February 1941
Glenn Seaborg with other UC Berkeley scientists synthesize Plutonium-239 through the bombardment of uranium.

December 7th, 1941
Japan attacks Pearl Harbor.

August 1942
U.S. Corps of Engineers assigned to head the Manhattan Project.

November 1942
U.S. Government selects Hanford Site for plutonium production facility.

December 1942
DuPont selected as Hanford's primary contractor.

February 1943
Over 1,500 residents in the 600 square-mile Hanford site are ordered to evacuate within 30 days.

March 1943
Construction of Hanford Engineer Works (HEW) begins.

December 1943
Fuel manufacturing begins in 313 Building.

March 1944
Experimental canning operations start in 313 Building.

September 1944
Startup of B Reactor, the world's first full-scale plutonium production reactor.

December 1944
Startup of D Reactor and T Plant. Major air and ground releases begin.

January 1945
Installation of 64 underground, single-shell waste tanks begins.

February 1945
Startup of F Reactor. Startup of B Plant. Construction of HEW complete.

July 1945
Germany surrenders. Trinity Test at Alamogordo, NM.

August 1945
Little Boy is dropped on Hiroshima on August 6th. Fat Man is dropped on Nagasaki on August 9th. Japan surrenders .

March 1946
Churchill delivers Iron Curtain speech.

August 1946
Atomic Energy Act passed. Hanford becomes a cilivilian operation. Manhattan Project ends.

September 1946
General Electric becomes primary site contractor at Hanford.

January 1947
Installation of 42 underground, single-shell waste tanks begins. Atomic Energy Commission takes charge former Manhattan Project Sites.

March 1947
Truman Doctrine and Cold War ensues. $350 million site expansion at Hanford follows.

Filters used for the first time on separation stacks.

October 1948
Waste pond dike breaks releasing 28 pounds of uranium into Columbia River.

July 1949
Startup of C Plant (REDOX). Plutonium Finishing Plant (Z Plant) is completed.

August 1949
Soviet Union detonates its first atomic bomb. Startup of H Reactor.

December 1949
The Green Run experiment releases 7,780 curies of iodine-131, 20,000 curies of xenon-133 into the atmosphere.

Installation of 18 underground, single-shell waste tanks begins.

October 1950
Startup of DR Reactor.

January 1951
Atmospheric atomic bomb testing at Nevada Test Site begins.

March 1951
Camp Hanford established.

July 1951
Iodine filters at Hanford processing plant fail. HEDR estimates 34,360 curies of radioiodine released in 1951 alone.

Startup of S Plant (REDOX). Startup of U Plant to recover uranium from T and B Plants. Experimental Animal Farm and Aquatic Biology Laboratory established.

November 1952
Startup of Z Plant. Startup of C Reactor.

Installation of 21 underground, single-shell waste tanks begins.

July 1953
Korean War Armistice signed. Nearly 250 curies of ruthenium-103 and 106 are released due to processing mishaps.

Atomic Energy Act of 1954 allows nuclear weapons facilities to operate without independent oversight.

Installation of Nike missile sites.

February 1955
300 curies of ruthenium-106 released from REDOX Plant. 300 curies of ruthenium-106 released from REDOX Plant.

December 1955
Startup of KW and KE Reactors—one of which experiences a partial fuel melt-down at startup.

Shutdown of B Plant. Startup of A Plant (PUREX).

March 1956
Shutdown of T Plant.

October 1957
Soviets launch Sputnik.

Shutdown of U Plant.

Shutdown of Nike missile sites. Shutdown of Camp Hanford.

April 1962
Accident at Plutonium Finishing Plant releases 1,200 curies of radioactive gasses.

October 1962
Cuban missile crisis.

President Kennedy attends ground-breaking for N Reactor. Installation of four underground, single-shell storage tanks.

August 1963
Limited Test Ban Treaty outlawing atmospheric, underwater, and outerspace nuclear tests.

March 1964
Startup of N Reactor.

May 1964
Startup of Plutonium Reclamation Facility.

December 1964
Shutdown of DR Reactor.

January 1965
Hanford labs renamed Pacific Northwest Laboratory by Battelle.

April 1965
Shutdown of H and F Reactor. Hanford Environmental Health Foundation formed.

August 1965
Douglas-United assumes responsibility for reactors and fuels.

January 1966
ISOCHEM assumes responsibility for chemical processing and plutonium finishing.

June 1967
Shutdown of D Reactor.

September 1967
Atlantic Richfield (ARCO) becomes primary operator and assumes chemical processing.

December 1967
Shutdown of S Plant (REDOX).

Installation of 28 underground, double-shell storage tanks.

February 1968
Shutdown of B Reactor.

April 1969
Shutdown of C Reactor.

January 1970
Shutdown of KW Reactor.

July 1970
Westinghouse Hanford Co. contracts to build and operate Fast Flux Test Facility.

January 1971
Shutdown of KE Reactor.

May 1973
Seattle Post Intelligencer reports billions of gallons of low-level wastes were discharged into ground for 30 years at Hanford.

June 1973
Hanford officials publically announce a 115,000 gallon leak in tank 106-T.

January 1974
President Ford abolishes AEC renaming it Energy Research and Development Administration.

January 1977
Hanford Reservation renamed Hanford Site. Rockwell Hanford assumes operations.

March 28th, 1979
Three Mile Island power plant partial core meltdown releases 15 to 24 curies of iodine-131.

February 1980
Startup of Fast Flux Test Facility.

January 1981
Spokane Unitarian minister, Bill Houff, delivers "Silent Holocaust" sermon, leads to formation of HEAL.

January 1984
USDOE temporarily shuts down PUREX plant. Hanford becomes candidate for a nuclear waste repository.

July 1985
Spokane-Spokesman Review publishes first article on Hanford downwinders.

December 1985
Washington State Nuclear Waste Board calls for an independent study of Hanford downwinders.

January 1986
HEAL and other groups file Freedom of Information Act request for Hanford documents.

February 1986
USDOE releases 19,000 pages of formally classified historical Hanford documents.

April 1986
Chernobyl accident releases 40 to 50 million curies of iodine-131 into the atmosphere. Hanford review panel recommends dose reconstruction (HEDR) and epidemiological study of thyroid disease study.

January 1987
Shutdown of N Reactor.

December 1987
Hanford removed from high-level nuclear repository list.

Plutonium production ends at Hanford. Shutdown of A Plant (PUREX).

May 1988
Congress mandates funds for Hanford Thyroid Disease Study (HDTS). USDOE, EPA, and Washington State Department of Ecology sign Hanford cleanup agreement.

August 1988
Cold War ends.

Hanford officials reveals tank explosion threat known since 1979.

July 1990
Preliminary HEDR results announced.

September 1990
Hanford Health Information Network (HHIN) funded by congress.

September 1991
Government investigators and press corroborate harassment of Hanford whistleblowers.

October 1992
HEDR announces 70 percent increase in iodine-131 releases than previously estimated.

Tri-Party Agreement calls for 99 percent of high-level waste to be vitrified.

Fred Hutchinson Cancer Research Center completes pilot phase of HTDS. Federal Advisory Committee on Human Radiation Experiments releases final report.

July 1996
Hanford Health Information Archives opens. Fluor Daniel and five other companies replace Westinghouse as contractors.

July 1997
USDOE launches Human Radiation Experiments information Web site.

August 1997
National Cancer Institute announces results from iodine-131 fallout study from Nevada Test Site bomb tests.

August 1998
National Institute of Occupational Safety and Health finds multiple myeloma among USDOE workers.

December 2000
First batch of irradiated fuel moved from water-filled K Basins to dry storage.

September 2001
9/11 attack. Work begins on vitrification plant.

December 2001
Secretary of Energy orders Fast Flux Test Facility to be shutdown.

Please note that the timeline was created for the original Safe As Mother's Milk project that was launched in 2003. An updated timeline noting events from 2001-2012 will be updated in future revisions.