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Three Mile Island, Pennsylvania |
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Update: October 14, 2008
Next Update: November 2009 Three Mile Island Nuclear Power Plant Net Generation and Capacity, 2007
Description: The Three Mile Island station is located on 814 acres of an island near the state capitol at Harrisburg. Three Mile Island may be the most widely known nuclear power plant in the United States due to an accident to its number 2 reactor. The second reactor was permanently shut down following an accident on March 28, 1979. A combination of equipment malfunctions and human error led to a loss of coolant. It remains the most significant accident on record at a U.S. nuclear power plant. The lessons learned from Three Mile Island, however, resulted in enhancements in training, safety procedures, emergency operation, and oversight. The Nuclear Regulatory Commission (NRC) has an excellent fact sheet on the subject. Three Mile Island, Unit 1
Nuclear Steam System Supplier (NSSS Vendor) = Babcock & Wilcox Pressurized-Water Reactor (PWR) In a typical commercial pressurized light-water reactor (1) the reactor core generates heat, (2) pressurized-water in the primary coolant loop carries the heat to the steam generator, (3) inside the steam generator heat from the primary coolant loop vaporizes the water in a secondary loop producing steam, (4) the steam line directs the steam to the main turbine causing it to turn the turbine generator, which produces electricity. The unused steam is exhausted to the condenser where it is condensed into water. The resulting water is pumped out of the condenser with a series of pumps, reheated, and pumped back to the steam generator. The reactors core contains fuel assemblies which are cooled by water, which is force-circulated by electrically powered pumps. Emergency cooling water is supplied by other pumps, which can be powered by onsite diesel generators. Other safety systems, such as the containment cooling system, also need power.
Containment: According to the U.S. Nuclear Regulatory Commission, the containment design is dry, ambient pressure.1 _________________________________________ 1Dry, Ambient Pressure: a reactor containment design whose safety has been evaluated on the basis of having a dry air atmosphere at ambient pressure (0 psig) prior to the onset of a loss of coolant accident or steam pipe break. The containment design (concrete and steel tendons) must be able to take the full thermal and pressure stresses associated with the rapid energy release (steam) from a major pipe break. |
see also:
annual
nuclear statistics back to 1953
projected electricity capacity to 2030
international
electricity statistics