Fusion Science and Technology / Volume 48 / Number 1 / July 2005 / Pages 317-323
Technical Paper / Tritium Science and Technology - Tritium Measurement, Monitoring, and Accountancy
Zirconium-Cobalt (ZrCo) tritium storage bed with "in-bed" gas flowing calorimetry has been developed as a self-assaying system for the Tritium Storage and Delivery System of ITER. The basic tritium accounting characteristics have been investigated and practical data on the accounting stability has been accumulated under gram level tritium storage for more than 8 years. The initial sensitivity of tritium was about 0.05 g and the accuracy (standard deviation of repeat measurements: two sigma) was about 0.15 g at full tritium storage of 25 g. This initial accounting performance has been maintained after tritium storage for more than 8 years by keeping constant accounting conditions at each inventory measurement. Almost no aging effect of tritium was found except accumulation of 3He in the primary ZrCo tritide vessel, which was easily evacuated to keep initial accounting condition before each inventory measurement.