More detail on what Kodak was doing with a neutron multiplier

Earlier today, David told you about a news story that's everywhere right now: The fact that the Kodak company ran a small nuclear facility at its research lab in Rochester, New York.

The facility closed down in 2007, but I can totally understand why this story interests people. It's nuclear! And it is really weird for a corporation to be sitting on 3.5 pounds of uranium. Like David said, this is unusual today. David did a good job covering this in a sane way. The TV news I saw this morning at the airport ... not so much. That's why I like the detail provided the Physics Buzz blog, where Bryan Jacobsmeyer explains, better than I've seen elsewhere, just what exactly Kodak was doing with their nuclear system. Turns out, it's really not all that odd for this specific company to own this specific piece of equiptment when they did. That's because of what Kodak was. We're not just talking about a corporation in the sense of middle managers and salesmen. We're talking about original research and development—a job for which a californium neutron flux multiplier is quite well suited.

In fact, these research reactors can be found on several university campuses, and they are operated under strict guidelines without any nefarious intentions.

Researchers working at Kodak wanted to detect very small impurities in chemicals, and Neutron Activation Analysis (NAA) proved to be one of the best techniques to find these impurities. During NAA, samples are bombarded with neutrons, and elemental isotopes from the sample will absorb a small fraction of these neutrons.

Many of these stable elemental isotopes will become radioactive after gaining a new neutron; consequently, they will emit gamma rays. With the right equipment, researchers can measure the precise energy levels of this radiation and narrow down which elements are in the sample.

Basically, it provided a way to sift through the components of a sample at a molecular level, and spot the things that shouldn't be there. Originally, the lab used just californium. Later, it added uranium plates that helped make the system more powerful.

Read the full Physics Buzz post

Via Jennifer Ouellette

Image: IMG_7391.jpg, a Creative Commons Attribution (2.0) image from jameskarlbuck's photostream


  1. I walked past a nuclear reactor almost every day during my four years of university – and most of the other 13,000 students didn’t have a clue they did, too. My mom attended the same school in the ’60s and remembered when they put it in.
    Later, when our local hospital was installing a nuclear reactor to make radioactive isotopes for cancer treatment, I figured out that the one the hospital installed was about twice the size of the one on campus. People here nuclear reactor, picture a Springfield-esque power plant and freak out over less radiation than you get from a malfunctioning microwave.

    1. I also went to a university with a nuclear reactor in the basement of one of the buildings.  I managed to find it one day when I found a window that had been covered by a big sheet of steel with a tiny view-port in it.

      There was a brief overreaction when someone who didn’t know it was there found out and brought up terrorism concerns, when in fact the whole reactor could generate about enough power to run a toaster oven.

    2. My university had one, as well.  One of our labs in Physics was to do a bucket calibration on the reactor…using a bucket lowered by rope into the water to collect samples at set points in time.

    3. I think what people “freak out over” is actually the potential for an accident.

      There is a superfund site where a Boy Scout built a (very poorly designed) micro-reactor. Kodak’s toy was much much more powerful, I would imagine that if it had been equally poorly designed most of the city would be uninhabitable. Thats a function of the materials on hand and the use of those materials, which in Kodak’s case was probably very responsible and fairly low risk (wouldn’t survive a plane crash would it? there is some risk).

      You’re implying that something like this is no more dangerous than a microwave- and that is bunk even if its normal operating design generally poses no more danger, an accident has the potential for widespread harm.

  2. Tbh I’d be more worried about uranium being used like a poison (rather than a bomb). Anyone know how much of it would be fatal? I’m guessing not much.

    1. Of course, you don’t have to guess.  But where’s the fun in not being able to say “oh noes, nooks!!  We’ze all gunna die!!”

    2. It would depend upon the isotope ratios and means of ingestion.

      Polonium is worse and is likely responsible for most lung cancer among smokers.

      Its a really bad thing to get hot particles of alpha emitters lodged in lung tissue. People often say “alpha particles are so weak they won’t go through a sheet of paper”. Yet because of their relatively extreme mass they are more damaging than beta or gamma. Because they are so massive they end up being stopped by a small amount of mass instead of “missing” it as they zip by. So they end up imparting all of their considerable damage to a very small bit of tissue, whether the cancer grows beyond the size of a grain of sand depends upon a wide variety of other factors, in experiments with dogs plutonium hot particles resulted in all dogs having lung cancer at ten years but none of them having a large enough cancer to kill them.

    3. My attempt to find a LD50 for U in humans turned up this:
      Health Phys. 2008 Feb;94(2):170-9
      from the abstract:
      “there has never been a death attributable to uranium poisoning in humans”
      “It is suggested that 5 g be provisionally considered the acute oral LD50 for uranium in humans.”
      For a 75 kg human, that would be 67 mg/kg, which is slightly less toxic than nicotine (50mg/kg) but 3x more toxic than aspirin or caffine (200mg/kg).

      I’ve got a ~30g chunk of (depleted) uranium metal in my basement that I bought on a whim from United Nuclear.

      1. Cool! You could make one or two bullets out of it.  Probably excellent ammo to go thru a Kevlar vest or an armored car. Of course, when it hits something hard enough to be pulverized or to start it burning, then you have DU vapor that can be inhaled & gets inside the lungs. Bad news.

        1. I think if you get hit with a depleted uranium round, I think the least of your worries is actually inhaling the vapor.

          1.  This refers to ‘shot at & missed . . .’  (which is part of the saying ‘OMG you look like someone shot at you & missed, and shit at you & hit.’)

  3. We talked to the folks at the Reed Research Reactor about NAA a few weeks ago. Depending on the sample, they can use NAA and gamma spectroscopy to detect parts per quadrillion in samples. 

    They do an exercise with high-school students who tour the facility. They have them bring fingernail clippings from their parents fingers. Using NAA, they can tell which clippings came from their parents ring fingers, because the process can detect the few atoms of gold that rub off when you put on or remove the ring. It’s pretty amazing.

  4. There’s a nuclear reactor in the Denver Federal Center used for carbon dating… Surprise! You’ve Got Radiation (less than from a granite counter top)!

  5. The part that got me was the photo accompanying the original post. The sad  californium neutron flux multiplier sitting in the corner like a sad, forgotten Golden Tee arcade machine at a dingy bar.

  6. Back in about 1986 I did a Neutron Activation Analysis experiment as part of an analytical chemistry course at Waikato University in New Zealand, using an Amercium source (if memory serves) – which was basically a big (50l?) lead-lined jar filled with a solution of Americium salts, with a lot for a test-tube. We left the test-tube in overnight, then put it in an old scintillation counter with pixie tube digital readouts – to count the radio-isotopes fissioning.

  7. Rochester is an interesting place for tech and research (though a depressing city in every other way). Kodak, Xerox, lots of chemical companies, and both the University of Rochester (where I went as an undergrad) and the Rochester Institute of Technology have incredible, deadly stuff, most of which local residents (and even students and faculty at the schools) don’t know about.

    Of course, nothing fires up the imagination of the public like nuclear stuff, so it’s understandable. UR may have one of the most powerful lasers in the world, but it can’t really cause any damage outside the lab (and can’t be weaponized really).

    That said, most people in Rochester don’t realize that there’s a nuclear power plant on the shore of Lake Ontario that provides a lot of the city’s power!

    (my uncle, who worked in Kodak research, built his own electron microscope etc. and lives right on the lakeshore also, once drove up the road to the power plant out of curiosity and was surrounded by humvees and guys with assault rifles!)

  8. MIT’s is located right on Mass Ave, next to the old NECCO factory and behind a used car lot.

  9.  If you think Rochester’s neat, go a little west and read up on the crap around Niagara. Pretty much Los Alamos east.

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