A technique is described for the noncontact testing of materials using laser deposition to generate a stress pulse and interferometry to record the transient surface displacement. The dilatational wave speed can be measured and, in the particular case of rod or plate specimens, sufficient information can be obtained to evaluate the two elastic constants of an isotropic material. Several applications illustrating the advantages of the approach are summarized.

An experimental program to evaluate candidate metals for use in the fabrication of canisters for long-term storage of vitrified radioactive wastes is described. The long-term compatibility of the candidate metal both with the contained vitrified radioactive waste and with the external environments expected in possible final storage locations will be determined. These tests involve heating combinations of waste forms and canister metals in intimate contact for up to 50,000 hr to accelerate any reactions that occur.

This paper describes an experimental program to evaluate candidate metals for use in the fabrication of canisters for long-term storage of vitrified radioactive wastes.

Theoretically, the geochemical barrier can provide a major line of defense in protecting the biosphere from the hazards of nuclear waste. The most likely processes involved are easily identified. Preliminary investigations using computer modeling techniques suggest that retardation is an effective control on radionuclide concentrations. Ion exchange reactions slow radionuclide migration and allow more time for radioactive decay and dispersion. For some radionuclides, solubility alone may limit concentrations to less than the maximum permissible now considered acceptable by the Federal Government. The effectiveness of the geochemical barrier is ultimately related to the repository site characteristics. Theory alone tells us that geochemical controls will be most efficient in an environment that provides for maximum ion exchange and the precipitation of insoluble compounds. In site selection, consideration should be given to rock barriers with high ion exchange capacity that might also act as semi-permeable membranes. Also important in evaluating the site's potential for effective geochemical controls are the oxidation potentials, pH and salinity of the groundwater.

The rotation and internal excitation limits of stability of superheavy compound nuclei (formed, for example, by heavy-ion collisions) are studied. The work is based on a macroscopic-microscopic description of the deformation of a nucleus. The two-center shell model for fission is generalized to include rotation (microscopic description) and internal excitations (statistical description). The physical basis for this study is described and the calculated results of the stability of fission barriers of superheavy elements are presented.

A scoping experiment to characterize the neutron field generated from a Light Water Reactor spent fuel assembly has been successfully completed. Solid State Track Recorder (SSTR) neutron dosimeters have been exposed at the surface of a spent fuel assembly from a Pressurized Water Reactor. Acceptable track densities were obtained. From these SSTR neutron dosimetry observations, an absolute neutron flux of roughly 8000 n/(cm/sup 2/.sec) was obtained at the surface of the spent fuel assembly three years after discharge. The deduced neutron energy spectrum, with a mean neutron energy of roughly 1.3 MeV, is intimately dependent upon the actinide content of the spent fuel. Hence, the results of this preliminary experiment have demonstrated that, with suitable calibration, SSTR neutron dosimetry can be successfully applied for non-destructive spent fuel actinide assay and for characterization of the radiation environment associated with spent reactor fuel assemblies.

Simulated transient tests were conducted on 234 cladding specimens from EBR-II irradiated mixed oxide fuel pins; approximately 75% of the specimens were from the fuel column region, with the remainder from the plenum and below the fuel column. The cladding specimens were taken from the N-E, N-F,, PNL-9, PNL-10, PNL-11, P-23A, P-23B, P-23C, and WSA-3 fuel pins irradiated at 15.2 to 37 KW/cm to burnup levels from 11 to 110 MWd/Kg. All the fuel pins used 20% cold worked Type 316 stainless steel cladding. Irradiation temperatures ranged from 370 to 725/sup 0/C with a peak fluence of 10/sup 23/ n/cm/sup 2/ (E > 0.1 MeV).