Hanford tank waste management

We oversee the safe storage, retrieval, and treatment of the dangerous waste in Hanford's underground tanks. There are 149 single-shell tanks and 28 double-shell tanks at Hanford. These 177 tanks hold the most dangerous radioactive and chemical wastes from decades of plutonium production activities.

I want to...

Turning nuclear waste into glass

Sample of vitrified glass that is black and shiny. — Sample of vitrified material at the U.S. Department of Energy's Office of River Protection.

For the past few decades, the most dangerous radioactive and chemical waste has been and continues to be moved from single-shell tanks to safer double-shell tanks at Hanford. The waste will remain in the double-shell tanks until it can be moved to the Waste Treatment and Immobilization Plant (WTP), which is under construction.

The Waste Treatment Plant is a complex combination of many facilities including a High-Level Vitrification Facility, Pretreatment Facility, Laboratory, Low Activity Effluent Management Facility, and Low Activity Vitrification Facility. Parts of the WTP is about to become operational including the Low Activity Vitrification Facility, the Effluent Management Facility and laboratory.

These facilities along with the Low Activity Waste Pretreatment System (which pretreat the tank waste and removes key radionuclides) will combine to treat the low activity liquid waste feed from the double shell tanks. Plans are for these to be operational in 2025. These facilities will produce Low Activity Waste containers filled with glass (a process called vitrification) waste that will be disposed of at the Integrated Disposal Facility Landfill at Hanford. It is important for any Low Activity tank waste disposed at Hanford to be vitrified as it is the robust waste form of glass that protects the aquifer beneath the landfill and the Columbia River. Other lesser waste forms have been analyzed and are not protective of the aquifer.

The other portions of the WTP are designed to vitrify the high-level waste feed from the double shell tanks. The High-Level Vitrification Facility will turn the high-level waste into glass, that will then be stored at the Hanford Site in high-grade stainless-steel canisters. This high-level glass will eventually be transferred to a deep geologic repository. While at Hanford this waste will still be highly radioactive, however the vitrified waste will no longer be able to seep into or pollute the air, water, and soil.

Without the retrieval from the tanks and treatment of the tank waste, any leakage would eventually reach the Columbia River. WTP is critical in helping to clean up Hanford and in reducing the possibility of further threats to the environment and all who live and work near the Columbia River.

Common questions about the Hanford tanks:

The tanks contain a mixture of liquid, saltcake and sludge, that is both radioactive and chemically hazardous. Similar to wet beach sand in consistency, the sludge comprises liquid mixed with solids. Some tanks have more waste than others, and the radioactive and chemical content can vary widely from tank to tank. In total, the 56 million gallons that are in the 177 single shell and double tanks is divided into equal thirds of liquid, saltcake and sludge, with the double shell tanks containing most of the liquid. Liquid that rises to the top is called supernatant. It's present in about 35 single-shell tanks and most of the double shell tanks.

The single-shell tanks are storing waste generated in the last century and do not meet the minimum state requirements for storage. For example, the tanks do not have double containment. Therefore, we are overseeing active waste removal (retrieval) of these tanks. As it's removed from the single-shell tanks, the waste is transferred to double-shell tanks for safer storage and waste management.

The U.S. Department of Energy keeps an estimate of inventory in all the single-shell and double-shell tanks.

These are large underground storage tanks. There are a total of 177, and 28 are double shell tanks (1 has been emptied and taken out of service). There are 149 single shell tanks and 22 have been emptied.

If existing problems aren't addressed and the waste isn't removed from the tanks, the tanks will continue to corrode and develop leaks, and contaminants will eventually reach the Columbia River at very high concentrations. The Tri-Party Agreement requires 99 percent of waste be retrieved, or as much as can be, using multiple techniques.

However, a more immediate concern is the waste that has already leaked from the tanks, contaminating the soil underneath. We must find ways to prevent that contamination from reaching the river. Currently there are pump and treat activities in the areas beneath the tank farms.

Waste at the treatment plant will be mixed with a glass-forming substance and melted into a molten glass which is then poured into robust stainless steel containers and cannisters where it will be unable to pollute the air or water. These containers and cannisters will hold one of two types of waste: low-activity waste and high-level waste. The low-activity containers will be transported for permanent disposal at an engineered disposal facility located on the Hanford site. The high-level waste canisters will be stored at Hanford until a national repository is identified for high-level waste.

Diagram shows how liquid waste may have entered the soil: from Hanford facilities, leaking underground tanks, or cribs where waste was dumped. Arrows show release of contaminates moving toward river. — Leaking liquid wastes flow into the Columbia River, impacting the environment and human health.

Hanford tank waste management

I want to...

Turning nuclear waste into glass

Common questions about the Hanford tanks:

Related links