The Millstone Nuclear Power Station is located near Waterford, Connecticut in an old quarry and it draws cooling water from Niantic Bay on Long Island Sound. There are two operating General Electric pressurized water reactors on the site. Unit Two is an 870 megawatt Combustion Engineering pressurized water reactor that started generating power in 1985 with a forty years license. Unit Three is an 1150 megawatt Westinghouse pressurized water reactor that started generating power in 1986 with a forty years license. Both units were relicensed in 2005 for an additional twenty years. The plant was built by Northeast Nuclear Energy and is currently owned and operated by Dominion Nuclear.
The population in the NRC plume exposure pathway zone with a radius of ten miles around the plant contains about one hundred and thirty thousand people. The NRC ingestion pathway zone with a radius of fifty miles around the plant contains about three million people. The NRC estimates that there is a low risk of an earthquake that could damage the plant.
In 1988, leaks were reported at Millstone. In 1991, eight control rods did not insert properly during emergency shutdown. In 1993, leaks caused Unit Three to be shut down and problems were discovered in the emergency power supply while Unit Two was shut down for refueling. In 1996, Northeast Utilities, the parent company for Northeast Nuclear Energy, voluntarily shut down Unit Two because it had some of the same problems that had been identified in a study of the Diablo Canyon nuclear power plant. Part of the reason for the shutdown was a lot of other problems that the plant had been having. Unit Two remained offline for three years as extensive changes were made to management and to the physical plant in light of the repeated inspections and warnings since 1991. Unit Three was shut down in 1996 because the NRC determined that the containment isolation valves did not comply with regulations. It remained offline for two years while repairs were made.
In 1999, two subsidiaries of the corporation that owned Millstone pled guilty to twenty five violations for environmental and nuclear laws and paid a ten million dollar fine. The charges included problems with nuclear training and environmental impact at Millstone. The problems at Millstone prompted a deep review of NRC procedures. A cover story in Time magazine in 1996 discussed the problems at the Millstone reactor. Following a review of the procedures for inspections and warnings, the NRC made extensive changes to its system of inspections and notifications. Only the Three Mile Island accident prompted more changes in the inspection and regulation of nuclear reactors in the United States. In 2000, the Millstone plant was sold to Dominion Nuclear and since the sale, the reputation of the plant for following NRC regulations has improved considerably.
