New measurement of the ²⁴²Pu(n,γ) cross section at n_TOF-EAR1 for MOX fuels: Preliminary results in the RRR

¹ Universidad de Sevilla, Spain
² Centro de Investigaciones Energeticas Medioambientales y Tecnológicas (CIEMAT), Spain
³ Johannes Gutenberg-Universität Mainz, 55128 Mainz, Germany
⁴ Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden, Germany
⁵ European Organization for Nuclear Research (CERN), Switzerland
⁶ University of Lodz, Poland
⁷ Institut de Physique Nucléaire, CNRS-IN2P3, Univ. Paris-Sud, Université Paris-Saclay, 91406 Orsay Cedex, France
⁸ Technische Universität Wien, Austria
⁹ CEA Saclay, Irfu, Gif-sur-Yvette, France
¹⁰ Istituto Nazionale di Fisica Nucleare, Sezione di Bari, Italy
¹¹ Charles University, Prague, Czech Republic
¹² University of Manchester, UK
¹³ University of Zagreb, Croatia
¹⁴ University of York, UK
¹⁵ University of Santiago de Compostela, Spain
¹⁶ Universitat Politècnica de Catalunya, Spain
¹⁷ INFN Laboratori Nazionali del Sud, Catania, Italy
¹⁸ Dipartimento di Fisica, Università degli Studi di Bari, Italy
¹⁹ Instituto de Física Corpuscular, Universidad de Valencia, Spain
²⁰ Paul Scherrer Institut (PSI), Villingen, Switzerland
²¹ Instituto Superior Técnico, Lisbon, Portugal
²² Goethe University Frankfurt, Germany
²³ Horia Hulubei National Institute of Physics and Nuclear Engineering, Romania
²⁴ Japan Atomic Energy Agency (JAEA), Tokai-mura, Japan
²⁵ European Commission, Joint Research Centre, Geel, Retieseweg 111, 2440 Geel, Belgium
²⁶ Karlsruhe Institute of Technology, Campus North, IKP, 76021 Karlsruhe, Germany
²⁷ National Technical University of Athens, Greece
²⁸ School of Physics and Astronomy, University of Edinburgh, UK
²⁹ Agenzia nazionale per le nuove tecnologie (ENEA), Bologna, Italy
³⁰ Istituto Nazionale di Fisica Nucleare, Sezione di Bologna, Italy
³¹ Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, Germany
³² Dipartimento di Fisica e Astronomia, Università di Bologna, Italy
³³ Istituto Nazionale di Fisica Nucleare, Sezione di Legnaro, Italy
³⁴ Consiglio Nazionale delle Ricerche, Bari, Italy
³⁵ Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, Italy
³⁶ Dipartimento di Fisica e Astronomia, Università di Catania, Italy
³⁷ University of Ioannina, Greece
³⁸ University of Vienna, Faculty of Physics, Vienna, Austria
³⁹ University of Granada, Spain
⁴⁰ Department of Physics, University of Basel, Switzerland
⁴¹ Centre for Astrophysics Research, University of Hertfordshire, UK
⁴² Bhabha Atomic Research Centre (BARC), India
⁴³ Australian National University, Canberra, Australia

^a e-mail: jlerendegui@us.es

Published online: 13 September 2017

Abstract

The spent fuel of current nuclear reactors contains fissile plutonium isotopes that can be combined with ²³⁸U to make mixed oxide (MOX) fuel. In this way the Pu from spent fuel is used in a new reactor cycle, contributing to the long-term sustainability of nuclear energy. The use of MOX fuels in thermal and fast reactors requires accurate capture and fission cross sections. For the particular case of ²⁴²Pu, the previous neutron capture cross section measurements were made in the 70's, providing an uncertainty of about 35% in the keV region. In this context, the Nuclear Energy Agency recommends in its “High Priority Request List” and its report WPEC-26 that the capture cross section of ²⁴²Pu should be measured with an accuracy of at least 7–12% in the neutron energy range between 500 eV and 500 keV. This work presents a brief description of the measurement performed at n_TOF-EAR1, the data reduction process and the first ToF capture measurement on this isotope in the last 40 years, providing preliminary individual resonance parameters beyond the current energy limits in the evaluations, as well as a preliminary set of average resonance parameters.