title: Nuclear archeology in a bottle: evidence of pre-Trinity U.S. weapons activities from a waste burial site.
abstract: During World War II, the Hanford Site in Washington became the location for U.S. plutonium production. In 2004, a bottle containing a sample of plutonium was recovered from a Hanford waste trench. Here, state-of-the-art instrumental analyses, reactor model simulations, and investigative science techniques were used to provide insights as to the origin of this unknown sample, a process collectively termed as nuclear archeology. Isotopic age dating conducted on the sample in 2007 indicated the sample was separated from the spent fuel 61.6 +/- 4.5 years earlier. The isotope (22)Na, a detectable product of a secondary nuclear reaction, proved useful as a powerful tool for nuclear forensic analysis as (1) an easily detectable signifier of the presence of alpha emitting actinides, (2) an indicator of sample splitting, and (3) a measure of the time since sample splitting. Analytical results of minor actinide isotopes and reactor model simulations confirmed the material originated from the X-10 reactor in Oak Ridge, TN. Corroborated by historical documents, we concluded this sample was part of the first batch of Pu separated at T-Plant, Hanford, the world's first industrial-scale reprocessing facility, on December 9, 1944. This sample represents the oldest known collection of man-made (239)Pu in the world.
authors.affiliation: Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352, USA. jon.schwantes@pnl.gov
authors.forename: Jon M
authors.initials: JM
authors.lastname: Schwantes
authors.forename: Matthew
authors.initials: M
authors.lastname: Douglas
authors.forename: Steven E
authors.initials: SE
authors.lastname: Bonde
authors.forename: James D
authors.initials: JD
authors.lastname: Briggs
authors.forename: Orville T
authors.initials: OT
authors.lastname: Farmer
authors.forename: Lawrence R
authors.initials: LR
authors.lastname: Greenwood
authors.forename: Elwood A
authors.initials: EA
authors.lastname: Lepel
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Orton
authors.forename: John F
authors.initials: JF
authors.lastname: Wacker
authors.forename: Andrzej T
authors.initials: AT
authors.lastname: Luksic