The Disposition Dilemma Controlling the Release of Solid Materials from Nuclear Regulatory Commission-Licensed Facilities (2002) / Chapter Skim
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6 Measurement Issues
6 Measurement Issues
Pages 115-124
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From page 115... ...
The magnitudes of the dose factors chosen to derive screening levels from the primary dose standards; · The specific instrumentation used in measuring radioactive material concentrations in a source: 115
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From page 116... ...
NUREG-15() 7, Minimum Detectable Concentrations with Typical Radiation Survey Instruments for Various Contaminants and Field Conditions (USNRC, 1997)
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From page 117... ...
Detection limits for both field survey instruments and laboratory instruments play a critical role in selecting the instrumentation and measurement procedures used in the analysis. Background radiation from naturally occurring radionuclides and cosmic radiation influence the sensitivity of the measurement process.
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From page 118... ...
Namely, existing measurement capabilities for surface contamination are sufficiently sensitive to reach the screening levels for surface contamination derived in these same technical analyses. Although the Health Physics Society (HPS)
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From page 119... ...
. Table 6-2 compares the MDCs from TSD 97 with the derived screening levels from TSD97 for volumetric contamination corresponding to primary dose standards of 15 mrem/yr, 1 mrem/yr, and 0.1 mrem/yr.
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From page 120... ...
ES-17. Thus, for both volume-contaminated and surface-contaminated solid materials, measurement of radionuclide activity concentrations at levels being considered for dose-based standards is not the limiting factor if the primary dose standard is at or above 1 mrem/yr in both laboratory and field measurements.
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From page 121... ...
Thus, the cost of sampling and analysis by itself does not appear to be a limiting factor when selecting a primary dose standard at or above 0.1 mrem/yr. (However, as noted above, at screening levels corresponding to a primary dose standard of 0.1 mrem/yr, the detection capability of field instruments is such that only 11 of 40 key radioncuclides can be detected.)
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From page 122... ...
Licensees that generate controlled materials during operations currently survey all potentially contaminated waste materials prior to shipment. Those that are determined to have no licensee-generated radioactive material present are treated as nonradioactive waste.
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From page 123... ...
MARSSIM strongly recommends that the effort expended be weighted toward those survey units4 more likely to contain elevated levels of residual radioactive material. 4A geographical area consisting of structures or land areas of specified size and shape at a remediated site for which a separate decision will be made whether the unit attains the sitespecific reference-based cleanup standard for the designated pollution parameter.
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From page 124... ...
, the majority of radionuclides can be detected at reasonable costs in a laboratory setting, under most practical conditions. For a 0.1 mrem/yr standard, the measurement capability falls below the upper bound of minimum detectable concentrations for some radionuclides in some laboratories, although 85 percent of radionuclides are still detectable.
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