Tank Storage, Operations & Closure (TSOC) Project

Protecting Groundwater

The primary focus of the project is the safe retrieval and storage of wastes in Hanford's 28 double-shell tanks (DSTs) and 149 single-shell tanks (SSTs). Specifically, for DSTs, the project will include operations, upgrades, permitting, safety, characterization, systems inspections, and waste volume projections. The project for SSTs will cover operations, interim stabilization, leak detection, characterization, system inspections, safety, and groundwater issues.

Jeff Lyon (509-372-7914) is the Tank Storage, Operations and Closure (TSOC) Project manager.

Project Goals & Mission

The goals of the TSOC Project are the safe storage, management, and retrieval of all tank wastes to complement the treatment and disposal of tank wastes. Project staff support a systematic approach to the closure of the tank system and the safe treatment of any remaining materials.

The TSOC Project mission is to:

• Regulate how tank waste is treated and stored
• Ensure that the U.S. Department of Energy maintains DSTs, prevents harmful releases to the environment, and conducts safe operations
• Govern the closure of SSTs and the retrieval of waste from SSTs and its subsequent transfer to DSTs

The TSOC Project oversees management of highly radioactive waste in 177 underground storage tanks at the Hanford Site. The tanks range from 50,000 to more than one million gallons in capacity. The 149 SSTs are well beyond their planned life expectancy of 20 years.

Out of these 149 SSTs, 67 have been declared as known or assumed leakers that have released more than one million gallons of waste to the soil and groundwater. The released tank waste is now moving toward, but has not reached, the Columbia River. Other, less toxic contaminants from cribs, ditches, and ponds reach the river today, but the amounts are very small and are immediately diluted once the groundwater enters the river.

To provide safer storage for tank wastes, the 28 DSTs were built. In 1999, we negotiated an agreement with the U.S. Department of Energy to move all the pumpable liquid out of the SSTs into DSTs. More than three million gallons of liquid waste has been moved from the SSTs into the DSTs. To date, there have been no leaks to the environment from the DSTs.

Eventually, the tank waste will be transferred to the Waste Treatment Plant for vitrification. See our Tank Waste Disposal page for more info.

Terms to Know

• Single-shell tank (SST): Undgerground storage tank built with only one wall
• Double-shell tank (DST): Undgerground storage tank built with two walls
• Vitrification: Process by which tank waste is turned into glass

Waste Management Area C (WMAC) Resources

241-C-301 Catch Tank Waste Retrieval Study (RPP-RPT-45723) | Ecology's review

241-C Tank Removal Study (RPP-RPT-47167) | Ecology's review

Integration of RCRA and CERCLA (RPP-46459) | Ecology's review

Pipeline Feasibility Evaluation (RPP-RPT-47559) | Ecology's review

Ecology's response to Organic Analyses Optimization

Notice of Violation of Single-Shell Tank Leak Response Plan

Ecology's review of Single-Shell Tank Closure Plan

USDOE Order 435.1 Waste Determination Process for Tank Waste Residuals