Re: Nuclear Reactors & Blackout

["John R. Strohm" <strohm@airmail.net>]

"Alexander Kopilovitch" <aek@vib.usr.pu.ru> wrote in message
news:e2e5731a.0308151726.371b895f@posting.google.com...
> Robert C. Leif wrote:
>
> > According to the US press, the reactors in New York State and other
areas
> > had to be shut down because there was a risk of an incident if the
auxiliary
> > power from the rest of the grid was lost.
>
> Well, not exacly shut down, but nuclear plants should be detached from the
> damaged part of the power network as quickly as possible. Not because of
lack
> of auxiliary power, but because jumps of the power are very dangerous for
this
> type of electrical plants. So, it was proper and actually necessary action
in
> this situation.
>
> > This approach to hazard analysis should be named Fail-For-Sure.
>
> Well, this was not "hazard analysis", it was mandatory emergency action.
> I think that that you statement is not just ignorant, but also arrogant.
> If I were a terrorist I would dream you become director of a nuclear
plant.
> You may be good inventor and good scientist, but remember, that Chernobyl
> story began when scientist (physist, but without significant experience
> with real working nuclear plants) was assigned to a commanding position.
> He invented his owm method and procedure for testing. The result of that
> testing immediately became (in)famous worldwide.

Alexander, with all due respect, this is an oversimplification.

Part of the problem is that the people who designed the Chernobyl reactor
had absolutely impeccable Party credentials, but did not know beans about
reactor safety.  They designed a reactor with a positive void coefficient of
reactivity, which creates a built-in thermal runaway hazard, and thermal
runaway is EXACTLY what happened at Chernobyl.

The Chernobyl design is illegal in the United States of America, for damned
good reason.  Ed Teller, who wrote the law, figured that life would be
simpler for everyone if reactors were simply not capable of thermal runaway
at all.  So all U.S. reactors are required to be designed with a negative
void coefficient of reactivity.

The U.S. has yet to experience anything even remotely resembling a Chernobyl
accident.

If you want more information, do a search on "void coefficent".  Here are a
couple of starters:
http://www.nrc.gov/reading-rm/basic-ref/glossary/void-coefficient-of-reactiv
ity.html
http://www.world-nuclear.org/info/chernobyl/voidcoef.htm