The operating license of Chinshan NPP Unit 1 was the first to expire. The expiration took effect in December 2018, followed by Unit 2 in July 2019. The operating licenses of Kuosheng Unit 1&2 expired in December 2021 and March 2023, respectively. After that, the operating licenses of Maanshan Unit 1&2 expired in July 2024 and May 2025, respectively. After the operating licenses of these three NPPs expired, they entered the decommissioning phase accordingly.

The spent fuel pools of the Chinshan and Kuosheng NPPs have almost reached their full capacity. Therefore, during the transitional period, the spent fuel assemblies in the reactors could not be defueled until the spent fuel dry storage facilities become operational. In order to strengthen spent fuel safety during this transitional period, the NSC continues to implement regulatory inspections of the maintenance and testing of related systems and equipment, in accordance with the quality requirements for operating NPPs.

The NSC has adjusted performance indicators that are either: Not applicable during an NPP’s decommissioning period or; The indicators for mitigating systems that are no longer needed after an NPP is permanently shut down. Certain adjustments were also made to the inspection procedures in accordance with the safety requirements of the NPP decommissioning period. The NSC is to inspect, measure, and assess the safety and security performance of those NPPs in the process of being decommissioned, taking necessary regulatory measures accordingly.
 
 Performance Indicators
 Inspection Findings
 The Thresholds of Performance Indicator