Fisher said he also had doubts about the report’s contention that China had limited access to plutonium. Estimates of the size of China’s plutonium stock, the report says, are uncertain, but imply that the number of new warheads that could be produced from that stock would be limited, probably from “very few” to a “several hundred.”
However, while China has halted production of military plutonium, it has not declared an official moratorium. And while Beijing officially supports negotiations on a Fissile Material Cut-off Treaty that would ban all future production for weapons use, Chinese concerns about US missile defense systems have diminished its enthusiasm for the treaty, the UCS report said.
There are also reports that China recently began operating a pilot plant for reprocessing spent fuel rods from civilian nuclear reactors and operates an experimental fast breeder reactor. If it chose, China could divert plutonium from those two plants for weaponization, it said.
“How do we know there does not exist a separate underground PLA network for fissile production that we would likely never see? There is also the matter of the PLA deciding to make warheads with smaller amounts of fissile material, meaning any fixed amount can result in a greater number of warheads,” Fisher said.
Yet another factor could be technologies that enable more efficient use of available fissile material, he said, adding that lack of current, detailed information on China Academy of Engineering Physics research institutes and factories that could be actively involved in warhead-related work was another blind spot.