China’s Nuclear Expansion: New Sites & Secret Tests Revealed

Deep in the mountainous terrain of southwest China, a significant expansion of nuclear facilities is underway, raising concerns about Beijing’s intentions as global safeguards against nuclear proliferation weaken. Satellite imagery analyzed by experts reveals extensive construction at sites in Sichuan Province, including new bunkers, protective walls, and complexes designed to handle hazardous materials.

The Zitong nuclear site, in particular, has seen substantial development since 2022. New bunkers and ramparts have been constructed within a lush valley, and a new complex featuring an extensive network of pipes – indicative of facilities dealing with highly hazardous materials – has been added. Experts suggest these bunkers are likely being used for high-explosives testing, a crucial step in refining the chemical detonators used in nuclear warheads. “You have a layer of high explosives and the shock wave at the same time implodes into the center. This needs blast tests to perfect them,” explained Hui Zhang, a physicist at Harvard University’s Kennedy School of Government, after reviewing the satellite findings.

Further bolstering these concerns is activity at the Pingtong facility, also located in Sichuan. Secured by double fencing, the site is dominated by a 2026-refurbished 360-foot-high ventilation stack, now equipped with new vents and heat-dispersal systems. Additional construction is taking place adjacent to the main structure. Experts believe Pingtong is a key location for the production of plutonium-packed cores for nuclear warheads.

The accelerated pace of construction, noted by geospatial intelligence expert Renny Babiarz, suggests a significant ramp-up in China’s nuclear capabilities since 2019. Above the entrance to the Pingtong facility, a prominent slogan from Chinese leader Xi Jinping – “Stay true to the founding cause and always remember our mission” – is visible even from space, underscoring the strategic importance placed on these projects.

These developments come amid heightened tensions and a shifting global security landscape. Last week, the United States accused China of conducting secret nuclear weapons tests, including a yield-producing test on June 22, 2020. U.S. Undersecretary of State for Arms Control and International Security, Thomas DiNanno, publicly disclosed the intelligence finding at the Conference on Disarmament in Geneva, alleging that China is employing a technique known as “decoupling” to conceal its activities. China has vehemently denied these allegations, dismissing them as “outright lies” and accusing the U.S. Of fabricating excuses to justify its own potential resumption of nuclear testing.

The U.S. Claims center around a technique called “decoupling,” which aims to mask the signature of nuclear explosions. While the U.S. Asserts evidence of such tests, independent verification remains elusive. Seismic data from June 22, 2020, the date of the alleged test, has not shown a definitive signature of an explosive event near China’s test site, according to some analyses.

The accusations and the observed expansion of Chinese nuclear facilities are occurring at a time when the global norm against nuclear testing is fraying. The last full-scale nuclear test took place in North Korea in 2017, and the potential for further testing by major powers raises serious concerns about a renewed arms race. The unraveling of these safeguards is particularly worrying given the development of new hypersonic weapons, which may require new types of warheads to be effective.

The Chinese government has not publicly addressed the specific findings from the satellite imagery, but the scale of the construction at Zitong and Pingtong suggests a long-term commitment to expanding its nuclear arsenal. The facilities’ remote locations and the secrecy surrounding their operations further contribute to anxieties about China’s strategic intentions. The expansion is taking place as China modernizes its military across all domains, including the development of advanced missile systems like the DF-17, which was showcased in a military parade in Beijing in September 2025.

The situation is being closely monitored by international observers, who fear that a lack of transparency and dialogue could escalate tensions and undermine efforts to maintain global stability. The combination of alleged secret testing, rapid facility expansion, and a deteriorating international arms control regime presents a complex and potentially dangerous challenge to global security.