Search

Highlights • An integrated analysis of blanket and EDPP is carried out with the conventional FE method code (ANSYS). • The EDPP has larger influence on the EM loads distribution of the IB blanket compared to the OB blanket. • A diagnostic port plug with small front openings could be useful to reduce its effect on the EM loads of the blanket system. Abstract The Chinese Fusion Engineering Test Reactor (CFETR) is the next step in China's research into fusion energy. In phase I, the preliminarily design of diagnostic systems for the CFETR was completed; however, the material and spatial position of the diagnostic systems severely affect EM loads distribution in blanket modules. In order to evaluate the effect of a diagnostic port plug on the EM loads distribution in the blanket system of CFETR, a finite element (FE) model with an equatorial diagnostic port plug (EDPP) was established using ANSYS. The EM forces and moments are calculated and discussed, followed by a comparison of EM loads in the helium-cooled ceramic breeder (HCCB) blanket to verify the EM effect of the EDPP. Simulation results show that the EM loads in the inboard (IB) and outboard (OB) blanket modules and segments were changed with the EDPP, but the direction of the main loads on the blanket system did not change. The results also show that the EDPP has a greater influence on the EM loads of the IB blanket compared to the OB blanket, meaning it is necessary to take into account the effect of the EDPP during the evaluation of the mechanical design of the blanket system in further studies. The investigation presented here may also serve as a technical reference for the design and optimization of diagnostic port plugs in the future. [ABSTRACT FROM AUTHOR]

• The EBW test of different weld penetration and scale FW with W/Cu sheets was realized. • When the weld penetration is small, the surface focus welding is the best. Otherwise, the lower focus welding is the best. • Reduced scale FW welding with weld width less than 4 mm and good surface forming is realized. Water- cooled ceramic breeder (WCCB) blanket is one of the candidate blanket for China Fusion Engineering Test Reactor (CFETR) independently developed by China Institute of plasma physics. The first wall (FW) is a component of WCCB, which directly faces the plasma. FW contains flow channels and has complex shape structure, therefore, it is difficult to complete the full-scale manufacturing by one kind of welding process. Hence, in the development process, the components of FW are first connected by hot isostatic pressing (HIP), and then connected by electron beam welding (EBW), so as to form the full-scaled FW connection. In this paper, the EBW process of FW was studied. The results showed that when the electron beam current was 50 mA and the focus was on the surface, the welded joint with 20 mm penetration and good shape can be formed. After the one time welding and the twice welding (overlapping first welding) of the weld, the tensile test fracture occurred in the base metal. The impact energy of the one time welding was 13 MPa, 18 MPa, and 21 MPa, respectively, and the impact energy of the twice welding was 19 MPa, 20 MPa, and 51 MPa, respectively. The microstructure of the joint was composed of δ-ferrite and lath martensite. When the weld penetration was increased to 50 mm, the lower the focus is, the smaller the porosity at the bottom of the weld is. Similarly, when the lower focus was used, the porosity at the bottom of the weld disappeared basically; The EBW test on the scaled FW with W/Cu sheets showed that when the we took the test pieces with the W-Cu sheet spacing is 4 mm, the welded joint with good surface shape and no internal defects can be formed without scanning deflection electron beam welding, and ultrasonic testing showed that EBW does not affect on the HIP interface. This provides a favorable basis for the future test of equal ratio FW test piece and the welding of actual FW. [ABSTRACT FROM AUTHOR]