During the main thrust of the HCDA studies, it was found that sodium uranates, especially Na/sub 3/UO/sub 4/, were formed when the Na-U-O system was subjected to high temperatures approximating those of the HCDA. Mechanisms through which these rather complicated compounds are formed remain unknown. The purpose of these SIMS and ESCA studies was to detect the formation of any precursor ion species to the sodium uranates. The ESCA results agree with theory and support the presence of U/sub 2/O/sub 7/ /sup 2 -/ in Na/sub 2/U/sub 2/O/sub 7/; however, SIMS analyses show no evidence of possible uranate precursor formation in an Ar/sup +/ sputtered ion beam.

The characteristics of Mirror Fusion Reactors, i.e., steady state operation, a low neutral gas density and a large gas throughput require unique vacuum pumping capabilities. One approach that appears to meet these requirements is a liquid helium cooled cryopump system in which a fixed portion can be isolated and degassed while the remainder continues to pump. The time to degas a rotating, fixed portion of the pumping area and the ratio of that area to the total area fixes the gas inventory in the chamber. It follows that the active pump area maintains the required neutral gas density and the time averaged degassing rate equals the gas throughput. We have built such a cryopump whereby the gas condensed (deuterium) on the liquid helium cooled panel can be transferred to a collector pump and subsequently to an exterior mechanical pump and exhausted. At panel loadings as high as .55 torr-litres/cm/sup 2/ the gas leakage during degassing is less than 8% and the degassing time is less than 10 minutes. Scaling to reactor size appears to be feasible.

The objective of this program is to develop nuclear waste packages that meet the Nuclear Regulatory Commission`s requirements for a licensed repository in tuff at the Nevada Test Site. Selected accomplishments for FY82 are: (1) Selection, collection of rock, and characterization of suitable outcrops (for lab experiments); (2) Rock-water interactions (Bullfrog Tuff); (3) Corrosion tests of ferrous metals; (4) Thermal modeling of waste package in host rock; (5) Preliminary fabrication tests of alternate backfills (crushed tuff); (6) Reviewed Westinghouse conceptual waste package designs for tuff and began modification for unsaturated zone; and (7) Waste Package Codes (BARIER and WAPPA) now running on our computer. Brief discussions are presented for rock-water interactions, corrosion tests of ferrous metals, and thermal and radionuclide migration modelling.

Both operational and technical objectives are being pursued at the Spent-Fuel Test-Climax (SFT-C). The principal operational objective is to demonstrate the safe and reliable packaging, handling, and storage of spent nuclear reactor fuel in a deep geologic media and to retrieve the fuel afterward. Packaging of the spent fuel at the Engine Maintenance, Assembly and Disassembly (EMAD) facility, initial emplacement 420m below surface in the Climax granitic stock, and three subsequent exchanges of fuel canisters between EMAD and the SFT-C has demonstrated that application of straightforward engineering practices provides a safe and highly reliable system with no significant radiation exposure to the operating personnel. The primary technical objectives of the test are simulation of the thermal effects occurring in a panel of a large repository and comparison of the relative effects on the granitic host rock of heat alone versus heat in combination with ionizing radiation. Other technical objectives direct project activities toward instrument evaluation, ventilation effects, thermal and thermomechanical response of a jointed rock mass, and computer model validation. Recent findings from field measurements and laboratory studies are briefly discussed for: performance of data acquisition system and instrumentation; near-and intermediate-field temperature measurements; ventilation and dewpoint measurements; acoustic emission monitoring …