In reply to Jeff Berkowitz's message of Sat, 24 Nov 2012 13:20:24 -0800: Hi, [snip] >"Around two-thirds" is right. Many online sources quote 32% and I recall >33% from a class I took eons ago. > >Two other things: > >1. Controlling the reactivity of an operating reactor is extremely complex. >See for example Section 3, "Core Cell Improved Design", here: >http://www4.ncsu.edu/~doster/NE405/Manuals/BWR6GeneralDescription.pdf > >2. For any large generator, the load has got to roughly match the >generating capacity unless you want to damage or destroy the equipment. >This why generating plants (of all types) trip offline so aggressively when >something goes seriously wrong with the electrical grid. > >The idea of the operators trying to modulate the plant reactivity and also >switch in massive dummy loads to match the plant output, all in the midst >of an accident scenario that may have left the plant in an unknown >condition, seems wildly unrealistic to me. > >Jeff
It is. :) However that's not quite what I had in mind. To start with, it would probably require some physical modifications to the plant, and also changes to automated control. BTW they shouldn't need to switch in massive dummy loads. The sort of things that could be done are: 1) Reduce power output to a minimum by inserting control rods. 2) Dump steam directly from the secondary coolant circuit if needed initially. 3) Restrict steam flow to a single turbine (not necessarily one of the main turbines; this could be a smaller turbine with little more than enough capacity to power the plant). I suspect that similar measures are already taken when a reactor is scrammed anyway. IOW what I have in mind is more like reducing the power output of the plant to a bare minimum rather than a complete scram, with any remaining excess power dumped as heat into the cooling system rather than being converted into electric power. Regards, Robin van Spaandonk http://rvanspaa.freehostia.com/project.html
