Development of a new facility for dating old ground waters and ice cores using 81Kr.

• Main Authors: Lavielle, B., Gilabert, E., Thomas, B.
• Other Authors: RAEN, Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)
• Format: Conference Object
• Language: English
• Published: HAL CCSD 2011
• Subjects: [CHIM.ANAL]Chemical Sciences/Analytical chemistry; ice core
• Online Access: https://hal.in2p3.fr/in2p3-00663814

Krypton-81 is produced by nuclear reactions induced by cosmic rays in atmosphere while Krypton-85 is released from nuclear installations. With respective halflifes of 229 ky and 10.76 y, these isotopes are considered as ideal tracers for dating groundwater or ice core [1-6]. The measurement of 81Kr from a groundwater sample was first demonstrated using several isotopic enrichment steps followed by RISTOF technique [1-3]. Due to the very low abundance of 81Kr in groundwater - 1200 atoms/l in modern water - the dating generally requires sample volumes of at least several hundred liters [5,7]. Since 2003, in a collaborative work with IRIM, CNAB is developing a set of four instruments in order to measure 81Kr in groundwater using reasonable volume of water (20 l). Each instrument is dedicated to perform important steps in the dating process: