Quote Originally Posted by Nemesis View Post
hey Aco, i always thought a SCRAM would instantly stop a meltdown from happening, is it because what my knowledge is based off of is nuc subs instead of giant reactors? and also, by SCRAMing it with the raw sea water, it'll be totally destroyed, right? as in that is a last ditch effort, once you expose it to sea water you'll never be able to use it again...yes?
meltdown does not mean explosion. that's called an explosion. meltdown means just that; the radioactive fuel becomes so hot they actually melt/burn through their containment structure (literally 'melting down') SCRAMing isn't done to reduce heat (though often they'll perform those opperations in conjunction) it's designed to halt the fission taking place. it's done by lowering the control rods into the core in the fastest possible manner. depending on the method of SCRAM used, reactors could be started up easily, or with very much difficulty. the most common SCRAM involves shoving the control rods all the way into the core at one time, halting fission completely. backups for this (and possible primary systems, but i hope not) amount to basically dumping buckets of neutron-absorbing material into the core.

since water (even ion-rich sea-water) doesn't attenuate radiation very well, SCRAMing w/ seawater is not feasible. what they were probably doing, was pumping seawater into the coolant pipes to keep temperatures down while they fixe the main coolant system