Three Mile Island

Three Mile Island

On March 4th, 1979 a nuclear power plant in Middletown, Pennsylvania experienced a mechanical failure that resulted in catastrophic meltdown of a core nuclear reactor. The cause of the meltdown was a result of both design flaws and factory worker errors that basically led to the overheating of the power plant. This accident had many effects, both primary and secondary, that encouraged a different approach to the safety precautions and management procedures required to run a nuclear facility.

The accident began at about 4:00 a.m. on March 28, 1979, when the plant experienced a failure in the secondary, non-nuclear section of the plant. The main water pumps that ran to the core reactor stopped running, caused by either a mechanical or electrical failure, which prevented the steam generators from removing heat. After the sudden change in temperature, the cooling turbine and reactor automatically shut down. Immediately afterwards, the pressure in the primary system (the nuclear portion of the plant) began to increase. In order to prevent that pressure from becoming excessive, the manually operated relief valve opened. The valve should have closed when the pressure decreased by a certain amount, but it did 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.

Nuclear Radiation due to the meltdown contaminated Three Mile Island and led many to wonder the adverse effects that it had on the people, animals, and plants. This is an example of a primary effect of the meltdown. Although the island was evacuated, samples from the environment showed that the radiation given off from the core reactor had very little effect due to quick containment. The damage to