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Students Build Reactor For Scavenger Hunt
MattJ writes "At the end of this NYT story about a scavenger hunt at UofChicago, you discover two physics students got points for building a working nuclear reactor, in a day, from scratch. It's a bit scary how easy it was for them to actually produce plutonium. " Reminds me of some of things we did in Biochem. But the lawyer says I'm not supposed to talk about that.
At the Chicago Maroon (UofC student newspaper), there's a longer story about the scav hunt with more info on the reactor: http://www.chicagomaroon.com /articles/a926450700.shtml.
Here are the explanatory posts by the two guys
who made the reactor on the University of
Chicago local newsgroups: Enjoy!
Alright, I just want to set a couple things straight, so here are some
responses to oft heard comments the last few days:
1. "I assume they used U-238 to get to Pu-239..." we did not start
with any uranium or plutonium, that would have ruined the fun, and the
point was to make fissionable materials. Our starting material was
thorium, which can be found at any hardware store. we happened to have
some in our dorm room... The final products were Uranium 233 and
Plutonium 238. I'm not going to spoon feed the decay chains to anyone,
you can figure it out yourself if you really need to.
2. "You endangered the life of my son!" We created a neutron source
using some shit we pulled out of a trash can. This source was safer and
less radioactive than the radioisotope Americium 241 found in the smoke
detector in each of your rooms.
3. "Someone said your roommate lost his job because he built a nuclear
reactor" Neither I nor my rommmate have lost our jobs since doing this.
4. "I hear you paid another group to steal Plutonium for you" We did
not steal Uranium or Plutonium from anywhere. Nor did we have anyone
else steal some for us.
5. "but to qualify as a true breeder, doesn't the reaction have to be
self-sustaining?" No. A breeder reactor just means taking advantage of
all those tasty neutrons flying off from whatever source you have, be it
a sustained fission reaction or a naturally radioactive source. The
best neutron source on campus would be the Physics Dept's neutron
howitzer. But since the howitzer produces neutrons from the decay of
Plutonium, you have to agree it would be silly to use it to try and make
plutonium.
6. "(I'll be really impressed if the two come up with a micro-fusion
reactor.)" We'd fly back next year just for that one...
- Juniper Tasks
Just some clarification for the readers who've forgotten their nuclear
physics:
U-235 is the fissionable used in the Hiroshima bomb and Pu-239
in the Nagasaki bomb. U-238 is used in fast breeder reactors
to make weapons grade Pu-239. (U-238 is also used in fission-fusion-fission
bombs, so technically it is fissionable with a net gain of energy
but you need really fast neutrons).
Thorium was to have been used in slow breeder reactor technology which
turns out U-233 as its fissionable. (Is Pu-238 fissionable at low neutron
energies with a net gain? The even Z makes me think not...)
I thought you had started with depleted uranium to make a fast breeder;
didn't know the thorium isotope available from hardware stores was the
one used in slow breeders.
Well, with a small sample of thorium and a neutron source, you can make
the U-233. But with a fully functioning breeder don't you need some of the
U-233 created to fission and transform the rest of the thorium without
running away and slagging the reactor or damping out so you never
end up with more thorium than whatever's directly exposed to your
neutron source? I suppose the nuclear engineering definition of a
breeder has to be more pragmatic.
Fred and Justin didn't begin with any uranium.
(Uranium, after all, ain't a commonly available thing.) They began with some
thorium and an alpha source, which they just happened to have lying
around. They used the alpha source to make a neutron source, and bombarded
the thorium. This induced a chain of reactions, the final products of
which were fissionable uranium and plutonium.
That's actually an exaggeration started by Helen Caldicott and perpetuated by anti-nuke activists like Karl Grossman. I suggest an interesting article by Ilya Taytslin to be found at Dr. Caldicott and the Truth About Plutonium. The article largely discusses the space probe Cassini and the uproar over it's use of an RTG power supply, but the points made are generally applicable.
I went to the same high school as Dave, and I was in his scout troop (troop 371). :-) was obsessed with radioactive material, and didn't care about taking any safety precautions (he used to carry chunks of Americanicum around in his front pocket without any shielding)
Dave (or Glow Boy as we called him, not Radioactive Boy like the Harper's article says
I've heard several stories from him on how he got caught. One was that he got caught when he was pulled over by the local cops who thought he was stealing tires from cars. The looked in his trunk and freaked out when he warned them it was radioactive. Another was that a chemical spill sensor at a railoroad crossing kept going off at the same time every day (when he was heading to school).
Very strange guy... I got a letter from him a while ago - he's writing a book, and apparently a movie is in the works.
As pointed out elsewhere here, the nuclear reactor is entirely believable. I might point out that the chief danger from plutonium in small amounts is not its radioactivity, but its poisonousness. Even 1 gram could kill a heck of a lot of people.
Like the article hints, you don't win these days without setting up a LAN and using some database technology. There are too many items to track otherwise. The big items everyone remembers, but there are lots of little 5- and 10-pointers, like ostrich eggs or whatever, that tend to get forgotten. Read the list, and you'll be amazed, but some teams get almost everything within 72 hours.
Back in my day, we got an airplane, a one-ton animal, a telephone pole, and a marching band. We found a collector of turn of the century train cars from the Chicago Elevated to loan us an El car, but we couldn't get permission from the city to take such a heavy load on the streets.
Teams that really contend for the top prizes are made up of 100 or more people, of whom at least 25 must be willing to dedicate the ENTIRE 72 hour period to collecting and building. Usually, you specialize, putting your smooth talkers onto tasks like wheedling Olympic medalists into loaning their medals, your skilled researchers onto finding the answers to obscure questions like the location and population of Waldo, your exhibitionists in the latex paint-on pants, etc.
I have never done anything more fun in my entire life.
May be found at: http://student-www.uchicago.edu/orgs/scavhunt/
http://student-www.uchicago.edu/orgs/scavhunt/list 99.txt
It's really fscking long, so I won't post it directly.
http://www.ryans.dhs.org