A preliminary design study, Phase I of the ALPR project, has been made in accordance with the Army Reactors Branch specifications for a nuclear "package" power plant with a 200-260-kw electric and 400 kw heating capacity. The plant is to be installed at the Idaho Reactor Testing Station as a prototype for remote arctic installations. The "conventional" power plant as well as the exterior reactor components are described in the accompanying report and cost estimate by Pioneer Service and Engineering Company, Architect-Engineers for the project."Nuclear" components of the reactor are designed by Argonne National Laboratory as described in the present report.

This seventh Annual Report is a summary of some of the progress in scientific and engineering research and development carried on at Argonne National Laboratory during 1961. As is customary in this series, only those portions of the total program that have reached such a stage that they may be of general interest are recorded. Thus, a comparison with the Annual Reports for 1959 (ANL-6125) and for 1960 (ANL-6275) will reveal the description of a generally different set of scientific activities. A more detailed presentation of any work covered in this report or of the many ANL projects not mentioned may be obtained by perusing the various progress and topical reports issued by the Laboratory during 1961. A list of the publications in the scientific journals during 1961 by Argonne personnel has been given as an Appendix.

This report describes corrosion rate of uranium in hydrogen-saturated water appears to be constant with respect to time after a brief induction period and to involve only one type of over-all reaction, in which pitting effects are slight or nonexistent.

Report issued by the Argonne National Laboratory discussing high-flux research reactor design studies. As stated in the summary, "this report presents a reactor design to meet the needs of the basic research program at Argonne National Laboratory. The program requires some irradiation in thermal flux...and some beam experiments..." (p. 5). This report includes tables, and illustrations.

Report issued by the Argonne National Laboratory discussing the variety of work done at the laboratory during the year of 1956. This report includes tables, illustrations, and photographs.

Report issued by the Argonne National Laboratory discussing the variety of work done at the laboratory during the year of 1957. This report includes tables, illustrations, and photographs.

Report issued by the Argonne National Laboratory discussing the variety of work done at the laboratory during the year of 1958. This report includes tables, illustrations, and photographs.

Report issued by the Argonne National Laboratory covering a summary report of the work conducted by the Idaho Division. Experimental work and progress made on reactors are presented. This report includes tables, illustrations, and photographs.

Report issued by the Argonne National Laboratory discussing a summary of projects conducted with the Idaho Division. Descriptions of each project are presented. This report includes tables, and illustrations.

On October 7, 8, and 9, 1953, the Atomic Energy Commission Division of Reactor Development held a reactor information meeting at the Argonne National Laboratory. The objective of the meeting was exchange of information among people actively concerned with the design of reactors for power to the end that the power reactor program would move more speedily and more economically to another milestone of success. In this volume all the papers presented at the meeting are listed. Copies are given of those papers which are available, and references to published reports are indicated where know for those papers not included in this collections. In order to facilitate handling, this volume is being issued in six parts: Part I Power Reactors; Part II Reactor Physics. Critical and Exponential Experiments Measurements; Part III Reactor Components. Reactor Economics Considerations. Reactor Safeguard and Control; Part IV Fuel Element Design and Problems. Corrosion and Chemistry; Part V Heat Transfer; Part VI Processing. The Author Index is being bound and distributed with Part I of this volume.

The tests described in this report were static tests devised to afford a basis for a quick evaluation of the resistance of uranium to attack by lithium. The work was done at the same time as the tests of beryllium, thorium, and various engineering metals in lithium (described in ANL-4990); but the results with uranium are given in the present classified report so that the results of the other tests can be published as an unclassified document. The procedure for carrying out the tests is described in ANL-4990.

Water corrosion tests on mechanically jacketed and pinholed thorium slugs show that these slugs fail in a manner similar to that observed for mechanically jacketed and tested uranium slugs. The proposed mechanism for the water corrosion of these jacketed slugs is analogous to the water corrosion mechanism of jacketed uranium slugs presented in the project lecture. A bare thorium slug appeared to be more resistant to corrosion by water than a mechanically jacketed slug during the first half of the autoclave test. After approximately 90 hours of testing both the bare and the mechanically jacketed thorium slugs were severely corroded by water.

Report of equations for calculating decay of U235. The introduction states" Calculations have been made on the U235 fission product decay schemes. The results for a typical example, that of a reactor operating at 1000 kilowatts for 180 days, have been tabulated and graphed. General formulae have been used so that the results can be applied for any power level and any time of irradiation" (p. 2).

New reactors presently in design or construction stages, as well as revised operating procedures for existing reactors, have shown an increasing emphasis on extending the exposure time of the reactor fuel elements. However, operating experience at Hanford, as at other installations, has demonstrated that as the amount of burn-up in uranium metal is increased an increase is also noted in operational difficulties resulting from the dimensional behavior of the fuel. During reactor irradiation uranium slugs or rods have been observed to change in length and diameter, to warp, and to develop surface roughening.

The cup assembly of the Experimental Breeder Reactor (EBR) consists of blanket bricks, inner rings, and safety plug, all of natural uranium. The design of the finish machined brick is shown in Figure 1. These pie shaped bricks when stacked together, 12 bricks arranged in circular form and stacked seven rings high, comprise the cylindrical portion of the outer blanket, 17.875" I.D. x 30.875" O.D. after machining and canning. The inner ring, which is shown in Figure 2, fits inside the bottom layer of bricks. The circular opening in the center of the inner ring is closed by the safety plug shown in Figure 3.

Measurement of radioactive carry-over was made on borax III operating at 300 psig and at power levels ranging from 4 to 14 mv. Decontamination factors of from 1.5 x 104 (at 14 mv) were obtained. These data are in essential agreement with those predicted by previous laboratory experimental work.

A fused fluoride process for dissolution of zirconium-uranium fuel alloys is being developed. The alloy is dissolved in an equimolar sodium fluoride-zirconium fluoride melt at 600°C by sparging the system with hydrogen fluoride. The uranium is volatilized from the melt as the hexafluoride by a sparging operation with fluorine or bromine pentafluoride vapor. This product is then decontaminated and purified by fractional distillation.

Development work was continued on the fused fluoride process for the recovery of enriched uranium from zirconium-matrix fuel alloys. The alloy is dissolved by immersing it in molten sodium fluoride-zirconium fluoride at 600°C and passing hydrogen fluoride vapor through the system.The dissolved uranium tetrafluoride in the melt is then volatilized as uranium hexafluoride by sparging with fluorine. The uranium hexafluoride product is purified and decontaminated by fractional distillation. Additional corrosion tests were made on a variety of metals in an effort to find a material of construction suitable for the fluorination step. All the metals tested, with the exception of Hastelloy B, were attacked rapidly in the fluorinated melt. The attack was particularly severe at the melt-gas interface when tests were made with partially submerged specimens of the metals.

Dissolution of the large number of samples obtained from the natural uranium blanket of the Experimental Breeder Reactor after approximately 485,000 kw.-hr. of operation has been completed, and analysis of these samples for uranium consumed and plutonium formed is well along. An attempt is being made to distinguish quantitatively between uranium-238 and uranium-235 fission in the blanket area by determining the ratio of ruthenium-106 to cesium-137 in the fission products.

Progress is reported on (1) direct cycle boiling reactor studies, (2) solvent extraction, (3) fluoride volatilization separation process, (4) elevated temperature separations, (5) fluidization studies, (6) development of analytical techniques, (7) processing and utilization of radioactive wastes.

Additional runs have been made in the six-inch, continuous-flow mixing chamber to study the rate of mass transfer between isobutanol and water. These runs were inconclusive because the effluents were mutually saturated. A new four-inch cell has been designed and is being fabricated; this will permit a reduction in the time available for mass transfer. Consideration has been given to other liquid pairs which may transfer more slowly than isobutanol-water. The system nitrobenzene-ethylene glycol appears attractive.

Development work continued on a fused salt process for the recovery of uranium from zirconium-matrix fuel alloys. The fuel is dissolved in a sodium fluoride-zirconium fluoride melt at 600°C by hydrogen fluoride sparging. The melt is then sparged with fluorine gas which volatilizes the dissolved uranium as the hexafluoride. The final decontamination and purification of the uranium hexafluoride are accomplished by fractional distillation. The testing of graphite as a container material for the hydrofluorination step was continued. Additional thermal cycling experiments were performed, using a helium sparge in equimolar sodium fluoride-zirconium fluoride melt at 600°C. The extent of penetration of the fused salt into the graphite was determined. No mechanical degradation was present. Dimensional change data were also obtained for graphite vessels in which the fused salt was sparged with hydrogen fluoride.

Progress is reported on (1) experimental breeder reactor program, (2) solvent extraction, (3) fluoride volatilization separation process, (4) elevated temperature separations, (5) denitration of uranyl nitrate in a fluidized bed, (6) development of analytical techniques, (7) processing and utilization of radioactive wastes.

A final series of runs was made in a four-inch continuous-flow mixing chamber to study the transfer of isobutanol into water and nitrobenzene into ethylene glycol. Satisfactory techniques were developed to provide for the rapid analysis of these systems. In addition, a light-scattering correlation was prepared to provide a measure of the interfacial area of the yellow-colored nitrobenzene-ethylene glycol mixtures.