Mile Island: The Inside Story
cover of the report of the investigative commission
appointed by President Jimmy Carter immediately
following the accident. The wrecked reactor is
inside a steel pressure vessel inside the cylindrical,
domed concrete building in the foreground.
America’s worst accident at a civilian nuclear
power plant occurred on March 28, 1979. Unbeknown to anyone, half
the fuel melted in one of two nuclear reactors on Three Mile Island
near Harrisburg, Pa. Large quantities of radioactivity leaked from
the reactor, but most of it was contained. In all probability, no
one received a harmful amount of radiation. The enormous damage
to the reactor was revealed only years later when TV cameras and
a specially developed ultrasonic, sonar-like imaging system looked
inside the reactor vessel.
In recognition of the 25th anniversary of this event, the National
Museum of American History devoted its History-in-the-News display
case during spring 2004, to the accident in Unit 2 of the Three
Mile Island nuclear power station (TMI-2). That exhibit featured
the 1983 computer-controlled ultrasonic survey. It included the
sonar probe and a precise topographic scale model of the upper third
of the reactor’s destroyed core that was prepared to present
in visual form the numerical sonar data.
of topographic scale model of the upper third
of the TMI-2 reactor’s destroyed core, constructed
on the basis of data gathered and analyzed in
1983 by the Idaho National Engineering and Environmental
Laboratory’s sonar survey team.
This Web site has been created in order to provide more information
about the Three Mile Island nuclear power plant; about the course
of the accident there; about the steps—extending over almost
15 years—through which the nature and extent of the damage
were gradually revealed; and, especially, about the sonar survey,
and the topographic maps and models that were prepared with the
survey data, providing a full and detailed picture of the first
and most astonishing discovery: a cavernous void in the core of
the reactor, where once there had been a dense forest of fuel rods.
Continue to the Exhibit