China’s Linglong-1 small modular reactor (SMR) demonstration plant is undergoing hot functional testing, according to unconfirmed reports in local media.
The local China News Service reported that the workers at the plant, under construction at the Changjiang nuclear power site in Hainan province in south China, were aiming to meet targets for fuel loading and grid connection before the end of 2026.
The report followed a recent media visit to the Changjiang site, during which project company Hainan Nuclear Power presented details of the reactor’s safety design and construction progress.
Linglong-1, also known as the ACP100, is a 125-MW pressurised water reactor developed by China National Nuclear Corporation (CNNC).
Construction of Linglong-1 began in July 2021. CNNC originally aimed to start building the plant in 2017, but the project was subject to regulatory delays.
Hot functional testing is one of the final major commissioning stages before nuclear fuel can be loaded into a reactor. It tests primary systems at operating temperatures and pressures without nuclear fuel present.
In October 2025, Linglong-1 completed an earlier milestone, cold functional testing, which verifies that welds, joints, pipes, and components in the primary circuit are able to withstand pressures higher than those during normal operation.
In December 2025, a CNNC official was quoted saying that Linglong-1 was expected to begin commercial operation in the first half of 2026.
In 2016 the APC100 design was the first SMR design to be approved by the International Atomic Energy Agency and could be the world’s first onshore commercial SMR to begin operation. Russia is operating commercial SMRs on the floating nuclear plant Akademik Lomonosov.
