Surface and subsurface cleanup protocol for radionuclides Gunnison, Colorado, UMTRA Project Processing Site. Revision 3, Final report
The supplemental standards provisions of Title 40, Code of Federal Regulations, Part 192 (40 CFR Part 192) require the cleanup of radionuclides other than radium-226 (Ra-226) to levels ``as low as reasonably achievable`` (ALARA), taking into account site-specific conditions, if sufficient quantities and concentrations are present to constitute a significant radiation hazard. In this context, thorium-230 (Th-230) at the Gunnison, Colorado, processing site will require remediation. However, a seasonally fluctuating groundwater table at the site significantly complicates conventional remedial action with respect to cleanup. Characterization data indicate that in the offpile areas, the removal of residual in situ bulk Ra-226 and Th-230 such that the 1000-year projected Ra-226 concentration (Ra-226 concentration in 1000 years due to the decay of in situ Ra-226 and the in-growth of Ra-226 from in situ Th-230) complies with the US Environmental Protection Agency (EPA) cleanup standard for in situ Ra-226 and the cleanup protocol for in situ Th-230 can be readily achieved using conventional excavation techniques for bulk contamination without encountering significant impacts due to groundwater. The EPA cleanup standard and criterion for Ra-226 and the 1000-year projected Ra-226 are 5 and 15 picocuries per gram (pCi/g) above background, respectively, averaged over 15-centimeter (cm) deep surface and subsurface intervals and 100-square-meter (m{sup 2}) grid areas. Significant differential migration of Th-230 relative to Ra-226 has occurred over 40 percent of the subpile area. To effectively remediate the site with respect to Ra-226 and Th-230, supplemental standard is proposed and discussed in this report.
- Research Organization:
- Jacobs Engineering Group, Inc., Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-91AL62350
- OSTI ID:
- 10162233
- Report Number(s):
- DOE/AL/62350--68F-Rev.3; ON: DE94014399; BR: EW2010102/EX2040010
- Country of Publication:
- United States
- Language:
- English
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Surface and subsurface cleanup protocol for radionuclides, Gunnison, Colorado, UMTRA project processing site. Final report: Revision 1
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Related Subjects
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
54 ENVIRONMENTAL SCIENCES
540230
540250
ABANDONED SITES
COLORADO
COMPLIANCE
CONTAMINATION
COST
EXCAVATION
FEED MATERIALS PLANTS
HEALTH AND SAFETY
PROGRESS REPORT
RADIOACTIVE MATERIALS MONITORING AND TRANSPORT
RADIOECOLOGICAL CONCENTRATION
RADIUM 226
REGULATIONS
REMEDIAL ACTION
SITE RESOURCE AND USE STUDIES
THORIUM 230
US EPA