Four pounds of nuclear fuel missing in California...

[hunter]

http://www.msnbc.msn.com/id/5537224/

PG&E on hunt for missing nuclear fuel at Eureka plant

Officials hope 4 pounds of radioactive material safely at bottom of storage pool

By MIKE GENIELLA / THE PRESS DEMOCRAT

PressDemocrat.com

July 28, 2004 - After a three-week search, PG&E Co. said Tuesday it's still no closer to solving the mysterious whereabouts of four pounds of radioactive nuclear fuel missing from its shuttered Humboldt Bay Power Plant near Eureka.

Since July 7, PG&E workers have used robotic equipment and underwater cameras in an unsuccessful attempt to find three pieces of a nuclear fuel rod that may be among hundreds placed in a deep storage pool at the plant before it closed in 1976.

---

Hmmm, maybe I should have put "We're All Gonna Die!" in the subject line. ;)

I have an old friend who was an anti-nuclear activist who worked to shut this plant down. In the end, the plant was shut down mostly for economic reasons. It was a smaller nuclear plant, basically of the sort designed to power Navy ships. The maintainence costs were high.

PG&E fought pretty hard to keep the plant open, mostly, I think, because they didn't want to establish any precedents for shutting down any nuclear plants they built later.

The site of this plant isn't geologically safe. If the earthquake doesn't get you, the tsunami will.

There is an interesting story about the "smoke" stacks of this plant. (You didn't know nuclear power plants had smoke stacks, did you?) After the plant was shut down engineers started to worry that the stacks might fall down in an earthquake or tsunami and pierce portions of the plant that are still very radioactive. It turned out that the stacks themselves were radioactive, so the contractor taking them down had to be very careful not to make any dust.

[NNadir]

1. Thanks for this illustrative article.

First there is the matter that this is considered important news, while millions and billions of tons of other pollutants, that are actually killing people and causing environmental collapse are not.

Now let's take a look at the details:

No article with the word "nuclear" in it is complete with out reference to September 11, and "terror" and as required here it is:

"He said there's no chance the missing nuclear rods might have managed to get into the wrong hands, a scenario that anti-terrorism experts fear in today's edgy post-Sept. 11 era."

Next let see if this requisite line has any connection with any matter remotely connected to reality in even the most tenuous way as a remote approximation of something that potentially if we stretch things we might possibly have a minor level of concern about.

The "missing" piece weighs 4 kilograms. In spent nuclear fuel, 97% of the material is Uranium which is slightly enriched to about 3% fissionable Uranium-235. Therefore we have 4 kg *0.97*0.03 = 0.116 kg or 116 grams of U-235. 1% of the mass, depending on the fuel burn-up, is likely to be Plutonium, of which 80% will be fissionable plutonium-239 meaning 4*0.01*0.8 = 0.032 kg. Thus the total fissionable material is 0.148 kg or 148 grams. A typical bomb, of course requires about 10 kg of material, but, our media is making sure that we all have that important terror! terror! terror! word associated with nuclear! even though the terror implications of this situation are essentially zero.

Wouldn't be nice, BTW, if it were front page news everytime an energy company made a report because it couldn't account for 4 kg of missing waste over a thirty-two year period?

Maybe our environmental issues would be trivial in this case.

[Throckmorton]

2. Weren't the smoke stacks from two oil fired units

that were retired after Humboldt and shared the same site?

[NNadir]

3. I don't know, but we should be clear: Nuclear power plants can and do

release small amounts of radioactive material from stacks, with which all of them are equipped. Typically the material released are radioactive gases Kr-85, small amounts of the nobel gases Xe-133, Xe-135, and, to a lesser extent, the sometimes volatile halogen isotopes I-131 and I-129. Most other fission products are not volatile, and thus are not released. In an extreme failure, such as at Chernobyl, Cesium isotopes can be released, but as all Cesium compounds are extremely soluble in water, they typically are contained in cooling or moderating water and not volatilized. Cesium does not go up the stacks.

These gases, all of which are fission products, are typically released from fuel rods that have developed cracks over the years. (An individual fuel rod can remain in a reactor for up to five years, depending on the particular reactor's fuel loading characteristics.) Of course not all fuel rods crack, but some do and the stacks represent yet another of a series of fail safe devices.

It is interesting to note that the radioactivity release from nuclear powerplants is highly regulated, while the radioactivity release from coal fired plants are not regulated at all. It actually happens that coal fired plants typically release more radioactivity than do nuclear plants, in fact on a much grander scale.

http://www.ornl.gov/info/ornlreview/rev26-34/text/colmain.html

It is interesting to note in the above link that the amount of released by some coal plants actually contains more energy as Uranium than the coal burned to make the Uranium containing ash.

[hunter]

5. Ah, found some links...

It happens all the time, I rember something I heard years ago, I mention it, and then I have to do the research...

Yes, it was a 250 foot stack for the nuclear portion of the plant.

The containment portions of a nuclear power plant must be vented to prevent pressure buildups, both during normal operation, and during abnormal "events." They are vented through a stack. Between the containment and the stack's opening are various filters and valve systems that do not quite catch every last radioactive molecule.

In the days when most of the public still viewed nuclear power as a "good" thing, these stacks were built in a coventional way. When the public began to fear nuclear "contamination" the stacks were built in a different manner. On power plants with round containment domes they are sometimes the "nipples." The incongruity of that has always bothered me...



(picture from the BBC)

[NNadir]

6. Personally I prefer the feminine imagery of the domes and nipples

to the priapic image of the "smoke" stack. Just a matter of personal taste.

I actually love to look at nuclear power plants. I think they're beautiful.

[hunter]

7. Here's a good picture of the Humboldt stack...

... before they tore it down.

http://geoimages.berkeley.edu/GeoImages/BainCalif/CAL400/HUMNUC.HTML

It's the tall red and white stack. The other stuff is mostly the gas fired plant.

Oh yeah, here's another interesting picture, that will give you an idea of the scale of this nuclear plant:

http://americanhistory.si.edu/csr/powering/images/gallry12.htm

(edited to add second link.)

[NNadir]

8. Thanks. I've been to this particular museum and have seen this picture.

They have a full scale model of Fermi's original nuclear reactor there. They also have Glenn Seaborg's actual first sample of plutonium on display along with his Nobel medal, which he donated to the Smithsonian. It's very, very cool and impressive, an overlooked part of the museum I think. I recommend it to anyone who goes to the Smithsonian. I am as you can tell a bit of a nerd, but I confess I was quite emotional looking at it.

I should note that the first sample of Plutonium was in fact the 238 isotope which has a half-life of about 87 years. Therefore if you actually want to be in the presence of an actual sample of what was actually the third artificial element ever prepared, you should plan on visiting in the current millenium. :-)

As for the scale of the reactor, I don't know much about the Humbolt Bay Reactor, but I should note that nuclear cores can be very small and still be very powerful because of the high energy density of nuclear fuels. Most of what you see outside a nuclear plant is actually containment strutures and turbines. This is particularly true of fast reactors which are necessarily very, very compact because of physics considerations and high enrichments relative to thermal reactors.

[NNadir]

9. Here are the dimensions of the 4 Indian fast breeder reactors being built.

http://www.npcil.org/nupower_vol16_1_2/articles.pdf

These reactors are designed to operate at 500 MWe and the core is a meter high and less than 2 meters in diameter.

I am, for the record, not particularly enamoured of this liquid metal fast breeder design, although, I very much doubt that these reactors will be as dangerous as the coal facilities they will replace.

I am working on my own on an alternative fast spectrum design, but we'll see if I ever complete it.

[DrWeird]

4. Did they check behind the copy machine?

That'd be the first place I'd look.