Krypton-85 chronometry of spent nuclear fuel

We describe the use of the radionuclide ⁸⁵Kr, which is produced by nuclear fission and has a half-life of 10.76 years, to determine the age of spent nuclear fuel. The method is based on mass-spectrometric measurement of the relative abundance of fissiogenic Kr isotopes extracted from a fuel sample, and we show that it can be applied to micron-scale particles of spent fuel that are analogous to particles that have been released into the environment from various nuclear facilities in the past. ⁸⁵Kr chronometry is potentially valuable for identifying and attributing nuclear materials, grouping samples into collections of common origin that can be used to reconstruct the origin and irradiation history of the material, and verifying declared nuclear activities in the context of international monitoring programs.. Authors: Balco, Greg [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)]; Conant, Andrew J. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)]; Reilly, Dallas D. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)]; Barton, Dallin [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)] (ORCID:0000000151687250); Willett, Chelsea D. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)]. DOE Contract: AC52-07NA27344. Subjects: 11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS; Nuclear science and engineering