Hanford Site

The Hanford Nuclear Site was established in 1943 as the largest of 3 production sites for the Manhattan Project. The site was chosen in southern Washington state because it was a large, flat, and remote tract of land with access to clean running water from the Columbia River. There were no towns or more than 1,000 people closer than 20 miles. The ground was also strong enough to bear heavy loads. The Hanford housed the B reactor, which was the first full-scale plutonium production reactor in the world. The Hanford site is mostly decommissioned today, and it is in the process of being cleaned up at the cost of approximately $100 billion.

There are 64 metric tons of plutonium at the Hanford site, and 50 million gallons are highly radioactive. Hazardous chemical waste is housed in 177 underground storage tanks (USTs). 67 of these USTs are known/suspected to be leak. There are also 2100 metric tons of spent nuclear fuel in storage basins near the Columbia River. Beneath the site lies 270 billion gallons of contaminated groundwater. There are also 1900 capsules of radioactive strontium and cesium being stored at the Hanford site, totaling 37% radioactivity.
Beneath the surface of the Hanford site lies 790,000 cubic meters of solid waste at a total of 1700 waste sites. There are also 500 contaminated facilities that must be removed, and 4 metric tons of plutonium.
Much progress has been made in the cleanup of the Hanford Nuclear Site. First, they started to resolve the UST issues and tank safety, which involves removing all Hanford tanks from the congressional watch list. They are also removing pump-able liquids from 131 shell tanks. Another priority is deactivating the nuclear chemical processing plants and moving half of the nuclear waste from the underground storage pools to a safe, dry storage on site. They are packaging plutonium solutions and residues to be shipped offsite for disposal. They're actively dealing with the groundwater plume and dismantling reactor complexes so they can be removed. Two reactor cores are being cocooned for storage and they're working on 3 more. They're moving 4 million tons of contaminated material away from the Columbia River shoreline (40% total).
The original clean up plan cost too much and took too long, so the Department of Energy (DOE) developed a plan to reduce risk and clean up by 2035:
The DOE will cocoon 6 reactors for long term storage, which stabilizes the waste threatening the Columbia River. They also plan on removing the contaminated buildings on site. They are also going to eliminate near-term threats to groundwater. 53 million gallons of liquid sludge and solid waste is stored in 177 USTs. Many are decades beyond design life, and even the newer updated tanks are also showing signs of wear. The DOE plans to remove the waste from the tanks, then treating and closing them. The DOE plans to accelerate these activities, and remove the waste 10 years earlier than scheduled. The waste will be vitrified, meaning it will be heated to 2000 degrees and turned into a stable glass material. The glass will be put into robust containers and transported off site. This is expected to be completed by 2028. Next, the DOE plans on dealing with the risk posed by spent fuel plutonium. They will stabilize and package the material into long term storage. This includes 2100 metric tons in K. West reactor basins. It will be conditioned for dry, long term storage. More waste will be removed from the K. East basin, which are more corroded and some remain open. They will use a fuel transfer system, which moves to K. West for washing and loading before sending off for dry storage. The DOE plans on expediting these activities to reduce exposure. This was to be completed by 2006.

The biggest risk is the 4 tons of plutonium in various forms. This will be appropriately packaged for use and storage by 2004. Vent ducts were to be cleaned by 2006. In addition to plutonium, there is also strontium and cesium stored in capsules on site, which contain 130 curies of radioactivity. These capsules are stored in water, and are going to be moved to dry storage for more protection. The DOE plans on accelerating waste disposal of 40,000 drums equivalent to low level waste and some amount of "true" waste. This buried waste was to be removed by 2010, which is accelerated by 4 years from the original schedule. DOE also plans to accelerate 15,000 drums of suspect transuranic waste. There are many buildings on site that are being scheduled in groups to accelerate cleanup. The buildings threatening groundwater are the highest priority. There is also an uplant regional closure plan, which encompasses the final disposition of the uplant canyon facility and smaller buildings around the plant and remediation of nearly waste sites. This will serve as a template of other large Hanford facilities. The cleanup of the Hanford Nuclear Site is very complex, expensive, and intense. It will create many jobs in the future, and give us clean up experience for future problems and help us identify new technologies. It will also teach us how to design safer nuclear facilities and reduce risk of exposure to hazardous chemicals.