Three Mile Island

Páginas: 3 (614 palabras) Publicado: 8 de diciembre de 2012
The accident at the Three Mile Island Unit 2 (TMI-2) nuclear power plant near Middletown, Pa., on March 28, 1979, was the most serious in U.S. commercial nuclear power plant operating history, eventhough it led to no deaths or injuries to plant workers or members of the nearby community. But it brought about sweeping changes involving emergency response planning, reactor operator training, humanfactors engineering, radiation protection, and many other areas of nuclear power plant operations.The sequence of certain events – equipment malfunctions, design-related problems and worker errors –led to a partial meltdown of the TMI-2 reactor core but only very small off-site releases of radioactivity.
The accident began about 4:00 a.m. on March 28, 1979, when the plant experienced a failurein the secondary, non-nuclear section of the plant. The main feedwater pumps stopped running, caused by either a mechanical or electrical failure, which prevented the steam generators from removingheat. First the turbine, then the reactor automatically shut down. Immediately, the pressure in the primary system (the nuclear portion of the plant) began to increase. In order to prevent thatpressure from becoming excessive, the pilot-operated relief valve (a valve located at the top of the pressurizer) opened. The valve should have closed when the pressure decreased by a certain amount, but itdid not. Signals available to the operator failed to show that the valve was still open. As a result, cooling water poured out of the stuck-open valve and caused the core of the reactor to overheat.Detailed studies of the radiological consequences of the accident have been conducted by the NRC, the Environmental Protection Agency, the Department of Health, Education and Welfare (now Health andHuman Services), the Department of Energy, and the State of Pa.. Several independent studies have also been conducted. Estimates are that the average dose to about 2 million people in the area was...
Leer documento completo

Regístrate para leer el documento completo.

Estos documentos también te pueden resultar útiles

  • Three Miles Island
  • El Accidente Nuclear De La Central Nuclear De Three Mile Island S
  • Three
  • thread
  • Thread
  • Island
  • Islandes
  • Islander

Conviértase en miembro formal de Buenas Tareas

INSCRÍBETE - ES GRATIS