In reply to Jed Rothwell's message of Thu, 28 Apr 2011 18:54:36 -0400: Hi, [snip] >They cannot supply electricity for their own use only because they are not >designed to run at a tiny fraction of regular output, say 0.1%. I believe >that is about all they need to keep themselves going. (The energy overhead.) >It would like trying to idle your car engine to 1 rpm.
I thought about that, but I'm not sure it really makes sense. To start with, you can reduce the cooling water flow through the reactor such that it is precisely enough to create steam of the right pressure, based upon the current power output due to remaining decay heat. That steam will still drive a (nearly) unloaded turbine at high speed (they must have very good bearings). Because very little power is being drawn from the generator, it in turn places very little load on the turbine. If you are still generating too much power, then you can simply vent some of the steam in the secondary loop before it reaches the turbine. The combination of reduced cooling water flow and steam venting should allow you to throttle back as far as is required. ...unless of course the decay heat is insufficient to run the pumps (even at reduced load)? After Fukushima, somehow I doubt that. Regards, Robin van Spaandonk http://rvanspaa.freehostia.com/Project.html
