Secrecy Continues About Hanford’s Largest Radiation Emission — 74 Years After Infamous Green Run

This weekend, December 2-3, marks the 74th anniversary of the largest radiation emission from the Hanford plutonium factory in south central Washington and serves as an apt reminder that citizens have an indispensable role in protecting democracy and public health. It was an episode whose very existence was classified for four decades. Driven by a desire for the truth, I’ve spent decades sifting through thousands of documents for nuggets of key information–and here is what I learned.

Conducted during the night of December 2-3, 1949, the Green Run was an intentional release of more than 11,000 curies of radioactive iodine-131 (the Three Mile Island accident released an estimated 24 curies). It was called green because the fuel being dissolved was only cooled for 16 days rather than the standard 90 days (“green” as in not yet ripe). The cooling time was the period between discharging the fuel from one of the reactors and the start of the chemical process to extract the plutonium. Hanford also disconnected the stack filters to further increase the amount of radiation released.

Radioactive Poisoning of Inland Northwest

The radioactive plume blanketed thousands of square miles in Eastern Washington, Northeast Oregon, and North Idaho. The Green Run was the largest single atmospheric release of radiation from the Hanford site, but no one instituted any controls on milk consumption, the primary exposure pathway for iodine-131 to enter humans, thereby endangering tens of thousands of people in the path of the radioactive plume. Because none of the human senses can detect radiation, people downwind couldn’t see, taste, or smell the radioactive contamination. For decades, people in the Northwest had no idea they had been exposed.

Reason for Secret Experiment

Why did this happen? The U.S. Air Force and the Atomic Energy Commission conducted the Green Run to test three types of airborne sampling equipment designed to gather information about Soviet plutonium production, just three months after the USSR had exploded its first atomic weapon. The Soviets entry in the arms race only four years after the atomic bombings of Hiroshima and Nagasaki had spurred a quick escalation of the U.S. atomic program.

The Air Force began developing the airborne sampling devices in 1948, conducting twenty-three test flights over Hanford and Oak Ridge, Tennessee. But the relatively low emissions from routine operations had not produced the desired results. Following the Soviet A-blast, the Air Force quickly prepared for a far greater environmental release from Hanford.

Numerous Failures during Green Run

The declassified document revealed that the Green Run encountered a host of problems including malfunctioning equipment, changing weather, and severe contamination of the laboratory used to analyze the radiation samples. Problems also plagued the Air Force’s specially equipped plane. Nearly everything that could have gone wrong did.

Public Seeks Truth

In the mid-1980s, however, alarmed by the resumption of plutonium processing for Reagan’s nuclear weapons buildup, citizens started demanding accountability for Hanford’s operations. Citizen groups such as the Hanford Education Action League (HEAL) demanded that classified documents on the history of Hanford operations be made public. During my ten years with HEAL, I filed over one hundred requests using the Freedom of Information Act (FOIA). When Hanford released the first batch of historical reports in 1986, the Northwest learned about the Green Run having taken place, but little else. It took three more years of persistence by me at HEAL and the Spokesman-Review to pry loose the official Green Run report. Even so, numerous key sections were blacked out. Another two years of effort forced the government to declassify a few additional pages. Even now, the federal government continues to withhold details about the Green Run including the names of who authorized it.

Secrecy remains as much a threat to our democratic republic now as it did during the Cold War. Citizens cannot hold their government accountable without timely access to critical information. Democracy cannot survive when citizens are kept in the dark. When Atomic Pilgrim is published, I will reveal the names of the two Air Force officials who authorized the Green Run.