MIT scientists have figured out a way to tell if a nuclear weapon is real or fake - a crucial step toward reducing the number of nukes in the world

• A new technology developed by MIT researchers can tell whether a nuclear warhead is real or fake.
• The technology encrypts its data, so any inspectors using it wouldn't have access to military secrets.
• The tool could encourage Russia and the US to allow warheads to be inspected.
• Visit Business Insider's homepage for more.

Even in peaceful times, stockpiled warheads can pose a danger if they're accidentally set off or fall into the wrong hands. Plus, there's always a chance conflict could escalate, which is why many experts support dismantling nuclear warheads around the world.

But most arms-control treaties don't require warheads to be inspected, since the process could reveal military secrets. And even if inspections were required, nuclear experts worry that nations could try to fool inspectors by offering imitation warheads.

To eliminate the risk that countries would lie about this, two MIT researchers have come up with a novel way to verify that a warhead is authentic - all without revealing how the weapon was built.

The scientists describe the new technology in a paper published in the journal Nature Communications. Their method uses neutron beams: streams of neutrons that can plunge deep into a warhead and reveal its internal structure and composition, down to the atomic level.

The technology, if implemented, could encourage countries like Russia and US to allow their warheads to be inspected and verified as real before they get dismantled.

Nations typically don't inspect warheads

The US and Russia recently dissolved the Intermediate-Range Nuclear Forces Treaty, which kept both countries from possessing, producing, or testing thousands of land-based missiles. Shortly after, each nation conducted a missile test, stoking fears of a nuclear arms race similar to the Cold War.

During the Cold War era, the US and Russia built up their arsenals of nuclear warheads. By 1967, the US had acquired the most warheads in its history - around 30,000. The Soviet Union reached its peak warhead supply in 1986, when it had around 45,000.

When the Cold War ended in 1991, the nations agreed to dismantle some of these weapons, but they didn't allow each other to inspect the actual warheads. Instead, they showed proof that the devices that carried these warheads, such as missiles and aircrafts, had been torn apart - which meant that the warheads couldn't be deployed.

The US, for instance, cut off the wings of B-52 bombers and splayed them out in a "boneyard" in the Arizona desert. Russian officials could then verify via satellite that the planes were out of commission.

Today, the US and Russia each have around 4,000 warheads left in their military stockpiles, in addition to around 2,000 warheads each that are "retired," or ready to be dismantled. The Federation of American Scientists estimates that Russia is dismantling up to 300 retired warheads per year, but confirming that number isn't easy.

That's where the technology from the MIT researchers comes in.

The tool captures a warhead's unique shadow, not classified details

The MIT researchers' tool can detect isotopes like plutonium, which are found in the core of a warhead, since those atoms release specific wavelengths of light. These measurements then pass through a filter that scrambles and encrypts them. This allows a warhead's unique structure to get probed without any resulting 3D image of its exact geometry. (It's kind of like looking at a shadow of the warhead rather than the object itself.)

The researchers estimate that the scan can be completed in less than a hour.

The test's encryption process is more secure than encrypting information on a computer, which can be hacked.

If nations are confident that their military secrets are safe, the researchers said, they could be more inclined to allow their warheads to be inspected. Of course, the method would need to be more thoroughly vetted before it could be implemented, they added.

But eventually, they said, it could help to "reduce the large stockpiles of the nuclear weapons that constitute one of the biggest dangers to the world."