Re: stupid question

["Robert I. Eachus" <rieachus@comcast.net>]

Shanon Fernald wrote:
> What programming language do you think would be best to use if you
> were building the software to manage a nuclear power plant and why?
> Which would let you sleep best at night knowing you lived next door to
> the plant?

My first choice would be "none."  There is no need to use software to 
control a nuclear reactor, and the safest nuclear reactors use that 
philosophy.  It is fine to use software to display the state of the 
reactor, calculate fuel burns and refueling patterns, and so on.  (My 
second choice would be SPARK, and it is certainly a reasonable choice 
for the software that controls the rest of the plant.)

For most nuclear reactors the response time to control inputs is 
measured in hours, and there are at most a dozen primary controls.  Yes, 
you can see the reactor begin to respond to control inputs in minutes, 
but the full response, even to a scram, takes hours to days.  A lot of 
people, including me, thought that the zirconium spacers that B&W used 
in the Three Mile Island reactors and a couple of others cut this 
"think" time to around eight minutes from say, four hours.  It did allow 
a few percentage points more of the fuel to be burned, but it didn't 
seem worth the agony relative to the Westinghouse PWR design.

GE reactors are boiling water reactors instead of pressurized water 
reactors.  I won't go into all the differences that makes, but it means 
that the water in the core is a mixture of steam and water when the 
reactor is running.  Since the reactor is designed with a negative void 
coefficient, and the steam is less dense than water, even under the 
reactor operating conditions, they are even more self-regulating.  With 
a BWR, if an operator makes one control change during his shift, it is 
probably to pretend that he has something to do other than to look at 
gages and check logs.

Liquid metal fast breeder reactors (LMFBRs) on the other hand may have 
response times to control inputs in seconds.  And with a positive void 
coefficient if you lose control, that's it.  Right now, the French are 
the only ones I know of who have LMFBRs.  If I lived in France, or even 
downwind, I'd move.

-- 
                                          Robert I. Eachus

"Quality is the Buddha. Quality is scientific reality. Quality is the 
goal of Art. It remains to work these concepts into a practical, 
down-to-earth context, and for this there is nothing more practical or 
down-to-earth than what I have been talking about all along...the repair 
of an old motorcycle."  -- from Zen and the Art of Motorcycle 
Maintenance by Robert Pirsig