Chernobyl — is near Kiev, Ukraine, in the former Soviet Union. Destroyed by steam and hydrogen explosions followed by fire, it caused many deaths on site, increased cancer rates in the thousands of square miles it contaminated.

Three Mile Island — Located 10 miles southeast of Harrisburg PA on the Susquehanna River. The accident, and radiation release, caused no immediate deaths. The cleanup cost more than $1.5 Billion. The Three Mile Island accident occurred in 1979 and 1986, Chernobyl occurred essentially killing the expension of nuclear energy. No other nuclear power plants have been ordered in the US since the late 1970’s.

T.M.I. Aaccount Chronology in Brief
1970’s AEC LOFT (Loss of Fluid Test) research canceled as economy measure.
September 12, 1978 T.M.I. Unit #2 dedicated.
January 1979 TMI #2 began commercial operation.
March 26, 1979 Emergency core cooling pumps tested, with diverter valves switched to disconnect
ECCS from reactor. Valves not switched back.

March 28, 1979, 4 a.m. Three Mile Island Incident began.
—Filter in inner loop switched offline to clean
—Pressure transient triggers shutdown sequence.
—Core overheats, pressure relief valve sticks open, in manual override
—Water in core begins leaking out open relief valve
—Emergency cooling pumps don’t work !
—After more errors, 1/3 of core exposed, partial meltdown of fuel rods results.
—2nd day someone closes relief valve (unrecorded).. situation stabilizes
—hydrogen gas bubble forms.
—Governor/NRC, order partial evacuation

Cleanup/termination cost $1.5+ BILLION.

Cleanup after the Three Mile Island Accident. After the Accident it was necessary to dispose of the radioactive gases, water, and contaminated debris from radioactive plumbing etc. The water had to be filtered to separate and concentrate radioactive contaminants for disposal.

After these were removed it was possible to begin dismantling the pressure vessel and extract the fuel rods. It was not until then that the inside of the core could be inspected.

As the damaged reactor was brought under control, it was known from radiation monitoring that there was a significant amount of radioactive material in the bottom of the pressure vessel.

In spite of this, the power company still maintained that the damage to the core had been minimal.

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