Summary: Stainless steel clad nuclear fuel cycle costs can be reduced to those associated with Zircaloy clad fuel or potentially lower by reducing the thickness of the clad tube wall until performance penalties offset the savings associated with the reduction in parasitic neutron absorption. To demonstrate the feasibility and investigate performance capabilities of thin clad fuel rods for power reactor application an assembly was fabricated with 0.0127 cm (5 mil) thick stainless steel cladding tubes for irradiation testing in the Vallecitos Boiling Water Reactor (VBWR). The fuel bundle was placed in the VBWR and irradiation was begun in November, 1961. The irradiation is scheduled to continue until the target exposure of 2.74 x 10(20) fissions/cc (10,000 MWD/T of uranium) average burnup is reached. Destructive examinations of fuel rods will be performed at regular intervals throughout life to determine fuel rod performance.

Technical report describing that as part of the AEC Fuel Cycle Program, tests are being conducted to evaluate the significance of current fuel design limitations that do not permit the maximum fuel temperature to exceed the melting point of UO2. The reliability of prediction of the fuel rod operating conditions that will cause melting of the UO2 was evaluated by means of a calibration test conducted in the Vallecitos Boiling Water Reactor. Conclusions: (a) The central portion of the 3.15-cm diameter uranium dioxide fuel column melted. It appears that the UO2 was molten to a radius of 1.22 cm in the peak power region. The maximum extent of melting probably occurred during the peak power run when the kdT in this region of the rod reached 171 watts cm. The estimated radius of melting from metallographic examination indicates the kdT for sintered UO2 is 89 watts/cm. This supports a calculated estimate for sintered UO2 thermal conductivity published by D. R. deHalas and G. R. Horn. The results of the previous calibration run and subsequent experimental data by Lyons are also consistent with the value. This conclusion is contingent on the interpretation of the post-irradiation crystal structure of the UO2. Insufficient …

The following report discusses experiments made during 1944 to develop the theory for the neutron intensity fluctuations of a water boiler.

Quarterly progress report discussing activities related to the Vallecitos Boiling Water Reactor (VBWR) and related facilities.

Quarterly progress report discussing activities related to the Vallecitos Boiling Water Reactor (VBWR) and related facilities.

In a previous report (NP-2010) the authors reported on the heats of solution of the metals and the anhydrous chlorides of the rare earths as well as on the heats of formation of the chlorides. The variation of the heats of solution of the chlorides suggested an investigation of the bromides and the iodides which is reported in this publication.

Abstract: Continued irradiation experience under the AEC - Euratom, UO2 High Performance Program provided five separate and distinct sets of data on UO2 thermal conductivity. Four of these results are expressed in terms of the value of the thermal conductivity. The first two of these measurements were applicable -- strictly -- to poly crystalline UO2. Recently, three additional sets of measurements have been obtained -- all pertinent to UO2 after the formation of large columnar grains. The extent of melting in the experiments on which the results are based ranges from slight, to greater than 70 percent of the fuel cross section. The conclusions from all of these thermal conductivity measurements considered together are: (1) The true value of the UO2 conductivity integral form 0 degrees C to melting (2805 - 15 degrees C) lies in the range from 90 to 96 W/cm. The most probable value is closer to 90 W/cm. To ensure no central melting and the associated clad swelling the maximum thermal performance level for solid pellet, UO2 fuel rods should not exceed 90 W/cm. (2) Any improvement in thermal conductivity due to the formation of large, columnar UO2 grains is small and not detectable within the …

Abstract: Some proportional fission neutron counters are described with information on methods of preparation and details of a circuit for a portable model. The portable instrument has an efficiency of .01% for neutrons from polonium beryllium sources.

This report records analyses on the fluorescence procedure of uranyl salts.

The extrusion forming of ceramic powders may be economically interesting in the field of nuclear fuel fabrication. When applied to the forming of rod-type uranium dioxide fuel, extrusion processes have been able to produce cylindrical bodies with length-to-diameter ratios much greater than those of the conventional die-pressed pellets. Furthermore, after being sintered, the extrusions have exhibited densities at least as high as those of sintered pellets. Thus, extrusion forming may offer reductions in handling during fabrication and, at the same time, provide a fuel with improved performance characteristics by decreasing the number of discontinuities in the fuel column. This report reviews the production of these extrusions, sets forth some of their characteristics, describes the materials and processes employed in cladding them, and records the pre-irradiation data pertaining to the finished fuel rods and fuel assembly. Irradiation of the fuel assembly in the VBWR was initiated on July 17, 1962.

Quarterly progress report discussing activities related to the Vallecitos Boiling Water Reactor (VBWR) and related facilities.

Report on the chemical separation of the uranium isotopes.

Technical report. From Abstract: "Experiments were performed in the Process Development Pile (PDP) with a critical mockup of the Heavy Water Components Test Reactor (HWCTR) lattice. Reactivity measurements served to determine control rod worths, the temperature coefficient of the reactor at low temperatures, the dependence of keff on concentrations of U235 and poisons in the "driver" region of the reactor, and the changes in keff that occur in certain conceivable accidents in the HWCTR. Flux distribution measurements were made to determine over-all flux shapes, local flux variations around individual components, azimuthal flux variations due to asymmetrical combinations of control rods, and vertical flux variations obtainable through the use of control rods of partial length. Sufficiently detailed flux measurements were made to permit the calculation of neutron economy tables and to determine the neutron leakage from the reactor. Suitable adjustments in the input parameters made it possible to fit the experimental results with a two-group calculation."

A selection of Russian papers on the geochemical prospecting for ores

Quarterly technical report including reports on chemistry of source, fissionable, and structural elements, nuclear chemistry, radio-organic chemistry, chemistry of separations processes, chemical physics, radiation chemistry, and instrumentation of the Chemistry Division of the Oak Ridge National Laboratory (ORNL). [From Abstract]

Abstract: This technical report contains a description of the nuclear analysis performed upon the SM-2 core and vessel for the period September 1, 1958 to December 31, 1959. Calculations are given for core reactivity, power distributions, lifetime, reactor control, kinetics, radiation problems, fuel and poison burn-ups, and the nuclear effects of poisons, temperature, and geometry. Wherever possible, experimental data is included in order to test the validity of the analytical models. The SM-2 nuclear analysis was performed by Alco Products, in. under Tasks 1, 8, and 10 of Contract No. AT(30-2)-326 for the Atomic Energy Commission.

From preface: This report is one of a series covering a design study of heavy water moderated power reactor plants with the objective of selection and recommendation of a conceptual design for providing optimum economics with slight fuel enrichment.

Report documenting research and developments made by the Health Physics Division of the Oak Ridge National Laboratory.

Second volume of a compilation of information about reactor containment, written by experts from a variety of organizations.

Data collected as part of a hydrogeochemical and stream sediment reconnaissance for the Green Bay quadrangle including field data as well as laboratory data on well, spring, and stream waters, and stream sediments.

Data collected as part of a report on the Greenville area including laboratory data on well water, stream water, and stream sediments as well as field data.