Agreed. People are used to hearing estimates based on annual production but that is only applicable to newer nuclear countries like Iran or North Korea where fissile material is limited.Right and my point is that China is well and truly above that and above that by quite far. It doesn't have the same issue of needing to show undisclosed facilities. Even Iran doesn't really need to. It doesn't show facilities it "does not have"
With China, it's been able to refine material since the 1960s. This isn't new to China. It's probably got many facilities refining material. None of these facilities need to be reported or shown. There is no treaty or rule saying China must show others what nuclear processing facilities it has. It's the exact opposite of how this works. Secret nuclear facilities are just that, secret.
France does not inspect all of China's nuclear facilities. It just looks over the French reactor and the materials going and leaving it.
China has two of its own reactor designs, French ones, Russian ones, and an American one. It should also have plenty of facilities that are off the books, dedicated to refining weapons material. This is a given since this is how nuclear weapons are made.
Therefore no country is able to put together a good enough picture of how many kilograms of refined U or Pu China has and how many kilograms of raw ore it has in the ground. This means it is no more possible to figure out how many warheads China already has and can have than it would be for China to determine how many warheads the US can have. The possible range makes such a calculation near worthless.
China's reported count of around 300 warheads is based on what China said in the 1980s, extremely dated and unreliable information. It may serve as a minimum bound guess but the upper limit is impossible to determine with accuracy because China has its own nuclear reactors, has its own uranium ore reserves, has facilities refining material beyond the knowledge of outsiders, and no independent investigator has any right to check all of China's nuclear facilities and stockpiles any more than they have the right to demand China show them where secret facilities are.
China has had reactors operating outside of IAEA safeguards for decades now. That means a stockpile several tons of fissile material.
In other words, China has as many warheads as it wants.