A short-term study was made to investigate the removal of radioiodine vapor from air-steam mixtures as could occur immediately following a nuclear incident in a pressurized water reactor. Activated charcoal traps, designed to simulate a small section of a commercial charcoal canister, were tested at gas velocities of 23.9 to 74.9 ft/min over the temperature range of 75 to 118°C. The iodine removal efficiency was found to range from 99.80 to 99.4% with an average of 99.9%. One test performed at a temperature of 105°C and with gas velocity of 290 ft/min indicated that the iodine removal efficiency was reduced to 99.54%. Activated charcoal exhibits a high efficiency for iodine vapor removal under these test conditions and appears suitable for application in the decontamination of air-steam mixtures.

A stimulation study of the deign as of June 1960 of the gas-cooled ORR Loop No. 1 was made using the ORNL analog computer. The proposed method of temperature control is evaluated, and the dynamic behavior of the loop for accidents and component failures is presented in graphical form.

This manual represents the recommendations of the Instrumentation and Controls Division committee on Electrical and Electronic Symbols and Drawing that have been issued to date. Section I consists of copies of the American Standards Association Graphical Symbols for Electrical Diagrams, with certain variations or additions that have been recommended by the Committee to clarify or more positively identify the device or element symbolized. Since publication of the present ASA standards, certain elements, such as the transistor, have come into common use. Committee and represent the symbols have been selected after considerable study by the Committee and represent the symbols that seem to be standard Reference Information series, Interim E--1.

On 3/14/60 the Applied Physics Corporation was awarded a subcontract for the design and development of a high-temperature high-pressure spectrophotometer system based on the Cary Model 14pm Spectrophotometer insofar as possible, and consistent with our specifications, No. CTD-2, December 16, 1959.

LITR Fluoride-Fuel Loop. — The inconel loop was dismantled for removal of the samples and for recovery of the uranium by using the remote cutting tools installed in a half cell of the Solid State Building. Disassembly proceeded without incident. An electric-arc cutting technique was developed for removal of the stainless steel enclosure around the pump bowl. Fission power and maximum flux were determined by irradiating a simulated loop, by heat-balance calculations, by radiochemical analyses for fission products in the fuel, by measuring the activation of cobalt foils attached to the loop, and by activation of the loop tubing itself. The determination of the power by these various methods gave 2.5 to 2.8 kw during operation of the loop, and the maximum power density was 0.4 kw/cc. Chemical analyses of the fuel were carried out to determine U, Zr, and the major constituents of inconel: Ni, Cr, and Fe.

From July 7 to August 31, 1955, 20 tons of uranium and 1,200 g of plutonium were recovered in 47 days of plant operation at an average rate of 833 lb/day of uranium and at a cost of $2.60/lb of uranium. Uranium and plutonium recoveries were, respectively, 99.9 and 95.5 per cent.

Equipoise-2, a two-dimensional, two-group neutron-diffusion code in R-Z geometry, has been programmed for the IBM-7090 computer. This code was designed to permit the running of large numbers of cases without requiring excessive machine time. Typical running times are of the order of one to three minutes per case for a 1000-point problems. The maximum number of mesh points that can be used is 1444.

Progress report of the Oak Ridge National Laboratory Metallurgy Division providing updates on various projects, experiments, and other work. This report includes a summary of scholarly output and summaries of general corrosion, dynamic corrosion, mechanical properties, nondestructive testing, welding and brazing, fabrication, physical chemistry of corrosion, HRP metallurgy, the package power reactor program, APPR absorber, metallurgical materials and processing, metallography, ceramics, fundamental physico-metallurgical research.

This report is a working document of the UB AEC Nuclear Cross Sections Advisory Group and is issued about twice a year for the purpose of stimulating important cross section measurements. The requests listed in this report have originated from various Atomic Energy Commission contractors, the Advisory Committee on Reactor Physics, and the Nuclear Cross Sections Advisory Group. The distribution is limited to members of the US Nuclear Cross Sections Advisory Group (NCSAG), the US Advisory Committee on Reactor Physics (ACRP), the Tripartite Nuclear Cross Sections Committee (TNCC), the European-American Nuclear Data Committee (EANDC), to US AEC off-site contractors, and to the requestors and measurers of the cross sections listed in this report. The contents of this document are not to be republished in part or in full without special permission of the chairman of the NCSAG, The unpublished data which appear in this report must not be quoted in publications without permission of the experimenter.

An analog simulation is made of the HRP in-pile slurry loop in the LITR. The radiolytic gas pressure in the pressurizer is determined. This pressure is a result of the generation of radiolytic gas in the loop core. A graphical result is obtained showing the effect of catalyst activity and pressurizer flow rate on the pressure rise from radiolytic gas. The thermal behavior of the system is studied, and the response to various controller settings is predicted. Controller settings very near optimum for the actual process were recommended from the analog study,

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 …

The development of nuclear reactors and other nuclear particle sources has given the analyst a new analysis method which can be successfully applied to the determination of microgram and submicrogram quantities of many elements. Known as "radioactivation analysis", this method is one in which an "activation" by some type of nuclear reaction is used to produce a radioactive isotope of the element to be determined. Since this radioisotope decays with its own characteristic radiations and half-life, it is possible to make radioactivation analysis a very specific analysis. Chemical separations of the radioisotope are employed whenever necessary and its radioactivity measured by some type of radiation counter.

Nuclear physics research with 22-Mev protons in the 86-in. cyclotron included angular-distribution measurements of neutrons from (p,n) reactions in nine target elements; measurement of the angular distribution of fission fragments from proton-induced fission of U233, U225, U228, Th230, and Th232; measurement of alpha-particle angular distributions from (p,α) reactions a study of the neutron-deficient isotopes of terbium and completion of an extensive program of the measurement of activation cross sections. Two more targets for cyclotron production of isotopes were developed, and the production yields for 14 radioisotopes are summarized. A new record for continuous beam power on a production target, 36 kw for 5 hr, was achieved. The design of a beam-deflector system for the 86-in. cyclotron has been completed, and several of the components have been fabricated ; a shutdown for installation is scheduled for October 8. The deflected N+++ beam of the 63-in. cyclotron was used in a study of the gain and loss of electrons by nitrogen lens passing through thin foils, and the equilibrium charge distribution of lens as a function of energy was thus obtained. The excitation functions were measured for nitrogen-induced reactions on both nitrogen and oxygen. Assembly restrictions of the prepared 114-in. heavy-particle cyclotron …

The installations of the beam deflector in the ORL 86-inch Cyclotron is sufficiently complete to allow initial testing the system permits the optional use of high-current internal targets. A survey of [illegible] cross sections made with 14-Mev neutrons indicates qualitative agreement with statistical theory. An internal-conversion ion spectrograph and a fission-fragment spectrograph were built and put in operation. The [illegible] functions severed proton-induced reactions of possible use in isotope production were measured. A capsule-type target is being used for the irradiation of chemical compounds. Nuclear physics research with 26-Mev nitrogen lens from the ORNL 63-inch Cyclotron concerned the following: a theoretical interpretation of elastic nitrogen-nitrogen scattering a detailed investigation of some nitrogen-nitrogen nuclear reactions; the measurement of reactions across sections in boron and aluminum; and the identification and the energy spectre of protons and alpha particles resulting from nitrogen-induced reactions with light elements. A study is being made of the practicality of a fixed-frequency cyclotron to accelerate protons to about 1 [illegible] for application in [illegible] research. Phase compensation would be obtained with an unusual magnetic-field configuration which has eight [illegible] cycles with about 72 deg of spiral, Also, a proposal was made to convert the 44-in. proton cyclotron a …

Simon (1960) has given a general steady state theory of plasma accumulation (without energy losses) in an OGRA device. Such a device is fed by injection of energetic molecular ions which dissociate to produce trapped protons. Initial trapping is achieved by dissociation in the background gas. Such a device is usually characterized by a critical input current of critical plasma density (a function of input current) above which plasma density builds up to a value limited by Coulomb-scattering losses. For a regime of operation of current interest at Oak Ridge National Laboratory (600-kev hydrogen molecular ion injection and dissociation, highly efficient ion-pumping action of the trapped plasma), extremely simple approximate formulas have been derived which describe with a fair degree of accuracy the critical current of density for plasma build-up.

The Thorex Pilot Plant at Oak Ridge National Laboratory was operated during 1955, processing reactor-irradiated thorium slugs to recover U233 and thorium and 12 MTR fuel elements to recover U235 and Np237. The radiation exposure received by operating personnel during this period averaged 60 mrcp/man-week. Most radiation exposure was received in areas that were intended to be only slightly or nonradioactive. However, because insufficient decontamination of process solutions was achieved and equipment surfaces became contaminated from equipment failures, these areas became primary sources of personnel exposure. The installation of additional shielding where needed and the prompt removal of surface contamination successfully reduced the radiation levels and exposures in these areas. Remote control of processing equipment and sampling of very radioactive solutions from process equipment was successfully accomplished, and assisted in the reduction of exposure to operating personnel.

Part I. Experimental Reactors: The design has been completed for all the major high-pressure and low-pressure components except the reactor pressure vessel. Contained in this report are the most recent revisions of the low-pressure-system flow sheet, a description of important details of the reactor cell, and the final design of the main heat exchangers, the inner dump tanks and separator. the recombiner and recombiner-condenser, and the outer dump tank and reflux condenser. Part II. Thorium Breeder Reactor: An analysis of the relative effects of major process variables on the economics and characteristics of two-region thorium breeder reactors is nearing completion, and the results to date are presented in this report. From these results most of the major reactor characteristics have been determined; they are reported with certain other engineering studies pertinent to the early phases of the program. Part III. Corrosion: One loop was removed from service and cross sectioned for inspection of the internal surfaces. This loop was of type 347 stainless steel pipe and had a cumulative operating time of more than 12,000 hr with uranyl sulfate solutions varying in concentration from 0.004 to 1.34 m. No excessive or localized corrosion attack was noted except in one highly …

Two methods were developed for the determination of uranium metal in UF3 with other fluoride compounds. A simplified method of determination which has a relatively high degree of precision (coefficient of variation 2 per cent) is carried out by decomposing the hydride in an atmosphere of carbon dioxide and subsequently measuring the hydrogen over an aqueous solution of potassium hydroxide. The ignition of the hydride in an atmosphere of oxygen and volumetric measurement of the water at reduced pressures provide a more sensitive method of determination. The coefficient of variation of the latter procedure is 7 per cent. The yield of gas from the reaction of the hydride with ammonia and gaseous hydrogen chloride was found to be neither stoichiometric nor reproducible.

A direct titrimetric method for the determination of trivalent uranium in uranium trifluoride and mixtures of fused fluoride salts was developed. The method is based on the stoichiometric oxidation of trivalent uranium to the tetravalent oxidation state with an acidic solution of methylene blue. The sample containing trivalent uranium is dissolved at room temperature in an excess of standard methylene blue solution in a carbon dioxide atmosphere; the excess oxidant is variation of the method is 1.5 per cent for 5 mg quantities of trivalent uranium. The method was applied to various mixtures of fluoride salts containing both trivalent and tetravalent uranium.

An experiment was performed at the ORR in order to find a good fission chamber location. Two locations on the pool side of the reactor tank were explored with a one inch diameter fission chamber. The thermal neutron flux attention was found to vary nearly exponentially with distance, and no shadowing effect could be seen during a reactor startup. The fission products high gamma flux could be discriminated without difficulties. Both positions seem to be adequate to locate a reactor control fission channel.

The hazard of Sr^90 arises in part from its fixation by phosphates in the skeletal system. It is natural then to consider compounds and minerals associated with the phosphate anion for applications in waste disposal. Calcium phosphate floc formation is widely used as a method for removing strontium from contaminated water. Also, calcerous soils are said to be effective for removing strontium from low-level wasters containing dissolved phosphates. It is suggested that one the mechanisms involved in strontium removal is the formation of calcium phosphate (apatite), with strontium substituting isomorphously.

The attached paper is a translation of a rough draft of the paper, "Operating Experience of the APS-1", presented by M. Minashin in Russian at the IAEA Conference on Small and Medium Power Reactors, Vienna, Austria, September 5-9, 1960.

This memorandum is the first in a series reporting progress in the program of critical experiments in the ORNLArmy Package Power Reactor Project. The critical assembly, designated as CA-25, is analogous to the APPR design core and consists of 45 fuel boxes, in a 7 x 7 array with the corners removed, contaIned in a large water tank. Two sides of each box are slotted for the insertion and positioning of any desired loading of eighteen plates of fuel, structural material, and poison. The array is submerged in water to provide a moderated and reflector. Enriched uranium metal, in two-mil-thick foils 2.5 x 22 in, is encased in type 304 stainless steel sheets, 2.7 x 23 x 0.0105 in., to form fuel plates. Stainless steel plates, 2.7 x 23 x 0.025 in. are used to simulate additional steel in the APPR core. It is, therefore, possible to maintain an essentially constant metal to water ration in the assembly when the fuel content is varied. The fuel is distributed as uniformly as possible in all boxes and a symmetrical distribution of materials is maintained in the core at all times. Fuel plates containing half-width (1.25 in) uranium foils are provided for …