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Discover the PRESENT

K Annex
K Area Cleanup

Reducing Risk near the Columbia River

In August 2023, DOE completed demolition of the K West Reactor Annex, marking another key step toward completing cleanup at the former plutonium production reactor.

Next steps in the K Area include debris removal and stabilization at K West Basin. The project includes draining and removing the reactor's spent fuel basin where the sludge was stored, then placing the reactor building in interim safe storage.

DOE is currently processing and segregating highly radioactive debris, such as contaminated equipment and tools, in the basin. Separating the material allows workers to safely remove water and eventually demolish the basin, reducing risk to the nearby Columbia River.

K West is scheduled for interim safe storage, or cocooning, in 2027.

In November 2023, DOE reintroduced super-sized dump trucks, aka “super dumps,” to advance cleanup of the 100K waste site. Upgrades and repairs were made to these large dump trucks, ensuring compliance with Department of Transportation regulations. The trucks play an important role in the Hanford cleanup mission, providing a safe and efficient means of transporting non-radiological waste, like oil-saturated soil, to the site’s engineered landfill for disposal.


In November 2022, DOE placed the former plutonium production K East Reactor into interim safe storage, a process known as "cocooning." The cocoon will protect the building while radioactivity in the deactivated reactor core decays over the next several decades, making it safe and easier to complete disposition.

This is the seventh of Hanford's nine reactors cocooned. The 100 K Area is the last reactor area in Hanford's Columbia River corridor where cleanup is still progressing.

Image of the 200 West Pump and Treat Facility
Treating Groundwater

Advancing the Site Cleanup Mission

Groundwater treatment has topped 2 billion gallons per year for the past nine years.

More than 31.5 billion gallons of groundwater have been treated – and more than 700 tons of contaminants removed – since the site’s treatment program began in the 1990s.

DOE continues to meet cleanup mission goals through the operation of six pump and treat facilities, monitoring well management and sampling.

Expansion of the system will increase capacity from 2,500 to 3,750 gallons per minute and allow for as much as 650 million additional gallons of groundwater to be treated annually. 


DOE recently installed 30 additional groundwater wells, conducted routine sampling and replaced filters at one of the pump-and-treat facilities located near the Columbia River. Groundwater is extracted through the wells and filtered to remove radiological and chemical contaminants. The treated water is then injected back into the ground to shrink areas of groundwater contamination.

324 Building Remediation

Ensuring worker and public safety

The 324 Building, located in Hanford's 300 Area, supported research on radioactive materials from 1966 to 1996.

Demolishing the building and remediating contaminated soil below the facility - designated the 300-296 Waste Site - is a priority for DOE, due to the facility's proximity to the Columbia River and city of Richland.

Demolition operations were postponed in 2010 after workers detected significant contamination in the soil under one of the building's "hot cells," which shielded workers from radiation while they used remotely operated equipment to conduct research. The contamination likely came from a spill of radioactive materials from one of the hot cells called B Cell.

The 324 Building remains in a safe and stable configuration. The contaminated soil beneath the structure has remained stable for decades, and underground monitoring shows the contamination has not migrated toward groundwater.

View the 324 Building Disposition Project Fact Sheet.

Crews collect waste from Tank SY-101 to create a formula for binding the waste in grout as part of a future test initiative.
Underground Tank Retrieval

Safely removing waste from 177 tanks

Hanford is home to 177 underground waste storage tanks: 149 single-shell tanks (SST), and 28 double-shell tanks (DST), ranging from 55,000 to 1.265 million gallons in capacity. Those tanks are organized into 18 different groups called farms. Currently, the site's underground tanks store approximately 56 million gallons of radioactive and chemical waste.

The overall mission of single-shell tank farm retrieval consists of safely retrieving tank waste from aging SSTs and transfer waste into newer, more robust double-shell tanks until it can be treated, immobilized and placed in long-term storage.

Preparations to retrieve radioactive and chemical waste from another group of large underground tanks at the Hanford Site are gaining momentum.

DOE recently drilled an opening through the thick concrete top of Tank A-106 to provide access for waste retrieval equipment.

Within the next year, workers will begin retrieving waste from six older single-shell tanks in the A Tank Farm, one of 18 farms at Hanford that received waste generated during plutonium production. Crews will transfer the waste to a newer double-shell tank for safe storage until it is treated.

Workers also recently installed a pump in Tank A-101, the first tank in A Farm scheduled for retrieval. Soon workers will install two more large pieces of equipment in the tank to break down waste during retrieval operations.

Waste retrieval in A Farm is scheduled to start in the summer of 2024. The A Farm tanks were built in the mid-1950s, and store waste generated by plutonium processing at the nearby Plutonium Uranium Extraction Plant during the Cold War era.

Hanford’s C Farm, with 16 underground tanks, was the first tank farm to be completely retrieved, five years ago. Retrieval of one tank in the S Farm was completed in 2007. Workers are retrieving waste from the last of the four tanks in the AX Farm.

Treating Tank Waste

Achieve effective tank waste treatment

In April 2024, the U.S. Department of Energy, Washington State Department of Ecology, and U.S. Environmental Protection Agency announced a landmark agreement that proposes a realistic and achievable course for cleaning up millions of gallons of radioactive and chemical waste from large, underground tanks at the Hanford Site. Read the press release.

Following voluntary, mediated negotiations that began in 2020, also known as Holistic Negotiations, the agencies have signed a settlement agreement and are proposing new and revised cleanup deadlines in the Tri-Party Agreement and Washington v. Granholm consent decree. The proposed changes uphold a shared commitment to the safe and effective cleanup of tank waste.

Highlights of the proposed modifications include the following:

  • Maintaining existing timeframes for starting treatment of both low-activity and high-level waste by immobilizing it in glass via vitrification
  • Using a direct-feed approach for immobilizing high-level waste in glass, similar to the Direct-Feed Low-Activity Waste Program
  • Building a vault storage system and second effluent management facility to support treating high-level waste
  • Retrieving waste from 22 tanks in Hanford’s 200 West Area by 2040, including grouting the low-activity portion of the waste for offsite disposal.
  • Designing and constructing 1-million gallons of additional capacity for multi-purpose storage of tank waste
  • Evaluating and developing new technologies for retrieving waste from tanks


In March 2024, DOE completed successful heat up of the second of the two world's largest melters at the Waste Treatment and Immobilization Plant. This achievement marks a significant milestone in the Department’s ongoing effort to address chemical and radioactive waste stored in underground tanks at the Hanford Site.

With both melters now at their operational temperature, the Hanford team will next begin running nonradioactive simulants through the WTP systems over the next several months prior to performing environmental performance testing.  This achievement builds on significant progress in the Direct-Feed Low-Activity Waste (DFLAW) program.

The two 300-ton WTP melters are the heart of the vitrification process, which will immobilize Hanford tank waste in glass. During vitrification, treated waste will be fed to the melters where it will be mixed with glass forming materials, heated to 2,100 degrees Fahrenheit and poured into specially designed stainless-steel containers for disposal at the Integrated Disposal Facility.

With the operating temperature successfully attained and a molten glass pool established, the next phase involves the removal of startup heaters. They will be replaced with bubblers, specialized equipment designed to introduce air into the molten glass, circulating it and maintaining an even temperature.

Photo of demolition equipment bringing down part of a building.
Reducing Risk

Committing to safe and efficient environmental protection

To date, workers have disposed of nearly 19 million tons of waste at the Environmental Restoration Disposal Facility.

To date, workers have disposed of nearly 19 million tons of waste at the Environmental Restoration Disposal Facility. The facility offers a safe and compliant location for the disposal of low-level radioactive, hazardous and mixed waste generated during cleanup activities on Hanford’s Central Plateau and in the nearby Columbia River Corridor. To protect the environment from contamination, ERDF has a liner with multiple layers that also capture runoff from weather and dust control, and directs it to holding tanks for treatment.

Workers at the 107-acre facility have disposed of demolition material from more than 800 facilities and solid material and soil from 1,300 waste sites since the facility’s operations began in 1996. The facility consistently receives an average of 10,000 to 15,000 tons of waste per month.

ERDF can hold 21 million tons of waste distributed across 10 large disposal cells, enough to support site cleanup work for a few more years. By 2025, DOE will begin construction of an eleventh cell that will provide capacity for about another 20 years of disposal of cleanup debris.


In the spring of 2024, DOE finished demolishing a former chemical storage area that supported the nearby plant during Hanford’s operations to produce plutonium. Demolition of the 211-A Chemical Storage Area included the removal of more than 20 empty tanks, a pumphouse and hundreds of feet of pipeline. This is the second chemical storage area next to PUREX that workers have demolished, allowing crews to begin cleanup activities inside the main PUREX facility. PUREX was key to Hanford’s plutonium production mission during the Cold War era. The plant processed nearly 70% of Hanford’s estimated 20 million reactor fuel rods to recover plutonium for further processing.

In February 2023, workers successfully removed a contaminated glovebox from the 231Z Building. This building, a former materials engineering laboratory, is one of the oldest structures on the Hanford Site.

Gloveboxes played a critical role in Hanford’s original plutonium-production mission, allowing workers to safely work on projects involving radioactive and chemical materials.

The glovebox was placed into a container for safe transport and storage at Hanford’s Central Waste Complex, bringing the 231Z Building one step closer to demolition.


Photo of two workers in yellow radiological protective suits.
Capsule Transfer Preaparations

Removing Hazardous Legacy Waste

Hanford's Waste Encapsulation and Storage Facility provides safe, compliant underwater storage for 1,936 highly radioactive capsules containing cesium and strontium.

Workers recently finished extensive modifications at the Hanford Site’s Waste Encapsulation and Storage Facility (WESF), a significant step in preparations to move 1,936 radioactive capsules of cesium and strontium from the facility’s water-filled basin into dry storage casks starting in 2025.

The stainless steel capsules are generally 21 inches long and 2 ½ inches in diameter and are stored under 13 feet of water that provides shielding from radiation and keeps the capsules from overheating.

The next significant step will be installing equipment for moving the capsules from the underwater basin into dry-storage casks, and then moving the dry-storage casks to a nearby concrete pad that will provide safe and compliant storage until a final disposition path is determined.

Moving the capsules to dry storage eliminates a long-term risk in the unlikely event of a larger-than-expected earthquake causing water to leak from the basin.

Most of the modifications were made in three areas of the facility where capsule transfer equipment will be installed — a shielded hot cell, an operating “canyon” and a truck loading area.

Meanwhile, at an on-site mock-up facility about 15 miles from WESF, engineers and technicians began testing the capsule transfer equipment.

The mock-up contains replicas of the WESF hot cell, operating canyon and truck loading area, and helps workers train on using the capsule transfer equipment in a non-hazardous facility before starting operations at WESF.

View the Waste Encapsulation and Storage Facility Fact Sheet.

Aerial photo of construction of the new Water Treatment Facility
24/7 Critical Infrastructure

Building for the future

Hanford's mission requires critical infrastructure that provides power, water, electricity, roadways, and other services supporting environmental cleanup and the Hanford Site's transition to the 24/7 mission.

As cleanup of large areas has completed, infrastructure has been right-sized to meet the future mission. At the same time, demand for safe and reliable services in operations areas increases. The acceleration of infrastructure projects across the site ensures DOE can be successful in its mission to protect workers, the public and the environment.

Currently under construction, a new water treatment facility will support DFLAW and the transition to the 24/7 mission. The new facility will be capable of producing a minimum of 3.5 million gallons of clean water a day and can be expanded to provide five million gallons per day, if Hanford Site demands increase.

In 2022, DOE finished a new $13.5 million, 17,600-square-foot office building to provide a safe, modern office space for workers as the Hanford Site prepares for the 24/7 mission and increased laboratory testing services. The new space will house administrative and technical staff for Hanford's 222-S Laboratory.

The laboratory's primary mission is to provide analytical support for storage and treatment of tank waste at the site. That includes testing for tank waste retrieval, 242-A Evaporator campaigns, tank waste transfers, waste management, and soon the DFLAW Program.

The new office space replaces a 50-year-old office building in the 200 West Area.

View the Infrastructure Needs for the Future Fact Sheet.

Image of a drone flying over a building near the Columbia River.
Using Innovative Technology

Improving efficiency across Hanford

The Hanford Site uses an unmanned aircraft drone that provides DOE an opportunity to improve operating processes out in the field.

The flights can capture surface imagery or video and evaluate a building's exterior or conduct utility or land stewardship inspections.

DOE can use a drone to capture images around an electrical substation, allowing electrical workers to speed up analysis of the gear, complete better line maintenance and improve the way outages are managed. The images also help provide video and data that is used for 3D modeling.

Last Updated 05/21/2024 6:09 AM