RELEASES: The Green Run
"ALTHOUGH THE GREEN RUN was not as direct as handing a patient orange juice laced with radioactivity, or giving someone an injection, The Green Run was every bit as intentional, every bit as experimental, every bit as unethical and immoral..."
— Lynne Stembridge, executive director of Hanford Education Action League at the 1994 Advisory Committee on Human Radiation Experiments.
Early in the evening of December 2nd, 1949, General Electric officials in conjunction with representatives from the Department of Defense and the Atomic Energy Commission (AEC) unleashed the largest single known incident of intentional radioactive contamination at the Hanford site. Known as the "Green Run," this fuel processing experiment utilized raw, irradiated uranium fuel elements cooled for only sixteen days only before dissolving in acid. Under normal conditions, irradiated fuel would be cooled for at least 83 to 101 days to allow short-lived radioactive materials (such as iodine-131) to sufficiently decay before processing and subsequent release into the environment. The formally classified report Dissolving of Twenty Day Metal at Hanford states that Hanford officials initially planned to release approximately 4,000 curies of iodine-131 and 7,900 curies of xenon-133 but ended up releasing in actuality 7,780 curies of iodine-131, along with 20,000 curies of xenon-133 into the surrounding area's atmosphere within a seven-hour period.  In comparison, the March 1979 Three Mile Island accident released between 15 and 24 curies of radioactive iodine. The Green Run operation remained classified and unbeknownst by the public until 1986 when the release of 19,000 formally classified documents became available through the Freedom of Information Act.
The Green Run experiment was planned with certain atmospheric weather conditions in mind. Specifically, a local inversion of air was required to dilute radioactive materials before reaching the ground so no rain or fog could be present as it would prevent airborne radiological data collection efforts. A west to southwest wind spread of at least fifteen miles per hour at 200 feet above was required to allow for the radioactive emissions to stay aloft long enough to collect data.  Initially the experiment was planned for late November but was postponed due to unsatisfactory weather conditions. It seems that unfavorable conditions continued and at the scheduled time of the planned December 2nd run, Hanford scientists expressed concern recommending, "it (the release) not be run at the time...The time was wrong."  Nevertheless, the Department of Defense (headed by General Dwight D. Eisenhower) insisted that the run take place and at 8 p.m. on December 2nd, 1949. The material was released from a spare dissolver at Hanford's T plant. Michelle Gerber in On the Home Front, points out that at least two individuals in knowledgeable positions have stated that the Green Run "went awry." It is acknowledged that the release was so large that it consequently contaminated much of the field monitoring and laboratory equipment producing "high background signals that made it difficult to distinguish radioactivity on the equipment from radioactivity in the environment."  The Health Instruments Deputy Chief, Carl Gamertsfleder was quoted in saying that along the Columbia River between Hanford and The Dalles, Oregon, the radioiodine cloud "probably got as many people as it could." 
At the beginning of the release, air scrubbers used to filter an estimated ninety percent of the radioiodine from the effluent gas were intentionally deactivated to maximize the amount of radioactive material released into the atmosphere. Air Force planes equipped with air-sampling radiological measuring devices monitored the movement of the radiation until late in the afternoon of December 3rd. The overall pattern of deposited iodine-131 on ground vegetation "extended in an elongated shape about forty miles wide and 200 miles long lying northeast and southwest of the Hanford site."  The highest levels of iodine-131 produced by the experiment were found on vegetation samples taken from Kennewick. These were nearly one thousand times higher than the then acceptable daily limit.  Animal specimens collected from the reservation received thyroid irradiation up to eighty times the acceptable daily dose. 
Although specific reasons for the operation remain classified it is generally acknowledged that the Department of Defense was attempting to simulate production capabilities of one of the Soviet Union's secret plutonium processing plants—possibly Mayak, a Cold War production facility located in the Southern Urals about forty miles north of Chelyabinsk. U.S. reconnaissance showed that the Soviets detonated their first atomic bomb on September of 1949 .  The blast was not announced but was detected by Hanford's atmospheric monitoring equipment located in various points throughout the Pacific Northwest and Alaska. Gamertsfleder later recounted that the AEC assumed that the Soviet's rush to produce atomic weaponry was forcing them to use short-cooled fuel. Through implementation of the Green Run experiment the AEC and military officials hoped to "develop a monitoring methodology for intelligence efforts regarding the emerging Soviet program." 
We may never fully know the true intention of the Green Run. Were the AEC and the military conducting the experiment in order to produce results for the shortest cooling time possible to speed up production or was there a more sinister objective in mind? As Michelle Gerber states in "On the Home Front," "the question of whether the Green Run was a radiological warfare experiment, designed to test harm to foodstuffs and living creatures, is still open."