In-situ Gamma-ray Site Characterization of the Tatum Salt Dome Test Site in Lamar County, Mississippi

Abstract

Field surveys of gamma-ray emitting nuclides and soil core sampling were conducted at 12 sites on the Tatum Salt Dome Test Site and surrounding control areas to determine exposure rates from surficial radioactivity. 137Cs was the only man-made radionuclide detected and was most abundant at three off-site locations on cultivated lawns. 137Cs inventories at all of the on-site survey locations were lower than expected, given the high annual precipitation in the area. The vertical distributions were more extended than those reported for undisturbed sites. Pressurized ion chamber measurements indicated no significant differences in exposure rates on and off the test site.

Variability of water content and of depth profiles of global fallout 137 Cs in grassland soils and the resulting external gamma-dose rates

“…Unfortunately, the number of studies concerning 137 Cs from global fallout is rather limited. Most of them were performed in the 1970s and 1980s, in forest as well as in grassland soils (e.g., [3][4][5][6][7]). Later, after deposition of the Chernobyl fallout, it was possible to compare the migration behavior of 137 Cs from both sources (Chernobyl and global fallout) in the soil [8][9][10][11][12][13].…”

A method for determining the analytical form of a radionuclide depth distribution using multiple gamma spectrometry measurements

“…The calibrated responses of in situ detectors for those approaches are typically determined by using a pre-determined analytical model of the distribution (EML Procedures Manual, US DoE, 1997;Helfer and Miller, 1988;Faller, 1992;Whetstone et al, 2011). The distribution that is selected is based upon historical knowledge of the site, previous sampling results at the location or similar locations, the chemical and physical radionuclide characteristics, and the site's properties.…”

A Numerical Method for the Calibration of in Situ Gamma Ray Spectroscopy Systems

“…THE AVAILABILITY of greater than 80% efficiency high purity germanium (HPGe) detectors has made the use of in situ gamma ray spectroscopy more feasible (Karlberg 1990; Korun and Martincic 1991;Faller 1992;Korun and Likar 1994;Miller and Shebell 1994;Tyler et al 1996;Benke and Kearfott 1997;Chesnokov and Fedin 1997;Tyler 1999;Golosov and Walling 2000). In situ measurements have the benefit of providing near instantaneous feedback about the isotopes and activities present in media of interest, which allows for more flexible and comprehensive sampling strategies.…”