Hanford Site: Plutonium, Downwinders, and America's Costliest Cleanup

In March 1945 a Japanese paper balloon bomb drifted across the Pacific, hit a power line in Washington State, and triggered an automatic shutdown of a secret nuclear reactor whose workers did not know what they were building. This episode tells the story of the Hanford Site, a 586-square-mile stretch of desert that went from farmland and ancient indigenous fishing grounds to the birthplace of the plutonium used in the Trinity test and the Nagasaki bomb. It explains why the Manhattan Project chose the site, how the government used the Second War Powers Act to evict thousands of farmers and displace the Wanapum, Yakama, Nez Perce and Umatilla tribes, and why DuPont agreed to build it for a fee of one dollar.

From the B Reactor's 1,200-ton graphite core and 30,000 gallons of Columbia River water per minute to the windowless concrete separation canyons operated by remote control, the episode covers the engineering marvels of the war years and the Cold War expansion under General Electric. It then turns to the hidden costs: radioactive water dumped into the river, iodine-131 drifting over farms and dairy herds, the intentional Green Run release of 1949, the downwinder lawsuits, and 53 million gallons of high-level waste in leaking tanks. It closes with the vitrification plant, the site's evolution into the Pacific Northwest National Laboratory and LIGO, and a planned one-gigawatt solar array.

• The 1942 site criteria, including 25,000 gallons of water per minute, 100,000 kilowatts of power, and no town of more than a thousand people within 20 miles, and why Oak Ridge was rejected
• Life in the secret city: over 45,000 workers by June 1944, fewer than one percent aware of the goal, strict racial segregation, and the subsidized suburban boom town of Richland
• How engineers fixed the Wigner effect by running the reactor hotter to anneal swelling graphite, and why Camp Hanford was ringed with anti-aircraft guns and Nike missiles
• The declassification of 19,000 pages in 1986, the health findings on thyroid disease and cancer, and the mass tort lawsuit brought by 2,000 downwinders that was resolved by 2015
• Why the cleanup contract awarded for 4.3 billion dollars in 2000 has grown to well over 100 billion, and what it means to design containment for plutonium-239 with a 24,100-year half-life