Helium Gas Release Behavior of Highly Microstructure-Controlled B4C-Based Ceramics Irradiated with Helium Ion Beam

K. Yoshida R. Maki, J. Maletaskic, A. Gubarevich, T. Katabuchi, T. S. Suzuki and T. Uchikoshi

Boron carbide (B 4 C) pellets have been commonly used as neutron absorber materials in fast reactor system. In this study, highly microstructure-controlled B 4 C ceramics with carbon nanotube (CNT) and tubal pores were fabricated by two processes; strong magnetic field (12 T)-assisted colloidal process or normal slip casting process, and the B 4 C/CNT composites were irradiated with a 30-MeV alpha beam. After irradiation, the helium gas release behavior of the alpha-implanted samples was evaluated by measuring the release of helium gas by heating the samples. The alpha-implanted samples with tubal pores showed the peak which would attribute to the helium gas release clearly from around 250℃ in TG-MS, whereas alpha-implanted dense sample without porosity did not show the peak clearly. It was confirmed that helium gas was released more rapidly from the B 4 C/CNT composites with tubal pores. The results of TG-MS and TEM suggested that helium gas can be released effectively from inside the B 4 C/CNT composites even with the same porosity of 5-10% as that of B 4 C used as neutron absorber materials in fast reactors by introducing tubal pores by highly microstructure control.

Progress in Nuclear Science and Technology

7

207

213

DOI: 10.15669/pnst.7.207