Study On The Improved Quasi-Static Nodal Green's Function Method Under Cylinder Goemetry

The full scale simulator for High-temperature Gas-cooled Reactor (HTGR) is under development in Institute of Nuclear and New Energy technology, Tsinghua University. One of key technology for full scale simulator is to develop the fast physical dynamic calculation module. This physical dynamic module not only requires fast enough, but also can deal with the cylindrical geometry used in HTGR, and can be linked with thermo-hydraulic module and other simulating modules. Therefore, the Improved-quasi-static Cylindrical Nodal Green's function Method (IQS/CNGFM) is proposed and implemented and validated in this paper.All the mathematical formulas for the IQS/CNGFM method under cylindrical geometry are deduced and implemented in program code for the first time, based on the Nodal Green's Function Method for Cylindrical Geometry on Neumannn Boundary Condition and Improved-Quasi-Static Nodal Green's Function in Cartesian geometry. One of prerequisite for IQS/CNGFM is the physical nodal adjoint flux under cylindrical geometry. Through preliminary numerical verification, the IQS/CNGFM method is proven as feasible and reasonable.IQS/CNGFM approach is a good and fast method for cylindrical reactors's dynamic simulation. It provided good basis for building the fast physical simulation module for HTGR full scale simulator, although it should be improved in many aspects, such as iteration techniques, benchmark problem verification, real time technology, coupling with other modules, and etc.