https://fas.org/blogs/security/2011/12/chinanukes/
Only the Chinese government knows how many nuclear weapons China has. As in most other nuclear weapon states, the number is a closely held secret. Even so, it is possible to make best estimates of the approximate size that benefit the public debate.
A recent example of how not to make an estimate is the study recently published by the Asia Arms Control Project at Georgetown University. The study (China’s Underground Great Wall: Challenge for Nuclear Arms Control) suggests that China may have as many as 3,000 nuclear weapons.
Although we don’t know exactly how many nuclear weapons China has, we are pretty sure that it doesn’t have 3,000. In fact, the Georgetown University estimate appears to be off by an order of magnitude.
Fissile Material
The most fundamental problem with the 3,000-warhead estimate is that there is no evidence – at least in the public – that China has produced enough fissile material to build that many warheads. Not even close.
An arsenal of 3,000 two-stage thermonuclear warheads with yields of 300-500 kilotons would require 9-12 tons of weapon-grade plutonium and 45-75 tons of highly-enriched uranium (HEU).
Based on what is known about China’s inventory of fissile materials, how many nuclear weapons couldit build?
According to the International Panel on Fissile Materials, China has produced an estimated 2 tons of plutonium for weapons. Some has been consumed in nuclear tests, leaving roughly 1.8 tons. The estimate is consistent with what the U.S. government has stated and theoretically enough for 450-600 warheads.
Total production of HEU is thought to have been approximately 20 tons. Some has been spent in nuclear tests and research reactor fuel, leaving a stockpile of some 16 tons. That’s theoretically enough for roughly 640-1,060 warheads.
Another critical material is Tritium, which is used in thermonuclear weapons. China probably only produces enough Tritium at its High-Flux Engineering Test Reactor (HFETR) in Jiajiang to maintain an arsenal of about 300 weapons.
The U.S. intelligence community concluded in 2009 that China likely has produced enough weapon-grade fissile material to meet its needs for the immediate future. In other words, no vast warhead expansion is in sight.
Nuclear Warheads
With this stockpile of fissile material on hand, how many nuclear weapons might China currently have?
First, it is important to keep in mind that nuclear weapon states do not convert all of their fissile material into nuclear weapons but use part of it for weapons and leave the rest as a reserve for future needs. Therefore, one cannot simply translate the amount of fissile material into weapons.
Second, nuclear warheads need nuclear-capable delivery vehicles, missiles and aircraft that can bring the warheads to their intended targets. Delivery vehicles can give a better idea of the size of a nuclear arsenal. Most of China’s ballistic missiles are conventional or dual-capable, but the Georgetown University study includes all missiles in its 3,000-warhead projection, including short-range DF-11 and DF-15 missiles and medium-range DF-21C missiles.
Taking those and other factors into account, our current estimate is that China has approximately 240 nuclear warheads for delivery by nearly 180 missiles and aircraft. Nearly 140 of the operational missiles are land-based. Less than 50 of those can reach the continental United States.
The 240-warhead estimate also includes warheads produced for China’s ballistic missile submarine force (which is not yet operational), weapons for bombers, and some weapons for spares.
Our estimate is consistent with the estimate made by the U.S. Defense Intelligence Agency in 2006: “China currently has more than 100 nuclear warheads.”
