What happened at the Taishan Unit 1 nuclear plant in China?

June 14, 2021, CNN reported that the Chinese Taishan Unit 1 EPR nuclear reactor experienced unusual operating conditions. Specifically, Framatome warned of an “imminent radiological threat”. The warning included an accusation that the Chinese safety authority was raising the safety limits for radiation detection limit to avoid having to shut it down. June 16, 2021, fuel failures at Taishan 1 were confirmed by the World Nuclear News. I was directly involved in analyzing the EPR for control system cyber security. The EPR’s initial “approved” design could not meet nuclear safety requirements. It is unclear whether Taishan is utilizing those or other cyber insecure systems or have interconnected control and safety systems. Consequently, I was surprised when Taishan Units 1 and 2 were given approvals to connect to the grid considering the ongoing safety issues of the EPRs in Europe. However, just like the issue with the hardware backdoors with the Chinese transformers, the information released by the Chinese creates more questions than answers. Most troubling to me are two questions: why would the Chinese continue to operate a nuclear plant with known fuel failures that increases risk to the plant staff and off-site population; and why didn’t the plant automatically shut down? What happened at the Taishan Unit 1 nuclear plant in China?


Control Systems Cybersecurity Expert, Joseph M. Weiss, is an international authority on cybersecurity, control systems and system security. Weiss weighs in on cybersecurity, science and technology, security emerging threats and more.