Nuclear Archeology in a Bottle: Evidence of Pre-Trinity U.S. Weapons Activities from a Waste Burial Site

• Published in: Analytical chemistry (Washington) 2009-02, Vol.81 (4), p.1297-1306
• Main Authors: Schwantes, Jon M, Douglas, Matthew, Bonde, Steven E, Briggs, James D, Farmer, Orville T, Greenwood, Lawrence R, Lepel, Elwood A, Orton, Christopher R, Wacker, John F, Luksic, Andrzej T
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Applied sciences; Archaeology; Chemical reactors; Chemistry; Chromatographic methods and physical methods associated with chromatography; Exact sciences and technology; Isotopes; Nuclear chemistry; Other chromatographic methods; Plutonium; Pollution; Radioactive wastes; Spectrometric and optical methods; Wastes
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac802286a

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 22Na, 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 α 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 Corroborated by historical documents, we concluded this sample was part of the first batch of Pu separated at T-Plant, Hanford, the world’s first industrial-scale reprocessing facility, on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 239Pu in the world.