In reply to David Roberson's message of Fri, 23 Nov 2012 23:07:53 -0500 (EST): Hi, [snip] >That is the same question I asked myself when the problem first came up. I >concluded that a scram most likely was necessary since the output of the >reactor is normally many times the requirement to supply the backup equipment >load. I suspect that it would be extremely difficult to back the power output >downward enough without loosing system stability. In fact, the power >resulting just from the nuclear decay elements might exceed the load required >with no ability to dissipate the excess energy safely. One might wonder if >the left over heat could be deposited within the inlet water as long as the >pumps were operating. I suppose that it might have been possible had the >personnel at the reactors been trained to handle the problem in that manner.
I think the thermal efficiency of most nuclear plants is around 25-30%. That means that they usually dispose of around two thirds of their full power output as waste heat. IOW if the auxiliary equipment is operating, then they can easily dispose of even the total power output at a reduced operating level. Regards, Robin van Spaandonk http://rvanspaa.freehostia.com/project.html
