Archive for January, 2010

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Albuquerque, Ground Zero

January 16, 2010

May 27, 1957. N34.99°, W106.57°.  A lone steer was grazing this windswept expanse of mesa five miles south of the Albuquerque airport under the noonday sun.  Overhead, a B-36 “Peacemaker” churned toward the runway, ferrying a Mark 17 nuclear bomb from El Paso to Kirtland Air Force Base for service.  Such routine Cold War traffic would not normally be sufficient to jar the animal from his bucolic reverie.  But on this day, owing to a freak accident (the cause of which officially remains unknown), our bovine was about to receive airmail of a highly disruptive nature.

The 42,000-pound two-stage H-bomb–historically the largest nuclear weapon in the American arsenal–was dropped by mistake as the B-36 descended through 1700 feet.  Though the plutonium pit was not on board for safety reasons, the bomb did contain its fissile second-stage “spark plug” made from either plutonium or enriched uranium, as well as the tamper (probably uranium).  It plunged nose-first into the cow-populated mesa, whereupon the shock wave from 300 pounds of detonating high explosive puréed the unfortunately-situated ruminant with inconceivable violence†.  Thunder pealed off the distant hills; Burqueños gaped in awe at the fireball rising in the southern sky.

The acrid fog of charred cow pulp had barely settled when the crack AFSWP (Armed Forces Special Weapons Project) team from Kirtland arrived to discreetly liquidate the consequences of the “broken arrow.” They encountered a 25-foot crater with gamma exposure readings of 0.5 mR / hr at the rim.  Although the Army filled in the crater and recovered most of the weapon, to make a clean sweep of the several square miles peppered with debris would have been a Herculean task.  They did a job that was good enough for government work–in other words, plenty of radioactive H-bomb components still litter the desert for the interested public to collect.  That’s the good news, and I’ll discuss my collection of bomb chunks shortly.

There’s some bad news, however. The inexorable tide of urban sprawl has engulfed just about anything resembling a “windswept expanse of mesa” in the Albuquerque vicinity, and such is the imminent fate of this one.  Forest City Covington NM, LLC has begun marketing the land as a master-planned development called “Mesa del Sol.”  Now it would be a crying shame if this unique venue for radioactive  material collectors got overrun by banal New-Urbanist homes, schools, and shoppes.  Let me make a plea to you, dear reader: If you respect the history of this place, and believe that the wonderful actinide-laden goodies in the topsoil ought to remain accessible to the collecting public rather than gumming up lawnmowers in the front yards of yuppie-stuffed townehomes, please send your thoughts to the developers by clicking here.

†Note: some creative license has been taken with this description of cow’s demise

Links to further historical information:

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Collecting nuclear weapon parts is fun and suitable for the whole family.  Both radioactive and non-radioactive components of the Mark 17 bomb may be obtained on the site (which is publicly accessible on dirt roads with a high-clearance vehicle, or by passenger car with some caution).  I am greatly indebted to Taylor Wilson for bringing my attention to this location.  He has a very nice summary of his findings at his website.  The mesa is devoid of large vegetation, so prepare for wind and weather.  Bring water.  Do not enter the Sandia shooting range to the north of the  bomb site, or approach the Sandia fenceline on the east.   Activity is almost entirely alpha and beta radiation; charged-particle spectroscopy is pending to identify the nuclides responsible.  A pancake Geiger counter is my preferred field instrument.  Shown here is a 15-pound sheet of lead with a surface reading of about 1300 cpm.

Example components of the bomb (click thumbnail for numbered image), relative to calipers set at 2 inches for scale.  Some pieces have identifiable function, others are more mysterious.  Details about the Mark 17 construction remain classified.  Any readers with a better technical eye for these components please feel free to correct my guesswork in the comments, and I will update the list accordingly:

  1. Laminated cork composite from bomb liner.  Cork is very abundant, but never radioactive.
  2. White solid plastic resembling polyethylene, perhaps from interstage.  Most shows signs of melting and charring.  Frequently radioactive.
  3. Black plastic or composite.  Brittle, unlike #2 material.  Never radioactive.
  4. Aluminum casing components, still retaining the greenish-yellow exterior paint.  Never radioactive.
  5. Part of a wiring harness, containing remnants of wires.  Only example found.  Not radioactive.
  6. Fabric sheath / strap material.  Only example found.  Radioactive.
  7. Gear (not radioactive).
  8. Aluminum sheet (no exterior paint).  Not radioactive.
  9. Steel.  Rarely radioactive.
  10. Lead metal, probably from the bomb’s radiation reflector.  Sometimes radioactive.

My spiciest findings are shown at left.  The most radioactive is a small piece of lead, one surface of which registers 13,000 CPM on a 2″ pancake Geiger counter.  The most radioactive plastic piece registers about 7,000 CPM, apparently due to a small embedded object.

My heaviest finding is a contorted piece of lead tipping the scales at almost 30 pounds.  (Sadly, the behemoth is not radioactive.)

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Nuclear Collection (Part IV)

January 12, 2010

Radioactive pottery and glassware are ubiquitous at antique malls.  Most items are affordable,  attractive, and retain their utilitarian function for serving food and beverages.  Plus, it’s always fun to pass a Geiger counter over a dinner guest’s plate just after the meal is finished and watch his face as the counter roars.  The vast majority of such articles can be categorized as shown below.  Uranium is present in their composition as a colorant and the radioactivity is merely incidental.  Some ceramic quack health products were intentionally radioactive.  My collection is by no means exhaustive, but is fairly representative of what a few weekends in local flea markets can turn up.

The red stuff owes its distinctive color to a leaded uranium glaze.  This glaze is most frequently encountered in so-called “California pottery” of the 1930s-50s, a style featuring bright, solid colors evocative of Moorish tile.  The best-known example is Fiesta made by the Homer Laughlin China Company.  Red Fiestaware contained natural uranium from 1936 to 1943, when wartime demand for uranium stopped production.  Production resumed in 1959 with depleted uranium and ended for good in 1972.  The selection in the photo at left includes Fiesta, as well as items made by Bauer, California Pottery, Pacific, and various unknown potteries.  Uranium red glazes can produce up to about 30 kcpm on a 2″ pancake Geiger detector.  Some kinds of California pottery are collectible and command high prices (e.g. Fiesta), but many uranium-glazed items of lesser pedigree can be found that cost no more than a couple dollars.

The yellow stuff, glazed with a transparent uranium glaze, is generally much less radioactive than the red (ranges up to about 5 kcpm on a 2″ pancake Geiger detector), and more stylistically diverse.  Examples of the California style can be found (the Franciscan Ware cup and saucer at left), but so can fine English bone china (small Paragon pitcher at center back), floral-patterned ware (Hall’s pitcher; Limoges “Golden Glow” plate, center-right) even special childrens’ dishes (front, with romantic verse and decal).  In general, the deeper the yellow tint, the hotter the product.  Most fluoresce a greenish tint under ultraviolet light.

The green stuff is uranium glass, made by including a highly variable amount of uranium oxide in the melt.  Colors range from amber to blue-green; some is transparent, some opaque.  Regardless of color or opacity, almost all fluoresces brilliant green under ultraviolet light.  Major sub-varieties are known as vaseline glass, jadeite, custard glass, and canary glass.  Uranium green glass was especially popular during the Great Depression; “elegant glass” and the cheaper “Depression glass” of a green color frequently contain some uranium.  Cullet, tubing, and marbles of modern production are widely available.  Uranium glass was also once widely used in making graded glass-to-metal seals because of a favorable coefficient of thermal expansion.  Its use in that application is represented by the Eimac 35-TG vacuum tube at right.  The hottest specimen in this tableau is the large hand-blown vase.  Though not particularly fluorescent, it puts out 5 kcpm into a 2″ pancake Geiger counter.

Quack crockery. “Revigators”  made in the 1920s are still surprisingly (frighteningly!) commonplace.   They were to Americans of the flapper age what acai-berry weight-loss supplements are to the Linda Litzke types of today.  Lined with a porous and highly-radioactive torbernite-charged grout, these jars dispensed drinking water saturated with radon gas and its radioactive progeny.  Health benefits were claimed, but the only proven reality of the radioactive water craze was a number of cases of terminal bone cancer.  Needless to say, the Revigator and similar offerings from other manufacturers aren’t safe to use as intended!  Radioactive quack crockery is highly collectible, so expect to drop a few benjamins on specimens in good condition.  My Revigator was a cheap local bargain, but it is missing the matching stand and lid.  It blows nearly 50 kcpm on a 2″ pancake Geiger counter placed within.

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Neutron Experiments on Video

January 10, 2010

Here are my inaugural YouTube offerings treating neutron production, detection, and use for producing radioisotopes in the home laboratory.  See an americium-beryllium neutron source (made from smoke detectors) in action!  I hope to make more such videos in the future.

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