3+mile+island

Andrew Welde 3 MILE ISLAND The three mile island accident is one of the worst nuclear accidents in U.S history. It was near Harrisburg, Pennsylvania. The accident to unit 2 happened on 28 March 1979. It involved relatively minor malfunction in the secondary cooling circuit which caused the temperature in the primary to rise. This in turn caused the reactor to shut down, shut down took about one second. At this point a relief valve would not open. The coolant started to drain away from the power plant. The core as severely damage as a result.

The map below shows the 5, 10, and 20 mile evacuation zones around the Three Mile Island Nuclear Power Plant. During the Three Mile Island nuclear materials release, pre-school and pregnant or nursing moms were evacuated within 5 miles of the plant and people were cautioned to stay indoors within a 10 mile radius. 20 miles is the expect ed maximum evacuation zone in a radiation emergency if the public has Potassium Iodide (KI) or KIO3 pills, which helped to fight against radiation sickness. Some radioactive gases did escape to the atmosphere. The estimated average dose to area residents was about 1 millirem, about 1/6 the exposure from a full set of chest x-rays, and about 1/100th the natural radioactive background dose for the area. The maximum dose to a person at the site boundary would have been less than 100 millirem. Despite the severe damage to the reactor, there was very little damage done to the environment or people. Thousands of test have been taken but a small amount of radiation could have been from the accident. The reactors are permanently shutdown. All the radioactive waste has been shipped away and disposed of properly. The TMI-1 plant will expire April 1, 2014. The owners says when it expires both plants will be decommissioned. Sources [] [] []