Recent disclosures have raised serious concerns that China may have gained access to powerful U.S. government funded supercomputing systems and used them to support military modernization, including nuclear weapons research. Lawmakers now warn that American taxpayers may have unintentionally helped advance China’s strategic capabilities.

The issue was brought to light by Rep. John Moolenaar, chairman of the House Select Committee on the Chinese Communist Party. In a January 15 letter, he asked the National Science Foundation to explain why Chinese institutions appear to have access to its supercomputing infrastructure. His letter argues that this access may directly undermine U.S. export controls and national security.

At the center of the controversy is the Advanced Cyberinfrastructure Coordination Ecosystem: Services and Support, known as ACCESS. Although run by a civilian agency, ACCESS is the main supercomputing hub for U.S. academic research in sensitive fields such as nuclear science and artificial intelligence. These systems are essential for advanced simulations, weapons modeling, and frontier AI development.

How China Allegedly Gained Access

Under current rules, ACCESS users must be based in the United States. However, U.S. based researchers are allowed to add foreign collaborators to their projects. According to the congressional investigation, this loophole may have been exploited. Screenshots reviewed by investigators and journalists show dozens of Chinese universities listed as approved entities, including institutions tied directly to the Chinese military.

Among the universities reportedly able to access the system is the National University of Defense and Technology, an institution under U.S. export controls for its role in developing military technology. Several of the so called Seven Sons of National Defense, which train engineers and scientists for China’s defense sector, also appear to have standing access.

High performance computing is a cornerstone of modern weapons development. These systems can simulate nuclear detonations, model missile performance, train advanced AI systems, and accelerate materials research. Lawmakers warn that remote access to U.S. supercomputers could allow Chinese military researchers to conduct sensitive work without buying export controlled chips or hardware.

Failures That Allowed the Breach

The primary failure appears to be weak oversight of federally funded research programs. While export controls block the sale of advanced supercomputers to China, remote access through academic collaboration may have bypassed those safeguards. Investigators also point to insufficient vetting of foreign institutions and a lack of routine audits to ensure compliance.

The full extent of the damage remains unclear. The National Science Foundation has not yet confirmed which Chinese entities accessed the systems, what projects they worked on, or how long access may have lasted. Lawmakers fear that Chinese researchers could have completed advanced simulations while American scientists waited in line for computing time.

This is not the first time China has been accused of exploiting U.S. research programs. A separate congressional study found that the Department of Energy had funded thousands of nuclear related research papers authored by Chinese academics linked to military and defense industries. These findings come as China rapidly expands its nuclear arsenal and displays all three legs of its nuclear triad.

Reporting by Nextgov/FCW confirmed that Chinese institutions appear in ACCESS system listings. Lawmakers warn that this may allow blacklisted entities to bypass export controls entirely. Rep. Moolenaar’s letter argues that Chinese users could run advanced simulations from within China while relying on U.S. funded infrastructure.

The concern is heightened by past enforcement failures, including a case where Cadence Design Systems admitted to selling chip design tools to Chinese front companies tied to military universities.

Calls for Immediate Action

Members of Congress are urging the NSF to audit the ACCESS program, revoke access for any institution linked to an adversarial military, and tighten research security rules. They also want federal agencies to ban joint research with sanctioned Chinese institutions and push the Department of Justice to prioritize academic espionage cases.

The controversy has reignited debate over whether U.S. research openness is being weaponized against American interests. Even as export controls tighten, recent decisions to allow limited sales of advanced chips like the Nvidia H200 to China have drawn criticism from lawmakers who argue that enforcement gaps remain wide. For critics, the ACCESS case is a warning that without stronger safeguards, America’s own scientific infrastructure could continue fueling the military rise of its chief strategic rival.