, there's just no need. And showers screw up my blood sugar (don't ask me how, but that's why I took the shower before getting breakfast) so I tend to try to schedule them before meals--unless I'm already suffering a reaction, in which case I skip the shower and eat.

The best part is, nobody cares.

*sigh*

Sleep let me put the student loan situation in perspective. Absolute worst case, I hand over most of my IRAs to them, and the problem goes away. It sucks to be me, but I don't have to worry about them taking my cars and computers and blab slab, and books and anime and everything else I own and auctioning it to satisfy the debt.

That's the worst case: I have less money in the bank.

...it's aggravating and annoying to be in this position, but I'm not totally boned--at least not yet--and hopefully I can get some legal assistance.

Not surprisingly, bankruptcy lawyers aren't interested in helping you when it's a problem with a student loan. The government has very carefully excused itself from the rules it makes everyone else follow; that's why I was panicking: they can take everything you own and leave you standing on the street in a barrel and there is no legal protection for you. No variety of bankruptcy will shelter you from them.

So I need to find someone who can help me with the legal aspect who will understand that there's no quick buck in it for him. Bankruptcy is pretty well cut-and-dried, and a lawyer can make good money on them without expending a lot of effort; but a situation like mine requires actual work and it's billed by the hour, so rather than spend 20 minutes reviewing work done by his secretary and then bill the client for $250 (or whatever) he actually has to talk to people and shuffle papers and review cases and-and-and.

He'll make perhaps $100 advising me on my situation; he can make $750 in the same amount of time processing bankruptcy filings. You do the math.

But all that has to wait for business hours, and it's not even 7 AM yet.

#2656: It wasn't the student loans.

...it was something that fell through the cracks of my move from Cedar Rapids to Illinois.

Well.

I feel a lot better now, and that one's dealt with, so I guess I can resume my non-miserableness.

Good luck getting that back. *sigh*

#2657: Why can we recycle nuclear fuel?

There seems to be some confusion among the nuclear-ignorant about the utility of used nuclear fuel, which is why they don't get that we can recycle the stuff easily and reuse it.

If you mine uranium ore and smelt it into uranium metal, you end up with uranium which is mostly U-238 and about 0.7% U-235. This is the natural distribution of isotopes; there are a few others besides those two but they're the majority. (U-233, for example, is some piddlin' little fraction that's so small it's not worth mentioning here.)

It's possible to "enrich" uranium--to increase the fraction of U-235--by running it through various machines which separate the two isotopes, and given enough time and machinery you can take a lump of uranium and make two lumps, one of pure U-238 and one of pure U-235. "Weapons grade" U-235 is about 90% pure.

U-235 is the isotope we find most useful for various kinds of nuclear reactions because of its neutron capture cross-section and other physical characteristics. While you can build a nuclear reactor which uses natural uranium, it's more practical (given that we have the capability to enrich uranium) to enrich it a bit.

Most reactors use fuel that's been enriched to 3% U-235. This isn't nearly enough to make a nuclear weapon, and in fact the unused fuel is so safe the only shielding you need to protect yourself from it is a paper bag. (Not even that, actually--the fuel pellets are encased in zinc cladding, and these little zinc cans are themselves encased in rods. An unused fuel element is no more dangerous than a curtain rod.)

After it's spent time in a reactor, though, there are all kinds of very active isotopes with short half-lives and dangerous emissions (neutrons, betas, gammas, etc) which means you do not want to get cozy with used fuel elements. Here's where the confusion comes in: while it's true that the used fuel element has less U-235 in it than a fresh one, that's not why we stop using them.

We stop using fuel elements because of the buildup of fission products. E=mc2 is what provides the energy--as fission occurs, energy is released--but the energy we extract from nuclear fuel is the barest fraction of a whisper of the total energy available. When any atom splits, there's a tiny bit of energy released but most of the atom's mass remains behind, only in smaller chunks. This is why they call it "fission": the atom's nucleus splits.

It usually does not split into equal chunks, and there's no way to predict what elements a particular atom will split into. It's all random. The important thing, though, is that it's not uranium.

That's important because of that characteristic I mentioned above, "neutron capture cross-section". The easiest way to imagine that is to think of a big brick wall with a window set in it, high up, into which you are trying to throw a ball. If you get the ball through the window, you win a cookie and get another ball to try again.

The problem is, the window is an inch wide, and the ball is a softball.

So you move to a different wall. This wall has a huge French Door set in its side; you can easily throw the ball through the window--but because you moved to the easy wall, you don't get a cookie or another ball.

There's another wall nearby, just behind the easy wall, which has a window about a foot on a side. You would have gotten a cookie and another ball had your ball gone through that one's window, but the easy wall was in the way.

The ball is a free neutron; the wall is an atomic nucleus; and the window is its neutron capture cross-section. The cookie is useful energy of one form or another (up to and including another free neutron). The hard wall is an atom of U-238; the easy wall is a "poison", and the wall behind the easy wall is a U-235 atom.

We can make the ball appear to change size by making it pass through a medium we call the "moderator". It doesn't actually change the ball's size; it changes its speed--but this is a weird quantum ball, and the size of the window is dependent on the speed of the ball. (For the purpose of this analogy we assume you can only throw at one speed, but you get the idea by now, I'm sure.) The slower the ball, the larger the window--up to a point--and passing the ball through the moderator enlarges the windows of all the walls, but it's most noticeable with the U-238 wall. Too slow, of course, and you can't get the ball high enough to go into the window; so you need to change its speed so that it's got just enough to make it into the window.

The function of the moderator is to slow down neutrons, but only enough to get them into the neutron capture cross-section of the reactor fuel. Neutrons come out at a variety of speeds, and it's the slower ones that we find useful--too fast and they just blast through a nucleus without slowing down or affecting anything, and you want the nucleus to capture the neutron.

But you also want the nucleus to give off a neutron or two when it splits, because that's how you sustain a nuclear chain reaction. If the neutron vanishes into a nucleus and nothing comes out, the chain reaction dies out.

This is what happens with used nuclear fuel: stuff builds up in the fuel elements that soaks up neutrons and doesn't give any back, nor does it give off any useful energy. This is why they're called "poisons": they poison the nuclear chain reaction.

Fortunately, all this stuff is not uranium, so it can be chemically separated from the fuel. It's easy-peasy to make chemically pure uranium. ("Isotopically pure" is hard, but we don't need that.)

Once you've finished with that process, you have a small pile of stuff you really don't want to stand next to, but your fuel is ready to go back into the reactor.

The thing is: there is less U-235 in this fuel than there was before you used it, but it's still useful.

"Why enrich it at all, then? Or why enrich it to 3% if less will work?"

A higher concentration of U-235 is useful because it's so good at soaking up neutrons, splitting, and releasing new neutrons. But because most of the fuel (97% of it) is U-238, that's where most of the fission occurs and that's where most of the energy is coming from. The U-235 serves primarily as a jump-starter for the reactor. Its capture cross-section is pretty large, it generally gives off a neutron or two when it fissions, and it's pretty abundant in nature. (Compared to other isotopes? You bet.) You can make a reactor that uses natural uranium--the first one in history, Fermi's "atomic pile" under the bleachers at University of Chicago, was made with unenriched uranium--but there tend to be engineering considerations that make them impractical.

In practice, when reprocessing used fuel, you need to add enough uranium to the fuel elements to make up for what you lost--energy and fission products alike. And that's it. You want to try to keep it around 3% U-235, but that's not as hard as it sounds.

You certainly do not need to take--say--97 pounds of used fuel and add another three pounds of fresh U-235 to it to get back to 3% enriched fuel.

* * *

Opinion: it seems to me that the proportion of isotopes would remain approximately the same, in fact. My example above exaggerates the difference in cross section between U-238 and U-235; they're actually not all that far apart. The distribution of U-235 in enriched uranium is random, and it's only 3% of the total; the speed and direction of emitted neutrons is also pretty random, though speed is confined to a certain range.

A neutron has no choice about what it runs into, and U-238 will fission if it captures a neutron that smacks into it. It therefore seems that the general proportion of isotopes in the fuel will remain approximately the same, and that the total percentage of uranium will simply decrease over time.

* * *

The important thing to remember is that used nuclear fuel is not useless. If you're allowed to remove the poisons from it, you can stick it back in the reactor and use it again.

Right now, we use nuclear fuel the way a rich man with no sense uses cars: "Oh, my, this Ferrari is dirty. Time to buy a new one!" The car only needs a wash and wax, but instead of doing that, the idiot just lets the slightly used cars pile up in his garage.

Then he complains that there are too many used cars around, and that we have to stop making cars because of the problems we're having with storing the used ones.

#2658: There was something else....

...but I'll be switched if I can remember what it was.

I sat down here to post a bit about recycling nuclear fuel (which turned into a huge essay) and something else; but the "something else" was struck from my mind when I noticed that I'd mis-numbered the last dozen or so posts.

Yeah, starting at #2642, I spoonerized the number into #2462, and went on sequentially from there.

*sigh*

So after correcting the numbers, I realized that the other, non-nuclear bit had been pushed out of my brain.

* * *

Just now, there was a vague knock at the front door, and it turned out to be a guy from TruGreen trying to sell lawn service.

I ought to put up a "no solicitors" sign, I suppose.

...I interrupted his spiel before he could get started and told him I'm not interested. He looked a little annoyed at that. Sorry, pal; I know you're just doing your job, but even if I did have the money to spend on your service, I'm not in the market for anything of the sort.

We had ChemLawn treating our lawn for a couple of years. It worked fine as long as it rained; but then we got to 1988, which was nearly a record-breaking drought year. Even though the rain stopped falling, they kept spraying; we ended up with crispy brown grass. No thank you.

As for him being annoyed--dude, when you knocked, I was sitting here in my underwear. Just be grateful that I bothered to put on pants before answering the door.

* * *

So besides calling the paralegal guy about that bill that had fallen through the cracks, I also made a bunch of other phone calls I'd been putting off. (Mainly because I've been sleeping during the day.)

I:

1) scheduled a "furnace tune-up" which the bunker needs in order to keep the warranty on the furnace
2) scheduled a time to get Mom's taxes done
3) returned a phone call from the wife of one of Dad's friends, who wanted my aunt and uncle's address

The guy at the tax place was busy when I called, so I had to wait for him to call me back--but that wasn't a problem, anyway.

That bill that fell through the cracks--it's something I've been putting off dealing with, so it's my own damn fault, and I could have had this done with months ago if I'd been less of a slug about it. With interest and such it's not something I can pay off immediately, but they'll take $100 per month until it's paid. (And in fact I can call them again later and say, "Hey, take the rest now!" So hopefully that job in Rantoul will work out.)

I'm grateful it wasn't the student loan stuff. I still have to deal with that, but if it can just wait until I'm gainfully employed, then I can start funneling money into paying that off.

I seem to have regained my equilibrium even if I haven't returned to the level of cheerful optimism I'd reac--

No, I can't let that slide. I suppose my attitude yesterday morning was closer to "cheerful optimism" than I've been in years, but it's about like saying you're closer to the summit of Mount Everest because you climbed out of the water and onto the beach. So let me try again:

I seem to have regained my equilibrium even if I haven't managed to struggle back to the level of not quite dreading the future, which is where I was at yesterday morning.

...yeah, that's better. Meaning "more accurate".

* * *

Once the business was dealt with, I happily went to bed and slept for a few hours. And in fact I'm going back to bed in just a few minutes.

After my shower and McSkillet, I played WoW for a while and finished the "Drakkari Gods" quest chain in Zul'Drak--all but the last quest, the one that requires that you get help from other players.

The neat thing about the Cata revamp of quests is how they got rid of that: "Run all these quests, and then you need to form a group to finish it! Ha, ha!" That always was a royal pain in the ass; the quest chains in basic WoW no longer do that. A lot of the elite monsters have been removed, too. It makes leveling less of a pain, and it makes it more fun when you don't have to stop near the end of a chain and get help to finish it.

But this was only done to Azeroth; not Outland and not Northrend. So once you're past level 60, it's back to the old way. That's really not as bad as it sounds, but the new way is definitely better.

Ormus is 78th level; I tried going to Mount Hyjal and got killed by the first monster I encountered. It was an 81st level basilisk. Normally a 3-level difference is not fatal; you might not be in the best of shape after the fight, but you certainly ought to be able to live.

Not so here; so it's back to Northrend to grind some more, until Ormus hits 80th. *sigh*