Activity standardization of 134Cs and 137Cs

The paper presents the results from a primary standardization of 137Cs using two independent methods - efficiency tracing using PC-NaI coincidence and the TDCR method. The nuclides 60Co and 134Cs were used as the tracers. Primary standardization of the 134Cs is also discussed. The efficiency extrapolation was carried out by measuring samples of varying mass and using the wet extrapolation method. The results obtained are in good agreement; the differences did not exceed 0.5%. The advantages, pitfalls and also possibilities for improvement of the procedures are discussed.