title: Validation of reference materials for uranium radiochronometry in the frame of nuclear forensic investigations.
abstract: The results of a joint effort by expert nuclear forensic laboratories in the area of age dating of uranium, i.e. the elapsed time since the last chemical purification of the material are presented and discussed. Completely separated uranium materials of known production date were distributed among the laboratories, and the samples were dated according to routine laboratory procedures by the measurement of the (230)Th/(234)U ratio. The measurement results were in good agreement with the known production date showing that the concept for preparing uranium age dating reference material based on complete separation is valid. Detailed knowledge of the laboratory procedures used for uranium age dating allows the identification of possible improvements in the current protocols and the development of improved practice in the future. The availability of age dating reference materials as well as the evolvement of the age dating best-practice protocol will increase the relevance and applicability of age dating as part of the tool-kit available for nuclear forensic investigations.
authors.affiliation: European Commission, Joint Research Centre (JRC), Institute for Transuranium Elements (ITU), Postfach 2340, 76125 Karlsruhe, Germany. Electronic address: zsolt.varga@ec.europa.eu.
authors.forename: Z
authors.initials: Z
authors.lastname: Varga
authors.affiliation: European Commission, Joint Research Centre (JRC), Institute for Transuranium Elements (ITU), Postfach 2340, 76125 Karlsruhe, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Mayer
authors.affiliation: Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 8745, USA.
authors.forename: C E
authors.initials: CE
authors.lastname: Bonamici
authors.affiliation: CEA, DAM, DIF, F91297 Arpajon, France.
authors.forename: A
authors.initials: A
authors.lastname: Hubert
authors.affiliation: Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550, USA.
authors.forename: I
authors.initials: I
authors.lastname: Hutcheon
authors.affiliation: Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 8745, USA.
authors.forename: W
authors.initials: W
authors.lastname: Kinman
authors.affiliation: Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550, USA.
authors.forename: M
authors.initials: M
authors.lastname: Kristo
authors.affiliation: CEA, DAM, DIF, F91297 Arpajon, France.
authors.forename: F
authors.initials: F
authors.lastname: Pointurier
authors.affiliation: Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 8745, USA.
authors.forename: K
authors.initials: K
authors.lastname: Spencer
authors.affiliation: Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 8745, USA.
authors.forename: F
authors.initials: F
authors.lastname: Stanley
authors.affiliation: Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 8745, USA.
authors.forename: R
authors.initials: R
authors.lastname: Steiner
authors.affiliation: Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 8745, USA.
authors.forename: L
authors.initials: L
authors.lastname: Tandon
authors.affiliation: Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550, USA.
authors.forename: R
authors.initials: R
authors.lastname: Williams
keywords: Age determination; Nuclear forensics; Thorium; Uranium