Technical Assistance for Decommissioning

Program Brief

Statement of Problem:  The CNWRA^® supports NRC regulation of decommissioning radiological material sites by providing non-routine and in-depth assessments. Characteristic of complex sites include contamination by long-lived radionuclides, adverse impacts on groundwater, large volumes of contaminated materials, and conditions that could result in restricted release.

Approach and Accomplishments:  CNWRA has performed 15 task orders since 1997 under two NRC contracts providing technical assistance to licensing actions for complex decommissioning sites. The CNWRA team for this work has expertise in health physics, pathway dose modeling, statistics, performance assessment, environmental transport modeling, hydrology, geochemistry, geology, and environmental sciences. Site-specific experience includes evaluation of radiologically contaminated metal alloy and catalyst extraction and processing, nuclear test reactor, and depleted uranium firing range sites. The CNWRA has experience on decommissioning generic aspects of soil reuse, partial site release, indoor resuspension factor determination, control of solid materials, and use of pathway-dose models and computer codes.

Diverse products include evaluating site characterization information, determining radionuclide leaching rates, developing and evaluating environmental models and supporting data, assessing current land use and future scenarios, and identifying realistic exposure pathways and associated characteristics. CNWRA has constructed and exercised GoldSim-based environmental models and has experience using FRAMES-MEPAS, FRAMES-GENII, RESRAD-OFFSITE, and shielding computer codes for radiological dose analysis of complex decommissioning sites.

Client Benefits:  The expertise and experience providing technical assistance for decommissioning licensing actions at complex sites can benefit clients facing the need to collect and evaluate site characterization information, determine appropriate pathways of contaminant transport and human exposure, identify realistic land use scenarios, and perform pathway-dose assessments.