On Tue, 9 Oct 2007 13:00:58 -0400, "Ed Huntress"
wrote:


"Brian Lawson" wrote in message
.. .
On Tue, 9 Oct 2007 06:17:32 -0700, "azotic" wrote:

An interesting russian concept. Solves the problem of NIMBY, out of sight
out of mind.
No CO2 emmisions to boot. I wonder if these could be built and stored
unfueled for
use in an emergency, say fuel became unavailable for conventional land
based
power
stations we could simpley fuel the reactors and start generating power
fairly quickley
until another fuel supplier could provide fuel for the conventional land
based plants.

http://www.upi.com/Energy/Briefing/2...nuclear_plant/


Best Regards
Tom.

Hey Tom,

I can't say I follow exactly your equation, but here in Ontario we
are in a race (apparently!!) to close the coal-fired power generation
plants we have. This has become a hot political football, what with
the Ontario Provincial election coming tomorrow.
In any event, about your comment....Saturday I was at a fall fair a
few miles from where we live, and near the fair there is one of the
larger of the coal-fired plants that is under "attack". They had an
information booth set up at the fair, mostly handing out literature
about what a large scale employer they are, and the effect of loss of
those jobs on closure of the plant; about how they are not as bad a
polluter as they are ascribed to be, as they have some very late
technology scrubbing equipment in place already and are willing to do
more; and most important of all, the need for rapid and multitudinous
changes of power required over the course of any 24 hour period
(sometimes as high as 1500 change-orders per shift) and which nuclear
plants at present are not able to modulate. This last item is what
I'm writing about.

Nuclear power generation in land-based large plants is set to a "base
level" of possible production. Nominally, this seems to me to be
about 80%. In other words, a nuclear plant is ramped up from 0% to
80% over some period of many hours, if not of days, to this 80% level,
and then continues to produce that much power (80% of its full
capacity) regardless of the power usage requirement it is delivering
to !! The load variation of off-peak to full-peak times is presently
handled by the coal or gas fired plants. These plants are capable of
rapid changes and of short term rapid dissipation of excess (steam)
which the nuclear plants are not. Until the time when a viable method
of either controlling the nuclear output or delivering excesses of it
to either storage or conversion is standardized, the coal-fired plants
are required.

What the coal guy may not have explained is that the cost of fuel for nukes
is around 2% of their operating cost, so it's no hardship to run them at
high capacity all the time.


Hey again Ed,

You are correct, in that "costs" never came up in my chat with the
guy. At all !! I have heard someplace that it is scary to compare
the cost of establishing a nuclear plant to the cost of establishing a
coal fired plant, even when the same manufacturing companies do both
(Babcock-Wilcox et al).

But neither is your statement inclusive of all the points here. My
point, or rather their point, (and hence my previous reply/question to
the OP) is that the fuel "burning" plants have a great and fast
flexibility, and the "nuclear" plants do not. Can one of these
Russian inventions really BE used? The nuclear plants WILL produce at
a relatively "fixed" rate, whether it is required or NOT (at least in
short time terms). Hence, SCRAMing when that output consumption can
not meet production on an instantaneous distribution or use basis.

In the pro/con debates going on here in Ontario, and I assume across
Canada, one of the research thoughts being pursued would be for any
instantaneous excess nuclear generation be used to immediately produce
hydrogen, which can be stored and used at later time, thereby
consuming the over-production and nullifying the present problem with
this inflexible production (which is PART of what the coal-fired
plants do now). Whether the hydrogen produced would be used in motor
vehicles or other transportation, or even to replace the coal in
thermal plants with a "cleaner" fire, was not discussed. But it is a
starting point.

Personally, I hope that maybe you and I, or at least our children,
will see the day when nuclear will produce electricity in quantity
without steam as intermediary.

Take care.

Brian Lawson