Destroying Nuclear Weapons with High-Energy Neutrinos

TheMatt writes "As reported by PhysicsWeb, physicists are proposing a "futuristic but not necessarily impossible" method of destroying nuclear weapons via high-energy neutrinos sent through the earth. Based on current planned efforts, this 'vast extrapolation' of current technology would use 1000 TeV beams. This would require a 1000-km diameter storage ring using magnets orders-of-magnitude stronger than currently available. The cost would be around $100 million-plus and it'd use 50 GW of energy, the UK's current consumption. (And the slight problem that the process might set off the nukes, instead of just melting them...)"

Comments

It would require...

[ewhenn]

This would require a 1000-km diameter storage ring

Oh, is that all? A mere 1000km storage ring. For you US folks out there, that is approx 600 miles.

On a serious note, what happens if you miss with this thing? It is quite interesting scientifically, however interesting never implies practicality.

Dear North Korea

[jrivar59]

Dear North Korea,

Please allow me to express our deepest regrets and sympathies for vaporizing your country. Unfortunatly, while attempting to help save the world from future nuclear calamities, we accidently detonated all your nuclear warheads. We hope that this will not cause you any inconvenience, and we look forward to a prosperous trade relationship with your country at the conclusion of your nuclear winter.

Sincerly,

-George W Bush

Re:Dear North Korea

[mythr]

That's obviously a forgery. Our president could never write something that eloquent. ;)

Re:Dear North Korea

[NeoSkandranon]

PS: All your base are belong to us.

Use the Source, Luke...

[HotNeedleOfInquiry]

Read the original scientific paper here

Estimated cost is $100 billion+

[HotNeedleOfInquiry]

Not $100 million+ in /. header

sweet!

[sydlexic]

that's only about 1.5x what it costs to knock over a middle eastern country. I think we can fit that in the budget somewhere between a $350-750 billion tax cut. Unless, of course, this wasn't a priority.

All I could think of was Dr. Brown.

[BoomerSooner]

1.21 Gigawatts!!!!

Irradiating nukes

[Muhammar]

Shining a strong neutron source (in this case generated by neutrino beam passing through earth) on fission material would generate radioactivity and heat effect. The radioactivity would be much higher than the heat, so people around would see blue light and start dying right away.

Bombs would not go off, because the assembly of the core is always subcritical. Even if the high explosives of the implosion device goes off (because of the heat or fire, for example), the spontaneous nuclear explosion is very unlikely. These shaped charges in the implosion design have to be set off from a precise starting point at exactly same time. [Setting of the "implosion lenses" of the implosion device simultanneously was one of the major technical hurdles of the Fat Man development]

And, honestly I do not believe that such a strong neutron source could be realised using a neutrino beam.

Re:Irradiating nukes

[sigwinch]

And even if you could build it, how do you aim it? You can't exactly gimbal a 1000 km ring.

And how do you lock onto the targets? If you can get a conventional radiation detector close enough, you might as well just send in the Marines to pick up the nuke. You can't use neutrinos to detect them because (1) detector efficiency is abysmal and (2) fission reactors and the sun provide a tremendous background signal.

And suppose you do somehow build an aimable neutrino beam. What happens if a rogue operator points it at a fission reactor? You're right that it almost certainly cannot ignite the pit of a bomb because the storage configuration has a low reactivity. Reactors, on the other hand, operate near unity reactivity. I don't know enough about reactor physics to say what is possible, but I'd be very worried that the neutrino beam could liberate enough unexpected heat to put the reactor in a positive temperature coefficient of reactivity regime. Boom. Like the Chernobyl disaster, but potentially much bigger.

And hold the world ransom for... 1 Million dollars

[Radical Rad]

From the paper :
...this kind of device can not only target the nuclear bombs but ... any kind of living object including human. ...we sincerely hope that our proposal will motivate and stimulate the revival of the old idea of World Government...

I think Dr. Evil would like to make these guys an employment offer.

And where to build the device?
We first look for a mountain like in fig. 8 whose the surface does not touch many of the straight lines depicted as P1P2, P3P4, Q1Q2 or Q3Q4. We construct two synchrotron A and B which are both revolvable...

Might I suggest a slightly used extinct volcano with a retractable roof?

Re:Why not just use a fast reactor?

[Muad'Dave]

Uh, I think the point of the article is to destroy your enemy's nukes while they're not looking, not to destroy nukes as in 'decommissioning' them. This is more of a disarming first-strike thing than anti-nuke, flowers-in-your-hair weapon destruction party thing.

Re:An excellent opportunity for some DARPA funding

[Idarubicin]

...research into possible neutrino/hadron shielding materials and techniques.

The problem is that this technique is so grossly, extravagantly, embarrassingly inefficient. A neutrino beam can (and will, in this scheme) pass through a good fraction of the Earth without blinking. Astronomers build neutrino detectors on Earth at great cost and inconvenience because (among other reasons) most neutrinos from fusion the Sun's core travel directly to Earth without interacting with any of the matter in between.

This device would be so horrifically expensive because the vast majority (ninety-nine point several nines percent) of neutrinos are lost to space, out the other side of the Earth. To block a significant fraction of the neutrino beam would require a shield with tremendous density or thickness. We're talking several kilometres of neutron star material (at a density of tons per teaspoon) or light years of lead. Neither solution is particularly practical. Maybe a few decades down the road you could construct artificial black holes, and place them beneath your nuclear stockpile.

As we understand neutrino interactions, they essentially cannot be stopped (they won't pass through the black holes mentioned above--but we can't build those yet.) Your best bets for defense are to keep your nukes well hidded--so your adversaries can't target them--or launching a first strike--use your nukes to destroy this large, obvious, easy-to-hit neutrino generation facility. (An accelerator ring 1000 km across can't be concealed--heck, it won't fit in most countries, let alone be paid for--and it can't be moved to a place of safety.)

Gotta love /.

[JUSTONEMORELATTE]

After reading 36 of 46 comments, largely from folks saying "I have no clue about any of this, but what about ]blah[", I got the following tagline at the bottom:
It is much easier to suggest solutions when you know nothing about the problem.

Who knew /usr/games/fortune was so smart?

--

Re:Another stride toward peace

[Jerk City Troll]

"I do not know with what weapons World War III will be fought, but World War IV will be fought with sticks and stones." -Albert Einstein

Re:Nuclear Power Plants

[Wyatt Earp]

There is a bad taste in our mouths from the wild anti-nuclear BS thrown about.

It all started with the film the China Syndrome.

There are over a hundred operational energy nuclear plants in the US and about 3-4 times that many research and isotope production plants in the US and about a thousand military reactors and there has been 1 problem with them since 1975.

One problem - Three Mile Island.

Burning of coal produces more radiation every year in the United States than all the hundreds of reactors put out.

In Japan there have been some problems with poor handling of fuel.

In France there have been no significant problems.

In Russia, well they don't build very smart reactor complexes sometimes now do they?

For every lie the nuclear industry and government put out there is a lie put out by the Anti-Nuclear Movement.

Re:An excellent opportunity for some DARPA funding

[Tackhead]

> Your best bets for defense are to keep your nukes well hidded--so your adversaries can't target them--or launching a first strike--use your nukes to destroy this large, obvious, easy-to-hit neutrino generation facility. (An accelerator ring 1000 km across can't be concealed--heck, it won't fit in most countries, let alone be paid for--and it can't be moved to a place of safety.)

That's not a bug, it's a feature.

1) Only a few countries are big enough to hold such a device. They're already nuclear powers, and they're pretty responsible users thereof.

2) Because of how huge it is, it's probably not going to be near a coastal region. So you gotta bomb it or ICBM it (short range ballistic missiles aren't gonna cut it, nor is a flotilla of cargo ships with smuggled weapons. :)

3) It's a lot easier to defend a 1000km ring with anti-ballistic missiles for 15 minutes than it is to defend an entire continent. (You only need to set up your ABM tech every 100km or so around the circumference.)

4) For superpowers, the countermeasure is to build your own 1000 km neutrino ring. (And short of starting WWV, there's no way for Superpower Foo to prevent Superpower Bar from building one!) Two superpowers with such rings have effectively rendered each others' nuclear arsenals obsolete. That's effective deterrence without the sword of mutually-assured destruction hanging over everyone's head.

5) Meantime, all rogue nuclear states' base are belong to the superpowers, because rogue states don't have the land mass to ever build a countermeasure.

6) $100B isn't that pricy if you amortize it out over 10-20 years. And much like nukes, even though the weapons haven't been used in 60 years, one hell of a lot of science has been done along the way. Your MRI and PET scans are as much an offshoot of nuclear weapons research as the fission plants that provides a good chunk of your electricity without a gram of CO2 (for those that believe CO2 is a hazard).

Re:i thought...

[reverseengineer]

Well, that's really just it- neutrinos interact incredibly weakly with matter- whereas most particles have a mean free path (the average distance a particle will travel before colliding with another particle) on the order of microns (depends on particle "cross-section" (relates to its interaction with other particles, and is dependent on particle energy) and the average separation between particles (depends on density of matter in the medium). Neutrinos with a respectable 1GeV energy (1/1,000,000 of the energy proposed here) have a mean free path through solid lead (density of over 11000kg/m^3) of over a light-year.

Now, like I said, the mean free path is an average figure, so a neutrino may interact with a nucleon far sooner, or far later. In the case of earthbound neutrino detectors like Super Kamiokande, the neutrinos that are detected must make it out of the dense plasma of the sun from whence they arise, travel 150,000,000km through interplanetary space (which is basically empty for neutrino purposes), pass through the entire earth, and then into a deep mine shaft filled with something like heavy water or carbon tetrachloride (as you mentioned). A very, very small fraction of the constant torrent of neutrinos passing through this tank will bump into a nucleon and produce a detectable event. Now, if you boost the the energy of these neutrinos up to about 1,000 TeV, the mean free path of each one is reduced to roughly the diameter of the earth. While a tremendous number of neutrinos with this energy,released in a pulse, will either bump into particles somewhere in the earth's interior or will pass straight through, then through the nuke and straight out into space (a small amount would probably make it out of the galaxy eventually), there would probably enough neutrinos hitting particles in the vicinity of the nuke to produce that hadron shower and potentially ruin the bomb.

I do agree that the technology is unrealistic, however- unless a viable 100+ Telsa magnet is found (present record is about 15T for a magnet of the necessary type), the storage ring will have to be 600km in diameter. There are of course many practical problems with this design- the difficulty of aiming this sort of neutrino beam, the incredibly deadly neutron flux produced with the neutrino beam (the prospect of a misfire shooting down an aircraft or irradiating a city block is rather unappealing), and that the authors suggest that a detonation of roughly 3% of the expected nuclear device yield will still occur (or even a full detonation, if the device is a hydrogen bomb, and the "fizzle" explosion and tremendous neutron flux is enough to kickstart fusion). 3 percent of a 20-kiloton device is still the rough equivalent of 600 tons of TNT. If I were the madman dictator of a rogue state, I'd definitely think about keeping my nuclear warheads in populated areas, so the hypothetical "World Government" who holds the keys to the storage ring will have blood on its hands when they use the neutrino pulse to destory a nuke, and 10,000 of my citizens become collateral damage. That would also be an excellent pretext to retaliate with any nukes I have left.