Terrorists with basic and readily available knowledge of how nuclear plants operate can design their attack to maximize the chance of achieving a core melt and large radiological release.

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In like manner, I believe that reactors should be designed such that an earthquake of any magnitude could not destroy the reactor or its containment shell, further that if the reactor core was to start to melt down, the melt down itself would shut the reactor down and, at the very worst, the reactor would entomb itself with no potential release of radiation into the environment.

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That thinking changed on March 28, 1979, when a small valve stuck open, cooling water escaped and the reactor core of TMI's Unit 2 began to melt.

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