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Title: In-Situ Gamma-PHA Measurements to Support Unconditional Release of NSR Chiller Unit

Technical Report ·
DOI:https://doi.org/10.2172/775667· OSTI ID:775667

The Analytical Development Section of Savannah River Technology Center (SRTC) was requested by the Project Engineering and Construction Division (PE and CD) to conduct in-situ gamma-ray pulse height analysis measurements to support the unconditional release of the 221FBL/NSR chiller unit. The chiller unit was used to cool process water in the 221 FBL/NS facility, and it was serviced by its own cooling tower ''closed circuit'' system. This chiller unit had been in service for 18 years and has never been located within an SRS radiological area. The measurements' main goal is to confirm that there is no process-related contaminants present on the chiller and associated piping. To accomplish this, we have acquired 48 gamma-ray pulse height analysis spectra. All acquisitions were made using a portable HPGe detector and EG and G Dart system that contains high voltage power supply and signal processing electronics. A personal computer with Gamma-Vision software was used to control the Dart MCA and provide space to store and manipulate multiple 4096-channel gamma-ray spectra. Our results showed no activity above background. All peaks identified in the spectra are due to naturally-occurring radionuclides. This confirmed that these chillers are free of process-related gamma-emitting radioactive contamination. We estimate the chillers are completely clean of radioactive contamination to the limits of 1 nCi total gamma-ray activity. This report will discuss the purpose of the measurements, the experimental setup, data acquisition, calculations and results, and a conclusion of the study.

Research Organization:
Savannah River Site (SRS), Aiken, SC (United States)
Sponsoring Organization:
US Department of Energy (US)
DOE Contract Number:
AC09-96SR18500
OSTI ID:
775667
Report Number(s):
WSRC-TR-2000-00458; TRN: US0101620
Resource Relation:
Other Information: PBD: 7 Mar 2001
Country of Publication:
United States
Language:
English