Control and behavior of O/M, offgas and moisture during fabrication of mixed oxide (25 percent PuO$sub 2$--75 percent UO$sub 2$) for HEDL irradiation testing [report]

K. Chidester, W. Warden
1972 unpublished
In producing fuel for irradiation testing some variables of concern include 0/M, offgas and moisture in the finished pellet. Of these three we have found 0/M to be the most difficult to predict and control on any given batch fabrication. Our program over the past several months has emphasized three major areas where these variables must be considered. SLIDE 1: The first area of emphasis is fabrication of fuel pellets to RDT specifications. Fuel design people wish to have a record of performance
more » ... cord of performance of fuel meeting their stringent requirements. Until recently the 0/M specification was at 1.97 +0.02. Several batches were made to this specification and irradiated. The newest RDT 0/M specification defines the acceptable range for batch 0/M averages as 1.94 -1.97 with no individual pellet greater than 1.98. . The second area of emphasis has been fabrication of fuel for special experiments involving 0/Ms outside the RDT specification and adjusting 0/M within the RDT specification range. . The third area of major concern in most recent months has been the study of 0/M offgas and moisture stability after sintering. This includes the drift phenomena and methods of control. In discussing the first area "Fabrication of Fuel to RDT Specification" it would be most helpful to illustrate the type of furnaces used and the success achieved in each. SLIDE 2: (Brew furnace, Pereny furnace (schematics) sketches) The Pereny was used at the beginning of the program to fabricate fuel. It is a ceramic muffle furnace capable of 1690°C. The fuel sits here and the gas, Argon 8% ^ flows from this end out. The Brew is the furnace in use at present and is an all-metal furnace consisting of molybdenum heat shields, tungsten mesh heating elements and molybdenum sintering boats. The gas inlet is here (Point) and the out let here (Point). The furnace is
doi:10.2172/4595388 fatcat:5cd5p3d6f5a67fx26boijh7dtq