Special Nuclear Material

Albuquerque, Ground Zero

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.)