In this study, a gamma–gamma coincidence spectrometry was developed and examined for environmental low-level cosmogenic 22Na monitoring purposes. The spectrometry consists of two bismuth germanate scintillators (BGO) and XIA LLC Digital Gamma Finder
(DGF)/Pixie-4 software and card package. The developed spectrometry was optimized according to the considerations of output
count rate and gamma peak energy resolution. This spectrometry provides a more sensitive and effective way to quantify even
trace amounts of 22Na with critical detection limit of 9 mBq. A sophisticated computer simulation was also created with the goal of obtaining
a better understanding of the experimental results and gamma–gamma coincidence efficiencies at different sample geometries.