Timeline
December 31, 1978:
Unit 2 of Metropolitan Edison Company’s nuclear generating plant at Three Mile Island (TMI) on the Susquehanna River. Continue…
March 28, 1979 Day 1:
4:00 AM: Due to equipment failure and operator error, a partial nuclear core meltdown of the TMI’s Unit 2 reactor. Continue…
March 29, Day 2:
Plant officials were still attempting to fully assess the damage to the plant. Continue…
March 30, Day 3:
A “bubble” in the reactor vessel that led to some venting of radioactive material and garbled communications. Continue…
March 31, Day 4:
A false rumor that a “bubble” that had formed in the reactor and could potentially explode was squelched by the Governor’s office and Harold Denton’s impromptu press conference. Continue…
April 1, Day 5:
With television news in tow, President Jimmy Carter and Governor Richard Thornburgh visited the control room of the plant. Continue…
April 6, Day 10:
After operators regained control of the plant, Governor Thornburgh lifted the evacuation advisory and declared the Three Mile Island “crisis had passed.” The cleanup would take years.
October 25, 1979:
The Nuclear Regulatory Commission recommended the maximum fine permitted under law for Metropolitan Edison’s violations that contributed to the accident.
October 30, 1979:
The Presidential Commission (Kemeny Commission) issued its report. Continue…
1980:
For their coverage of the Three Mile Island accident, the staff of the Philadelphia Inquirer was awarded the Pulitzer Prize. Continue…
June/July 1980:
In preparation for entry into the reactor building, venting of radioactive gasses proceeded over an eleven day period. Continue…
July 23, 1980:
The first person since the partial reactor core meltdown entered the TMI-2 reactor building. Continue…
October 15, 1980:
The Nuclear Regulatory Commission began hearings on whether or not to restart Unit 1, which had been idle since July of 1979.
November 1980:
The Advisory Panel for the Decontamination of TMI-2 held its first meeting. State and local officials, scientists, and citizens were represented.
July 1981:
Governor Thornburgh proposed a one billion dollar cost-sharing plan to clean up the accident that required a partnership of state and federal governments and the nuclear industry.
May 18, 1982:
Central Pennsylvania voters in three counties voted to oppose the restart of Three Mile Island Unit 1. Continue…
July 1982:
An underwater camera surveyed the inside of the reactor vessel for the first time, revealing that the extent of the core meltdown was far greater than expected. Continue…
October 1985:
Workers began to remove the damaged core of the Nuclear 2 reactor. Continue…
July 1986:
Shipment of reactor core debris to an off-site storage facility began. Continue…
January 1991-August. 1993:
Processing of 2.23 million gallons of accident-generated water was completed. Continue…
Although a number of studies done by a variety of investigators have concluded that the accident did not impact the health of area residents, this issue is still debated. Continue…