Monitoring the fast neutrons in a high flux: the case for 242Pu fission chambers

Research output: Contribution to report/book/conference proceedingsIn-proceedings paperpeer-review

Authors

  • Philippe Filliatre
  • Christian Jammes
  • Ludovic Oriol
  • Benoit Geslot
  • Ludo Vermeeren

Documents & links

Abstract

Fission chambers are widely used for on-line monitoring of neutron fluxes in irradiation reactors. A selective measurement of a component of interest of the neutron flux is possible in principle thanks to a careful choice of the deposit material. However, measuring the fast component is challenging when the flux is high with a significant thermal component. The main problem is that the isotopic content of a material selected for its good response to fast neutrons evolves with irradiation, so that the material is more and more sensitive to thermal neutrons. Within the framework of the FNDS (Fast Neutron Detector System) project, we design tools that simulate the evolution of the isotopic composition and fission rate for several deposits under any given flux. In the case of a high flux with a significant thermal component, 242Pu is shown to be the best choice for measuring the fast component, as long as its purity is sufficient. If an estimate of the thermal flux is independently available, one can correct the signal for that component. This suggests a system of two detectors, one of which being used for such a correction.

Details

Original languageEnglish
Title of host publicationFirst International Conference on Advancements in Nuclear Instrumentation, Measurement methods and their Applications (ANIMMA), 2009
Place of PublicationPiscataway, NJ, United States
Publication statusPublished - 8 Jul 2010
Event2009 - ANIMMA - Advancements in Nuclear Instrumentation Measurement Methods and their Applications: International Conference on Advancements in Nuclear Instrumentation, Measurement Methods and their Applications - CEA, Marseille, France
Duration: 7 Jun 200911 Jun 2009

Conference

Conference2009 - ANIMMA - Advancements in Nuclear Instrumentation Measurement Methods and their Applications
Country/TerritoryFrance
CityMarseille
Period2009-06-072009-06-11

Keywords

  • Fission reactor measurements, Neutron detectors, Simulation

ID: 221225