Research On Real Time Simulation Of Fine Power Distribution

The distribution of reactor core power is a very important parameter to reactor safety. If the power distribution can be known in time, the reactor safety can be guaranteed, and further more, the output power will increase, which increases economy benefit. The reactor physics calculation program based on Nodal Green's Function Method was studied and was used to realize real time simulation to calculate reactor power distribution.As an advanced nodal method, Nodal Green's Function Method(NGFM) is good at its calculation speed and accuracy, and can provide parameters for pin power calculation. Started from the basic model and basic equations of Nodal Green's Function Method, the structure and relations between modules of NGFM program was analyzed. SimExec is a real time simulation system, the execute mechanism and the operation method of SimExec real time simulation system was studied, then the Nodal Green's Function Method program was modified and debugged, and then it was transplanted to the Simexec system.In this thesis, the Green's Function Method real time simulation program and the fine power distribution program were designed. Through a benchmark problem, the real time simulation program was verified; the results were compared with the NGFM program results before transplantation, which showed that the program was correctly transplanted, the computer CPU time showed that it can meet the requirement of real time simulation. After that, the program was used to calculate the power distribution of Qinshan- II nuclear power plant, and the results were analyzed.Fine power distribution method and a reconstruction program was studied, after that, the program was transplanted to SimExec. Fine power calculation program outputs of benchmark problem properly reflected the power distribution.