Tri-Party Agreement Milestone M-45-07A; complete evaluation of subsurface barrier feasibility: Summary report

The US Department of Energy (DOE) has established the Tank Waste Remediation System (TWRS) program to safely manage and dispose the low-level and high-level radioactive and hazardous wastes currently held in 177 tanks and approximately 1,900 sealed capsules located on the Hanford Site. The remediation of the entire Hanford Site is being conducted under the Hanford Federal Facility Agreement and Consent Order, otherwise known as the Tri-Party Agreement. The three parties that concluded the agreement are the DOE, the US Environmental Protection Agency (EPA), and the Washington State Department of Ecology (Ecology). The purpose of the Tri-Party Agreement is to ensure that Hanford Site activities are performed in a manner that protects the public health, welfare, and the environment. The agreement provides a framework and structure for the many different agencies and regulations under which work is performed on the Site, listing responsibilities and attaching scheduled dates of completion for minimum performances (known as milestones). The Tri-Party Agreement Milestone M-45-07A requires that an assessment of the feasibility of subsurface barriers to support retrieval of tank waste be performed. The activities to meet this milestone have been completed, and are documented herein.