One-region buckling measurements that were made on a series of D/sub 2/O- moderated lattices of heavy uranium metal tubes in the Process Development Pile at Savannah River Laboratory are presented. The purposes of these measurements are to provide normalization points for lattice bucklings and to extend the study of natural uranium- D/sub 2/O systems. The dependence of buckiing on the moderator-to-fuel ratio is studied for two types of lattices.

Report issued by the National Bureau of Standards over studies conducted on the effects of mortar on the strength of masonry. Materials, methods, and results are presented and discussed. This report includes tables, illustrations, and photographs.

Abstract: New experimental data and literature data are utilized to determine the upper temperature of usefulness of zirconium alloys. Three basic engineering assumptions are used; (1) service life requirements are on the order of four years; (2) tubular fuel cladding for rod-type fuel is considered with a maximum wall thickness of 1.27 cm; and (3) heat fluxes are above 157 watts/cm. The inter-relation of three basic factors, corrosion rate, corrosion embrittlement by hydrogen and oxygen, and strength are considered. An upper limit for an acceptable corrosion rate for long-term service of 1 mg/dm/day is set primarily by the effect of heat-transfer on corrosion. For the best alloys anticipated, this requirement (even without considering transient conditions) limits cladding surface temperatures to less than 540 degree C. Oxygen embrittlement of the alloy substrate by oxide film dissolution is not expected to be a limiting factor. Corrosion hydrogen embrittlement was studied in detail and found to limit acceptable service to cladding surface temperatures of less than 525 degree C for established experimental alloys. Hydrogen embrittlement may not be a limiting factor if alloys corrosion resistant enough to be acceptable above 600 degree C could be developed. Zirconium alloys designed for high strength to …