how nuclear inspectors can inspect other countries nuclear weapon inventories and uranium refining abilities in a way that can be trusted and not just staged by the inspected country


how nuclear inspectors can inspect other countries nuclear weapon inventories and uranium refining abilities in a way that can be trusted and not just staged by the inspected country

In: 1404

There are a few major elements.

1) Nuclear processing facilities are huge, specific and complex. A lot of the equipment can’t easily be moved. They tend to have limited use beyond nuclear weapons processing and it takes a long time to assemble and disassemble stuff.

2) They try to make the inspections with as little notice as possible.

3) There are some information sources we can access at any time. Those can tell us a lot about a facility too. Trucks, financial transactions, shipping manifests can provide further evidence.

Due to the rarity of plutonium, initially you pretty much have to start with uranium if you wish to build a nuclear weapons program. So, let’s start with uranium.

Uranium just taken out of the ground cannot be used for bombs or fuel. This uranium contains only about 0.7 percent U-235, the type of uranium that can sustain a nuclear reaction. For actual use as fuel you need something like 3 – 5%, and for use in nuclear weapons you need something like 20%.

It is necessary to process the uranium to make the type of uranium needed for either one in large centrifuges. Such a facility is very hard to hide, so if someone wants to process uranium in this fashion they will likely have to explain the processing plant as a plant for producing nuclear fuel for reactors and allow inspection.

A single pass through a centrifuge does not do the job. You have to have the output of one centrifuge fed into another in a chain until the end product has a high enough percentage of U-235 for your purpose.

Since fuel needs a lot less refining than bomb material, the bomb material chains of centrifuges are much longer than ones used for fuel. Given the size of the centrifuges, the difficulty in moving them about and reconnecting them, and being able to cover up the fact that you did this, all in a short period of time after you are told that an inspection is coming, it is effectively impossible to hide a nuclear weapons uranium purification plant by disguising it as a nuclear fuel plant.

Similar issues occur if you try to build a breeder reactor to make plutonium. You can’t just rebuild the reactor every time the inspectors show up, and so you cannot hide the fact that your reactor is producing plutonium. Since nearly the only use for even moderate amounts of plutonium is nuclear weapons, again, you are given away.

Minor edit: 20% is reported to be the minimum needed for weapons development, which I believe means used to create plutonium. It is at or just under 90% if you wish to use straight uranium. However, a straight uranium bomb is larger and harder to deliver than a plutonium one, and as much more likely to be used in creating a weapon

The International Atomic Energy Agency has a lot of different tools in their toolbox to verify that countries aren’t hiding nuclear activity. One of the most useful is authority to collect environmental samples. They rub a cotton pad over surfaces that collect dust and ship the samples to a lab for analysis. They can tell if there is any uranium or plutonium nearby and how enriched the uranium is from the analysis.

Maybe the inspection can’t be marked on a specific day, they would have to appear by surprise.

So with the “trust but verify” mind set the U.S. widely employed with these agreements it becomes part of the deal. For example the deal is we both agree to these weapons limits and we both can demand an inspection at any facility any time. To refuse is to violate the agreement. Goes both ways. We would go to Russia, Russians would come here. And there is different levels of this. Till recently the U.S. and Russia were allowed to fly over whatever military facilities in the other country they wanted and basically openly spy. The U.S. pulled out of the intermediate nuclear weapons agreement with Russia in part because Russia started refusing the inspection part, along with intel we had they were violating it as well. When the verify part broke down the agreement broke down.