Discussion on Retest of Total Radioactivity for Remaining Aerosol Sample

Objectives To discuss the feasibility on retest of gross radioactivity for the remaining aerosol samples.

Methods The Technical criteria for radiation environmental monitoring (HJ/T 61-2001)was referenced for sample pretreatment, the Water quality-determination of gross alpha activity-thick source method (EJ/T 1075-1998)and Water quality-Determination of gross beta activity-evaporation method (EJ/T 900-1994) were referenced for sample preparation and measurement, then analyzed the variation of gross radioactivity in aerosol as a function of time.

Results The gross radioactivity remained stable after the samples were placed for 120 h, but the relative deviation of gross α activity of retest of the remaining samples reached 34.7% after 32 days, which was close to the limit value in terms of the quality requirement, and it increased linearly after that.

Conclusions Retest of the remaining samples might not be the most appropriate routine quality control method.