Re: Nuclear Reactors & Blackout

[Ludovic Brenta <ludovic.brenta@insalien.org>]

According to the press here in Europe, it is perfectly possible that a
similar blackout, of similar magnitude, occur here.  The cause is not
related to software (i.e. a blackout could occur even with 100%
perfect software).  A blackout would be the result of a number of
factors.

1) Electricity cannot be stored (d'oh!) and therefore, there are
   dispatchers that are on watch 24 hours a day to match supply and
   demand.  These dispatchers are usually country-wide.  Their job is
   to ensure that the production of power is exactly balanced by the
   consumption, and that all electricity produced is properly carried
   over the grid.

2) The high-voltage lines in the grid have limited capacity; they
   overheat if too many ampers go through them (d'oh!). There are
   "fuses" that protect these lines against overheating.

3) All power stations in Europe are interconnected; they are all on
   the same high-voltage grid.  This is done so that if one power
   station fails for one reason or another, other power stations can
   supply more power to make up for it.  One third of Europe's power
   is from nuclear plants, but that's irrelevant.

Thus, if there is a big surge in demand for electricity, some lines in
the grid will shut themselves off in order not to melt down (I mean
the *lines*, not the *power plants*).  The other lines in the grid
will then have to carry the extra power.  They, in turn, run an
increased risk of exceeding their nominal capacity, and may also shut
themselves down.

It would appear that the blackouts in the US were caused by such a
surge in demand (hint: air conditioning devices throughout the US
account for 30% of all electric power consumption).  This was combined
with the fact that the demand in electric power has increased by 30%
in the last 10 years.  And this was further combined with the fact
that very little investment has been made, over the last 10 years, to
increase either the supply capacity of power plants, or the bandwidth
of the grid.  Basically, it's like a giant fuse went off because of
too much demand on the whole system.

I've heard that one power plant went off-line, and that that started
the whole process of quickly overloading the lines from all other
power plants.  Given the situation, I don't think that this is very
important.  I think other blackouts could, indeed *will* happen,
whether or not a power plant goes offline in the future.  It may very
well happen that one day there is just too much demand and too little
supply.  This has happened before in California, albeit to a lesser
scale.

-- 
Ludovic Brenta.