Graphs have been made which show the nuclearly safe parameters for uranium rods in light water with uranium enrichments up to five weight percent U-235. These data were to serve as a guide to those persons who may be involved with the maintenance of nuclear safety in handling and processing operations with slightly enriched uranium fuel elements. The data are applicable to fuel element fabrication and processing operations, and in general to those operations involving the handling and storage of fuel elements apart from reactors.

This report summarizes the research and development work carried out during December, 1959, and January and February, 1960, for Budget Activity 2790 - Separations Development for Non-Production Reactors. The major effort on Activity 2790 has been completed. Current efforts on the remaining problem areas will enable Hanford to begin reprocessing fuel elements from power reactors which employ depleted or slightly enriched uranium fuels in July, 1962.

Critical mass experiments to be conducted at HAPO will require dilute and concentrated plutonium solutions. Since very high plutonium concentrations (~2,000 g/l) cannot be attained in pumpable solutions, solid plutonium compounds will be utilized for this phase of the work. Mixtures of plutonium oxide and polyethylene, methyl methacrylate or paraffin compacted in containers have been considers for use in highly-concentrated plutonium systems of known hydrogen to plutonium atomic ratio (H/Pu).

A 19-rod Zircaloy-clad half-length PRTR spike element successfully irradiated to high plutonium burnout at full power in the ETR shoved partial bonding of the core and cladding. Unsatisfactory autoclave films on the Zircaloy cladding of the PRTR Al-Pu fuel elements are delaying final assembly of the first 30 clusters. Further conditioning of the autoclaves and the availability of permanent etching facilities are expected to correct the present difficulties.

The evaluation of the inductance of an electrical component is often important in understanding and operating an electrical circuit. Inductance is defined by several equations, the most common being e= -L d1/dt . This equation defines inductance as the constant which relates the back emf produced in an element to the time-rate-of-change of current.

Investigation of aqueous and steam corrosion at elevated temperature has been carried on at Hanford for several tears. A number of reports have been published on various phases of the corrosion program but, except for monthly reports, little has been written on the progress of the Corrosion and Coatings Operation alloy development program. This interim report will outline the more important current phases of the aluminum alloy program.

In the continuing search for better methods of effecting the secondary fusion welded closure in Alsi bonded aluminum clad uranium metal fuel element, an article on "The Twin-Argon Welding Process" by J. A. Donellon was recently found in the September 1954 issue if the British Welding Journal. From a review of the article, the process appeared to have enough possibilities to warrant exploring it. Communication were established with the General Electric Company, Ltd..

The measurements reported here are companion measurements to those reported earlier in HW-63585. The only significant difference between the measurements is that 1.8 w/o enrichment UO2 fuel was used for the first set, and 2.6 w/o enrichment UO2 fuel was used for the measurements described in this report. The new results will be presented graphically, and for completeness, the details of the measurement will be included here as well as in HW-63585.

The development of a miniature probe was desired for measuring approximate single nuclide beta dose rate in solution and in various animal organs. This probe designed for biological experiments, was to have maximum possible sensitivity to detect low levels of nuclide concentrations. The desired dimensions of the light pipe were to be approximately one-fourth-inch diameter with lengths of three to twelve inches.

A brief series of experiments was performed to study the high temperature reaction of the Zircaloy-uranium-aluminum system at the request of Reactor Engineering Operation, Irradiation Processing Department. Knowledge of the high temperature behavior of this combination of materials is important to the evaluation of reactor behavior during possible accidental over-heating of a fuel channel.

In order to prevent dangerous concentrations of combustible gases such as hydrogen and ammonia in Redox dissolvers, a continuous analysis of the off-gases is needed. Hydrogen is evolved from most fuel element dissolution processes now used or planned for use at Redox. Ammonia is also released from ammonium fluoride dissolution of zirconium and caustic dissolution of aluminum cladding. Oxides of nitrogen and hydrogen are formed during nitric acid dissolution of uranium or plutonium-aluminum alloys. Since no fixed ratio exists between the concentrations of any two of these gases, the determination of combustible gases in complex mixtures is not possible with a single bulk property analyzer.

A research and development program aimed at devising processes for the economical recovery of the potentially valuable long-lived fission products from Purex waste has been under wat at Hanford for several years. When this work has begun, the concentrated waste was primarily a nitric acid solution (6 to 10 M HNO3) containing the fission products and relatively small concentrations of iron, sulfate, and other corrosion products. Flowsheets based on classical separation schemes and rather similar to processes used by the Isotopes Division at the AEC's Oak Ridge operation served to separate the desired fission products from one another and from the corrosion products (1,2,3).These separation schemes employed careful step-wise pH adjustment to precipitate first the iron and then to separate the desired fission products from one another. The flowsheets were demonstrated on a pilot-plant scale with full-level plant waste. However, since the earlier work was complete, plant operations have been modified....

At the present time, cerium-144 and premtheium-147 are the two fission product rare earths that appear most promising for use as the heat source in isotopic power units. Under proper conditions, cerium and the trivalent rare earths can be extracted from the Purex fission product waste stream as an insoluble sodium-rare earth double sulfate. A reprecipitation as the double sulfate, dissolution of the hydroxide, serves to give almost complete separation from the corrosion products, inert constituents of the waste, and from most of the fission products. The cerium and the trivalent rare earths must then be separated from each other. In the case of cerium recovery, it is necessary to remove the trivalent rare earths in order to maximize the specific activity of the cerium. If promethium is the desired product, a preliminary cerium separation is desirable to protect the ion-exchange resin (used for separating promethium from its adjacent rare earths) from the intense high-energy radiation from cerium.

Four capsules containing Al-1.65 w/o Pu and Al-12 w/o Si-1.65 w/o Pu were charged into the MTR. These capsules will be irradiated to a burnup of 80-100% of the plutonium atoms to determine the stability of the material at high exposures. An additional sixteen capsules containing 5 to 20 w/o Pu in Al and Al-Si have been prepared. Eight are awaiting reactor space and should be charged soon. The remaining eight are being recanned to increase the end gap between the core and the can. Also four capsules containing high density UO2-PuO2 pellets canned in Zircaloy are awaiting assignment of reactor space.

In considering the problems associated with the measurement of SSNM content of Non-Production Fuels, two distinct problems are apparent. The first is the technical problem of obtaining highly accurate measurements in a complicated chemical and physical system. The second is the administrative problem of choosing a measurement system which provides a basic of financial settlement acceptable to both the seller (reactor operator) and the buyer (Commission).

The major portion of transfers and inventory in the Chemical Processing Department are dependent on volume measurement. Good volume measurements are therefore essential to good SS material control. Considerable attention has been given to the volume problem especially on primary transfer points. Document HW-57888 discusses the biasing effect pf temperature on manometer oil. HW- 57866 given the procedure for vessel calibration. Other undocumented correspondence has discussed recent calibrations and certain aspects of temperature considerations in the volume determinations. However, there is a need to document for future reference the consideration given temperature and provide at the same time information which covers the temperature angle on all volume methods used in the Chemical Processing Department.

The Interim Power Fuels Reprocessing Program, as established by the Atomic Energy Commission, provides the service of recovering uranium, thorium, plutonium, etc., from irradiated fuels discharged from non-production reactors of both public and private ownership. To provide this service on an interim basis and at minimum capital investment, the Commission has assigned the processing responsibility for the various fuel types to several AEC sites. The sites are to be assigned fuel types most similar to their normal production. As a result, HAPO has been assigned the responsibility for processing the low enrichment uranium and uranium oxide type fuels with isotopic content up to 5% uranium-235. In addition, some plutonium base fuels will be processed at Hanford.

The final percentage of xenon created by fission in uranium and plutonium is a function of the neutron flux intensity. The flux dependence results because axenon 133 and 135 can be converted to a a stable xenon isotope by neutron capture instead of decaying into cesium.

Because of the excessive vertical fragility and high replacement costs of mice-window G-M tubes used in vertical and horizontal lead-pig shelf counters, it was requested that a simple system of conversions to reliable scintillation detection be accomplished.

The HAPO Critical Incident Alarm, Model I, is an instrument designed to give an audible and visual alarm signal in the event of a critical incident to which it is exposed. There will be thirty-one (31) of these instruments installed and several spares located in the various manufacturing buildings in the Chemical Processing Department where there exists any possibility of a critical incident occurring. The instrument is intended as a post or after-the-fact warning device. It will offer no protection prior or leading up to, nor prevent, a critical incident. They are intended to be operated from the 115 V. A.C., 60 C.P.S. emergency line power. The instrument is self-contained, including the radiation detector, and will be calibrated to alarm at 500 mr/hour in a gamma field.

Nearly all nuclear reactors being designed and built today- whether for research, power, or productions of fissionable materials- use recirculating fluids for cooling. However, a number of production reactors are still operating with single-pass cooling by treated natural water. The Hanford Atomic Products Operation of the General Electric Company presently operates production reactors for the AEC at Richland, Washington. The first reactors were built during World War II, and utilized a standard water treatment which was designed to provide large quantities of settled, filtered Columbia River water for once-through cooling.

In early July, 1958, it appeared that Columbia River temperature at HAPO would be near 24.5ºC by the end of August. River temperature were averaging 4º to 5º above 1957 figures and were 3º to 4º above the ten year highs. It seemed desirable to examine the problem to determine if any corrective measure could be taken, since it was apparent that production losses were imminent.

A number of the questions which have been posed to us in the subject references are commented upon below. These have been reviewed by personanel of the Research and Engineering Operation and the Facilities Engineering Operation, Chemical Processing Department, and of the Chemical Research and Development Operation, Hanford Laboratories Operation. Particular acknowledment is given G. J Alkire, J. P. Duckworth, J. B. Fecht, R. G. Geier, E. R. Irish, H. M. Jones, G. C. Oberg, A. M. Platt, W. H. Reas, W. C. Schmidt, R. J. Sloat, W. H. Swift, M. T. Walling and L. L. Zahn of these organizations for assistance given assembling this information.

In HAPO solvent extraction processes there are two independent aspects of nitrous acid chemistry. One concern the decomposition of the solvent through nitration reactions and the attendant problems. These reactions are autocatalytic in the presence of nitric acid and have threshold values for both temperature and nitric acid concentration for a given solvent below which nitrous acid disappears and above which it is generated with continuous destruction of the solvent. These reactions are identical to those found in the prior study of the hexone system.