Somebody call Ripley’s: Uranium bomb part gains weight during machining operation at Y-12

uranium.jpgThe folks at the Y-12 nuclear weapons plant are mighty particular when measuring quantities of bomb-grade uranium, tracking the material virtually down to the atom to make sure that even the smallest amounts aren’t lost or diverted.

Therefore, it must have been a big surprise last month when a Y-12 engineer determined that a uranium bomb part had gained weight during a machining operation.

“A process engineer discovered that the documented post-machining weight of an enriched uranium part was greater than its documented pre-machining weight,” staff members with the Defense Nuclear Facilities Safety Board stated in their April 24 report to board headquarters in Washington, D.C.

As it turned out, there was some human error involved.

Members of Y-12’s Nuclear Material Control and Accountability team traced the source of the discrepancy to a “documentation error” by a worker in the plant’s 9212 uranium-processing complex. The worker reportedly logged the part’s assay (enrichment level) as the part’s weight.

According to the defense board’s report, “Special Nuclear Materials Operations personnel missed several opportunities to identify the discrepancy, including a procedurally-directed check to verify that the weight of item, as measured upon receipt in Building 9215 (where the machining apparently took place), matched the weight of the item recorded in Building 9212.”

The board memo said the responsible production team managers at Y-12 are evaluating ways to reduce error rates and prevent a recurrence.

Photo caption: Y-12 worker holds a “button” of highly enriched uranium. (NNSA photo)

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This entry was posted in CNS, DNFSB, Y-12 on by .

About Frank Munger

Senior Writer Frank Munger covers the Dept. of Energy's Oak Ridge facilities and many related topics — nuclear weapons, nuclear waste and other things nuclear, environmental cleanup and science of all sorts. Atomic City Underground is, first and foremost, a news blog, but there's room for analysis, opinion and random thoughts that have no place else to go.