Implementation of CIEMAT/NIST LSC efficiency tracing method in KRISS: (204)T1 standardization.

The CIEMAT/NIST efficiency tracing method has been widely used for radionuclide standardization. The method consists of the theoretical calculations of counting efficiencies and the experimental data obtained from a commercially available double photomultiplier detector. We have recently implemented the technique using (3)H as a tracer. Our implementation of the method was validated by participating into an international comparison of activity measurements of a solution of (204)T1. We report in this paper the procedure employed to implement the technique and compare our measurement result of (204)T1 activity with that of the international comparison.