For many years effort has been directed toward the development of means for the practical utilization of the heat evolved from the radioactive decay of certain fission and irradiation products. Fission products, in view of their availability in the plentiful, high-level wastes resulting from the processing of irradiated, nuclear reactor fuels have been most intensively studied for applications where their heat of decay might be converted into useful energy such as electricity for the operations of certain devices in place of chemical batteries . In addition other materials having desired radioactive properties may be produced by neutron bombardment of readily available elements.

It is desirable that a reactor exhibit a self-regulating effect. If this were not true any disturbance to the reactor would result in a continual increase in the magnitude of the disturbance and the reactor would be unstable. In this investigation the reactor is considered to have two reactivity feed-backs: metal temperature and water temperature reactivity effects. These two variables through a metal temperature coefficient and water temperature coefficient determine not only the reactor stability but also determine many operational characteristics.

The current concepts for reprocessing of non-production reactor fuels at Hanford and other AEC sites were reviewed at the AEC Symposium on "Chemical Processing of Irradiated Fuels from Power, Test and Research Reactors" held at Richland on October 20 and 21, 1959. A report on the symposium will be issued early in 1960 in Bulletin TID-7583. Current planning calls for location of the receiving and storage, mechanical treatment, dissolution, clarification and solution storage facilities at the Uranium Recovery Plant. Dissolver solution is to be piped to the Redox Plant for separation and decontamination of the uranyl and plutonium nitrates. The decontaminated uranium product will be shipped as a uranyl nitrate solution to another AEC site for calcination. No further treatment of the plutonium nitrate is planned in the present project.

In support of the Plutonium Recycle Program at Hanford, the properties of PuO2 are being investigated. This paper reports sintering studies on PuO2 and PuO2-UO2 mixtures and solid solutions; melting studies on PuO2 and UO2; thermal expansion data to 1000 C; and irradiation data on PuO2-UO2 mixtures. The existence of a continuous series of solid solutions formed during sintering has been established for the system UO2-PuO2. A linear relation between lattice parameter and composition exists. Extensive sinterability data on the isomorphous compound UO2 and PuO2 and their intermediate compositions has been obtained. The effect on sintered density of temperature, time, and concentration for both physical additions of PuO2 and additions of UO2-PuO2 solid solutions to UO2 have been studied. Evaluation data are supported by microscopic examination and X-ray diffraction.

Relatively frequent agitator failures in HAPO Separations Plants have interfered with process continuity, contributed to process difficulties, and resulted in considerable maintenance expense. Predominantly the failures have been because of gear-reduction drive unit break-down or because of metallic fatigue and degeneration of the shaft-paddle assemblies. A simplified, slow-speed, direct drive agitator, previously described in HW-52755, proved to be quite durable and satisfactory during extended testing, operating without incident for over 10,000 hours. Subsequent operation of the agitator in the Redox Plant has been equally smooth. Total operating time (combined test and production use) is now in excess of 21,000 hours. Since the slow speed agitation principle has been adequately demonstrated at Redox and Purex canyon applications. This report describes the development and testing of such a "universal" agitator.

This is the sixth in a series of interim reports describing various phases of the study of fuel element rupture kinetics and mechanisms. Previous reports issued are: No. 1- Experimental Methods and Procedures, HW-61378, No. 2- Coextruded Rod Elements with Pinhole Defects, HW-61379, No. 3 - Mechanism of the Uranium-Water Reaction, HW - 61799, No. 4 Coextruded Tube Elements with Pinhole Defects and Various Annular Spacings, HW- 62348, No. 5- Comparison of In-Reactor and Ex-Reactor Ruptures, HW-62766. This work is being done in cooperation with the Fuel Element Design Operation of the Hanford Laboratories Operation. J. W. Goffard has been particularly helpful in supplying samples and useful discussions of the results.

The current interest in a tube-in-tube type Zircaloy-2 clad UO2 fuel element for use in the power reactors provided the incentive for a study of the dissolution of cladding from an annular space. The objectives of the study were to compare the estimated rate of dissolution in the annuli with rates on fully exposed metal. Because of an interest from the design standpoint, heat balance data from the study are reported.

The Atomic Energy Commission has assigned the Hanford Atomic Products Operation the responsibility of providing the technology and facilities for the interim reprocessing of slightly enriched uranium fuels discharged from power and propulsion reactors. The fuel from the various reactors vary greatly in physical dimensions and in the composition of the core and cladding. For the purposes of chemical reprocessing, the fuels may be divided into the three main categories of aluminum, Zircaloy or stainless steel clad elements. The fuels may be sub-divided by the nature of the core material; e.g. metallic uranium, uranium dioxide, uranium-molybdenum alloys uranium-aluminum alloys, etc.

Design Test Request PR-20 Calandria Characteristics, outlined the need for experimental data concerning the performance of the calandria under transient conditions. Test data was required to confirm that the moderator dump system would drop the level the required 24 inches in less than one second. The original calandria dump chamber design was modified until the criteria was met. This information is recorded in HW-58333, Interim Report, Design Test PR-20, Calandria Characteristics, which lists the drop for the first 24 inches only.

The basic scheme for processing power reactor fuels at Hanford includes the removal of inert endfittings ("hardware") from the active sections of the fuels. Within Hanford Laboratories, research and development studies have been in progress on various types of saws which might be used for hardware cutoff. In the initial phase of the program, high-speed saws were investigated; more recently, studies on low speed saws have been conducted. This report summarizes the high speed saw studies and includes information on abrasive wheels, diamond wheels and metal "friction" blades which cut by actually melting metal ahead of the saw blade. At the completion of the low speed saw testing program currently in progress, basic saw types will be compared and the saw type to be included in the reprocessing complex will be selected.

The Fermi age of thermal neutrons in a lattice containing both water and graphite in some sort of weighted average of the age in water and in graphite independently, with correction for volumes of non-moderating elements or voids. The correct weighting function has been in question during design calculations for the NPR. This paper presents a very simple and direct approach to the problem, resulting in a weighting equation which seems to be theoretically sound. Unfortunately, simple theories cannot be guaranteed to give good results in complicated systems; nevertheless, it appears that the weighting dunction derived here is to be preferred over methods involving empirical relationships which are of doubtful validity in the NPR geometry.

The first series tests in the KER-REP-1 loop proved that a fisssion product contaminated loop could be decontaminated to a safe level for contact maintenance. The second series of tests ere scheduled for a more thorough evaluation of these processes includes specific decontamination factors, process corrosion rates, loop activity reduction factors (loop decontamination factors), and any preferential decontamination which may be present.

For purposes of an earlier consideration of the effects of in-reactor test loops on PRTR operation and program, the design of the high pressure, H20 cooled fuel test loop was assumed to be similar to that for the high pressure, gas cooled loop. Detailed design criteria for the H20 loop have recently been completed so that this assumption is no longer necessary. Therefore, to insure that the effects of all proposed in-reactor loops are fully evaluated with respect to Plutonium Recycle Program objectives, the present study has been carried out. Much of the qualitive discussion in the original analysis is still considered valid. Thus, rather than repeating the entire analysis as it pertains to the H20 loop, only those departures resulting from differences between the assumed design and the scope design are presented.

The purpose of this program is to determine the effects of neutron radiation and reactor gaseous atmospheres on the structural integrity of candidate materials for the PRTR gas-cooled loop. An exploratory investigation is being conducted to select a high temperature resistant alloy for the fabrication of tubes and supporting appliances for the PRTR gas-cooled loop. In addition to a low neutron cross section, the material must be able to withstand the operating conditions outlined in Table 1.

Considerable interest has developed in the use of ion-exchange in the nuclear energy field in the last decade. Aside from the obvious use of providing demineralized coolant water for reactors, the projected uses of ion-exchange include the recovery of fission products from aquaeous waste streams and the separation and purification of fissionable materials from spent reactor fuels. The latter process may be incidental to the over-all operation, as is the case with the Purex anion exchange facility, or it may be the prime separation process, as may be the case in the recovery of Pu or U from spent power reactor (PRTR) fuel elements.

At the request of the Hanford Operations Office of the Atomic Energy Commission, a criticality instrumentation meeting was held at Hanford on August 17 and 18, 1959. The purposes of the meeting were: (a) to review types of criticality control and/or alarm instrumentation at each site, their problems, shortcomings and potential obsolescence; (b) to discuss instrumentation in the area if approaching criticality; and (c) to consider for material balance purposes, the feasibility of devising instruments to detect the buildup of plutonium and enriched uranium bearing residues in process systems.

Early in the U.S. gas-cooled reactor program, it was recognized that a considerable research and development effort would be needed to utilize the full potential of gas cooling. Hanford Laboratories contribution to this program began in August, 1958 when a graphite studies program was initiated. The primary objectives of the Hanford program are: (1) to secure improved knowledge of the reaction of gas coolants with protected and unprotected graphites over a range of conditions of practical interest for gas cooled power reactors with tolerable damage to the graphite moderator.

Soil chemistry studies have been carried on at Hanford for a number of years in support of the disposal of low and intermediate level liquid wastes to the ground. Equilibrium type experiments were carried out to investigate the mechanisms of the reactions of Sr, Cs, and rare earth ions with soils (1, 3, 4, 5). Experiments were also conducted with simulated and actual wastes in soil columns and an empirical method was developed for prediction of radionuclide breakthrough from ground disposal facilities into ground water on the basis of short, laboratory soil columns and equilibrium experiments (6,7). In this method it is assumed that the shape and position of the breakthrough curve is the same under laboratory conditions as in the larger scale field case. It is also assumed that the "column volume" or amount of soil effectively used for fission product sorption is that directly under a disposal facility without considering any spreading of waste solutions. These assumptions are known to be on the conservative side, but the degree of conservativeness is not known.

Extremely radioactive particles result from the abrasive wheel cutting of irradiated fuel elements in the cut-off cell located in the 327 Building. Due to the use of water during the cutting operation these particles are in suspension and must be removed before the liquid can be discharged to the liquid waste tanks in the 340 building. The filters presently employed in the cell total activity discharged to the 340 Building tanks is attributed to the particles which pass these filters. With the start-up of a new, larger cut-off cell the cutting is expected to increase considerably, thereby increasing the amount of radioactive cuttings requiring disposal. The installation of equipment which would more efficiently remove the suspended particles would (1) reduce the activity level of wastes disposed to ground, (2) reduce the radiation exposure level to drivers who truck the wastes to the 200 Area, and (3) prevent the forming of localized high radiation zones due to the deposition of particles in the waste line in the 327 Building.

The Non-Production Fuel Reprocessing Program involves the chemical processing of valuable reactor fuels received from privately owned power reactors. It is necessary therefore, to accurately measure the fuel material received in order to insure proper payment to reactor operator and to provide the Atomic Energy Commission with appropriate accountability data. The volume measurement study described herein was conducted in order to determine the limits of accuracy that could be obtained in measuring relatively large volumes of solution under plant processing conditions.

Disposal of liquid radioactive wastes to ground requires knowledge of the area ground-water hydrology. Information is desired on direction and velocity of ground-water flow. Direction of flow can be determined from maps showing contours on the water table surface, such contours being derived from well water elevations. Ground-water velocity is more difficult to ascertain.

This report is being submitted to provide information and data on the planning and installation of a new mechanized drawing system which utilizes a new drawing index system and a 35mm microfilm image in a standard IBM card. The communication of engineering information to date has been primarily the full size contact print produced by exposing and developing light sensitive material. This method produces legible copies; but, it has the following disadvantages : (a) the original drawings are fragile, and become dirty and worn through excessive use and handling; (b) the sensitized paper has a limited shelf life; (c) the reproduction cycle is slow because it requires hand feeding and adjustment of the reproduction machine to the condition of the original; (d) the prints are large and unwieldy to handle as working documents; and (e) the filling of originals and copies is slow and expensive. In addition, providing reference prints which are accessible to engineering personnel in the widely separated areas from a central file and reproduction facility is slow, expensive and time consuming.

Through the years, considerable effort has been expended in studies of the explosive reactions sometimes observed in the dissolution of uranium-zirconium alloys in nitric acid. It has been shown (1) that such reactions result from the rapid oxidation of finely dived solids released by the preferential dissolution of the metallic matrix. The explosive portion of such solids has been identifies (1) as an intermetallic compound with the approximate composition UZr2. This compound, referred to as the epsilon phase in previous work, has more recently (2) been termed the delta phase. The latter designation will be employed here.

Presently rotary drum filters are being used for plutonium oxalate slurry filtration in the 234-5 Building. Changing of the filter cloth used on a rotary drum is a time consuming operation which involves ever increasing radiation exposure to maintenance personnel. Consequently, studies were conducted in the 321 Building on a disk type filter which could be adapted for simple and quick ("one-nut") replacement of the filter medium.