From introduction: "The ORNL-ANP liquid-to-liquid heat exchanger design and development effort has been based on an exceptionally high performance matrix of closely-spaced small diameter tubes that permits practically pure counter-flow operation. In the course of full-scale aircraft power plant design work a number of charts for this type of heat exchanger has been prepared. These charts were intended in part to show the effects of the various parameters in a readily understandable form, and in part to simplify and to reduce markedly the chore of making detailed design calculations. These charts have proved so helpful it seemed very worthwhile to assemble them into a report along with brief explanations and sample calculations."

From abstract: "On the 86-inch cyclotron a 41-kw beam has been calorimetered at a net ion loading efficiency of 40%; the average proton current was 1.85 ma at 22.5 Mev. Practical specific yields have been determined for (p,2n) reactions on zinc and bismuth. The investigation of products of proton-induced fission of uranium has been continued and new techniques are being used in measuring angular distribution of reaction products. The 63-inch heavy particle cyclotron is now in operation; N+++ particles have been accelerated to ~25 Mev. In preliminary tests, induced activities have been detected in carbon, nitrogen, and oxygen targets. A hot-cathode ion source is ready for test operation. The 22-inch cyclotron is being used in an investigation of the problems associated with the use of rf and dc electrodes for the acceleration of protons from the ion source into the dees. Radiation-induced corrosion in Inconel tubing containing #21 eutectic (ANP) has been produced by proton irradiation in the 86-inch cylclotron; it is shown that the corrosion was not due to thermal effects. Approximately 150 grams of highly purified U 238 (< 5 ppm U 235) have been prepared, and two grams of thorium 230 (ionium) has been enriched to 90.6%."

Technical report outlining the physical operability of 30% tributyl phosphate in a hydrocarbon dilutent for the extraction of uranium from more feed slurries. Operability had been satisfactorily demonstrated in jet mixing columns at the pilot plant of the Mallinckrodt Chemical Works. [From Abstract]

Several plates of 98.7% Th - 1.2% U 235 (clad in aluminum) were irradiated in the MTR for an integrated flux of 2.6 x 10 21 neutrons/cm2. Although these samples represent an early development in bonding of aluminum to thorium and there are better methods at present, the bond proved to be quite strong and both clad and core were dimensionally stable under irradiation. The production of uranium 233 was as much as theory would indicate and the total amount of fissionable material material after irradiation and after decay of the protactinium 233 was greater than before irradiation. A fuel element of this nature appears to offer excellent potentialities from the standpoint of radiation stability.

This report presents data obtained from processing 33 Clementine Reactor fuel elements in the ORNL Metal Recovery Plant to recover approximately 15 kg of plutonium and 0.16 g of americium.

Technical report containing a comprehensive study of the physical metallurgy of thorium and some of its alloys containing additions of Be, Si, Zr, Ti, Al, Nb, Cr, Mn, and Ce. Melting range, fabricating characteristics, and tensile properties were studied. [From Abstract]

The proposed ORNL Research Reactor is designed to serve as a general purpose research tool delivering a maximum thermal flux of 8x10^13 n/cm2-sec at the initial power level of five megawatts. Operation at power levels up to ten megawatts is proposed for such items as sufficient cooling capacity is available to handle the increased heat load. The reactor will use MTR-type fuel elements and beryllium reflector pieces in a 7 x 9 grid with moderation and cooling provided by forced circulation of demineralized water. The reactor tanks are submerged in a barytes concrete pool, filled with water, which serves as a biological shield. Experimental facilities include two 18" diameter "Engineering Test Facilities" and six 6" diameter beam holes. In addition, access to the core is available through the water of the pool. The result on the surrounding population of release to the atmosphere of a large fraction of the radioactive material in the core has been computed by two methods. It is shown that under certain conditions off-area personnel could be subjected to greater than the maximum permissible exposure. An analysis of the maximum hazard caused by the release of the entire contents of the core to the local watershed …

Technical report covering the metallurgy of thorium and on fabrication techniques. Report investigates the stability and corrosion resistance of thorium exposed to eutectic NaK, extrusion as a means of fabrication of thorium tubes or rods, and corrosion of large single metal crystals by liquid metals. [From Summary]

From abstract: "The Darex process developed for the recovery of uranium from stainless steel-containing reactor fuels consists of three steps: (1) dissolution of the fuel material in dilute aqua regia, (2) removal of chloride from the solution to prevent corrosion of downstream stainless steel process equipment, and (3) adjustment of the nitrate solution to solvent extraction feed conditions."

The fabrication, irradiation and evaluation of the first two superheat fuel assemblies is described in detail. Experimental data indicate that, in general, the nuclear superheat fuel elements have performed satisfactorily under the testing conditions used. Certain problem areas which will influence future fuel element designs have been defined.

This quarterly progress discusses the ongoing work at the Oak Ridge National Laboratory for the quarter ending in March 10, 1952. Topics discussed include reactor theory and design, shielding research, materials research, and includes appendixes with supplemental information.

This memorandum sets forth a recommended uniform basis for designing the ORN shield.This includes design values for power level and emergent radiation, standards values for various material properties, and basic radiation intensities.

The fabrication of heat exchangers and radiators to be used in conjunction with high-temperature nuclear reactors may present exceedingly complex problems. Rigid heat transfer requirements may necessitate the use of compact assemblies of thin-walled small-diameter tubes as integral parts of the heat transfer units. Intricate designs may also be required in which cooling fins must be securely joined to the tubes at closely spaced intervals. In addition to the difficulties in fabrication imposed by the designs themselves, the high operating temperatures involved require the careful selection of materials and joining techniques. The choice of fabrication procedure for a given component must not only be based upon the stresses and temperatures to be encountered, but also upon special factors peculiar to nuclear service. Since many reactor applications employ highly corrosive environments, compatibility of the structural ma terials with the corrosive media is of paramount importance. The low nuclear cross-section require ment for brazing alloys to be used inside the re actor also places stringent limitations on the possible choices of in-pile applications. The use of boron in alloys for certain service may not be considered feasible, for example, because of its high nuclear absorption cross section. Although welding is used extensively …