A first-order system analysis was used to evaluate various characteristics of /sup 233/U-producing hybrids. A cost model was also developed for the hybrid.

Studies of atmospheric aerosols have demonstrated that much of the /sup 55/Fe associated with the aerosol input to the oceans is present as either an amorphous or hydrous iron oxide or as very small particulate species attached to the surfaces of the large aerosol particles. By comparison, nearly all of the stable iron is bound in the mineral phase of aerosol particles. This difference in the chemical and physical forms of the radioactive and stable iron isotopes results in the /sup 55/Fe being more biologically available than is the stable iron. This difference in availability is responsible for the transfer of a much higher specific activity /sup 55/Fe to certain ocean organisms and man relative to the specific activity of the total aerosol or of sea water. This differential biological uptake of the radioactive element and its stable element counterpart points out that natural levels of stable elements in the marine environment may not effectively dilute radioelements or other stable elements of anthropogenic sources. The effectiveness of dilution by natural sources depends on the chemical and physical forms of the materials in both the source terms and the receiving environments. The large difference in specific activities of /sup 55/Fe in …

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.

Calcrete, dolocrete, and gypcrete carnotite are abundant in western Australia and Namib Desert, although only a few are of ore grade. The geology of these deposits are described. A genetic classification of calcretes emphasizing uranium favorability was developed, based on the distinction between pedogenic and nonpedogenic processes. Similarities between western Australia and South West Africa give support for the conclusions that lateral transport of U in groundwater is essential to ore deposition and that bedrock barriers or constrictions which narrow the channel of subsurface flow or force the water close to the land surface, greatly favor the formation of uraniferous calcretes. Criteria for uranium favorability deduced from the Australian and South West African studies were applied in a preliminary way to the southern Basin and Range Province of U.S. The procedure is to search for areas in which nonpedogenic calcrete or gypcrete may have developed. A caliche distribution map was compiled from soil survey and field data. Many areas were visited and some of the more interesting are described briefly, including parts of Clark County, Nevada, with occurrences of carnotite in calcrete. (DLC)

The analysis performed by Todd Shipyards concerning the ability of the LOFT CRDMs to withstand a dry scram is presented. A ''dry scram'' could result in the CRDM components yielding; however, it would probably not render the CRDMs inoperable. It also concluded that a dry scram is highly unlikely based on a typical LOFT depressurization curve and the temperature of the fluid in the upper pressure housing. At the time of scram, the fluid in the upper pressure housing will not flash to steam owing to the pressure-temperature relationship existing during the scram cycle.

A detailed dynamic analysis of the LOFT reactor core support structures was performed to determine the ability of the flow skirt/core filler and hold-down springs to withstand Loss-of-Coolant Accident (LOCA) plus Safe Shutdown Earthquake (SSE) loadings. A double-ended offset shear occurring in 15 msec (5 msec break time + msec for offset to occur) in the intact loop at the reactor vessel nozzle provided the basis for LOCA loads. The flow skirt/core filler and lower core support structure separate from the core barrel approximately 0.068 in. as a result of the hot leg LOCA. This small displacement and the resulting impact loads produce stresses in the springs, core barrel, flow skirt/core filler, and shear pins within allowables as specified in Section III of the ASME Code for faulted conditions.

For HTGR commercialization studies, an LWR/HTGR Technology Transfer program was devised. Candidate programs were identified out of a total of 208 EPRI NPD (Nuclear Power Division) projects. Of these, 26 project areas presented the highest probability for technology transfer. (DLC)

A method has been developed for fabricating uranium carbide/beryllium carbide/graphite fuel-element specimens for reactor-core-meltdown studies. The method involves milling and blending the raw materials and densifying the resulting blend by conventional graphite-die hot-pressing techniques. It can be used to fabricate specimens with good physical integrity and material dispersion, with densities of greater than 90% of the theoretical density, and with a uranium carbide particle size of less than 10 ..mu..m.

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).

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.

A high degree of crystallinity has been achieved in ingots cast. Since most of the growth took place near the solidification temperature, the top portion of the ingot was solidified by freezing from the surface. The thickness of this layer was reduced with the control of thermal flow characteristics in the furnace. The crucibles used in this study have a nonuniform bottom which is not conducive to proper heat transfer during solidification. In an effort to achieve high packing density of solar cells in the module with maximum material utilization, an attempt was made to cast a square cross-section ingot. Even though some minor cracking occurred in the first ingot, it appears feasible to cast square cross-section ingots by the Heat Exchanger Method. Higher feed forces results in higher cutting rates. However, this is accompanied by wire wander and increased surface damage depth. It has been established that the life of an impregnated blade can be prolonged by plating it after impregnation.

None

Mixtures of H/sub 2/--T/sub 2/ or D/sub 2/--T/sub 2/ will exchange to produce HT or DT due to catalysis by the tritium ..beta.. particle. The kinetics of the reaction D/sub 2/ + T/sub 2/ = 2DT may play an important role in designing liquid or solid targets of D/sub 2/--DT--T/sub 2/ for implosion fusion, and distillation schemes for tritium cleanup systems in fusion reactors. Accordingly, we have critically reviewed the literature for information on the kinetics and mechanism of radiation-induced self-exchange reactions among the hydrogens. We found data for the reaction H/sub 2/ + T/sub 2/ = 2HT in the gas phase and developed a scheme based on these data to predict the halftime to equilibrium for any gaseous H/sub 2/ + T/sub 2/ mixture at ambient temperature with an accuracy of +-10 percent. The overall order of the H/sub 2/ + T/sub 2/ = 2HT reaction is 1.6 based on an initial rate treatment of the data. The most probable mechanism for radiation-induced self-exchange reaction is an ion-molecule chain mechanism.

The LOFT Reactor Vessel 290/sup 0/ Downcomer Stalk Instrument Penetration Flange Stress Analysis has been completed using normal operational and blowdown loading. A linear elastic analysis was completed using simplified hand analysis techniques. The analysis was in accordance with the 1977 ASME Boiler and Pressure Vessel Code, Section III, for a Class 1 component. Loading included internal pressure, bolt preload, and thermal gradients due to normal operating and blowdown.

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.

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.

The setting up, calibration operation, characteristics, and problems of the precision long counter for neutron intensity measurements are discussed. (WHK)

Preliminary results are presented of a study of cross-field plasma injection in the 2XIIB mirror machine. Plasma accelerated by a coaxial deflagration gun was observed to pass 3.5M across the vacuum field, and some trapping was observed when the gun plasma intersected a plasma streaming along B at the center of the magnetic well. Parameters for the experiment are: gun plasma kinetic energy 50 to 200 eV, n/sub gun/ = 3 x 10/sup 13/ cm/sup -3/, streaming plasma 25 to 50 eV and n/sub streaming/ = 6 x 10/sup 11/ cm/sup -3/, duration of both 100 to 200 ..mu..sec. For the trapped plasma, n = 2.4 x 10/sup 12/ cm/sup -3/, and the decay time is t/sub /sup 1///sub 2// = 400 ..mu..sec consistent with Coulomb scattering loss at 100 eV mean ion energy.

A technique has been developed to fabricate poly-Si electrodes for charge-coupled devices. By controlling the microstructure of a poly-Si film, an anisotropic etchant was selected to provide essentially uniform electrode width dimensions. The electrode widths have only a 6% variation for the majority of the devices over the area of a 2 inch silicon wafer.

The program scope is to develop, fabricate, install, and monitor the operation of prototype solar heating and cooling systems. Application studies have been completed for three application categories: single-family residential, multi-family residential, and commercial. The program currently consists of development of heating and cooling euipment for single-family residential and commercial applications and eight operational test sites (four heating and four heating and cooling). Four are single-family residences and four are commercial buildings.

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.

Objectives of the Geologic Review Group are to study the long-term stability of rock units for commercial radioactive waste disposal, and to review all plans of the National Wastes Terminal Storage program. At this meeting in New Orleans, the Gulf coast Salt dome project and the impending reorganization of the office of Waste Isolation are discussed. (DLC)

The bases and procedure for plotting LOFT Technical Specification Figure 3-1, PCS Temperature vs. Pressure is presented. The curves define fracture toughness limits for the carbon steel vessels (Reactor vessel, pressurizer and steam generator) in the primary coolant system (PCS). An allowance is included for the lag between measured fluid temperature and metal temperature of the carbon steel components for the heat up situation. As a result the curves are conservative for the cooldown situation. However, no allowances for expected pressure and temperature instrument errors is included in the curves.