Three Mile Island

Permanently shutdown nuclear power plantThermal power plant, primarily used for electricity generati... near HarrisburgThe Three Mile Island Nuclear Power Plant with two pressuriz..., Pennsylvania, USA, with two pressurized water reactors. On 28th March 1979, a serious accidentUnplanned sequence of events which may result in an effectiv... with partial corePart of the nuclear reactor where the fission chain reaction... meltdown occurred in unit 2. The fission productsNuclides generated by fission or subsequent radioactive deca... were almost completely retained in the reactor pressure vesselThick-walled cylindrical steel vessel enclosing the reactor ... and in the containmentGastight case around a reactor and the circuit and auxiliary.... As the retention function of the containmentGastight case around a reactor and the circuit and auxiliary... functioned as designed, only activityActivity is the term used to characterise the number of nucl... releases of xenon-133 and very low portions of I-131 into the environment occurred, resulting in the statistical maximum doseMeasure of a radiation effect to be indicated more precisely... of 0.85 mSv. Unit 1 has been shut down on 20^th September 2019.