skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: 1993 yearly calibration of Pacific Northwest Laboratory`s gross gamma-ray borehole geophysical logging system

Technical Report ·
DOI:https://doi.org/10.2172/10104964· OSTI ID:10104964

This report describes the 1993 yearly calibration of a gross gamma-ray geophysical pulse logging system owned by the US Department of Energy (DOE) and operated by Pacific Northwest Laboratory. The calibration was conducted to permit the continued use of this system for geologic and hydrologic studies associated with remedial investigation at the Hanford Site. The calibration is limited to the probe identified as CG27A-97 and applies to a new probe detector crystal that replaced the former detector in January 1993, after a crack was discovered. Primary calibrations to equivalent-uranium units were conducted in DOE borehole model standards that reside on the Hanford Site. The calibrations were performed in borehole models SBL/SBH and SBA/SBB, which both contain sections with relatively low equivalent-uranium concentrations. Model SBH/SBL has now been countersunk at the site so that data were taken by suspending the probe downhole. Model SBA/SBB is still lying horizontally above ground at the site, so data were logged as in previous calibrations at the Hanford site by pushing the probe into the hole and drawing it out with the logging equipment. A previous correlation for relating observed count rate in before- and after-logging field calibrations to equivalent-uranium concentrations was confirmed for field source Ra-20S-82. A computer-based digital collection/recording system was used simultaneously on many of the procedures with the original analog system so that the performance of the two collection systems could be correlated and compared. The digital system was calibrated this year to confirm its linearity and to establish correlation with the analog data (i.e., chart-recorder output).

Research Organization:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
AC06-76RL01830
OSTI ID:
10104964
Report Number(s):
PNL-8895; ON: DE94003265
Resource Relation:
Other Information: PBD: Sep 1993
Country of Publication:
United States
Language:
English