Actions for Results from the preliminary conveyor evaluation of the high-energy beta scintillation sensor at the Fernald Soil Decontamination Pilot Plant [electronic resource].

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Results from the preliminary conveyor evaluation of the high-energy beta scintillation sensor at the Fernald Soil Decontamination Pilot Plant [electronic resource].

Published
Washington, D.C. : United States. Dept. of Energy, 1994.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
Physical Description
12 pages : digital, PDF file
Additional Creators
Pacific Northwest Laboratory, United States. Department of Energy, and United States. Department of Energy. Office of Scientific and Technical Information
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Summary
W tested a high-energy beta scintillation sensor to evaluate its efficacy in continually characterizing washed soils moving on a conveyor belt at Fernald`s Soil Decontamination Pilot Plant (SDPP). This sensor was originally developed for monitoring uranium-contaminated soils in the field. It has a multi-layer design that enables it to discriminate against lower-energy beta particles from natural sources. It can also distinguish, to some extent, gamma rays and cosmic-induced species. The sensor detects uranium activity indirectly, based on the assumption that secular equilibrium exists between the targeted radionuclide ({sup 234m}Pa) and its parent (²³⁸U). Several 1-h background counts were made at the SDPP each day of the evaluation period. The average background count rate was found to be comparable to that observed under previous laboratory conditions. Static runs were performed on soils from SDPP test runs No. 1 and No. 17 to determine the extent of any residual activity following the decontamination process. Soils were found to contain 158±30 pCi/g and 114±25 pCi/g of ²³⁴Th-{sup 234m}Pa (²³⁸U?), respectively. But the soils had considerable moisture, and concern existed that this moisture would act as an additional beta attenuator and thereby give results that were erroneously low. Therefore, a soil sample was baked overnight, and the hard-baked clay that resulted was ground into small fragments and counted. This sample was counted for 30 min as before, and the total activity was determined to be 313±44 pCi/g of ²³⁴Th {sup 234m}Pa (²³⁸U?). Based on the test No. 1 results, a dry-to-wet activity ratio of 1.98 has been established. Hence, if the moisture content of test No. 17 was equivalent to that of test No. 1, the actual ²³⁴Th-{sup 234m}Pa (²³⁸U?) activity level is expected to be approximately 226 pCi/g.
Report Numbers
E 1.99:pnl--9986
pnl--9986
Subject(s)
Other Subject(s)
Note
Published through SciTech Connect.
07/01/1994.
"pnl--9986"
"DE94016417"
Schilk, A.J.; Knopf, M.A.
Type of Report and Period Covered Note
Topical; 07/01/1994 - 07/01/1994
Funding Information
AC06-76RL01830
View MARC record | catkey: 14145894