Hybrid radioassay of multiple radionuclide mixtures in waste solutions by using liquid and NaI(Tl) scintillation monitors.

摘要

A new analytical technique for radioactive waste solutions has been developed by using a combination of a liquid and a NaI(Tl) scintillation monitor, which enables beta-emitter mixtures to be radioassayed using one calculation process with the method of least squares. This hybrid system can facilitate the analysis of beta-emitter mixtures with very similar liquid scintillation pulse height distributions, such as 3H, 51Cr, and 125I. All that is required for the technique are sets of quench standards of the nuclides to be analyzed and calibration standards for the gamma-emitters. Detection limits for seven nuclides were estimated to be about 0.005 Bq mL(-1), which are sufficiently low compared with the values of authorized safety guidelines.