Development of a new detection system for monitoring high-level tritiated water

To monitor high-level tritiated water in a fusion fuel circulation system, a new detection system for non-destructive measurements of tritium concentration was specially design and fabricated. A twin-type X-ray detector, which works as a detector of the low energy X-rays induced by β-rays from tritiated water, was equipped with the new detection system. Tritiated water flows in a narrow space surrounded by two X-ray detectors. Basic performance of the new detection system was examined using a poly-methylmethacrylate disk labeled with tritium and tritiated water. It was found that the present detection system satisfied the basic performance for measurements of the low energy X-rays and it is applicable to non-destructive measurements of high-level tritiated water in a flow system.