Document Details

Evaluation of Environmental Dosimetry Models for Applicability to Possible Radioactive Waste Repository Discharges
Subject Terms:
effluents, geological; repository, methodology; toxicity, radionuclides; waste, dosimetry, radioactive
Document Location:
DOE INFORMATION CENTER 1 Way, Oak Ridge, TN 37831; Eva Butler; Phone: 865-241-4780; Toll-Free: 800-382-6938, Option 6; FAX: 865-574-3521; Email:
Document Categories:
Science and Technology\Geology, Hydrology, Seismology, Site Studies; Science and Technology\Geology, Hydrology, Seismology, Site Studies
Document Type:
Publication Date:
1977 Sep 30
Declassification Status:
Never classified
Document Pages:
Accession Number:
Document Number(s):
Originating Research Org.:
Ebasco Services Incorporated
OpenNet Entry Date:
1998 Jun 16
This report was prepared under a subcontract with Union Carbide Corporation, Nuclear Division, a U.S. Energy Research and Development Administration contractor. This subcontract was administered by the Office of Waste Isolation (OWI), program manager for the National Waste Terminal Storage (NWTS) Program. OWI initiated this project to determine which, if any, of the existing computer models might be applicable for estimating radionuclide concentrations in environmental media and associated radiation exposures to members of the public attributable to repository operations. This report presents the independent evaluations of the subcontractor, Envirosphere Company, retained for that purpose. As a result of the evaluation of environmental dosimetry models for their applicability to the National Waste Terminal Storage facility (NWTSF), it was possible to arrive at a number of conclusions and observations. Regardless of which fuel cycle option is chosen, initially, the most important radionuclides which will require permanent disposal will consist of the long-lived fission products Cs-137 and Sr-90. Consideration of the potential for neutron activation of salt in the vicinity of the waste indicates that this activity will be negligable when compared to the activity in the canistered waste, but further investigation of this phenomenon is indicated because the induced activity could interfere with the in-situ radiation monitoring program and affect the interpretation of radiological monitoring data. Regarding methodologies for estimating atmospheric dispersion, it is concluded that consideration should be given to performing field tracer studies to obtain atmospheric dispersion data which would be characteristic for the NWTSF site. For releases lasting up to thirty days, averaging of actual dispersion data appears to be preferable to the interpolation scheme accepted by the Nuclear Regulatory Commission. For long-range, long-term atmospheric dispersion modeling, the plume-element model appears to be the preferred approach. There is a need to investigate the accuracy of alternative atmospheric stability classification schemes. Based on consideration of the various aspects of the environmental dosimetry codes which have been reviewed in this study, it is concluded that no one code is capable of comprehensive treatment of all the radionuclides, modes of release and environmental pathways which might be of relevance to the NWTS facility. It is recommended that for the assessment of accidental releases of radioactivity the WASH-1400 model be used. For a gross assessment of dose commitment to population due to release to transuranics from the NWTSF, the Liquid Metal Fast Breeder Reactor model appears to be of adequate scope. In the assessment of long-term population exposure to long-lived radionuclides which may be released from the NWTS facility, the incremental increase in population dose, relative to exposure to background radiation, is judged to be a more meaningful indicator of impact than the man-rem concept.

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