The Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM)
requires that Final Status Surveys be performed on materials and surfaces that vary
in surface smoothness and/or uniformity. To obtain accurate survey data, it may be
necessary to adjust detector response for these surface variations. NUREG-1507
refers to such surface efficiency adjustment factors as ��[subscript s], the source efficiency. This
parameter is meant to be a detector-independent, yet surface and nuclide-dependent
parameter that can be used to adjust observed count rate to provide a true measure of
the degree of contamination present. Key measurements in the calculation of (��[subscript s]) are
the energy of the radionuclide contaminant and the average height of the detector
above the contaminated surface. During the last year, Oregon State University,
Department of Nuclear Engineering and Radiation Health Physics provided technical
support for a Final Status Survey of a commercial nuclear plant. OSU NE/RHP has
conducted research and experimentation to determine site-specific source efficiency
(��[subscript s]) values for concrete surfaces which had undergone simulated decommissioning
activities, such as surface scabbling. Source efficiency (��[subscript s]) values were determined
for seven separate scabbled concrete surfaces which had been prepared using 5 tool
types. Fourteen concrete cores were intentionally contaminated with known amounts
of two beta emitting radionuclides: ��������Tl and ������Tc. The ��[subscript s] values were examined as a
function of the type of scabbled surface as well as the contaminating nuclide. / Graduation date: 2003
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/31684 |
| Date | 18 March 2003 |
| Creators | Bak, Michael T. |
| Contributors | Higley, Kathryn A. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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