en.Wedoany.com Reported - China's State Nuclear Power Automation System Engineering Co., Ltd. (SNPAS) has completed the on-site filling operation for the 100% domestically produced 1E-grade pressure and differential pressure transmitter (JE52) equipment supplied for the Sanmen Nuclear Power Project Unit 3. Accuracy tests have confirmed the results are qualified. This marks the first domestic supply of nuclear safety-grade pressure and differential pressure transmitters in China, providing crucial support for the autonomous development of the nuclear power industry chain.
The 1E-grade pressure and differential pressure transmitter is a core device for monitoring containment pressure in nuclear power plants. It performs critical monitoring functions under Design Basis Accident (DBA) conditions, and its performance directly impacts nuclear power operation safety. This device adopts a split-structure design: the sensing unit is installed inside the nuclear island containment, enduring high temperature, high pressure, and high radiation environments; the transmitter unit is installed in the plant building outside the containment, extending equipment lifespan and facilitating maintenance. The sensing unit and transmitter unit are connected via a capillary tube, which must be routed through the containment. Due to the long length and complex routing of the capillary tube, it is impossible to transport the pre-filled assembly from the factory. Therefore, vacuum evacuation and filling operations must be performed on-site after installation.
Previously, similar equipment for AP1000 projects relied on long-term imports. To address the challenge of achieving autonomous and controllable supply chains, SNPAS has spearheaded domesticization efforts since 2023, establishing an integrated "R&D and Supply" working mechanism. For the first time, SNPAS provided a one-stop service for a nuclear power project that includes not only equipment supply but also on-site nuclear-grade capillary tube welding, non-destructive testing, filling, and accuracy testing.
The on-site operation faced multiple technical and management challenges, with no mature operational procedures in China to reference. On-site filling involves special processes such as staggered welding of penetration assemblies, non-destructive testing, vacuum evacuation, and filling, for which related procedures and standards were previously non-existent in China. Simultaneously, the nuclear safety regulatory authority has stringent witnessing requirements for the installation process's workflow and quality control, necessitating the establishment of comprehensive operational specifications during the preparation phase for on-site services.
The filling work must be completed before the containment pressure test. SNPAS collaborated with Sanmen Nuclear Power, Shanghai Nuclear Engineering Research & Design Institute (SNERDI), Shanghai Automation Instrumentation Co., Ltd. (SAIC), and other units to advance the project, clarifying material lists and operational key points, and efficiently promoting preliminary preparations and process readiness. Under the supervision of the East China Nuclear and Radiation Safety Supervision Station and with the full cooperation of all parties, the team initiated material reporting during the Spring Festival period. From the start of on-site operations to the completion and qualification of accuracy tests, the team strictly implemented a continuous operation plan, ensuring seamless connection between all stages. This guaranteed the vacuum evacuation process was completed in one continuous operation, taking 22 days in total and securing a critical window for the subsequent containment pressure test.
This breakthrough is a concrete practice of SNPAS in implementing the core values of "Green, Innovative, Integrated, True Faith, True Action, True Achievement" upheld by State Power Investment Corporation (SPIC). It showcases the company's strategic layout in achieving autonomy in the nuclear power instrument and control equipment supply chain. Through the fully self-managed operation process, the team not only overcame technical challenges such as vacuum environment control and continuous operation process assurance, achieving a substantial breakthrough from "0" to "1" in domestic on-site filling services for nuclear-grade instruments, but also established comprehensive on-site filling operation specifications. This provides engineering practice validation for building domestic supporting capabilities and enhancing the security and resilience of the industrial and supply chains.
In the future, SNPAS will continue to focus on independent innovation in nuclear power instrument and control equipment, closely aligning with the national strategy for self-reliance and strength in science and technology. The company will persistently advance the domesticization process of key nuclear power instrument and control equipment, contributing solid strength to the iterative upgrading of China's nuclear power technology and the building of a nation strong in science and technology!
This article is compiled by Wedoany. All AI citations must indicate the source as "Wedoany". If there is any infringement or other issues, please notify us promptly, and we will modify or delete it accordingly. Email: news@wedoany.com
