Recharge Data Package for the Immobilized Low-Activity Waste 2001 Performance Assessment
Lockheed Martin Hanford Company (LMHC) is designing and assessing the performance of disposal facilities to receive radioactive wastes that are currently stored in single- and double-shell tanks at the Hanford Site. The preferred method of disposing of the portion that is classified as immobilized low-activity waste (ILAW) is to vitrify the waste and place the product in near-surface, shallow-land burial facilities. The LMHC project to assess the performance of these disposal facilities is known as the Hanford ILAW Performance Assessment (PA) Activity, hereafter called the ILAW PA project. The goal of this project is to provide a reasonable expectation that the disposal of the waste is protective of the general public, groundwater resources, air resources, surface-water resources, and inadvertent intruders. Achieving this goal will require predictions of contaminant migration from the facility. To make such predictions will require estimates of the fluxes of water moving through the sediments within the vadose zone around and beneath the disposal facility. These fluxes, loosely called recharge rates, are the primary mechanism for transporting contaminants to the groundwater. Pacific Northwest National Laboratory (PNNL) assists LMHC in their performance assessment activities. One of the PNNL tasks is to provide estimates of recharge rates for current conditions and long-term scenarios involving the shallow-land disposal of ILAW. Specifically, recharge estimates are needed for a fully functional surface cover, the cover sideslope, and the immediately surrounding terrain. In addition, recharge estimates are needed for degraded cover conditions. The temporal scope of the analysis is 10,000 years, but could be longer if some contaminant peaks occur after 10,000 years. The elements of this report compose the Recharge Data Package, which provides estimates of recharge rates for the scenarios being considered in the 2001 PA. Table S.1 identifies the surface features and time periods evaluated. The most important feature, the surface cover, is expected to be the modified RCRA Subtitle C design. This design uses a 1-m-thick silt loam layer above sand and gravel filter layers to create a capillary break. A 0.15-m-thick asphalt layer underlies the filter layers to function as a backup barrier and to promote lateral drainage. Cover sideslopes are expected to be constructed with 1V:10H slopes using sandy gravel. The recharge estimates for each scenario were derived from lysimeter and tracer data collected by the ILAW PA and other projects and from modeling analyses.
- Research Organization:
- Pacific Northwest National Laboratory, Richland, WA (US)
- Sponsoring Organization:
- US Department of Energy (US)
- OSTI ID:
- 781042
- Report Number(s):
- 820201000; 820201000; TRN: US0102707
- Resource Relation:
- Other Information: PBD: 30 Dec 1999
- Country of Publication:
- United States
- Language:
- English
Similar Records
Geochemical Data Package for the Hanford Immobilized Low-Activity Tank Waste Performance Assessment (ILAWPA)
Geochemical data package for the Hanford immobilized low-activity tank waste performance assessment (ILAW PA)
Related Subjects
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
HANFORD RESERVATION
RADIOACTIVE WASTE FACILITIES
LOW-LEVEL RADIOACTIVE WASTES
RADIOACTIVE WASTE DISPOSAL
PERFORMANCE
GROUND WATER
RADIONUCLIDE MIGRATION
GROUNDWATER RECHARGE
SOILS
SITE CHARACTERIZATION