Baseline Risk Assessment Supporting Closure at Waste Management Area C at the Hanford Site Washington

Conference · Wed Jan 07 04:00:00 EST 2015

OSTI ID:1167089

Singleton, Kristin M. ^[1]

---

1. Washington River Protection Solutions LLC, Richland, WA (United States)

The Office of River Protection under the U.S. Department of Energy is pursuing closure of the Single-Shell Tank (SST) Waste Management Area (WMA) C under the requirements of the Hanford Federal Facility Agreement and Consent Order (HFFACO). A baseline risk assessment (BRA) of current conditions is based on available characterization data and information collected at WMA C. The baseline risk assessment is being developed as a part of a Resource Conservation and Recovery Act (RCRA) Facility Investigation (RFI)/Corrective Measures Study (CMS) at WMA C that is mandatory under Comprehensive Environmental Response, Compensation, and Liability Act and RCRA corrective action. The RFI/CMS is needed to identify and evaluate the hazardous chemical and radiological contamination in the vadose zone from past releases of waste from WMA C. WMA C will be under Federal ownership and control for the foreseeable future, and managed as an industrial area with restricted access and various institutional controls. The exposure scenarios evaluated under these conditions include Model Toxics Control Act (MTCA) Method C, industrial worker, maintenance and surveillance worker, construction worker, and trespasser scenarios. The BRA evaluates several unrestricted land use scenarios (residential all-pathway, MTCA Method B, and Tribal) to provide additional information for risk management. Analytical results from 13 shallow zone (0 to 15 ft. below ground surface) sampling locations were collected to evaluate human health impacts at WMA C. In addition, soil analytical data were screened against background concentrations and ecological soil screening levels to determine if soil concentrations have the potential to adversely affect ecological receptors. Analytical data from 12 groundwater monitoring wells were evaluated between 2004 and 2013. A screening of groundwater monitoring data against background concentrations and Federal maximum concentration levels was used to determine vadose zone contamination impacts on groundwater. Waste Management Area C is the first of the Hanford tank farms to begin the closure planning process. The current baseline risk assessment will provide valuable information for making corrective actions and closure decisions for WMA C, and will also support the planning for future tank farm soil investigation and baseline risk assessments.

• Research Organization: Hanford Site (HNF), Richland, WA (United States); Washington River Protection Solutions LLC, Richland, WA (United States)
• Sponsoring Organization: USDOE Office of Environmental Management (EM)
• DOE Contract Number: AC27-08RV14800
• OSTI ID: 1167089
• Report Number(s): TOC-WP--14-4991-FP.Rev.0
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
54 ENVIRONMENTAL SCIENCES
CONTAMINATION
DECOMMISSIONING
GROUND WATER
HANFORD RESERVATION
HAZARDOUS MATERIALS
LAND USE
MONITORING
ORDERS
PLANNING
PUBLIC HEALTH
RADIATION DOSES
RADIOACTIVE WASTE MANAGEMENT
RADIOACTIVE WASTES
REMEDIAL ACTION
RISK ASSESSMENT
SAMPLING
SOILS
STORAGE FACILITIES
TANKS
TOXIC MATERIALS
WELLS