• Cold testing of third Sanmen unit completed Such tests are carried out to confirm whether components and systems important to safety are properly installed and ready to operate in a cold condition. • The main purpose of cold functional tests is to verify the leak-tightness of the primary circuit and components - such as pressure vessels, pipelines and valves of both the nuclear and conventional islands - and to clean the main circulation pipes. • The tests mark the first time the reactor systems are operated together with the auxiliary systems. • China National Nuclear Corporation (CNNC) said the completion of cold tests at Sanmen 3 on Tuesday “is a key turning point in the nuclear power plant commissioning process, laying a solid foundation for subsequent tasks such as hot testing and fuel loading startup”. • Cold testing will now be followed by hot functional tests, which involve increasing the temperature of the reactor coolant system and carrying out comprehensive tests to ensure that coolant circuits and safety systems are operating as they should. • Carried out before the loading of nuclear fuel, such testing simulates the thermal working conditions of the power plant and verifies that nuclear island and conventional equipment and systems meet design requirements.
Article Summaries:
- China National Nuclear Corporation (CNNC) announced that cold functional tests of the Sanmen Nuclear Power Plant’s third unit (Sanmen 3) were completed on Tuesday. The tests, which verify leak‑tightness of the primary circuit and clean main circulation pipes, marked the first operation of reactor and auxiliary systems together. CNNC said the milestone is a key turning point in commissioning, paving the way for subsequent hot functional tests and fuel loading. Sanmen 3 is part of the plant’s Phase II expansion, which will add two more AP1000 reactors and, once operational, is expected to generate over 40 billion kWh annually, cutting 30 million tonnes of CO₂.
Sources: