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Radioactive Waste Modeling

Performance Assessment

Certified GoldSim Solution Provider

A radiological Performance Assessment (PA) is conducted to provide reasonable assurance that performance objectives for radioactive waste disposal will be met. The PA is instrumental in the design, operation, and postclosure of waste storage facilities. Neptune is widely regarded across the United States as an expert in designing probabilistic models to support the overall PA process.

GOLDSIM MODELS DEVELOPED BY NEPTUNE

Our modeling efforts are aimed at supporting environmental decision making, though some modeling involves a great deal more in the form of worker protection and cost/benefit analysis. Examples of our GoldSim models include the following:

  • GoldSim Generic PA Model. A downloadable Generic Radiological Performance Assessment Model for a Radioactive Waste Disposal Site.

  • Contaminant Transport Model. Material Disposal Area G at Los Alamos National Laboratory (LANL), Los Alamos, New Mexico.

  • Contaminant Transport Model. West Beach Landfill, at the former Naval Air Station Alameda, Alameda, California.

  • Decision Analysis. Smoky Site, at the Nevada Test Site (NTS), Nevada.

  • Contaminant Transport and Exposure Assessment. Material Disposal Area H at LANL.

  • Contaminant Transport and Compliance Assessment. Greater Confinement Disposal Boreholes at the Nevada National Security Site (NNSS, formerly the Nevada Test Site).

  • Contaminant Transport, Dose Assessment, and Decision Analysis. Area 5 Radioactive Waste Management Site (RWMS) at the Nevada Test Site. This work encompassed waste operations decisions, as well as some challenging aspects of assessing the performance objectives of 40 Code of Federal Regulations (CFR) 191.

  • Contaminant Transport and Dose Assessment. Mochovce National Radioactive Waste Repository in the Slovak Republic.

  • Three GoldSim PA Models. DOE Savannah River Site's E-Area Low-Level Waste Facility, in collaboration with Savannah River National Laboratory (SRNL).

  • GoldSim PA Model to Evaluate Disposal of Depleted Uranium. Low level waste facility in Clive, Utah, operated by EnergySolutions. This model is the first of its kind in that DU is a highly unusual waste form in its long-term radiological characteristics. This model is available from the Utah Department of Environmental Quality. See UDEQ's web site on the EnergySolutions Depleted Uranium Performance Assessment and scroll down to near the bottom to find out how to obtain a GoldSim Player version of the model.

  • GoldSim PA Model to Evaluate an LLW facility in Andrews County, Texas. We developed a GoldSim PA model for the Compact Waste Disposal Facility and Federal Waste Disposal Facility at a site operated by Waste Control Specialists.

  • GoldSim PA Models Sensitivity Analyses. Neptune conducted sensitivity analyses for three significant PA models in Savannah River Remediation’s (SRR's) Liquid Waste side of the house. These models included the Saltstone Disposal Facility (SDF), and the F-Area and H-Area Tank Farms. These tank farms are host to several large (5000 m3) high-level waste tanks. When waste is removed from the tanks, some of that waste goes to the SDF, and the remaining structures are subject to analysis under the 2004 National Defense Authorization Act Section 3116. In essence, this is a Performance Assessment, with performance objectives of NRC's 10 CFR 61.