Milestone at world's largest cleanup site: Hanford nuclear basin removed

September 13, 2009 K East Basin, a nuclear reactor basin in the Hanford Site in the northwestern United States, has been removed. Hanford, which was once one of the world's largest nuclear production facilities as a component of the Manhattan Project, is now the site of the world's largest environmental cleanup effort. The leak-prone K East Basin, which stored radioactive waste, was considered one of the site's top environmental risks.

Removal of the basin, which was located 1,200 feet (370 m) from the Columbia River, will permit cleanup of contaminated soil along one of the river's tributaries. The step was noted by a U.S. Department of Energy executive as a significant event in the protection of the river and of the million people who live downstream. It will also permit a reduction in the footprint of the cleanup project.

With a capacity of 1.2 million gallons (4.5 million litres), the basin once held 1,100 tons (998 metric tonnes) of spent nuclear fuel from the site's nine plutonium production reactors; it also contained less radioactive sludge.

Contractor CH2M HILL Plateau Remediation's removal of the basin, completed on Wednesday, September 9, followed the removal of its toxic contents in 2004 and 2007. Initially, the DOE and CH2M had intended to complete the removal by the end of July, but higher-than-anticipated levels of radiation delayed the project. Measures to protect workers delayed the project. In the past, the project has held annual public meetings; the day after the removal was complete, however Hanford's top management invited workers to additional meetings September 17 and 18. These new meetings will not be open to the public or to the media.

A legal deadline calling for the removal of the basin by the end of September was met. CH2M will begin digging up the surrounding soil immediately; contaminants may include plutonium, uranium, cesium, strontium, cobalt, PCBs and/or chromium.