Application of the ²²⁶Ra-²³⁰Th-²³⁴U and ²²⁷Ac-²³¹Pa-²³⁵U radiochronometers to UF₆ Cylinders

Technical Report · Mon Jan 29 04:00:00 EST 2018

DOI:https://doi.org/10.2172/1430909· OSTI ID:1430909

Rolison, John M. ^[1]; WIlliams, Ross W. ^[1]

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1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Uranium-series radiometric dating was performed on two well-pedigreed UF₆ cylinder samples containing highly enriched uranium that were in use at the Portsmouth Gaseous Diffusion Plant between the mid-1970s and mid-1980s. Daughter-parent (i.e. ²³¹Pa-²³⁵U, ²³⁰Th-²³⁴U) radiometric ages determined on solid heel materials (e.g. UO₂F₂, UF₄) recovered from the emptied cylinders resulted in unrealistically old ages due to the preferential sequestration of progeny isotopes within the solid heels. However, limited elemental fractionation amongst the progeny isotopes themselves in the heel material allowed for useful age constraints on the fill dates of the UF6 cylinders to be extracted from the granddaughter-daughter systems (i.e. ²²⁶Ra-²³⁰Th, ²²⁷Ac- ²³¹Pa).

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC52-07NA27344
• OSTI ID: 1430909
• Report Number(s): LLNL-TR--746145
• Country of Publication: United States
• Language: English

Related Subjects

07 ISOTOPE AND RADIATION SOURCES
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
15 GEOTHERMAL ENERGY
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
U-series radiochronometry
age-dating
isotope dilution MC-ICP-MS
nuclear forensics
uranium hexafluoride