الفهرس | Only 14 pages are availabe for public view |
Abstract The thesis consists of two main parts.Part 1 deals with the preparation of sinterable UO2 powders suitable for ceramic nuclear fuel fabrication.This was achieved by the hydrogen reduction of APU to UO2.The time for complete reduction at 500,700,and 900 was found to be 6,2,and 2 mintes respectively.The effects of the reduction temperature,reduction time and the cooling medium on the resulting oxygen to uranium ratio were studied. Methods of powder characterization such as optical microscopy,air permeability,differential thermal analysis and x-ray line broadening were investigated. The results indicated the crystallite size to be 2154A,323!A and 4307A at 500,700 and 9000C. The powders were also characterized by the DTA to have peak seperations of 170,120 and 120 0c for the 500,700 and 900 C preparations,respectively. Sintering behaviour at 138 0C for 1 hr in H2 has shown the powder to be more sinterable compared to others investigations.Sintered densities up to 95% could be obtained in the present study. Part 2 deals with the development of a reduction sintering process for APU compacts. |