Computerised monitor for estimation of Pico-Curie level of activity in effluent

Estimation of pico-curie levels of activity of 99Mo and 131I in effluents could be made using gamma ray spectrometric method. A special container was designed which can have large volume of liquid 500 to 1000 ml and also expose the sample to the entire available area of NaI crystal used. A 5 inches x 3 inches NaI (TI) detector and three single channel analysers were used to get the peak counts of the activities. Suitable calibration and striping constants are computed and are fed to the portable microprocessor which print out the estimated activities in the sample in μCi/ml. This set up which is being used by RHC Unit, Vashi Complex to monitor the effluent released from Radio-Pharmaceutical Operations can measure the activities as low as 10-7 μCi/ml. (author). 2 figs., 1 tab