Speaker
Description
Xiaoyong Wang, Ziqiang Zhao, Zaixin Li
Southwestern Institute of Physics, No.5 Huangjin Road, Shuangliu District, Chengdu City, Sichuan Province, China
The breeding blanket is a key component of the DEMO reactor, essential for tritium breeding, energy extraction, and nuclear shielding. To achieve a higher Tritium Breeding Ratio (TBR), a novel helium-cooled ceramic breeder (HCCB) blanket with a casing structure has been proposed. This design features two concentric pipes: the inner pipe contains lithium silicate, and the annular gap serves as a helium cooling channel. Surrounding the outer pipe is a beryllium (Be) pebble bed, which enhances the blanket's performance.
The casing structure is designed for simplicity and robustness. Using two concentric pipes simplifies the accommodation of lithium silicate and the helium cooling channel, ensuring structural integrity and ease of manufacturing. This reduces the number of welds, minimizing potential weak points and enhancing reliability. The structure also optimizes material usage, reducing costs while maintaining high performance.
A comprehensive optimization analysis covering neutronics, thermo-hydraulics, and mechanics has been conducted. Neutronic analysis shows a TBR of approximately 1.2 for the entire DEMO reactor, even with windows for diagnostic and heating systems. Thermal-hydraulic results indicate that the temperatures of the Be pebble bed (561℃), lithium orthosilicate (870℃), and reduced-activation ferritic/martensitic steel (RAFMs) (538℃) are all below their respective limits, ensuring thermal stability and safety. Thermal-mechanical analysis shows a maximum stress of 265 MPa during normal operation and 371 MPa during an in-box Loss of Coolant Accident (LOCA), meeting safety requirements.
The HCCB breeding blanket with a casing structure represents a significant advancement in DEMO reactor technology. Its simple and robust design, reduced welds, and optimized material usage enhance tritium breeding efficiency and reactor safety. Future work will focus on refining the design, conducting experimental validations, and exploring scalability for practical application. This design provides valuable insights for future breeding blanket technologies.
