Rapid Method of Gross Alpha/Beta Analysis Using Liquid Scintillation Counter for Radiological Screening and Contamination Control Survey
Y.D. Pan and R.M. Davis (Perma-Fix Environmental Services, Inc.)
A rapid method of gross alpha/beta analysis method is developed and implemented in the daily facility contamination control survey, post processing, pre-release survey, and radiological waste screening at a TSD facility. This method is proven to be a fast, cost-effective method and can be used as a radiological screening method in the field of applied radiation protection and homeland security. This method is based on the recently available liquid Scintillation counting (LSC) systems with the ability of discrimination of alpha and beta emitter by the time distribution of the light emission each generates from scintillators, in the term of pulse shape discrimination (PSD) or pulse decay analysis (PDA). This method is developed and verified by following method development protocol of ANSI standard. The calibration standards for each matrices were prepared and used for LSC system alpha/beta discrimination optimizing and efficiency calibrations. The special sample preparations were addressed for each type of matrices. The potential of misidentifications between alpha and beta emitters were studied and controlled within the acceptable range. This method has the advantages of high counting efficiency, fast sample preparation, acceptable precision, accuracy and sample counting automation with a reasonable background level compare with other traditional methods. This method can be used for most environmental and bioassay sample matrices such as swipe filters, air filters, liquid and solid samples.