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 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. ----------------------------------------------------------------- gopher://quux.org/ conversion by John Goerzen of http://communication.ucsd.edu/A-News/ This Usenet Oldnews Archive article may be copied and distributed freely, provided: 1. There is no money collected for the text(s) of the articles. 2. The following notice remains appended to each copy: The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996 Bruce Jones, Henry Spencer, David Wiseman.