An Initial Evaluation Of Characterization And Closure Options For Underground Pipelines Within A Hanford Site Single-Shell Tank Farm

Conference · Thu Jan 10 04:00:00 EST 2013

OSTI ID:1060385

Badden, Janet W. ^[1]; Connelly, Michael P. ^[1]; Seeley, Paul N. ^[2]; Hendrickson, Michelle L. ^[3]

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1. Washington River Protection Solutions, LLC, Richland, WA (United States)
2. Cenibark International, Inc., Kennewick (United States)
3. Washington State Univ., Richland (United States). Dept. of Ecology

The Hanford Site includes 149 single-shell tanks, organized in 12 'tank farms,' with contents managed as high-level mixed waste. The Hanford Federal Facility Agreement and Consent Order requires that one tank farm, the Waste Management Area C, be closed by June 30, 2019. A challenge to this project is the disposition and closure of Waste Management Area C underground pipelines. Waste Management Area C contains nearly seven miles of pipelines and 200 separate pipe segments. The pipelines were taken out of service decades ago and contain unknown volumes and concentrations of tank waste residuals from past operations. To understand the scope of activities that may be required for these pipelines, an evaluation was performed. The purpose of the evaluation was to identify what, if any, characterization methods and/or closure actions may be implemented at Waste Management Area C for closure of Waste Management Area C by 2019. Physical and analytical data do not exist for Waste Management Area C pipeline waste residuals. To develop estimates of residual volumes and inventories of contamination, an extensive search of available information on pipelines was conducted. The search included evaluating historical operation and occurrence records, physical attributes, schematics and drawings, and contaminant inventories associated with the process history of plutonium separations facilities and waste separations and stabilization operations. Scoping analyses of impacts to human health and the environment using three separate methodologies were then developed based on the waste residual estimates. All analyses resulted in preliminary assessments, indicating that pipeline waste residuals presented a comparably low long-term impact to groundwater with respect to soil, tank and other ancillary equipment residuals, but exceeded Washington State cleanup requirement values. In addition to performing the impact analyses, the assessment evaluated available sampling technologies and pipeline removal or treatment technologies. The evaluation accounted for the potential high worker risk, high cost, and schedule impacts associated with characterization, removal, or treatment of pipelines within Waste Management Area C for closure. This assessment was compared to the unknown, but estimated low, long-term impacts to groundwater associated with remaining waste residuals should the pipelines be left "as is" and an engineered surface barrier or landfill cap be placed. This study also recommended that no characterization or closure actions be assumed or started for the pipelines within Waste Management Area C, likewise with the premise that a surface barrier or landfill cap be placed over the pipelines.

• Research Organization: Hanford Site (HNF), Richland, WA (United States)
• Sponsoring Organization: USDOE Office of Environmental Management (EM) (United States)
• DOE Contract Number: AC27-08RV14800
• OSTI ID: 1060385
• Report Number(s): WRPS--54367-FP-Rev.0
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES