Nuclear reactor accidents
2) Three Mile Island 1979 Pennsylvania US
That was the worst nuclear accident in the US.
It caused contamination of the surrounding area with radioactive gases, including iodine-131, that escaped the containment building. However, most of the contaminations remained inside the building.
It was curious that on the same month it was released the movie “China syndrome” –with Michael Douglas- whose storyline was about a nuclear reactor in the US where a near meltdown situation occurred. Even more curious is the fact that it includes a comment about “contaminating an area the size of Pennsylvania”!
There was a fear of a hydrogen explosion, which would possibly blow up the containment building and release large amounts of radiation but it didn´t happen.
It was PWR type reactor ( produced by Babcock and Wilcox) that suffered a LOCA (loss of coolant) accident. A valve was stuck on the high pressure circuit and most of the coolant (water) was ejected in the form of steam and the reactor was left with its fuel elements uncovered so that heat couldn´t be removed and the fuel melted releasing fission products in the water and steam that leaked into the containment building. Operators where not aware of the valve stuck open for a long time. They were not aware of the decreasing level of water in the reactor either. The reactor was shut down but the melt down was caused by the decay heat.
It was a total loss of a billion dollar equipment.