Pre-Conceptual Design and Analysis of a SCWR-FQT Loop Test Section Based on CSR1000

Two preliminary conceptual designs of test section for fuel qualification test loop based on China’s supercritical water-cooled reactor（CSR1000） fuel element is proposed, which are the 2×2 assembly design and the 3×3 assembly design. The MCNP code and the CFX code are used to proceed the neutron, the thermal-hydraulic analysis and the preliminary evaluation of different designs. The results show that the two designs are engineering feasible and meet the requirements of fuel qualification test, but there are significant differences in performance. The fuel rod power of the 2×2 assembly is 23.6 25.3 k W and the average power is 24.3 k W, while these values for 3×3 design are 15.9~26.7 k W and 21.4 k W, respectively. The radial power peak factor of fuel assembly for 3×3 design is 1.25, which is not conducive to fuel assembly power flattening, limiting the average power of the assembly. The preliminary thermal-hydraulic analyses with wireless fuel assembly indicate that the outlet coolant temperature of the two designs exceeds the quasi-critical temperature of the pressure of 25 MPa, and the fuel pellet temperature and the fuel cladding outer surface temperature are lower than the design limits, allowing certain safety margins.