The Blind Spots In the Nuclear Test Monitoring System

Lasrick writes The International Monitoring System managed by the Comprehensive Nuclear-Test-Ban Treaty Organization relies on detecting one or more of four distinct signatures from a nuclear explosion. Seismic detectors continuously listen for the shock waves passing through the earth from underground nuclear tests. Hydro-acoustic monitors listen for sound waves in the oceans from underwater tests. Infrasound detectors scan for pressure waves in the atmosphere. The fourth kind of signal involves radioactive gases generated by a nuclear explosion and released into the atmosphere. Ulrich Kuhn and Michael Schoeppner describe the system in detail, and point out that there are blind spots, particularly in the area of noble gas detection: "Our research has found that the noble gas detection part of the International Monitoring System is unlikely to work as it should because of the limited distribution of noble gas stations, neglect of important meteorological patterns in some areas, and the radionuclide background from emissions from the commercial production of medical isotopes." Kuhn and Schoeppner go on to describe possible fixes, and call on the 183 states that have signed the Comprehensive Nuclear-Test-Ban Treaty and the CTBTO to provide the resources to build extra monitoring stations where they are required and to curb activities that might limit the global capability to monitor possible nuclear tests.

Comments

Blind spot?

[SlayerofGods]

So if the other 3 detectors can detect the explosions under ground, under the sea, and in the atmosphere. Where exactly does that leave for a covert test that this gas sampling might miss?
Oh I see he thinks we need a world wide network of monitors to confirm what the other 3 sensors pick up. Gee if only there was some way to stick those gas detectors on something mobile.....
WC-135 Constant Phoenix

Re:Blind spot?

[AK Marc]

It's really hard to make tactical nuclear weapons. If it were a tac-nuke test on the smaller side, it'd have the results observed if it were a success. If that were true, then they are decades above where we think they are. So we now assert it was a dud or a hoax, which are both more comforting. When North Korea makes an "average" size nuke, the US is finished. There is nothing the US has that could even theoretically stop a ballistic nuke from NK fired east, aimed at, say, somewhere in Africa, that is detonated as it passes over the USA. The EMP of a low-orbit detonation should just about knock out all non-hardened electronics, and most power generation/distribution. And if NK wants to be sure nobody will mess with it, announce it as a moon probe before launch. Sure, everyone will notice it's not reaching stable orbit, but it'll be close enough we'll assume it's a failure, at least until it's too late.

One nuke would just about end the entire USA without a single direct fatality. Aimed properly, if it fails, nobody would ever be able to prove what's on it. If they had two, rather than one over Kansas, they could blow up two at the same time over Nevada and Kentucky, guaranteeing a 100% coverage of the 48 states. Chicago's blast would be a little weaker, but LA, NYC, and DC would have stronger blasts. Either way, the loss of power for weeks across most of the US would lead to rioting and looting that would leave the US in much worse condition than if the rest of the world combined attempted a ground invasion.

Re:Neutrino detectors

[Anonymous Coward]

Evidently the behavior of nuclear weapons is fairly well quantified neutrino wise - you get 1.3e23 MeV neutrinos per kiloton yield spread over 4pi steradians of a sphere.

The sub-GeV neutrino-nucleon cross section is about 1e-44m^2. At the Super-K neutrino detector presents a detection volume that contains roughly 3e31 nucleons, which means we need about 3 neutrinos to pass through a square .55 micrometers on a side to hit the cross section it presents to get 3 counts at once and sound the alarm.

The result is, "damn that miserably small cross section" because the result is that a ~10kt Little Tinpot's First Nuke would only register to Super-K if it were within 100km or so. I haven't run numbers for Icecube but it's not promising because range scales as the square root of detector size since neutrino flux dilutes as the square of distance but target count is only proportional to volume.