Abstract
Helium release behavior in post-irradiation heating tests was investigated for Li{sub 2}O single crystals which had been irradiated with thermal neutrons in JRR-4 and JRR-2, and fast neutrons in FFTF. It is clarified that the helium release curves from JRR-4 and JRR-2 specimens consists of only one broad peak. From the dependence of the peak temperatures on the neutron fluence and the crystal diameter, and the comparison with the results obtained for sintered pellets, it is considered that the helium generated in the specimen is released through the process of bulk diffusion with trapping by irradiation defects such as some defect clusters. For the helium release from FFTF specimens, two broad peaks were observed in the release curves. It is considered to suggest that two different diffusion paths exist for helium migration in the specimen, that is, bulk diffusion and diffusion through the micro-crack due to the heavy irradiation. In addition, helium bubble formation after irradiation due to the high temperature over 800K is suggested. (J.P.N.)
Yamaki, Daiju;
Tanifuji, Takaaki;
Noda, Kenji
[1]
- Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment
Citation Formats
Yamaki, Daiju, Tanifuji, Takaaki, and Noda, Kenji.
Helium release from neutron-irradiated Li{sub 2}O single crystals.
Japan: N. p.,
1998.
Web.
Yamaki, Daiju, Tanifuji, Takaaki, & Noda, Kenji.
Helium release from neutron-irradiated Li{sub 2}O single crystals.
Japan.
Yamaki, Daiju, Tanifuji, Takaaki, and Noda, Kenji.
1998.
"Helium release from neutron-irradiated Li{sub 2}O single crystals."
Japan.
@misc{etde_300393,
title = {Helium release from neutron-irradiated Li{sub 2}O single crystals}
author = {Yamaki, Daiju, Tanifuji, Takaaki, and Noda, Kenji}
abstractNote = {Helium release behavior in post-irradiation heating tests was investigated for Li{sub 2}O single crystals which had been irradiated with thermal neutrons in JRR-4 and JRR-2, and fast neutrons in FFTF. It is clarified that the helium release curves from JRR-4 and JRR-2 specimens consists of only one broad peak. From the dependence of the peak temperatures on the neutron fluence and the crystal diameter, and the comparison with the results obtained for sintered pellets, it is considered that the helium generated in the specimen is released through the process of bulk diffusion with trapping by irradiation defects such as some defect clusters. For the helium release from FFTF specimens, two broad peaks were observed in the release curves. It is considered to suggest that two different diffusion paths exist for helium migration in the specimen, that is, bulk diffusion and diffusion through the micro-crack due to the heavy irradiation. In addition, helium bubble formation after irradiation due to the high temperature over 800K is suggested. (J.P.N.)}
place = {Japan}
year = {1998}
month = {Mar}
}
title = {Helium release from neutron-irradiated Li{sub 2}O single crystals}
author = {Yamaki, Daiju, Tanifuji, Takaaki, and Noda, Kenji}
abstractNote = {Helium release behavior in post-irradiation heating tests was investigated for Li{sub 2}O single crystals which had been irradiated with thermal neutrons in JRR-4 and JRR-2, and fast neutrons in FFTF. It is clarified that the helium release curves from JRR-4 and JRR-2 specimens consists of only one broad peak. From the dependence of the peak temperatures on the neutron fluence and the crystal diameter, and the comparison with the results obtained for sintered pellets, it is considered that the helium generated in the specimen is released through the process of bulk diffusion with trapping by irradiation defects such as some defect clusters. For the helium release from FFTF specimens, two broad peaks were observed in the release curves. It is considered to suggest that two different diffusion paths exist for helium migration in the specimen, that is, bulk diffusion and diffusion through the micro-crack due to the heavy irradiation. In addition, helium bubble formation after irradiation due to the high temperature over 800K is suggested. (J.P.N.)}
place = {Japan}
year = {1998}
month = {Mar}
}