The Three Mile Island Unit 2 (TMI-2) reactor, near Middletown, Pa., on the Susquehanna River,  partially melted down on March 28, 1979. The accident showed that there were enormous risks from  nuclear power plants. It enhanced safety concerns among activists and the general public, resulted in new regulations for the nuclear industry, and contributed to the decline of reactor construction programs in the US and in some other countries. It gave a great impulse to the anti-nuclear movement, and discredited previous risk assessments such as the notorious 1975 Rasmussen Report sponsored by the U. S. Atomic Energy Commission statistically estimating extremely low risks from potential accidents in commercial nuclear power plants. It was carried out under the direction of Norman C. Rasmussen of the Massachusetts Institute of Technology. The risks had to be estimated, rather than measured, because although there were about 50 such plants operating, there had not been grave nuclear accidents in commercial reactors in the U.S. before the Three Mile Island meltdown. On March 30, 1979, Gov. Richard Thornburgh recommended an evacuation for preschool children and pregnant women living within five miles of Three Mile Island. According to some research, data collected since the meltdown  demonstrate a significant nexus between radiation exposure and adverse health impacts to women and children.  The US – until the accident - was expecting to derive about 14 percent of its generating capacity from nuclear power stations. The US industry had begun confidently taking new orders totaling 8,000 MW that year – more than any year since 1974. Instead, after Three Mile Island,  president Carter ordered an inquiry into the accident and said he would expedite efforts to expand the number of nuclear inspectors. But mid-April he added that “there is no way for us to abandon nuclear power in the foreseeable future,”

Estimated costs. Three Mile Island-1 (TMI-1) came on line in September 1974 at a cost of $400 million. Three Mile Island-2 (TMI-2) came on line in December 1978, its costs went over budget.. The plant had been online for just 90 days before the March 1979, accident. Then, at least one billion dollars has been spent to defuel the facility. TMI-2 cost is then close to $2 billion dollars in construction and cleanup bills.