Tritium trapping in silicon carbide in contact with solid breeder under high flux isotope reactor irradiation

Abstract The trapping of tritium in silicon carbide (SiC) injected from ceramic breeding materials was examined via tritium measurements using imaging plate (IP) techniques. Monolithic SiC in contact with ternary lithium oxide (lithium titanate and lithium aluminate) as a ceramic breeder was irradiated in the High Flux Isotope Reactor (HFIR) in Oak Ridge, Tennessee, USA. The distribution of photo-stimulated luminescence (PSL) of tritium in SiC was successfully obtained, which separated the contribution of 14C β-rays to the PSL. The tritium incident from ceramic breeders was retained in the vicinity of the SiC surface even after irradiation at 1073 K over the duration of ∼3000 h, while trapping of tritium was not observed in the bulk region. The PSL intensity near the SiC surface in contact with lithium titanate was higher than that obtained with lithium aluminate. The amount of the incident tritium and/or the formation of a Li2SiO3 phase on SiC due to the reaction with lithium aluminate under irradiation likely were responsible for this observation.

[1]  M. Shimada,et al.  Application of tritium imaging plate technique to examine tritium behaviors on the surface and in the bulk of plasma-exposed materials , 2011 .

[2]  E. Janzén,et al.  Diffusion of hydrogen in perfect, p -type doped, and radiation-damaged 4H-SiC , 2004 .

[3]  Lance Lewis Snead,et al.  Evaluation of neutron irradiated silicon carbide and silicon carbide composites , 2007 .

[4]  Lance Lewis Snead,et al.  Thermophysical and mechanical properties of near-stoichiometric fiber CVI SiC/SiC composites after neutron irradiation at elevated temperatures , 2010 .

[5]  T. Sample,et al.  The Compatibility of SiC/SiC Composites with Ceramic Breeder Materials , 1994 .

[6]  William R. Wampler,et al.  Tritium migration in vapor-deposited β-silicon carbide , 1993 .

[7]  Akira Hasegawa,et al.  Study on Compatibility Between Silicon Carbide and Solid Breeding Materials Under Neutron Irradiation , 2011 .

[8]  T. Muroga,et al.  Diffusional behavior of tritium in V-4Cr-4Ti alloy , 2007 .

[9]  S. Zinkle,et al.  Operating temperature windows for fusion reactor structural materials , 2000 .

[10]  M. Nishikawa,et al.  Correlation between tritium release and thermal annealing of irradiation damage in neutron-irradiated Li2SiO3 , 2007 .

[11]  Akira Kohyama,et al.  Issues and advances in SiCf/SiC composites development for fusion reactors , 2004 .

[12]  Sakae Tanaka,et al.  Dynamic hydrogen isotope behavior and its chemical states in SiC by XPS and TDS technique , 2005 .

[13]  B. Riccardi,et al.  Deuterium transport in SiCf/SiC composites , 2002 .

[14]  T. Yamanishi,et al.  Tritium permeation behavior in SiC/SiC composites , 2010 .

[15]  Retention of hydrogen implanted into SiC single crystals , 1984 .

[16]  Kuruvilla Verghese,et al.  Hydrogen Diffusion and Solubility in Silicon Carbide , 1978 .