Results are presented of work performed on the Advanced Gas-Cooled Nuclear Reactor Materials Evaluation and Development Program. The objectives of this program are to evaluate candidate alloys for Very High Temperature Reactor (VHTR) Nuclear Process Heat (NPH) and Direct Cycle Helium Turbine (DCHT) applications, in terms of the effect of simulated reactor primary coolant (helium containing small amounts of various other gases), high temperatures, and long time exposures, on the mechanical properties and structural and surface stability of selected candidate alloys. A second objective is to select and recommend materials for future test facilities and more extensive qualification programs. Included are the activities associated with the status of the simulated reactor helium supply system, testing equipment and gas chemistry analysis instrumentation and equipment. The progress in the screening test program is described, including screening creep results and metallographic analysis for materials thermally exposed or tested at 750, 850, and 950/sup 0/C.

Cracking in ASTM A106-B and A106-C feedwater piping was detected near the inlet to the steam generators in a number of pressurized water reactor plants. We received sections with cracks from nine of the plants with the objective of identifying the cracking mechanism and assessing various factors that might contribute to this cracking. Variations were observed in piping surface irregularities, corrosion-product, pit, and crack morphology, surface elmental and crystal structure analyses, and steel microstructures and mechanical properties. However, with but two exceptions, namely, arrest bands and major surface irregularities, we were unable to relate the extent of cracking to any of these factors. Tensile and fracture toughness (J/sub Ic/ and tearing modulus) properties were measured over a range of temperatures and strain rates. No unusual properties or microstructures were observed that could be related to the cracking problem. All crack surfaces contained thick oxide deposits and showed evidence of cyclic events in the form of arrest bands. Transmission electron microscopy revealed fatigue striations on replicas of cleaned crack surfaces from one plant and possibly from three others. Calculations based on the observed striation spacings gave a value of ..delta..sigma = 150 MPa (22 ksi) for one of the major cracks. …

Demonstrations of improved fuel management and burnup are being performed in the Fort Calhoun reactor. More efficient fuel management will be achieved through the implementation of a low leakage concept called SAVFUEL (Shimmed And Very Flexible Uranium Element Loading), which is expected to reduce uranium requirements by 2 to 4%. The burnup will be increased sufficiently to reduce uranium requirements by 5 to 15%. Four fuel assemblies scheduled to demonstrate the SAVFUEL duty cycle and loaded into the core in December 1978 were inspected visually prior to their second exposure cycle. In addition, seventeen fuel assemblies were inspected after their fourth exposure cycle having achieved assembly average burnup up to 36 GWD/T. One assembly has been reinserted into Cycle 6 for a fifth exposure cycle. The preliminary results of all visual fuel inspections which appear to show excellent fuel rod performance are presented in this report. This report also contains the results of a licensing activity which was performed to allow insertion of a highly burned assembly into the reactor for a fifth irradiation cycle.

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Mark White, regarding a legal question submitted for clarification; Whether a license may fill a prescription for a hearing aid from a physician without further testing of an individual's hearing acuity.

Weekly newsletter discussing natural resources, parks, hunting and fishing, and other information related to the outdoors in Texas.