Performance demonstration of 4πβ(LS)-γ coincidence counting system for standardization of radionuclides with complex decay scheme

• A 4πβ(LS)-γ coincidence counting system has been developed in the laboratory.
• The 4πβ(LS)-γ system was used for complex decay scheme radionuclides standardization.
• 134Cs and 131I were standardized to demonstrate applicability of 4πβ(LS)-γ system.
• Activity concentration measured by 4πβ(LS)-γ system was compared with that obtained with 4πβ(PC)-γ system, and CIEMAT/NIST.
• The activity concentrations obtained by different methods are comparable within uncertainty limits.

A standardization of 134Cs and 131I was carried out in order to demonstrate the performance and applicability of the 4πβ(LS)-γ coincidence counting system for standardization of radionuclides with complex decay scheme. The coincidence analyzer, capable of analyzing coincidence between beta and two gamma windows simultaneously, was developed and used for the standardization. The use of this dual coincidence analyzer has reduced the total experimental time by half. The activity concentrations obtained using the 4πβ(LS)-γ coincidence counting system, a 4πβ(PC)-γ coincidence counting system, and the CIEMAT/NIST method are in excellent agreement with each other within uncertainty limits and hence demonstrates its performance for standardization of radionuclides decaying with complex decay scheme. Hence use of this 4πβ(LS)-γ coincidence counting system can be an alternative method suitable to standardize radionuclides with complex decay scheme with acceptable precision.