Antineutrino Device Tackles Nuclear Proliferation

KentuckyFC writes "One of the biggest problems in nuclear proliferation is verifying that countries are not secretly transferring fissile material by taking it out of reactors and selling it. Now a group of US scientists say they've developed a machine that can remotely detect whether a reactor has been switched on and off by detecting the antineutrinos produced by nuclear reactions. The detector is about the size of a car engine and is designed to be left near a reactor to record data. The group has been testing a prototype at the San Onofre Nuclear Generating Station in Southern California and says it works well (abstract). Now it's up to the International Atomic Energy Authority in Vienna to decide whether to deploy the new machine."

Comments

Re:Detecting (anti)neutrinos?

[jpflip]

They are extremely difficult to detect, but not impossible. Moreover, nuclear reactors produce quite a lot of them.

As a recent example, the KamLAND neutrino experiment (http://kamland.lbl.gov/) used a 1000 ton detector in Japan to study the flux of neutrinos emitted from dozens of reactors in Japan and Korea, some hundreds of miles away. KamLAND performed precision studies of the propagation of neutrinos over distance, and was also able to detect the rising and falling neutrino fluxes as various reactors powered up and down.

The detection device described in the article is much smaller, but it's located much closer to the reactor. I've heard talks on this, and it seems quite reasonable.

Re:Detecting (anti)neutrinos?

[JustinOpinion]

The neutrino interaction is indeed very weak, so they are difficult to detect. A major problem is that the other sources (cosmic rays, ambient radiation) can give false positives.

However the proposal is to place the device rather near to a nuclear reactor. A reactor generates enough flux that big detectors can measure the neutrino flux from miles away. So a small (and probably less shielded) detector that is much closer (<100 m) will receive enough flux to get statistically significant data.

The preprint says:

For example, cubic meter scale hydrogenous scintillator detectors, containing 10^28 target protons Np, will register thousands of interactions per day at standoff distances of 10-50 meters from typical commercial nuclear reactors. The proposal thus requires the detector to be installed on-site at the nuclear reactor. You may wonder "Is this actually useful for monitoring, then? If someone wants to lie about their reactor usage and burn rate, they will just falsify the detector records, too." Well, the idea is that this local detector is completely independent from the reactor (it doesn't rely on sensors hooked into the reactor, for instance). Thus it can be locked and sealed off completely; installed and managed by a completely independent oversight organization.

Re:Sensitivity?

[Smidge204]

You're citing an experiment performed in the 1950's.

They can make machines that are MUCH more sensitive now, and if you're only interested in detecting presence and not actual study, they don't need to be that fancy.
=Smidge=

Re:If I read this right...

[Carnildo]

Then this machine can only detect whether the reactor is operating above 80% power or above. So, if you operate at 50% power it cannot tell if the reactor is off or not.

One of the things that makes reactor operation so hard is that they don't like being run at low power. If you run a reactor at 50% power for more than a few minutes, the buildup of fission byproducts will cause the reactor to shut down, requiring a very expensive restart process.