3rd generation reactors do not need external power to run cooling. In any case you cannot shut down the reaction going with control bars down all the way, the risk is to kill reaction. You would loose millions in a minute. They are totaly unflexible it takes days to bring the neutron k factor to ~ 1, usually they work with k a little above unity to produce enough heat. But you let the reaction go too much above 1 you *loose* control totally.
2011/4/28 <[email protected]>: > In reply to Alan J Fletcher's message of Thu, 28 Apr 2011 12:37:55 -0700: > Hi, > [snip] >>http://www.reuters.com/article/2011/04/28/utilities-tva-storms-idUSN2718319320110428 >>All 3 Browns Ferry sites lost outside power and switched to diesel power. > > This I don't understand. Why can't fission reactors supply electricity to > their > own pumps? IOW why do they automatically shut down completely when grid > connection is lost? Are they so inflexible in their power output? Even if the > main reactor is shut down, one would think that even the heat from decay of > radioisotopes would provide more than enough power for their own pumps, > perhaps > even for months? In short, why do they need diesel generators to kick in > straight away? > Regards, > > Robin van Spaandonk > > http://rvanspaa.freehostia.com/Project.html > >
