China’s nuclear warheads require both plutonium and uranium, with its older uranium stock expected to deplete sooner. The enrichment capabilities added at the Emeishan facility since 2022 could address this deficit in a matter of months, according to estimates from Hui Zhang of the Bulletin of the Atomic Scientists.
A new report suggests that China’s aging uranium reserves can only equip approximately 670 warheads, prompting increased production at the Emeishan plant. In response, India must avoid merely trying to catch up.
It is believed that China halted the production of fissile materials for weapons, including uranium and plutonium essential for nuclear bombs, in the late 1980s. Unlike the United States, Russia, Britain, and France, China never officially announced this cessation. Instead, researchers have deduced this information from the memoirs of former nuclear personnel, statements from retired officials, academic publications, and satellite imagery, forming a consensus among arms control experts. Under this assumption, China’s nuclear stockpile, which remained around 200 warheads for three decades, has now increased to approximately 620, all derived from materials produced prior to the supposed halt.
The Bulletin of the Atomic Scientists’ latest analysis indicates that this pre-1987 uranium stock is nearing its limit. It estimates that only around 670 warheads can be armed with this older uranium. In contrast, the United States anticipates that China’s arsenal could exceed 1,000 by the year 2030. This analysis leads to the conclusion that China has likely resumed the production of weapons-grade highly enriched uranium (HEU) at its expanding Emeishan facility.
If accurate, this development would remove the primary constraint on the growth of China’s nuclear arsenal, putting pressure on India to enhance its own capabilities in response to China’s military expansion.
Details from Emeishan
Natural uranium consists of only about 0.7% uranium-235, the isotope responsible for sustaining a nuclear chain reaction. Power reactors typically use uranium enriched to between 3% and 5%, while weapons-grade uranium requires enrichment to 90% or higher. The enrichment process is carried out using fast-spinning centrifuges, and a plant’s output is measured in separative work units (SWU), which quantifies the effort involved in separating lighter uranium isotopes from heavier ones.
China does not disclose its enrichment capabilities, but the analysis reconstructs this information plant by plant based on satellite imagery and Chinese-language resources. The China National Nuclear Corporation (CNNC), the state-owned entity overseeing the nuclear fuel cycle, operates three enrichment facilities located in Lanzhou (Gansu), Hanzhong (Shaanxi), and Emeishan. In 2020, their combined output was approximately 7.4 million SWU annually, projected to increase to about 15.4 million by the end of 2026. Emeishan has experienced the most rapid growth, increasing from around 2.2 million SWU per year until 2022 to an expected 5.4 million.
Three factors distinguish Emeishan from other facilities. Firstly, it is not necessary for China’s power reactors. Between 2010 and 2025, Chinese reactors produced roughly 92 million SWU, surpassing the reactors’ requirements of about 89 million, resulting in a surplus of around 41 million SWU by 2025. Secondly, the facility operates under a veil of secrecy; the annual reports of China’s civilian nuclear regulatory body mention Lanzhou and Hanzhong but omit Emeishan entirely, and the site has never been made available for inspection by the International Atomic Energy Agency (IAEA). As one of the five nuclear-armed states recognized by the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), China is not obligated to permit inspections. Lastly, Emeishan is managed by Plant 814, which previously operated the Heping gaseous diffusion plant, one of China’s sources for bomb-grade uranium from 1970 to 1987.
China’s need for uranium stems from the construction of modern warheads. The primary stage typically consists of a fission bomb made from plutonium, which detonates the secondary stage that generates the majority of the explosion, relying on HEU. Analysts have largely questioned whether China possesses sufficient plutonium for its arsenal expansion, but findings suggest uranium is the more critical limitation. Estimates indicate that China’s older plutonium could arm around 1,200 warheads, but to achieve a stockpile of 1,000 by 2030, approximately 7 additional tonnes of HEU would be required.
Emeishan could rapidly fulfill this requirement. At its projected capacity for 2024-25, it could generate the necessary 7 tonnes in less than five months.
The timing aligns with significant developments. In late 2015, President Xi Jinping upgraded the Second Artillery Force, the missile arm of China’s military, to the People’s Liberation Army Rocket Force. Since 2020, China has established three fields containing over 300 missile silos, and work on Emeishan’s third plant resumed in 2019, becoming operational in 2023, coinciding with an annual increase of about 50 warheads.
While the analysis acknowledges that the evidence remains circumstantial and that China has made no official declarations, it posits that there is no civilian rationale that adequately explains the surplus, secrecy, military necessity, and the timing of these developments. Unlike the other nuclear powers, China’s lack of a formal cessation means that resuming production does not breach any public commitments. However, it contradicts Beijing’s assertion of maintaining its nuclear arsenal at the minimum level required for national security.
India’s Position in the Nuclear Landscape
China’s expansion appears primarily aimed at countering the United States. Historically, Beijing maintained a small arsenal based on the belief that a limited number of warheads would suffice to deter adversaries. However, recent American advancements have unsettled this belief.
The first concern is missile defense. In May 2025, then-President Donald Trump unveiled the Golden Dome initiative, a proposed $175 billion defense system of satellites, sensors, and interceptors aimed at safeguarding the American homeland. Beijing fears this system could neutralize the limited number of missiles a small Chinese force might launch in retaliation following an attack. At a summit in Beijing this May, Xi Jinping and Vladimir Putin criticized the initiative.
The second concern arises from the capabilities of American conventional weaponry. Precision long-range missiles, supported by an extensive network of surveillance satellites, could potentially locate and incapacitate Chinese launch sites without deploying nuclear arms. The tensions surrounding Taiwan intensify both of these apprehensions. The first new silo fields in China were revealed in 2021, leading the Global Times, a state-run media outlet, to assert that possessing sufficient nuclear capability to deter the United States regarding Taiwan would be essential for China’s national interests.
The weaponry being developed in China reflects this trajectory. Analysts believe the newly constructed silos in its northern deserts are intended for the DF-41 intercontinental ballistic missile, which has an estimated range of 12,000 to 15,000 kilometers. The Center for Strategic and International Studies (CSIS), a think tank based in Washington, indicates that it could reach the continental United States in approximately half an hour. None of these developments, however, are specifically directed at threatening India, which has long been within range of shorter-range Chinese missiles such as the DF-21 and DF-26. Manpreet Sethi, a distinguished fellow at the Centre for Air Power Studies in New Delhi, noted in August that Beijing’s primary goal is to
