A neutrino emitting weapon could neutralize nuclear bombs anywhere on the planet.

But the "muon storage ring" generator needed to propose the neutrino beam would need to be 1000 kilometres wide. It would also require 50 gigaWatts of power to operate - the same as used by the entire UK - and would cost an estimated $100 billion to construct.

The development of such a device would take many years.

However, the researchers stress that the method is well beyond the capabilities of current particle accelerators and would require substantial R&D and financial investment by many nations

Such a weapon as a defense against nukes runs up against some major problems. It has to be aimed at within a few meters of a nuke to disable it. So it is useless against a well hidden nuke. The biggest nuclear threat the United States faces in the future is probably from nukes smuggled in by terrorists. Therefore the value of this as a defense against the primary threat is questionable. Also, it would cause serious and probably fatal damage to any human hit by the beam.

Some comments in the full text of the paper draw attention to other problems with this approach: the nuke will still explode at a lower level and it will take a few minutes to make that happen.

We have shown that it is possible to eliminate the nuclear bombs from the surface of the earth utilizing the extremely high energy neutrino beam. When the neutrino beam hits a bomb, it will cause the fizzle explosion with 3% of the full strength. It seems that it is not possible to decrease the magnitude of the explosion smaller than this number at this stage. It is important to decrease this number to destroy bombs safely. We are not sure what this means when the plutonium or uranium is used to ignite the hydrogen bomb. We may just break the bomb or may lead to a full explosion. The whole process takes a matter of a few minutes in the case considered in this paper although, of course, it depends on the intensity of the neutrino beam. When the bombs are stored in the form of plutonium ball separated from the explosives, what we can do is to melt them down or vapor them away. It takes substantially longer time for this process to occur.

If it takes a few minutes to knock out a nuke then the beam device can not knock out a large number of nukes rapidly. If it can do one nuke in 3 minutes then at most it can knock out 20 nukes in an hour. Therefore it could not stop a large scale attack of ICBMs even if the beam could somehow be directed accurately to fast moving targets. Also, the nukes will still emit a small fraction of the amount of energy they would emit if they exploded normally. A particle beam designed to simply make an ICBM malfunction and explode during boost stage seems a more reasonable approach than to attempt to knock out a nuke on a travelling ICBM.

Because of the large surface area needed for the device the Moon becomes a candidate worth considering for the site of construction. Though the costs of hauling materials to the Moon to construct it would be very high it could be reduced if most of the needed materials could be mined and processed on the Moon.