March 07, 2010

150 Kiloton Nuclear Verne Gun

The core idea for the nuclear verne launch gun is simple though dramatic: Dig a kilometers deep shaft—a salt layer would be easiest to penetrate (some exist 3.5 kilometers thick) —build at the bottom a giant shell, from components lowered into place, layer by layer enclosing its internal payloads with external structures (such as a supporting sabot) and sealing the unit to flight-ready status. Place sets of guide rails around the perimeter of the shaft with ‘slippers’—metal contact shoes—touching the rails from the edges of the Wang Bullet. Finally, after all is in readiness, pump reaction mass through an access shaft under the sabot into a prepared chamber and place a thermonuclear explosive device in the midst of the reaction mass.

The reaction mass (in our conceptual model, water, but many other substances would work) not only becomes the propulsive hypersonic plasma and impulsive gas but also serves as an accelerative, radiation (boron included against neutron flux) and impact shield relative to the extreme violence of the blast chamber. So it is not the nuclear blast that directly accelerates. The blast acts on the propellant and filler.
Pictured are project Orion nuclear pulsed propulsion, this system is variant with only one charge instead of hundreds and where the explosion is underground with all fallout and electromagnetic effects contained like hundreds of previous underground nuclear tests performed throughout the 1950s-1980s.

Terms -
Nuclear Verne BlowGun - the entire system, the hole, the nuclear device, the cistern of propellant and the projectile
Wang Bullet - the projectile being launched
Friedlander Sabot - the base of the projectile

Purpose and Main Benefit

The reason for this system is to develop a massively cheaper launch system which could be developed in as short a time as possible. The launch system described here could achieve $5-20 per pound. The price could be even lower with a scaled up launch, but that would not be compliant with existing treaties. The nuclear bombs exist and work, underground tests have been done hundreds of times, deep holes are dug for mining and oil and gas projects all the time, so this system has very little uncertainty. Launching thousands of times at time is beyond the chemical launch systems that have been developed. The cumulative payload that has been launched into space over the last 50 years is less than 10,000 tons.


Basic Feasibility

This idea hinges on surviving, beyond the acceleration forces, the thermonuclear explosion itself.

A quote from George Dyson: "Project Orion — The Atomic Spaceship 1957-1965", Penguin Books, 2003, ISBN 0-140-27732-3 is found at
http://www.walthelm.net/inverted-aerobraking/ProjectOrion.htm
[page 71]
Lew Allen performed a similar series of experiments in Nevada, hanging spheres of material from shot towers in the desert during the Teapot test series in April 1955. [...] At a February 1957 conference, Livermore physicist Tom Wainwright noted that nonmetallic material such as Bakelite suffered markedly less ablation, a phenomenon that became the key to protecting Orion's pusher plate from repeated blasts. [...] says Bud Pyatt [...]: "You can go and see these famous iron balls that, in terms of temperature, were within the 150,000 degrees Kelvin range of the fireball. The phenomena of the self-protection from ablation through the creation of a hot layer that was opaque enough to protect the remainder of the ball from any of the radiation were important observations in terms of could we create a layer of pusher that could exist that close to a nuclear explosion?"

Lew Allen’s steel spheres survived not only the nuclear explosion itself (20 kilotons at about 10 meters) but also the accelerative and decelerative events! These were undoubtedly in the thousands of Gs range.

The Wang Bullet and its’ base, the Friedlander Sabot, will not have direct contact with the device, i.e. not be sitting on the bomb like a kid’s can on a firecracker. It will be sitting on a pre-dug spherical cistern centered on the bomb itself and filled with a fluid to be energized. Ideally within this fluid—of a quantity to be sufficient to dilute the emergent plasma’s temperature to the hundred thousand degree Kelvin range-- would be elements chosen to maximize opacity and absorption of the energy, such as hydrogen, carbon, oxygen and nitrogen. Right around the bomb would be a healthy admixture of boron to greatly reduce neutron irradiation of the mass, to keep things as clean as possible.

Note that here the nuclear explosion is heating chemical propellant into super-heated gases and plasma that are pushing the projectile. Nuclear power is providing the energy. Propulsion is still in the form of chemicals. Just chemicals made hotter and faster than a chemical reaction can achieve and done on a larger scale all at once. The energy of a thousand Saturn Vs in a microsecond is rhetorical shorthand to describe it, but not far from the truth.

The Pascal-B nuclear test a ~ 500 ton surprise yield nuclear explosion launched a 900 kg concrete plug allegedly at 5-6 times escape velocity. If so it almost certainly burned up before achieving space.

This 500 ton explosion should then have been able to send 20 ton plug at 1.2 times escape velocity. 150 kilotons would then launch about 6000 tons (reduced somewhat by launch inefficiencies -so say 3000 tons). A 3000 ton projectile could be made about 15 meters tall if mainly solid metal. Basic structural calculations indicate that such a projectile would be able to withstand the acceleration forces.

The detailed work on the Quicklaunch gas gun and the preceding experimental gun launch systems show that a smaller projectile can survive passage through the atmosphere after being fired from a gun. Quicklaunch is looking at one thousand pound payloads, but larger projectiles and systems as well. Cellphone electronics can be easily G-force hardened for Quicklaunch, just replace the transformers and epoxy.

Treaty Compliance

of Project Orion which would be permitted under the Partial Test Ban Treaty. (wikipedia) and the Threshhold Test Ban Treaty
Partial Test Ban Treaty banning Nuclear Weapon Tests In The Atmosphere, In Outer Space And Under Water.

The Treaty on the Limitation of Underground Nuclear Weapon Tests, also known as the Threshold Test Ban Treaty (or TTBT), was signed in July 1974 by the USA and the USSR. It establishes a nuclear "threshold," by prohibiting nuclear tests of devices having a yield exceeding 150 kilotons (equivalent to 150,000 tons of TNT).

The Comprehensive Test Ban Treaty has not yet entered into force

Underground nuclear explosions are permitted up to 150 kilotons.

Cost Estimate
Dig a deep 2 mile hole (like the deeper oilwells but a bit wider). Cost about $10 million. Conservatively round up to $40 million.

About 3000 ton projectile (depends upon coupling efficiency). Set it off and launch it at 5000Gs into orbit or towards the moon.

$10 million for the projectile and the propellant.
$20 million for the work of setting it up.
Launch costs for supplies and refined metals would become $10/lb. (assuming the nuclear bombs in stockpile are donated)

Launch people and delicates the regular way. The supplies and refined metals would allow for industrialization of space.

Nuclear Devices in the US stockpile

The U.S. nuclear arsenal is divided into three levels of stockpile readiness:
Operationally Deployed (fully operational and mated to delivery system),
Active Stockpile (Fully operational weapons but not deployed)
and Inactive Reserve (Weapons kept intact but not maintained).

150 kiloton weapons

W80 mod 1 (cruise missile warhead) 1450 active, 361 inactive

There are 384 inactive W84 cruise missile warheads. They would need a full load of tritium added to get them to their 150 kiloton yield and back to active status.

The largest bombs in the US stockpile are B83 which can go up to 1.2 megatons. (320 active and 306 are inactive)

B61 -mod 3 (170 kilotons) could have some reduction in tritium to reduce it to 150 kilotons. (200 active, 186 inactive)
W62-Mk-12 (170 kilotons, 580 active or inactive)
W76-Mk4 (100 kilotons, 3030 active or inactive)

Russia's nuclear arsenal

China's nuclear arsenal is here and here

FURTHER READING
The above article reviews the underground nuclear propulsion into space design that I had (along with detailed work with Joseph Friedlander) and which I have described a few times before

Videos of Underground Nuclear Test, Project Orion and the Quicklaunch Gas Gun Proposal

Amchitka 5 Megaton Test


Project Orion


Quicklaunch



Underground Nuclear Tests Safety and Past Tests

http://en.wikipedia.org/wiki/Nuclear_weapons_testing

The nuclear powers have conducted at least 2,000 nuclear test explosions

United States: 1,054 tests by official count (involving at least 1,151 devices, 331 atmospheric tests), most at Nevada Test Site and the Pacific Proving Grounds in the Marshall Islands, with ten other tests taking place at various locations in the United States, including Amchitka Alaska, Colorado, Mississippi, and New Mexico (see Nuclear weapons and the United States for details
Soviet Union: 715 tests (involving 969 devices) by official count most at Semipalatinsk Test Site and Novaya Zemlya, and a few more at various sites in Russia, Kazakhstan, Turkmenistan, and Ukraine.
France: 210 tests by official count (50 atmospheric, 160 underground), 4 atomic atmospheric tests at C.E.S.M. near Reggane, 13 atomic underground tests at C.E.M.O. near In Ekker in the then-French Algerian Sahara, and nuclear atmospheric tests at Fangataufa and nuclear undersea tests Moruroa in French Polynesia. Additional atomic and chemical warfare tests took place in the secret base B2-Namous, near Ben Wenif, other tests involving rockets and missiles at C.I.E.E.S, near Hammaguir, both in the Sahara.
United Kingdom: 45 tests (21 in Australian territory, including 9 in mainland South Australia at Maralinga and Emu Field, some at Christmas Island in the Pacific Ocean, plus many others in the U.S. as part of joint test series)
China: 45 tests (23 atmospheric and 22 underground, at Lop Nur Nuclear Weapons Test Base, in Malan, Xinjiang)
India: 6 underground tests (including the first one in 1974), at Pokhran



My previous look at underground nuclear tests
The effects of an underground nuclear test may vary according to factors including the depth and yield of the explosion, as well as the nature of the surrounding rock. If the test is conducted at sufficient depth, the test is said to be contained, with no venting of gases or other contaminants to the environment. In contrast, if the device is buried at insufficient depth ("underburied"), then rock may be expelled by the explosion, forming a crater surrounded by ejecta, and releasing high-pressure gases to the atmosphere (the resulting crater is usually conical in profile, circular, and may range between tens to hundreds of metres in diameter and depth). One figure used in determining how deeply the device should be buried is the scaled depth of burial, or -burst. This figure is calculated as the burial depth in metres divided by the cube root of the yield in kilotons.

Although there were early concerns about earthquakes arising as a result of underground tests, there is no evidence that this has occurred. However, fault movements and ground fractures have been reported, and explosions often precede a series of aftershocks, thought to be a result of cavity collapse and chimney formation. In a few cases, seismic energy released by fault movements has exceeded that of the explosion itself.

Congressional study from 1989 of underground nuclear test safety
If a person had been standing at the boundary of the Nevada Test Site in the area of maximum concentration of radioactivity for every test since Baneberry (1970), that person's total exposure would be equivalent to 32 extra minutes of normal background exposure (or the equivalent of 1/1000 of a single chest x-ray).

A worst-case scenario for a catastrophic accident at the test site would be the prompt, massive venting of a 150-kiloton test (the largest allowed under the 1974 Threshold Test Ban Treaty). The release would be in the range of 1 to 10 percent of the total radiation generated by the explosion (compared to 6 percent released by the Baneberry test or an estimated 10 percent that would be released by a test conducted in a hole open to the surface). Such an accident would be comparable to a 15-kiloton above ground test, and would release approximately 150,000,000 Ci. Although such an accident would be considered a major catastrophe today, during the early years at the Nevada Test Site 25 above ground tests had individual yields equal to or greater than 15 kilotons

Since 1970, 126 tests have resulted in radioactive material reaching the atmosphere with a total release of about 54,000 Curies (Ci). Of this
amount, 11,500 Ci were due to containment failure and late-time seeps.

The report also has a list of american tests and the amount of radiation from each test, what happens in an underground nuclear explosion and there are thousands of page documents that explain how to contain an underground explosion.
Amchitka Island follow up Environmental work, years after the 5 megaton test

Dr. Volz hand catches Eider Ducks on Amchitka Island, Aleutians, for Radionuclide Internal Dose Assessment

University of Alaska study of Amchitka Island: "There were no indications of any radioactive leakage, and all that was really wonderful news."


==so all of those who say it is not safe - put some data and cite some references.

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