Kichizo Tanaka

Tritium process laboratory at the JAERI

Abstract An overview is given of the design, construction and initiation of the operation of the facility, Tritium Process Laboratory, JAERI, to study and develop tritium processes for fusion fuel cycle and safe handling technology.

Chemical behaviors of tritium produced by the 6Li(n, α)T reaction in lithium oxide

Abstract The chemical forms of tritium released from neutron-irradiated crystalline powders of Li2O, LiOH and Li2CO3 have been investigated over the temperature range of 100–600°C with radio-gas chromatography and mass spectrometry. When the target materials are heated to 600°C under vacuum after the irradiation, more than 96% of tritium is released as hydrogen oxide, HTO, and collected in the cold trap cooled at −72°C. Tritium is also released in forms such as HT (and T2), CH3T and CnH2n+x − T (n = 2, x = 0, 1, 2), although their percentages are rather low. The release of HTO is interpreted by supposing that recoil tritium produced by the 6Li(n, α)T reaction is first stabilized as LiOT in the solids and then released by the reaction LiOT·LiOH(c)→Li2O(c)+HTO(g) at a temperature between 250 and 400°C.

Commissioning of the tritium process laboratory at the JAERI

Abstract The Tritium Process Laboratory (TPL) was constructed at the Japan Atomic Energy Research Institute (JAERI) in June, 1985. The objectives of this laboratory are the research and development of the fusion reactor fuel processing system and safe handling technology of large amounts of tritium. Total tritium inventory in the facility is 10 g and each experiment will be conducted with up to 1 g. Safety systems have been in operation since 1985 and have been tested without tritium. Tritium removal systems, gloveboxes, vacuum pumping system and tritium storage systems etc. have been proven to work as designed so that tritium can be handled safely in this facility. The various items of experimental apparatus were designed, fabricated, installed and checked early in 1988. First tritium was shipped from Oak Ridge National Laboratory in February, and then the “hot” operation was initiated in March, 1988.

Recoil ranges of 2.73 MeV tritons and yields of 18F produced by the 16O(t,n)18F reaction in neutron‐irradiated lithium compounds containing oxygen

The 16O(t,n)18F reaction induced by recoil tritons in neutron‐irradiated crystalline lithium compounds containing oxygen has been studied with emphasis laid upon the determination of recoil triton ranges. The physical parameters required for quantitative description of successive (n,α) – (t,n) processes have been enumerated. The yields of 18F predicted from the calculation agreed well with the observed ones for a variety of lithium compounds. Mean cross sections, averaged over the triton recoil range, for the 16O(t,n)18F reaction in solids were rather constant [?F= (9.87±0.35) ×10−26 cm2] and were independent of the triton range. The triton ranges in polycrystalline substances can be determined from 18F yield measurements. Ranges derived from the present results include 6.2±0.4 mg cm−2 [Li2O(s)], 7.1±0.6 mg cm−2 [LiOH (s)], and 7.0±0.6 mg cm−2 [Li2CO3(s)].