What happens if nuclear power plants become inaccessible?

Question

if a mass disaster happens witch makes it impossible for workers or anyone to get to a nuclear power plant what will happen will it melt down?

Answer 1

Lets say that the entire population of springfield gets turned into zombies like Dawn of the Dead, completely devoid of any cognative reasoning skills.  

the United States learned alot from the mistakes of Chernoble, on of which is design flaws including having a nutron moderator with a positive temperature coefficent of reactivity.   Meaning that the hotter that it gets, the more radiation that it produces, and the more ratiation that it produces, the hotter it gets.  A vicious cycle.  New models for reactors in the United states have a NEGATIVE temperature coefficent of reactivity so it is actually more stable and much less likely to "melt down"

Annother thing that would keep it from burning up is that every aspect of a reactor is monitored, even the change from second to second is recorded and analyzed by computer, thousands of calculations per second, looking for trends and functions.  So if the reactor was to c**p the bed and s***w the pooch, the reactor control devices would come into play and cut power to the devices that keep the reactor up and running and it would be "off line" in less than 2 seconds.  So even if electricity was to be cut to the powerplant, it would still not pose a risk.

Now, if a reactor plant is left alone and at stable power demand for extended, I mean EXTENDED periods of time, eventually, the fuel in the core would be "burnt" and go "cold" too cold to boil the feed water and turn the turbins and make electricty not only for external use, but for self sustaining purposes only, causing the colling pums to trip offline due to the "low voltage safety trip", then , in turn the reactor would shut down due to low power to flow, and be put in a "shut down" position.

The only way an unmanned reactor could pose a risk is if an explosion, which is, let me make this clear, CANNOT BE CREATED BY NUCLEAR REACTORS, detonates near, or in the plant. This would cause a wide spread movement of the nuclear material from the reactor core, if it was breached, to the affected areas, which would be different bases on geographical turrain, wind currents, and water sources.  

Conclusion:  Reactors in modern United States are built well and safely, in addition they have fail safe mechanisims that render them safe after reaching critical if unforseen and dangerous events happen. +

Answer 2

The basic thing that will happen is that the residents will be no more supplied by electricity. Except if they have generators that store electricity.

Hope I helped. :)

Answer 3

eNuclear power plants has many safety features built into it.

They will automatically shut down the reator if any paramater of any importance goes above range.

Danger happens when this safety devices are bypassed for some tests or periodic checks.

Accidents happens only more than two mistakes happens by the crew.

Answer 4

A nuclear plant has a large staff on duty all the time. In case of a disaster, the first job would be to put the reactor in a safe state; essentially a complete shut down. It is hard to conceive of a disaster that would prevent shutdown except a direct hit by a meteor or a nuclear bomb.