Numerical Analysis of a Concrete Biological Shielding Wall under Neutron Irradiation by 3D RBSM

• Kambayashi Daisuke

  Graduate School of Environmental Studies, Nagoya University, Nagoya, Japan.

• Sasano Hiroshi

  Ove Arup & Partners Japan Ltd., Tokyo, Japan.

• Sawada Shohei

  Nuclear Power Department, Kajima Corporation, Tokyo, Japan.

• Suzuki Kiyoteru

  Nuclear Safety Division, Mitsubishi Research Institute, Inc., Tokyo, Japan.

• Maruyama Ippei

  Graduate School of Environmental Studies, Nagoya University, Nagoya, Japan. Graduate School of Engineering, The University of Tokyo, Tokyo, Japan.

Abstract

In nuclear power plants, concretes used for biological shielding walls are exposed to radiation such as neutrons and gamma rays over the long-term operation of the plant. Previous studies have reported that neutron irradiation causes aggregate expansion due to the metamictization of quartz and feldspar leading to reduced density and a loss of the compressive strength and Young' s modulus of the concrete. Therefore, it is crucial to understand the current state of a concrete biological shield (CBS) and predict its future soundness. In this study, a rigid-body spring model, which can easily evaluate fracture behavior by using springs between each element, is used to conduct numerical analyses on a CBS. A three-phase (mortar, aggregate, and interfacial transition zone) model of a 2000 mm thick CBS is used to investigate the varying deformation responses depending on the presence or absence of reinforcing bars (rebar), creep, and an inner steel plate with five types of analyses, i.e. analysis to understand the impacts of temperature distribution, re-inforcement bars, an internal steel plate, and creep of mortar. The results show that cracking and delamination occur inside the CBS, resulting in a lack of cracking on the outside. They also show that the cracks are reduced by rebar and creep, resulting in cracks extending from the innermost edge to a depth of approximately 150 mm.

Journal

• Journal of Advanced Concrete Technology

  Journal of Advanced Concrete Technology 18 (10), 618-632, 2020-10-27

  Japan Concrete Institute

Keywords

• General Materials Science
• Building and Construction

Details

• CRID: 1390849376470483200
• NII Article ID: 130007930789
• DOI: 10.3151/jact.18.618
• ISSN: 13473913
• ISSN: 13468014
• Web Site: https://www.jstage.jst.go.jp/article/jact/18/10/18_618/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed