Aucbvax.1447
fa.energy
utzoo!duke!decvax!ucbvax!RWK@MIT-MC
Fri May 29 21:23:57 1981
Energy Digest
Black & White/More than two sides
Direct mail reply
Energy as a digest
Clipping Service - Nuclear Industry Series, part 5
----------------------------------------------------------------------
Date: 29 May 1981 10:30:12-EDT
From: cjh at CCA-UNIX (Chip Hitchcock)
To: energy at mit-mc
Subject: Re: black & white
Cc: cjh at CCA-UNIX
That's just not so; the problem is that, as in any debate nowadays,
the ones who shout the loudest are the ones who are heard the most, and
in a case where emotions run as high as they do in the nuclear debate
(and don't tell me emotions aren't involved in an argument between
ever more power and the preservation of Mother Earth) the ones with the
most assured opinions shout the loudest. The worst offender in such
selective hearing is of course the press (although there are many others);
too many reporters (and others) are looking for a quick, vigorous,
ready-made opinion---reporters don't have/take time to extract useful
information from balance or waffling, and the people who just want to
believe \\something// are only interested in making an absolute choice.
(In this they are frequently supported by traditional authorities.
Do any of you recall the hymn with which King opened THE STAND:
"Once to every man and nation comes the moment to decide
In the strife of truth and falsehood for the good or evil side.
Then it is the brave man chooses while the coward stands aside
And the choice goes by forever, 'twixt the darkness and the light."
And this is from the Episcopalian church, not the Catholic or any of the
austere sects. Authorities of any stripe don't \\like// having their subjects
think.)
------------------------------
RMS@MIT-AI 05/29/81 18:23:07 Re: More than two sides
To: energy at MIT-MC
I agree with Vaughan. This phenomenon, of people joining one of
two sides neither of which is right, seems to occur in every major
public issue. It happens, for example, on issues of strategic weapons.
The structure of the phenomenon is that each side proposes a plan
of action, which is flawed, and each side presents valid criticisms
of the other side's plan; then each side persistently restates its
criticisms while never acknowledging the criticisms directed against it,
much less trying to disprove them.
This may have a connection with the two-party system.
------------------------------
Date: 29-May-81 16:41:00 PDT (Friday)
From: Hamilton.ES at PARC-MAXC
Subject: Re: direct mail reply
To: Energy@MC
cc: Hamilton.ES
As of a couple of weeks ago, CSVAX.Upstill@Berkeley had (it was either in Human-nets or SF-Lovers) offered to act as a gateway between Arpanet and that university net with all the "!"s.
--Bruce
------------------------------
Date: 25 May 1981 23:27-EDT
From: Robert Elton Maas <REM MIT-MC AT>
Subject: Clipping Service - Nuclear Industry Series, part 4
To: Schauble.Multics at MIT-MULTICS
cc: ENERGY at MIT-MC
I'd like to see the size of a nuclear power plant broken down to a per capita
basis, that is divide the size of the plant by the number of people whose
residential electrical needs could be supplied 100% by it if no industrial
users tapped into it. Then its size can be fairly compared to the size
of do-it-yourself things like windmills and on-roof-solar-collectors and
methanol breweries. Let's see, I'll make a crude estimate...
1200 megawatts, each person like me uses about one kilowatt, thus the
plant serves 1,200,000 people. It uses 2/3 of a million cubic feet of
concrete, that's about half a cubic foot per person served. I'd like
to see anybody keep a windmill from blowing down in a breeze unless
there's at least one cubic foot of concrete or other material sunk into
the ground to fasten the support cables to (not to mention the materials
used to actually build the windmill).
Anybody want to do a more complete per capita analysis of the nuke?
------------------------------
Date: 27 May 1981 03:00 edt
From: Schauble.Multics at MIT-Multics
Subject: Energy as a digest
To: energy at MIT-AI
Last October, Roger Duffey contributed a summary of the requirements
for a mailing list to be turned into a successful digest. I am
reproducing extracts of that message here.
--------------------
SHOULD ENERGY@MC BECOME ENERGY DIGEST?
I do not recommend changing an immediate redistribution list into a
digest list unless the mail servers are having difficulty in handling
the volume of mail through the list or the following three criteria
are met:
First, the list should cover a fairly broad area which encompasses
many different discussions of general interest.
Second, the list should have a relatively constant volume of mail
flowing through it. A weekday average of 4-6K chars per day
appears to be a good threshold for the current environment.
Third, several different topics are in contention over the list.
The present volume of mail and the current number of subscribers do
not pose an insurmountable problem for the mail servers. At present
MC handles the bulk of the redistribution load. I recommend sharing
the load between AI, MC, and ML. That should eliminate any current
problems and also leave some margin for growth as well.
The three criteria are designed to determine whether the discussions
will be self sustaining as a digest list. The first condition is met.
ENERGY has a vast array of issues that it might discuss fruitfully.
However, the second and third conditions are not met.
I do not see a compelling reason to turn ENERGY into a digest list at
this time. If you choose to go ahead I think that somebody is going
to be taking on a great deal of work without real need. I also suspect
that you would have a more difficult time starting and sustaining
discussions with the digest form given the current composition of the
list.
--------------------
When this was written, ENERGY was producing a half dozen or so
messages per day. It still failed to meet the volume criteria. The
traffic recently has been even lower. We have gone several times for
a week without any traffic. Roger's comments about the difficulty of
starting and sustaining a discussion in digest format have proved
remarkably accurate.
I think we should go back to immediate distribution until the
volume grows to meet the Duffey criteria.
Paul
------------------------------
Date: 27 May 1981 03:00 edt
From: Schauble.Multics at MIT-Multics
Subject: Clipping Service - Nuclear Industry Series, part 5
To: energy at MIT-AI
This is the fifth in a many part transcription of a Phoenix Gazette
series on Three Mile Island and the nuclear industry. All material is
by Andrew Zipser, Gazette reporter.
This section is an elementary explaination of the operation of a
nuclear fission reactor. If you are familiar with the general
principles, you will lose little by not reading this.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Where does the energy come from?
If the nuclear industry has suffered a lot of ups and downs, it
has, nevertheless, made considerable gains.
Today there are 72 reactors operating in the United States, some
with a capacity as small as 60,000 kilowatts, some more than 100
times larger. Together they produce approximately 11 percent of all
the electricity we consume -- 270.7 billion kilowatt hours in 1979
alone, or almost a third of all world nuclear production.
In some states the percentage is much higher. Almost 80 percent
of Vermont's electricity, for instance, comes from the fissioned
atom. In eight other states more than 30 percent of all electricity
is generated by nuclear reactors.
Elsewhere in the world, nuclear plants have also proliferated.
More than 100 reactors were in operation in 1979 in the non-Communist
countries. Great Britain, for instance, had 33, Japan 20, France 15,
West Germany 10. About 150 reactors are believed to be in various
stages of construction.
All that nuclear power adds up to a lot of energy that was barely
imagined 30 years ago. Where does it come from? How is it harnessed?
Despite its technological complexity, the method by which the
world turns a piece of matter into energy is relatively easy to
explain. The nuclear reactor is in one sense like any coal or oil
fired power plant: it produces heat, which boils water, which
produces steam, which turns a turbine. The big difference is the
manner in which the heat is generated.
Nuclear reactors are fueled by the splitting of uranium atoms.
Uranium, like other radioactive elements, emits tiny particles called
neutrons. When a neutron strikes another uranium atom it causes still
more neutrons to fly off -- and those neutrons strike still other
uranium atoms, etc. This is known as a chain reaction, and a chain
reaction produces heat -- lots of it, in fact.
How much heat? One way to measure it is in terms of BTU's, with
one BTU roughly equivalent to the energy released by burning a wooden
match. Burning a ton of coal will release 22 million BTU's, burning a
cord of hardwood will release 20 million btu's, and burning a barrel
of oil will release approximately 5.5 million BTU's.
One gram of fissionable U-235, however, will release 74 million
BTU's.
Uranium found in the ground is of two varieties, or isotopes,
called U-235 and U-238. U-235 is the kind that is useful in chain
reactions, but its natural concentration is so limited that the atoms
normally get little chance to interact with each other. So, when it
is made into fuel for a nuclear reactor the concentration of U-235 is
enriched, to about 3 percent. An atom bomb, which works in a similar
way but on a much grander scale, requires still greater
concentrations -- over 90 percent -- before it can explode.
Because the concentration of fuel isn't high enough, a nuclear
reactor can't explode in the same way an atom bomb can. The fuel can,
however, get so hot it would melt any container that can be devised
to hold it.
This problem is met in two ways. One is through the use of
control rods made of boron. Boron has an appetite for neutrons,
soaking them up in much the same way as a sponge soaks up water. So,
if a lot of boron is placed in and around the uranium, all the
neutrons thrown off by the fuel are absorbed and the chain reaction
is stopped.
But even stopping the chain reaction won't stop the heat. As
uranium fissions it changes into other elements that are still
radioactive, and those elements give off heat long after the uranium
is all gone. The way nuclear plants get rid of all this excess heat
is to flood the reactor with water, which cools it off.
How are these components -- uranium, boron, and water --
assembled in a nuclear plant? The uranium is manufactured into tiny
pellets, approximately half an inch in length, which are then
inserted into rods about 12 feet long. The fuel rods are then placed
in an arrangement that leaves room for the control rods to slip
between them.
When a plant is running at full capacity, the control rods are
pulled out almost all the way; when it has to be "throttled back",
the control rods are lowered part way. Lowering the control rods all
the way stops the chain reaction.
At a nuclear plant the size of those at Palo Verde, each reactor
has more than 36,000 fuel rods, containing about 130 tons of fuel,
arranged in what are called fuel assemblies. The fuel assemblies are
in a reactor vessel, a 500 ton steel container with walls 6 inches
thick.
Each of the reactor vessels at Pale Verde will be housed in a
domed structure called a containment building. The containment
buildings are the tallest structures at Palo Verde and are built of
steel and concrete walls up to 10 feet thick. This thickness is a
safety measure: containment buildings are designed to withstand a
direct crash of a Boeing 707. They are also supposed to contain a
steam explosion inside the building, which could happen if the
reactor overheated and the fuel melted.
From this point on the rest of a nuclear generating plant is
almost conventional in arrangement. In a plant like Palo Verde and at
Three Mile Island, the water flowing around the fuel rods is in a
closed pressurized loop. When it has been heated to about 620 degrees
it flows to one of two steam generators, where it transfers most of
that heat to a second closed loop. The second loop is not
pressurized, so its water turns to steam and is then pushed through a
turbine that turns a generator.
One final note deserves mention. The most prominent features of
the Three Mile Island units are the tall, concave cooling towers.
Don't look for them at Palo Verde. Here, because of the higher
ambient temperatures, the cooling towers are build on a different
principle and are much smaller.
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