Radioactive Material Released
- After shutting down the fission reaction, Tower Number 2 reactor’s fuel core became uncovered and more than one third of the fuel melted.
- Inadequate instrumentation and training programs at the time hampered operators’ ability to respond to the accident.
- The accident was accompanied by communications problems that led to conflicting information available to the public, contributing to the public’s fears
- A small amount of radiation was released from the plant. The releases were not serious and were not health hazards. This was confirmed by thousands of environmental and other samples and measurements taken during the accident.
- The containment building worked as designed. Despite melting of about one-third of the fuel core, the reactor vessel itself maintained its integrity and contained the damaged fuel.
- Applying the accident’s lessons produced important, continuing improvement in the performance of all nuclear power plants.
- The accident fostered better understanding of fuel melting, including improbability of a “China Syndrome” meltdown breaching the reactor vessel and the containment structure.
- Public confidence in nuclear energy, particularly in USA, declined sharply following the Three Mile Island accident. It was a major cause of the decline in nuclear construction through the 1980s and 1990s.