Technical Basis and Implementation of Groundwater Pathway Models Used for INL's RH LLW Disposal Facility Performance Assessment - 19440

Conference · Mon Jul 01 04:00:00 EDT 2019

OSTI ID:23005336

Rood, Arthur S. ^[1]; Sondrup, A. Jeff; Schafer, Annette L.; Orchard, Brady J.; Welty, Brett D. ^[2]

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1. K-Spar Inc., 4835 Foxtrail Lane, Idaho Falls, ID 83402 (United States)
2. Idaho National Laboratory, Battelle Energy Alliance, P.O. Box 1625, Idaho Falls, ID 83415 (United States)

The Idaho National Laboratory's (INL's) Remote-Handled Low-Level Waste (RH LLW) Disposal Facility has been designed and constructed to receive waste generated by INL in support of the Office of Nuclear Energy (NE) and Naval Reactors (NR) missions. RH LLW is generated on the INL site from spent nuclear fuel handling and operations at the Naval Reactors Facility (NRF), the Advanced Test Reactor (ATR), and at the Material and Fuels Complex (MFC) in addition to other miscellaneous research activities. The facility has been designed to receive RH LLW currently in storage at INL facilities and new waste generated by nuclear research programs. RH LLW received at the facility is solid waste consisting of surface contaminated materials, ion exchange resins used to purify cooling water, and activated metals generated during reactor core change outs, Naval spent fuel management, and nuclear R and D. The facility has been designed to meet the requirements of DOE Order 435.1, Radioactive Waste Management for all-pathways including groundwater and air, radon emissions limits, and inadvertent intrusion limits. The facility design includes a vault system incorporating robust concrete vaults oriented vertically in close-packed arrays, a hydraulic drainage system designed to limit water contact with the stainless steel waste canisters and concrete vaults, and a robust monitoring system. Per the environmental assessment (EA), all waste will be disposed of in stainless steel waste canisters. During facility design and construction, site-specific data was collected to provide laboratory and field scale performance characteristics for the concrete vault and hydraulic drainage systems. Field-scale infiltration tests were conducted and monitoring data was interpreted using numerical simulation. Based on interpretation of the observed laboratory and field test data, the facility performance assessment (PA) was developed. The PA groundwater pathway source release model differentially credits release from surface contaminated waste, ion exchange resins, and activated metals. It also credits steel waste canisters with failure rates based on actual corrosion data. Once released, radionuclide transport through the vadose zone and aquifer to downgradient receptor locations was simulated in the PA using a one-dimensional modeling approach based on three-dimensional modeling of historically-contaminated INL sites. This paper provides an overview of the groundwater pathway source release models and their technical implementation in the PA. It also describes the one-dimensional transport model used for the vadose zone and multi-dimensional model used for the aquifer. (authors)

• Research Organization: WM Symposia, Inc., PO Box 27646, 85285-7646 Tempe, AZ (United States)
• OSTI ID: 23005336
• Report Number(s): INIS-US--21-WM-19440
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
COMPUTERIZED SIMULATION
CONCRETES
CONTAINERS
DESIGN
GROUND WATER
HYDRAULICS
IDAHO NATIONAL LABORATORY
LOW-LEVEL RADIOACTIVE WASTES
METALS
PLUTONIC ROCKS
POLLUTION REGULATIONS
RADIOACTIVE WASTE MANAGEMENT
RADON
RECEPTORS
RESINS
SHIP PROPULSION REACTORS
SOLID WASTES
SPENT FUEL STORAGE
SPENT FUELS
STAINLESS STEELS
TEST REACTORS