Study of HTR-10 Initial Core Loaded with homogeneous Mixture of Spherical Graphite and Spherical Fuel Elements

摘要

For HTR-10 the initial core is loaded with homogeneous mixture of spherical graphite andrnspherical fuel elements. The mode of fuel management of the HTR-10 was studied, including thernsimulation of the fuel shuffling process and the measurement of the burnup of a fuel element. Thernprior consideration was the design of the equilibrium state. Based on this the fuel loading of therninitial core and the fuel shuffling mode from the initial core through the running-in phase into thernequilibrium state were studied. The code system VSOP was used for the physical layout of thernHTR-10 at the equilibrium state and in the running-in phase. For the equilibrium state, in order tornlessen the difference between the peak and the average burnup, 5-fuel-passage-through-the-corernwas chosen for the fuel management. The average burnup of the spent fuel for the equilibriumrncore is 80000 MWd /t, and the peak value of it is less than 100000 MWd /t when the burnup ofrnthe recycled fuel element is under 72000 MWd/t. The initial volume fractions of the fuel and therngraphite elements were 0.57 and 0.43 respectively. During the running-in phase, the volumernfraction of graphite will decrease with the fresh fuel elements being loaded from the top of therncore and the graphite elements discharged from the bottom of the core. The fuel shuffling modernis similar to that of the equilibrium state. The burnup limit of recycled fuel element is also 72000rnMWd /t and the peak burnup is less than 100000 MWd /t. Finally the core will be full of fuelrnelements with a certain profile of burnup and reaches the equilibrium state.