Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site ssc-vax.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxl!houxm!hogpc!houti!ariel!vax135!cornell!uw-beaver!ssc-vax!alcmist From: alcmist@ssc-vax.UUCP Newsgroups: net.followup Subject: Re: more on alternate energy sources (fusion) Message-ID: <59@ssc-vax.UUCP> Date: Mon, 20-Aug-84 15:56:40 EDT Article-I.D.: ssc-vax.59 Posted: Mon Aug 20 15:56:40 1984 Date-Received: Tue, 21-Aug-84 07:13:07 EDT References: <9681@gatech.UUCP> Organization: Boeing Aerospace, Seattle Lines: 52The subject is drawbacks of fusion power, specifically damage to reactor walls from high-energy neutrons. > From: dmcnh!gts@sii > Return-Path: > Date: Fri, 10 Aug 84 12:20:17 edt > Subject: Re: alternate, hopefully safe, energy sources (fusion) > References: <806@ihuxx.UUCP>, <9520@gatech.UUCP> > > I thought that liquid lithium would flow along the inside of the walls > of the fusion containment chamber. Not only does this absorb the neutrons > to prevent damage to the solid permanent walls, but in so doing, captures > the heat of the reaction and can be used as a heat transfer medium. The answer depends on the type of fusion reactor. They come in two flavors. A fusion reactor can hold its fuel in a more-or-less steady magnetic bottle, which is called magnetic confinement, or it can hit a pellet of fuel with high-energy lasers and hope a lot of energy is released before the pellet flies apart. That's called inertial confinement. In either kind of reactor, the main reason for having lithium is to breed more fusion fuel. When lithium is struck by neutrons from a fusion reaction, it turns into tritium, which can be used in the fusion reaction. (Tritium is an isotope of hydrogen ...) A magnetic-confinement reactor has to work in a vacuum, otherwise junk gets into the plasma and screws things up. Lithium inside the reaction chamber would evaporate and contaminate the plasma. In a magnetic-confinement reactor, the lithium would flow *outside* the wall of the reactor. An inertial-confinement reactor doesn't have the problem of needing a superclean vacuum. It could use jets of liquid lithium to absorb neutrons, breed fuel, transfer heat, and even absorb some of the shock from the explosions of fuel pellets. By the way, you really don't need tritium for a fusion reaction. It's just that the fusion between deuterium (naturally occurring and edible) and tritium (man-made and radioactive) is the easiest to start. Second generation fusion plants would probably use a reaction that throws off charged particles instead of neutrons. Doing so is a lot harder but would allow direct conversion to electricity. (There would also be less radioactive material to handle). Fred Wamsley -- UUCP:{ihnp4,tektronix}!uw-beaver!ssc-vax!alcmist ARPA:ssc-vax!alcmist@uw-beaver I am not speaking as a representative of the Boeing Company or any of its divisions. Opinions expressed are solely my own (if that) and have nothing to do with company policy or with the opinions of my coworkers, or those of the staff of the Software Support Center VAX.