tlijy@cc.curtin.edu.au (05/07/91)
From: tlijy@cc.curtin.edu.au Please bear with my poor knowledge. I am wondering if some one can tell me how a nuke is tested underground? Is there any negative impact to the earth crust stability underneath? -- Jason Y. Li Satellite & Remote Sensing Res. Group |1) PSImail: psi%050529452300070::TLIJY Dept. of Applied Physics __________|2) Internet: TLIJY@cc.curtin.edu.au Curtin Univ. of Tech. |3) Bitnet: TLIJY%cc.curtin.edu.au@cunyvm.bitnet Perth, West. Australia |4) UUCP : uunet!munnari.oz!cc.curtin.edu.au!TLIJY
patterso@ADS.COM (Tim J. Patterson) (05/08/91)
From: patterso@ADS.COM (Tim J. Patterson) >Please bear with my poor knowledge. I am wondering if some one can tell me >how a nuke is tested underground? Is there any negative impact to the >earth crust stability underneath? There was an IEEE spectrum article on this topic about 3 years ago. The discussion was in the context of testing and treaty verification. A reasonable overview for those of us who aren't really in the know on this topic. Tim
jfs@beno.CSS.GOV (Jim Scheimer) (05/09/91)
From: jfs@beno.CSS.GOV (Jim Scheimer) Underground Nuclear Testing - Geologic Effects The question asked is unclear. If the question is whether there is some widespread effect on seismic risk due to underground tests or if such tests can trigger earthquakes at large distances (say, more than a few tens of km.) , the short form answer is simply NO. However, (isn't there always an however?) when a test is conducted in a region where there are pre-existing faults, the shock from the test can trigger what is known as local tectonic strain release. This is not a problem from an environmental sense, but it does add some more energy to the seismic wave radiating from the vicinity of the test and can add uncertainties to estimates of the yield of the test based on seismic measurements. Tectonic strain release has been observed for both U.S. and Soviet underground tests. French tests are conducted on an atoll which is not, apparently, heavily faulted. Also, the nominal equivalent of the largest test allowed (150 kiloton yield) is an earthquake of magnitude between 5.5 and 6.5. this means you don't want it to be set off under you town, but it's no big shakes if it goes off 30 or so km from you. (Sorry, I couldn't help the awful pun.) Testing Procedures If the question is about procedures, we basically drill a large diameter hole (about 2.5m to 3.5m in diameter) to a depth of several hundred meters. The larger the expected yield, the deeper you bury it. The depth also depends on material properties (e.g. rock types, strengths, etc.). The test canister is lowered in the hole with a plethora of cables coming to the surface for diagnostics. The hole is then filled with some of the original material removed during drilling and a special epoxy grout is used for the last several 10's of meters. The actual design of the emplacement and amount and type of grout is the responsibility of the containment program at each weapons lab. The bottom line is that we don't want to allow any "venting" of radioactive material into the air. Jim Scheimer, S-Cubed, Reston, Virginia. My opinions only, don't hold anyone else responsible.
deichman@cod.nosc.mil (Shane D. Deichman) (05/09/91)
From: deichman@cod.nosc.mil (Shane D. Deichman) In article <1991May8.034438.11095@amd.com> tlijy@cc.curtin.edu.au writes: >[H]ow a nuke is tested underground? O.K., let me blow some cobwebs from my memory... The United States conducts all of its nuclear testing at the Nevada Test Site, located in the southern portion of the state. All tests are done underground due to reasons which are inappropriate for this newsgroup (gotcha, Carl! :-). [Hee hee --CDR] The basic process involves drilling a hole into the ground (depths are classified) big enough to fit the "physics package" into. Then concrete is poured into the hole (with experimental equipment such as "collapsizers" which can determine the rate of expansion of the shock wave) to seal it off. Usually, there is another hole drilled within a mile or so for other experimental equipment. The data shack is located near this other hole. The detonation itself doesn't really affect the earth's crust (remember that the continents rest on plates separated by faults, which make great energy dissipators). Of course, Las Vegas feels it pretty strongly when a big test goes off (around 150 kt, the limit imposed by the threshold test ban treaty). Also, since the surrounding dirt/rock/etc. is being compressed by the effect of the detonation, it creates a cavity which sometimes collapses upon itself. This results in the large sinkholes you may have seen on the news, making a pockmarked landscape. The Soviets used to do most of their testing at the Semipalatinsk site in Soviet Central Asia -- until the local residents, spooked by the outcome of Chernobyl and related nuclear hysteria, made enough noise to cause the Strategic Rocket Forces (the guys with jurisdiction over all Red Nukes) to move their operation to Novaya Zemlya, an island in the easternmost portion of the Barents Sea. I believe they use a similar method to the Americans, but it's really not my department.... -shane [Oh no! You used the T word!! :-) --CDR]
brian@uunet.UU.NET (Brian Douglass) (05/10/91)
From: edat!brian@uunet.UU.NET (Brian Douglass) tlijy@cc.curtin.edu.au writes: >Please bear with my poor knowledge. I am wondering if some one can tell me >how a nuke is tested underground? Is there any negative impact to the >earth crust stability underneath? A hole is drilled to 1500+ foot range upon which various siesmic test are run. Called Well Logging in the oil business. These tests detect faults lines, soil composition, water content, etc. The hole is concreted and eventually a bomb is placed at the bottom. An instrument package is placed on top of this (up to 6 stories tall) with realtime recording handled at the surface. There can easily but 500+ channels of data coming out of the package back to recorders on the surface. Those are the trailers you see in the distance on the surface of ground zero. The hole is sealed with concrete and when everything is right, the bomb is set off. A typical blast will generate a localized earthquake usually less that a 4 on the Richter Scale. People in high buildings are typically warned in advance on high yield tests. There has been well over 200 underground tests, most being operational tests of tactical and strategic warheads. In fact, a year or two a technician found a design flaw, it was confirmed by an actual test, and a recall was issued. As far as crust instability, nah. A caldier (large crater) usually sets in some time after the blast as the earth column above the vaporized blast area collapses inward, but that is actually designed into the test to happen correctly and is called containment science. The only real long term effect is the irradiation of the ground water table. A tremendous about of tritium and yritium (?) is generated. However, these tables flow at about 6 feet per year and the Nevada Test Site is ringed with monitor wells. The last estimates I saw were 22,000 years for such contaminated water to reach the Las Vegas water supply. Hope that answers your question. Brian Douglass Voice: 702-361-1510 X311 Electronic Data Technologies FAX #: 702-361-2545 1085 Palms Airport Drive brian@edat.uucp Las Vegas, NV 89119-3715
eugene@amelia.nas.nasa.gov (Eugene N. Miya) (05/10/91)
From: eugene@amelia.nas.nasa.gov (Eugene N. Miya)
Well if two with some knowledge can post and not get in trouble....
To add to what has been posted.
There are two kinds of tests performed underground. The first are
refered as "Device tests." Designed to test principles or fission and
fusion. These make up may 80-85% of US tests. The second remaining
are "effects tests." Here the research is in what happens when
something is hit by fusion/fission products. Very large horizontal
tunnels are dug with a relatively narrow vaccuum tube into an
experimental chamber where things are placed to expose them to the
nuclear environment prior to large-scale physical blast products,
shock-waves, etc. Special heavy doors closed using conventional
explosives go off (many doors) and cut off the shock.
The engineering occurs on an impressive scale. An officemate designed
several devices tested at NTS and and old division chief also has
unclassified stories. Another friend spoke of an NTS tour (lots of
radiation signs and many miles of thick copper wire).
Testing yield is an interesting exercise. It was an initial surprise
to me when I first moved to the Bay Area that LLNL had an extensive
geophysics program. The other two people covered the basic geophysics.
Some settling and product release does happen on occasion.
Planning is also interesting, making effect use of the 3-D space around
the device is challenging.
Besides the Spectrum article. Numerous books exist which show configurations
of how tunnels are dug, what device canisters look like (The Norris
Bradbury museum at LANL is interesting). The AB Museum at Kirtland AFB is
also open and interesting. Devices can be very small.
--eugene miya, NASA Ames Research Center, eugene@orville.nas.nasa.gov
NASA has nothing to do with nuclear weapons (directly)
we just review some of their "requirements"
Resident Cynic, Rock of Ages Home for Retired Hackers
{uunet,mailrus,other gateways}!ames!eugene
Let's see what waves this creates.Bruce_Dunn@mindlink.bc.ca (Bruce Dunn) (05/10/91)
From: Bruce_Dunn@mindlink.bc.ca (Bruce Dunn) There is a museum at Kirkland AFB in Albuquerque which deals with nuclear weapons. One display indicates that in some cases, horizontal tunnels are dug from the weapon, with instrument packages at the end of the tunnels. Between the instrument packages and the weapon are heavy steel shutters which are open at the time of ignition. After the instruments have had a look at the radiation from the blast, the steel shutters are driven shut in fractions of a millisecond by explosive charges. Amazingly, it seems that this can be done fast enough to protect the instruments from the blast wave. The instruments can be recovered, as could material samples. This type of research has obvious applicability to SDI, where outer space explosions would mainly destroy things by radiation at all wavelengths. I believe also that this type of testing is being used to develop the famous SDI nuclear-pumped X-ray laser. -- Bruce Dunn Vancouver, Canada Bruce_Dunn@mindlink.bc.ca
prentice%triton.unm.edu@ariel.unm.edu (John Prentice) (05/11/91)
From: prentice%triton.unm.edu@ariel.unm.edu (John Prentice) jfs@beno.CSS.GOV (Jim Scheimer) writes: > However, (isn't there always an however?) when a test is >conducted in a region where there are pre-existing faults, the shock >from the test can trigger what is known as local tectonic strain >release. This is not a problem from an environmental sense... I seem to recall that there are some concerns that the French tests are doing serious harm to the structure of some South Pacific islands however. I don't remember the details, but it was something like destroying the intregity of the coral that many of these islands are built up on (?) . There has been a lot written about this in the Bulletin of the Atomic Scientists over the last few years. Anyone know what the concerns actually are? [This now leaves the realm of sci.military; all replies via e-mail to the author, please. --CDR] -- John K. Prentice john@unmfys.unm.edu (Internet) Dept. of Physics and Astronomy, University of New Mexico, Albuquerque, NM, USA Computational Physics Group, Amparo Corporation, Albuquerque, NM, USA
prentice%triton.unm.edu@ariel.unm.edu (John Prentice) (05/11/91)
From: prentice%triton.unm.edu@ariel.unm.edu (John Prentice) deichman@cod.nosc.mil (Shane D. Deichman) writes: > ... The basic process involves >drilling a hole into the ground (depths are classified) big enough to >fit the "physics package" into. Then concrete is poured into the hole >(with experimental equipment such as "collapsizers" which can determine >the rate of expansion of the shock wave) to seal it off. There are also tests done by drilling horizontally into a mountain. These are very expensive tests and the purpose is usually to look at the effects of radiation on military systems (RV's, electronics, etc...). The tunnels drilled for these types of tests are truly amazing. Very large diameter and they do a good job building them. The chamber containing the device will have pipes running out of it which are used to give the radiation a pathway while still allowing some containment. They also help shield experiments from each other and some are there just to bring out cables. Doing experiments in these types of tests can be a bit of trial because of the radiation environment. I have had more than one experiment ruined because the instruments or film got dosed too severely. -- John K. Prentice john@unmfys.unm.edu (Internet) Dept. of Physics and Astronomy, University of New Mexico, Albuquerque, NM, USA Computational Physics Group, Amparo Corporation, Albuquerque, NM, USA
brian@uunet.UU.NET (brian douglass personal account) (05/14/91)
From: edat!brian@uunet.UU.NET (brian douglass personal account) A couple of add ons to some of the other posters comments. Almost all tests emplace a test package above the bomb to measure things like radioactivity, particle type, etc. In the U.S., a second hole is drilled parallel to the first offset in meters (not miles). Within this hole a coax cable is placed and sealed. The resulting blast does something to the signal running through the cable, the effects of which are used to determine effective yeild. This system is called CORETEX. The horizontal shots are often used when the instrument package exceeds 6 stories in size, or when the soil composition is inappropriate for the type of measurements needed. These tunnels are cut right into a solid granite mountain. Physical containment measures can sometimes be extraordinary. As a kid, I took a science tour of the NTS back in the 70s. They showed one test designed to determine if a U.S. communications sattellite could withstand the EMP and radiation of nuclear explosion within 1500 feet in outerspace. They drilled a hole, with approximately a 6 foot diamater. The bomb was emplaced at the bottom, and a tube run all the back to the surface where it connected to a cylindrical chamber about 30 feet in diameter. Hung from bungy cords inside the tank was an actual defense comm-sat fully operational. They even had a lamp to simulate the sun. Then this entire enviroment, chamber, tube and all was evacuated to 10^-17 TOR to simulate a geosynchronous orbit. They said then it was the largest manmade vacuum ever. Once the trigger signal set off the blast the signal (dc or something) also set off containment devices, such as crushers, conventional explosives, doors, etc, the radiation nanoseconds behind the trigger. Eventually, between the tube and the tank, two one-ton doors closed in 1 micro-second, having been gas charged to 20 atmospheres. Once closed, the tank was separated from the tube and pulled (the sled was tractored) by two 20,000 hp wenches, one diesel, one electric, before the caldier set in. The neat thing was that all this equipment was common equipment they had from earlier tests. Most of the testing is not theoretical testing (20%), as I understand, but rather operational (80%) testing of warheads or warhead design. As far as the properties of nuclear weapons, that is supposed to be pretty well understood. As a side note, 3 years ago the Joint Verification Experiment was held where U.S. experts went to Semipalytinsk (?) and tested the yeild of a Soviet nuclear weapon using CORETEX, while a Soviet team came here and measured a U.S. weapon using Seismic means. DOE spokesmen said the tests were successful. As I understand it now, the JVE is going active again with the goal being permanent on site verification of the threshold test ban treaty. Someone also said the site in Semipalitynsk (maybe this one) was closed. I understand that both are active, and that the second in Siberia is possibly for different soil composition reasons. Afterall the first JVE was in 88, well after Chernobyl. But that is a guess. It is hard to differentiate this conversation between weapons testing, EE science, poly sci and all else, but then again, who ever thought nuclear weapons were just bigger bombs in a smaller package? :-; Brian Douglass Voice: 702-361-1510 X311 Electronic Data Technologies FAX #: 702-361-2545 1085 Palms Airport Drive brian@edat.uucp Las Vegas, NV 89119-3715
brian@uunet.UU.NET (brian douglass personal account) (05/15/91)
From: edat!brian@uunet.UU.NET (brian douglass personal account) prentice%triton.unm.edu@ariel.unm.edu (John Prentice) writes: [deleted stuff] >There are also tests done by drilling horizontally into a mountain. >Very large diameter and they do a good job building them. >The chamber containing the device will have pipes running out of it >which are used to give the radiation a pathway while still allowing >some containment. They also help shield experiments from each other >and some are there just to bring out cables. The Tunnel I toured in the 70s was approximately 30 feet in diameter, and upwards of 1/2 mile long. All experiments are supposed to be in line of sight with the bomb to allow the direct radiation exposure (if that is what the experiment needs), hence the tunnel had a stepped funnel cut to it, that is wider near the emplacement point and narrower at the entrance. Speaking of trial and error, a few years ago apparently one of the containment devices failed and the shock wave destroyed the test package. Some radiation was leaked out and there was hell to pay according to media. The reporters said somehere betwen $5 and $10 million worth of experiments were ruined. Unfortunately, a couple of workers got sizeable dosage exposure due to someones negligence. The dosages weren't lethal, but no one is sure of the long term effect. Such is the price of freedom. -- Brian Douglass Voice: 702-361-1510 X311 Electronic Data Technologies FAX #: 702-361-2545 1085 Palms Airport Drive brian@edat.uucp Las Vegas, NV 89119-3715