Measurement of Fuel Importance Distribution in Non-uniformly Distributed Fuel Systems.

• YAMANE Yoshihiro

  Department of Nuclear Engineering, Nagoya University

• HIRANO Yasushi

  Department of Nuclear Engineering, Nagoya University

• YASUI Hazime

  Department of Nuclear Engineering, Nagoya University

• IZIMA Kazunori

  Department of Nuclear Engineering, Nagoya University

• SHIROYA Seiji

  Research Reactor Institute, Kyoto University

• KOBAYASHI Keiji

  Research Reactor Institute, Kyoto University

Abstract

A reactivity effect due to a spatial variation of nuclear fuel concentration is an important problem for nuclear criticality safety in a reprocessing plant. As a theory estimating this reactivity effect, the Goertzel and fuel importance theories are well known. It has been shown that the Goertzel's theory is valid in the range of our experiments based on measurements of reactivity effect and thermal neutron flux in non-uniformly distributed fuel systems. On the other hand, there have been no reports concerning systematic experimental studies on the flatness of fuel importance which is a more general index than the Goertzel's theory.<BR>It is derived from the perturbation theory that the fuel importance is proportional to the reactivity change resulting from a change of small amount of fuel mass. Using a uniform and three kinds of nonuniform fuel systems consisting of 93.2% enriched uranium plates and polyethylene plates, the fuel importance distributions were measured. As a result, it was found experimentally that the fuel importance distribution became flat, as its reactivity effect became large. Therefore it was concluded that the flatness of fuel importance distribution is the useful index for estimating reactivity effect of non-uniformly distributed fuel system.

Journal

• Journal of Nuclear Science and Technology

  Journal of Nuclear Science and Technology 32 (4), 285-294, 1995

  Atomic Energy Society of Japan

Keywords

• fuel reprocessing plant
• fuel importance
• fuel concentration
• nonuni-form fuel distribution
• optimum fuel distribution
• flatness
• perturbation theory
• reactivity effects
• experimental data
• critical assembly
• Goertzel's theory

Details

• CRID: 1390282679072253184
• NII Article ID: 10002072331
• NII Book ID: AA00703720
• DOI: 10.3327/jnst.32.285
• COI: 1:CAS:528:DyaK2MXltFaktbk%3D
• ISSN: 18811248
• ISSN: 00223131
• Text Lang: en
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed