Experimental Study on Temperature Coefficient of Reactivity in Light Water-Moderated and Heavy-Water-Reflected Cylindrical Core Loaded with Highly-Enriched-Uranium or Medium-Enriched-Uranium Fuel.

• SHIROYA Seiji

  Research Reactor Institute, Kyoto University

• MORI Masaaki

  Department of Nuclear Engineering, Kyoto University Nuclear Engineering, Ltd.

• MISAWA Tsuyoshi

  Department of Nuclear Engineering, Kyoto University Department of Nuclear Engineering, Nagoya University

• HAYASHI Masatoshi

  Research Reactor Institute, Kyoto University

• KOBAYASHI Keiji

  Research Reactor Institute, Kyoto University

• KANDA Keiji

  Research Reactor Institute, Kyoto University

Abstract

By using the Kyoto University Critical Assembly (KUCA), a series of critical experiments was performed to measure the temperature coefficient of reactivity in a light-water-moderated and heavy-water-reflected cylindrical core loaded with highly-enriched-uranium (HEU) or medium-enriched-uranium (MEU) fuel. The measurement was performed for the approximately 20 to 70°C range to examine the effects of the size of light-water region in a heterogeneous multi-region type core, the reduced ²³⁵U enrichment, and the existence of boron burnable poison (BP) on this quantity by using six types of core configurations. In all the six types of cores, there were large light-water regions at the center of core and between the outer fuel region and the heavy-water reflector region, and it was found that these light-water regions caused a remarkably positive effect on the temperature coefficient of reactivity. In the present study, the temperature coefficients of the MEU core and the core without BP were more positive than those of the HEU core and the core with BP, respectively. The size of light-water region had a larger effect on the temperature coefficient rather than the reduced ²³⁵U enrichment and the existence of BP. The negative temperature coefficient would be realized by reducing the thickness of light-water layer existed in the core.

Journal

• Journal of Nuclear Science and Technology

  Journal of Nuclear Science and Technology 32 (11), 1081-1089, 1995

  Atomic Energy Society of Japan

Keywords

• temperature coefficient
• reactivity
• reactivity coefficients
• critical experiment
• light-water moderation
• heavy-water reflection
• research reactor
• region size
• reduced enrichment
• burnable poisons
• cylindrical core
• flux trap
• highly enriched uranium
• medium enriched uranium
• nuclear fuels
• KUCA
• RERTR

Details

• CRID: 1390282679072834944
• NII Article ID: 10002073500
• NII Book ID: AA00703720
• DOI: 10.3327/jnst.32.1081
• COI: 1:CAS:528:DyaK28XltVam
• ISSN: 18811248
• ISSN: 00223131
• Text Lang: en
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed