Heat transfer calculations were performed with the aid of the IBM 7090 to determine whether or not feasible graphite channel coring patterns could be adopted at the five older Hanford Reactors. The purpose of front and rear process channel coring is to significantly reduce or eliminate net expansion of the fringe graphite by raising the operating temperature above the annealing temperature of 300{degree}C. The results of the study show that such coring patterns are possible. Also, it was found to be possible, and indeed desirable, to standardize the patterns into one front face coring pattern and one rear face coring pattern for all five of the reactors: B, D, F, DR, and H. The resulting coring patterns are presented. These coring patterns will significantly reduce the net rate of expansion in the filler blocks and consequently reduce the inlet and outlet humps in the process channels. This will allow standard 8-inch fuel elements to be charged in all tubes. The afore-mentioned coring patterns will limit the pile gas atmosphere to a range of between 90% He - 10% CO{sub 2} and 100% He. If a greater percentage of CO{sub 2} were used following the adoption of the coring patterns, the …

Mathematical relations are presented for estimating the release fractions of gaseous fission products from coated fuel particles and fuel elements containing them. The relations are based on simplified models of the release process, with particular emphasis on the following mechanisms: recoil, diffusion from fuel, diffusion through particle coating, and diffusion through fuel element matrix. The characteristics of fission-gas release by these mechanisms, acting singly and in combination, are considered, and the application of the theoretical relations to experiment planning and interpretation is discussed. Special attention is given to methods for analysis of data from continuous, in-pile (sweep capsule) release experiments and neutron-activation release experiments. (auth)

Evidence of bowing was observed in an MTR beryllium shim rod section during the Cycle 184 shutdown. Inspection and measurements of this and other selected beryllium lattice pieces confirmed this observation. Preliminary measurements were made along a vertical transverse between the north and south reflector walls with some bowing again noted. An inspection of the north wall revealed cracking and spalling of the beryllium sections, primarily in the vicinity of the HB-2 thimble. (auth)

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