From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,873e3ac877e7b6b6 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2003-08-20 13:45:19 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!headwall.stanford.edu!newshub.sdsu.edu!elnk-nf2-pas!newsfeed.earthlink.net!wn14feed!wn13feed!worldnet.att.net!204.127.198.203!attbi_feed3!attbi.com!rwcrnsc54.POSTED!not-for-mail Message-ID: <3F43DDDC.7020802@attbi.com> From: "Robert I. Eachus" User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.0.2) Gecko/20021120 Netscape/7.01 X-Accept-Language: en-us, en MIME-Version: 1.0 Newsgroups: comp.lang.ada Subject: Re: Nuclear Reactors & Blackout References: <3F3E3B4D.5893@mail.ru> <3F3F7342.29A8@mail.ru> Content-Type: text/plain; charset=KOI8-R; format=flowed Content-Transfer-Encoding: 7bit NNTP-Posting-Host: 24.34.139.183 X-Complaints-To: abuse@comcast.net X-Trace: rwcrnsc54 1061412317 24.34.139.183 (Wed, 20 Aug 2003 20:45:17 GMT) NNTP-Posting-Date: Wed, 20 Aug 2003 20:45:17 GMT Organization: Comcast Online Date: Wed, 20 Aug 2003 20:45:18 GMT Xref: archiver1.google.com comp.lang.ada:41743 Date: 2003-08-20T20:45:18+00:00 List-Id: Dmytry Lavrov wrote: > Heh,if net are overloaded,SUPPLIES are diconnected??? > Why not disconnect some towns to save network (as in xUSSR "-)?? > What's , USA network are so simple and based on plants connected in > parallel ,works as one plant,and towns in parallel,works as one > consumer? If so,it's simply idiotism. > > There is so simple to make non-buggy (by overloading) network: > let's each supply provides energy for nearest towns(let's call it > "sector"),and maximal power of towns = power of supply.When supply > aren't 100% used,some energy are transmitted to other regions.If supply > are overloaded by local towns,it's only consumes energy from another > plants.There are buffers between sectors that newer overlod plants,only > transmits as many energy as sector aren't uses. And if one sector are > overloaded,when it's overloaded more than can get from another > sectors,some non-critical pards of the sector are disconnected,and other > sectors aren't overloaded. In Russia,there are as many short circuits a > year,and we should have blackouts every week if network work same way as > in USA. I hate to say it, but simple, straightforward, and unworkable. The problem is best described as the distributed properties of the network. All of the interactions between generating stations and power consumers occur at transmission line speeds. (Which are significantly slower that the speed of light in a vacuum, but not enough to help. Call it 1/2 to 3/4 c depending on the type of line.) When you detect an overload at a generator, even if you could break a circut and shed some local load, the overload "in the pipe" of the transmission line may be enough to burn out the generator. Of course, if you have studied, or worked with, high voltage power transmission, you know that breaking the circut and making it stick is a non-trivial operation. In the 1965 blackout, NYC was drawing 3 Gigawatts from the TVA. This was being distributed over the PJM interconnect, but they needed to be able to break the circut if something like this happens. Imagine a twenty foot high circular tank about 4 feet in diameter filled with oil and with baffles and a blowout panel on top. (The baffles are designed to catch as much oil as possible while letting the gasses and plasma out.) Through this tank bottom to top pass four 1/2" by 3" copper bars arranged in a square. Fill the tank with oil, and suspend a 1/2 pound block of C4 in the center of the hollow square, about 5 feet from the bottom. That is your basic 1 Gigawatt breaker. (Actually rated at 5,000 amps load at 330 KV.) There were three of these sitting near the border between Pennsylvania and New York State. One of the power engineering magazines had a picture of one being tested, and about a year later, a picture of the actual devices firing. (No big trick, they had a TV camera showing these breakers in the PJM interconnect control room, and a movie camera triggered when the arming circut blew the breakers.) I may have told this story before, but I lost a bet with my father over the day the blackout would happen, my brother was in the pool as well, but we had all picked days that week over a month before. I won't go into all of the details, but ConEd had two big nuclear plants down for refueling, a judge had some coal fired plants owned by the Transit Authority shut down for pollution reasons, and it was the week after daylight savings ended. So think of the power from Naigra Falls flowing through transmission lines to NYC as an express train. Throwing any breaker along the way converts it into a runaway train that is going to destroy whatever it dead-ends into. You have to have something to sacrifice at the end of the line, and deadending into houses or most commercial loads is going to cause disasters. You have to have some breakers like the ones I described above that can take the load and terminate it. The arcing lasted for milliseconds, and the total energy quenched was over 100 times the explosive energy of the C4. PJM shed load at Conowingo and elsewhere until the TVA could back off what they were delivering, and so there were no major power failures south of Trenton, NJ. The instantaneous demand from New York when those breakers went was 3 million amps. (Yes, that is an instantaneous demand equivalent to several hundred nuclear power plants. The problem as I said was that the Lake Erie Loop can become an amplifier. The pulse that flowed down the line became a peak followed by a trough that reversed voltage.) As long as you refuse to run interconnects in or near amplifying states, the normal procedures are fine. But once you have an actively amplifying network you are up the creek. Right now they are looking at three transmission lines in Ohio that shut down a couple of hours before the main event as the trigger. My bet is that they will find that those failures set the stage, and the next sneeze, even bringing one of those lines back into operation, caused the actual event. The Lake Erie Loop mentioned above consists of transmission lines both above and below Lake Erie, and yes, they do form a loop. The direction of power transmission in this loop reversed just before the blackout... -- Robert I. Eachus "As far as I'm concerned, war always means failure." -- Jacques Chirac, President of France "As far as France is concerned, you're right." -- Rush Limbaugh