Tritium localisation and release from the ceramic pebbles of breeder

• Published in: Journal of nuclear materials Vol. 329; pp. 1287 - 1290
• Main Authors: Kizane, G, Tiliks, J, Vitinš, A, Rudzitis, J
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-08-2004
• Subjects: B0200; R0600; F0800
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/j.jnucmat.2004.04.229

Magnetic field (MF) effects on the radiolysis and tritium release from Li
4SiO
4 (FZK) and Li
2TiO
3 (CEA) ceramic pebbles were investigated. The tritium chemical forms in Li
4SiO
4 were estimated by means of lyomethods. In the case of the neutron fluence
F
n⩽10
18 n
m
−2, the tritium is mostly in the T
+ form, but in the case of
F
n≈10
25 n
m
−2, the T
+ form accounts for 86–95% of the tritium. A high subsurface concentration of tritium is characteristic of a separate pebble and correlates with the distribution of radiation-induced defects. The MF increases the radiolysis of Li
4SiO
4 by 20–25%. Irradiation with electrons to 1000 MGy at 1200 K increases the grain size by 5–10%, decreasing the parameters of tritium release. The increased grain size was observed for the Li
4SiO
4 pebbles irradiated in EXOTIC-8. A considerable tritium detention (up to 40%) was observed after annealing to 1120 K in the MF of 2.4 T.