The "inherently safe" nuclear reactor designs rely upon the laws of physics to prevent disaster. The reactors can never heat to the point of meltdown and combustible materials are not used.
However, deliberate terrorist actions must now be considered in the designs.
Yeah, we know that now. I think the argument was made that since emergency cooling was furnished by air, it couldn't overheat. The whole problem of fire was overlooked because they had fire extinction apparatus. Fire was the "easy problem". Problem was, the fire was started by a power spike that made a much bigger and hotter fire than they anticipated and overwhelmed the fire fighting capability.
Air cooling, the "inherently safe" feature precluded Western style containment structures.
Are Nuclear Plants Really Terrorist Targets? - http://www.atomicinsights.com/AI_04-26-05.html
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Nuclear plants are not natural targets. They are surrounded by protective shells that are generally constructed of several layers of thick, strong materials like concrete and steel. I have seen physical displays with portions of these containment vessels exposed - a typical example was a wall more than three feet thick reinforced with closely spaced steel rebar that was about the same diameter as my forearm. I am not a huge person, but I have been getting to the gym on a fairly regular basis for about 30 years.
In the extremely unlikely event of breeching the containment shell with anything less than a penetrating weapon with better capability than those designed to attack armored tanks, there are still more obstacles between an attacker and his ability to cause the release of radioactive material. I have a pretty active imagination, but I have a very difficult time conceiving of a possible path for releasing enough of the material in the core in a manner that would cause any injuries. In addition, nuclear plants have buffer zones, fences, a large security force, and a number of other measures that put them at the very bottom of my long personal list of concerns. I worry more about the possibility of getting hit by lightning on a sunny day on my way home from winning the New Jersey lottery. (I never buy lottery tickets and do not live in New Jersey.)
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