What is Hanford?


The Hanford Nuclear Site

Less than three hours east of Seattle, WA is the most contaminated site in the United States--The Hanford Nuclear Reservation. Hanford stores 56 million gallons of radioactive waste in old, leaky underground tanks just a few miles from the Columbia River. There is a plan to clean up this 56 million gallons of waste. But after more than 20 years, none of the worst waste has been cleaned up.

Cleaning up Hanford is a huge undertaking. Cleaning up Hanford costs $2.4 billion dollars a year, and requires technologies and engineering solutions never used before. And it must be done safely. Because, a really bad day at Hanford, could be a really bad day for a 3-state area.

Hanford Background Information

Hanford is located in Southeastern Washington state and is 586 square miles, or almost half the size of Walla Walla County. Today, the Department of Energy, a federal agency, owns the Hanford Site. And although it owns the site and controls major cleanup decisions and priorities, the DOE doesn’t actually do any cleanup. Instead, it hires private contractors—like Bechtel, AECOM, and CH2MHill—to do all of the actual cleanup.


Along the river, there are nine old nuclear reactors, most of which have been cocooned. Cocooned basically means that they put a building over the core of the reactor, which is hot from radioactive materials, and let the radioactivity inside naturally decay to a more manageable level before workers enter to finish cleaning them up.

The Central Plateau, located in the center of the site, is where the tank farms and the worst of the waste is located. The Central Plateau is also where the Waste Treatment Plant is located. This plant is designed to turn the liquid waste in the tanks into a solid glass (a process called vitrification), which will then be buried in a deep geological repository. This plant has been in the news a lot because of the high costs, missed deadlines, and design flaws. For example, the plant was originally supposed to cost a little over $4 billion dollars and start making glass in 2008, but the latest estimate for treating dangerous waste is 2036 and will cost more than $16.8 billion dollars.

Brief Hanford History


Hanford was originally part of the larger Manhattan Project to produce the world’s first nuclear weapons. Thousands of people showed up from all across the nation to work on a top secret project. Many of them had no idea what they were all working towards for many years. Secrecy was a top priority.

Hanford’s main role in the Manhattan Project was to produce the plutonium for US nuclear weapons. The plutonium produced at Hanford was used in the first nuclear bomb tested at the Trinity Site in New Mexico and used in “Fat Man”, the bomb dropped on Nagasaki, Japan on August 9, 1945.

Plutonium production at Hanford created a lot of waste. Hanford produced plutonium so fast that they started ‘disposing’ of hazardous wastes through a variety of means. This included discharges directly into the air, directly into the Columbia River, directly into unlined trenches, and for many years, waste was poured directly into the soil—a total of 450 billion gallons of nuclear and chemical waste. That’s the equivalent of more than 680,000 Olympic size swimming pools. However, Hanford did eventually build 177 tanks to hold the most dangerous waste at Hanford.

Hanford’s Dangerous Wastes


The tanks at Hanford currently store 56 million gallons of high-level waste. And over 1 million gallons has leaked into the soil. Most of the tanks are single-shell steel tanks, which were built between 1943 and 1964. The tanks were built to last 40 years, so the tanks are now well passed their design life.

Each Hanford tank is the size of a four-story apartment building. Yet the waste inside these tanks is harmful in microscopic quantities.

More than 1800 chemicals have been identified in the tank waste. Of these, about 1,500 are present in the headspace of the tanks, which is the space between the top of the waste and the roof of the tank. These chemicals in the headspace must be vented to prevent an explosion in the tanks.

Plutonium-239, which is found in the tanks and other locations onsite, has a half life of 24,100 years. And it takes 10 half-lives before it is considered to cease its radioactivity. This waste will be dangerous for hundreds of thousands of years.

Hanford continued to produce plutonium throughout WWII and up until the end of the Cold War. All in all, Hanford made 74 tons of plutonium, which is 2/3 of the United States total stockpile.

Transition to Cleanup

Headspace sampling 2.jpg

The Department of Energy signed a cleanup agreement with the Environmental Protection Agency and the State of Washington on May 15, 1989, called The Tri-Party Agreement. The goal of the Tri-Party Agreement is to reach compliance with federal environmental laws. Under the Tri-Party Agreement, the cleanup was expected to take 30 years. However, Hanford is not going to be cleaned up next year, but instead cleanup is expected to take another 75 years.

Currently, there are approximately 9,000 people working on Hanford cleanup and even though cleanup has been slow, there has been a lot of progress. Workers have moved 7.5 million gallons of waste from the oldest and most leaky tanks to newer and more robust double shell tanks. Keeping more waste from reaching the soil and groundwater. And workers have treated over 18 billion gallons of contaminated groundwater, keeping more contamination from reaching the Columbia River. With all of the negativity around Hanford cleanup, it is really important to recognize that the workers have done a lot of great work and that there has been a lot of progress.

Hanford Challenge

As more and more concerns about the cleanup arose and some workers were even being fired after publicly raising safety concerns, a nonprofit, Hanford Challenge, was created to advocate for workers at the site in 2007.

Hanford Challenge focuses on building relationships with workers and listening to their concerns. We get a lot of our information from insiders doing the actual cleanup—engineers, health physics technicians, construction workers, inspectors, and government officials. Our hope is that by protecting every workers’ ability to raise concerns, it will create a robust safety culture that will make the cleanup safer for workers, the public, and the environment. Read more about our work, here.