USA HISTORY

Detailed explanation-1: -The principles established by the Reactor Safety Guide were given an unexpected test in 1979 when Three Mile Island Unit 2 near Harrisburg, Pennsylvania, suffered a severe accident.

Detailed explanation-2: -The most serious accident in U.S. commercial nuclear power plant operating history occurred at the Three Mile Island nuclear station in Pennsylvania.

Detailed explanation-3: -What happened at Three Mile Island? The Three Mile Island nuclear plant had two pressurized light-water reactors. On March 28, 1979, a cooling malfunction caused part of the core to melt in Reactor 2. Some radioactive gas was released but not enough to cause adverse health effects, as noted in numerous health studies.

Detailed explanation-4: -In 1979 at Three Mile Island nuclear power plant in USA a cooling malfunction caused part of the core to melt in the #2 reactor. The TMI-2 reactor was destroyed. Some radioactive gas was released a couple of days after the accident, but not enough to cause any dose above background levels to local residents.

Detailed explanation-5: -At 4 a.m. on March 28, 1979, the worst accident in the history of the U.S. nuclear power industry begins when a pressure valve in the Unit-2 reactor at Three Mile Island fails to close.