Satellite imagery shows new construction and upgrades at several nuclear-related sites in China's Sichuan province, including facilities analysts link to warhead component work, as U.S. and Russian limits on strategic arsenals lapsed this month.
A New York Times report, reprinted Sunday by Business Standard, described activity at a valley site known as Zitong, saying engineers built new bunkers and ramparts and added a complex "bristl[ing] with pipes," which analyst Renny Babiarz said suggested handling "highly hazardous materials."
At another valley site known as Pingtong, the report said experts believe China is making plutonium pits, the metal cores of nuclear warheads, and that a main building dominated by a 360-foot ventilation stack has been refurbished with new vents and heat dispersers, with additional construction underway.
Babiarz, a geospatial intelligence expert who analyzed satellite imagery and shared his findings with the Times, said the visible pattern across the sites suggests a broad expansion.
"There's been evolution at all of these sites, but broadly speaking, that change accelerated starting from 2019," he said.
The report also noted prominent signage above Pingtong's entrance with an exhortation attributed to Chinese leader Xi Jinping: "Stay true to the founding cause and always remember our mission."
The Sichuan facilities were built decades ago under Mao Zedong's "Third Front" effort to move sensitive production inland, and the report said the sites continued operating even after other facilities closed or shrank in the 1980s.
The recent buildup includes a large laser ignition laboratory in Mianyang that could be used to study warheads without detonating them.
Some experts cautioned that satellite imagery can show construction but not production outcomes.
Hui Zhang, a physicist at Harvard Kennedy School cited in the report, said imagery alone offers limited information and that some changes could be safety upgrades.
"We don't know how many warheads have been produced, but we just see the plant expansion," he said.
The report described the buildup as a growing point of friction with Washington after U.S. arms control official Thomas G. DiNanno accused China this month of secretly conducting "nuclear explosive tests" in 2020.
Reuters reported DiNanno said one "yield-producing test" occurred June 22, 2020, while the Comprehensive Nuclear-Test-Ban Treaty Organization's monitoring chief said the system did not detect an event consistent with a nuclear test at that time.
China's Foreign Ministry called the allegation "completely groundless" and accused the U.S. of "fabrication of pretexts" for its own potential resumption of testing.
The scrutiny arrives amid a wider arms-control gap.
The New START Treaty between the U.S. and Russia expired Feb. 5, and U.N. Secretary-General Antonio Guterres urged the two countries to negotiate a successor framework.
Reuters contributed to this story.
Jim Thomas ✉
Jim Thomas is a writer based in Indiana. He holds a bachelor's degree in Political Science, a law degree from U.I.C. Law School, and has practiced law for more than 20 years.
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