Re: Nuclear Reactors & Blackout

["Robert I. Eachus" <rieachus@attbi.com>]

Wes Groleau wrote:
> 

> Each section should disconnect from the grid
> if the grid threatens to demand from them
> more power than they can provide safely.  If they
> are a net consumer, and the grid stops providing,
> they must shut down if their local demand would
> exceed capacity dangerously.

No that worked, and the grid fractured into multiple parts.  I was just 
looking at a map of the pieces. (Whoops! Actually for the 1965 blackout: 
http://www.cmpco.com/about/system/blackout.html) Once that happened, as 
you point out, areas that were net consumers of electricity--at the 
moment when it happened were SOL.  This probably did not apply to the 
PJD interconnect (Pennsylvania, New Jersey, and Maryland) because they 
tend to keep most of Conowingo Dam on-line idling to deal with peaking 
problems.  There are probably other regional interconnects that do the 
same.  Conowingo only generates 512 Megawatts, but its generators are 
significantly overbuilt by modern standards and can handle a short 
overload in the multi-gigawatt range.  It had to in the 1965 blackout. 
Before the surges in the interconnects south of New York were balanced 
out, Conowingo exceeded three gigawatts out AND two gigawatts in, but 
each of those peaks was on the order of three or four cycles (1/15th to 
1/20th of a second).

Here is a half decent story on what happened. 
http://www.washingtonpost.com/ac2/wp-dyn/A63438-2003Aug15?language=printer 
  The current thinking is that the trigger was a plant in Michigan.  But 
the important point is that the Lake Erie loop can act as an amplifier 
for transients when heavily loaded.  (Power normally flows east both 
north and south of the lake.  But transients cause phase shifts, and if 
the shifts north and south of the lake are out of synchronization, a lot 
of power flows in a circle.  During the blackout, it flowed first one 
way, then reversed direction...



-- 
"As far as I'm concerned, war always means failure." -- Jacques Chirac, 
President of France
"As far as France is concerned, you're right." -- Rush Limbaugh