STUDY ON IN-CORE FUEL MANAGEMENT AND OPTIMIZATION FOR URANIUM ZIRCONIUM HYDRIDE RESEARCH REACTOR

In this paper the in-core fuel management and optimization of refueling loading pattern for the uranium zirconium hydride research reactor is studied and a set of practicable valuable code packages in engineering is developed. The scattering mechanism of H in ZrH is studied by the general scattering law. Considering the acoustic (DEBYE spectrum) and optic (GAUSS spectrum) model of hydride zirconium, its frequency spectrum distributing function is given， the scattering law and the scattering kernel in the thermal region of H in ZrH are also obtained. Then in accordance with the structure and the form of the 69-group library of WIMS the microscopic cross-sections of H in ZrH and Er are prepared. A few-group neutron macroscopic cross section for all types of cells are generated using WIMS-D/4. The global core analysis is performed using SIXTUS and CITATION. The excess reactivity, neutron flux, power distribution and power peaking factors are studied. The code package HEX-ICFM is encoded for the in-core fuel management. Finally, the orthogonal design model and the program HEX-ORTH is developed for the optimization of refueling loading pattern for the uranium hydride zirconium reactor. In order to reduce the fuel cost, the loading patterns of four cycles are calculated with the objective function Max(Keff BOC ). The calculated results demonstrate that HEX-ORTH can give out automatically the optimum refueling plan and higher objective values.