γ-ray-source geometry corrections for use in gaseous radioactivity measurements

A new technique has been developed to determine geometric corrections for γ-ray counting for gaseous radioactivity measurements. A known amount of standardized non-volatile radioactivity, homogeneously mixed with vermiculite or any granular material with a bulk density of <approximately 0.15 g cm-3, is used as a mock standard for the gaseous activity contained in a sample container. An empirical equation is obtained to calculate correction factors for the gaseous radioactivities contained in a 14.1-ml boiling water reactor (BWR) off-gas sample-vial and counted on Ge(Li) detectors. Experimental data are also reported for the corrections for gaseous radioactivities relative to the liquid standard contained in the 14.1-ml glass vial. (author)