Calibration of an automated high resolution gamma-ray spectroscopy system for in-situ real-time monitoring of a processed waste effluent stream

Abstract

A pilot plant is being designed at the U. S. Department of Energy's Savannah River Site (SRS) to demonstrate the removal of ⁹⁰Sr, ¹³⁷Cs, and transuranics from a high-level liquid waste stream prior to encapsulation in a Saltstone Facility. In-line monitors are required to determine the concentration of all radionuclides on this processed waste stream. Calibration standards containing ⁶⁰Co, ¹³⁷Cs, and ⁹⁰Sr were prepared and counted. Efficiency curves were generated. Strontium-90 is readily observable above the system background in the calibration standard count, and is observable at less than 3 nCi/ml in a mixed solution having the maximum allowable concentration of all other activities present in the proposed SRS effluent stream.