Tritium release from beryllium discs and lithium ceramics irradiated in the SIBELIUS experiment

• Published in: Journal of nuclear materials Vol. 212; pp. 966 - 970
• Main Authors: Johnson, C.E., Baldwin, D.L., Kopasz, J.P.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.1994
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/0022-3115(94)90978-4

The SIBELIUS experiment was designed to obtain information on the compatibility between beryllium and ceramics, as well as beryllium and steel, in a neutron environment. This experiment comprised irradiation of eight capsules, seven of which were independently purged with a He/0.1% H 2 gas mixture. Four capsules were used to examine beryllium/ceramic (Li 2O, LiAlO 2, Li 4SiO 4, and Li 2ZrO 3) and beryllium/steel (Types 316L and 1.4914) compacts. Isothermal anneal experiments have been run on representative beryllium and ceramic disks from each of the four capsules at 550 to 850°C in steps of 100°C. The results indicate that tritium release from the beryllium did not exhibit burst release behavior, as previously reported, but rather a progressive release with increasing temperature. Generally, ∼99% of the tritium was released by 850°C. Tritium release from the ceramic discs was quite similar to the behavior shown in other dynamic tritium release experiments on lithium ceramics. The tritium content in beryllium discs adjacent to a steel sample was found to be significantly lower than that found in a beryllium disc adjacent to a ceramic sample. Recoil of tritium from the ceramic into the beryllium appears to be the source of tritium entering the beryllium, probably residing in the beryllium oxide layer.