This report supersedes ORNL CF-57-2-1, which was an extension and revision of ORNL CF-54-6-72. Details concerning a recommended system of flow-plan symbols and drawing are given. The system is designed to identify the function of all major instrument components and to show schematically the operation of the instrument relative to the particular process. The system is used for identification and designation. The system is a modification of the Instrument Society of American Recommended Practice (RP 5.1).

Experiments in the controlled melting of irradiated fuel specimens, particularly of the APPR, STR, and MTR types, have confirmed that prolonged heating in air at temperatures in excess of the melting point results in the release of a large portion of the radioactivity. On the other hand, a moderate amount of heating in air or steam sufficient only to melt a specimen results mainly in the partial volatilization of rare gases, iodine, bromine, cesium, and rubidium. In the presence of air or water vapor, strontium and other fission products are not released. At trace concentration of fission products, slow melting of the APPR plate at 1525 C in air or steam effected the release of 50% of the rare gases, 33% of the iodine, 9% of the cesium, and traces of strontium. After 25% burn-up, the cesium value increased to about 60%. Aluminum alloy of the MTR type, also at trace concentration, upon melting at 700 C released up to 2% of the iodine, 10% of the rare gases, and negligible portions of other fission products. Zirconium alloy of the STR type after 15% burn-up, when melted at 1850 C, released up to 95% of the rare gases, 90% of …

A series of two-group calculations has been made on the Oracle for the purpose of obtaining critical-mass and flux distribution data for various ORR core configurations. The 3G3R code of Bate, Einstein, and Kinney was used, together with the RSP code developed by Nelson. This made it possible to obtain results for the three-dimensional case. The results, which are presented graphically, are intended to serve as a guide for the design of experiments until such time as actual measurements are available. The calculations were performed for the "clean cold" case, and it should be realized that the presence in the core of experiments and of fission products built up during operation will materially alter the flux patterns found. It is believed that the critical-mass data are accurate to within 10%. Within the fuel region it is believed that the thermal-flux patterns are the also accurate to this degree. Comparison of the results with MTR critical experiments, however, indicates that the thermal flux in the reflector in the vicinity of the fuel-reflector interface may have been underestimated by a factor of as much as 1.3. It should also be recalled that in a two-group calculation the "fast flux" is often a …

This report is presented in order to provide a satisfactory system of symbols and identifications for process-instrumentation equipment and to promote a uniformity of practice that will simplify and expedite instrumentation work. It is intended that the systems presented here should be capable of designating and identifying the multitude of instrumentation items which are used for control and operation of conventional processes, as well as for specialized work peculiar to ORNL. Instrument Society of America standards have been adhered to whenever practical.

A general program has been written to plot curves on the Oracle curve plotter. The supplement includes changes to slow down some of the loops and minimize the possibility of read-around errors and changes to handle special cases.

The continuous dissolution of 304 stainless steel and stainless steel-UO2 alloy in dilute aqua regia was studied with subsequent stripping of the dissolver product to remove chloride ion. The process has the advantage of producing, by means of a simple head end treatment, a solvent extract feed in a conventional nitric acid medium so that existing solvent extraction processes, materials of construction and waste disposal methods can be used. The purposes of this study were to investigate the variables affecting the dissolution process and to obtain dissolver scale-up data, and to investigate the removal of chloride from the dissolver product and the variables affecting the stripping operation. A continuous flooded pot dissolver was used. It has the advantages of stability of operation and ease of control in comparison with column dissolvers and requires a minimum of mechanical processing prior to dissolution. Stripping of the dissolver product to remove chloride ion was studied in a 4-in. diameter Pyrex bubble-cap column containing 12 single bubble cap plates. Continuous dissolution rates and dissolver product stainless steel loading were correlated with aqua regia feed composition, acid feed rate and surface area exposed to reaction. Profiles of chloride concentration down the stripping column were obtained …

An annual report is given on the operation and costs of waste-disposal facilities at ORNL laboratories and operating buildings in the Bethel Valley area. The operations of the hot-chemical and metal-waste systems, the process-waste system, and the radioactive-gas-disposal system which utilized the 250-ft stack located in the Radioisotope area are discussed. The miscellaneous operations which include the SS (source and special nuclear) material control, SS material recovery, off-shift service for research divisions, water demineralization plant operations, and hydrogen liquefaction are included. However, the disposal of cooling water from LITR, off-gases from the Hot Pilot Plant, and the ORNL Graphite Reactor building are not covered by the report.

Section 9.0 is the "Chemical Processes for Fission Product Concentration, Removal or Fixation" section of the Status Report on the Disposal of Radioactive Wastes. The report is divided into four areas: (1) Introduction; (2) Summary of waste processes; (3) Concept of a multipurpose waste processing facility; and (4) Details of some of the waste processes.

An estimate has been made of the critical fuel concentration in the HRT, taking into account the effect of the core corrosion sample assembly. The estimate is based on a number of previous calculations of critical concentration in an un-poisoned reactor and one calculation of critical concentration as a function of poison level. The makeup of the first core corrosion sample assembly was used in calculating equivalent neutron poisoning effects. Figure 1 shows the estimated critical concentration as a function of temperature with the corrosion sample assembly in place. At 280°C, the assembly raises the critical concentration by 0.6 g U-235/kg D2O. This effect is equivalent to a uniformly distributed poison equal to 4.1% of the fission cross section. The equivalent poison is greater at lower temperatures, where the uranium concentration is lower.

Experiments in the controlled melting of irradiated fuel specimens, particularly of the APPR, STR, and MTR types have confirmed that prolonged heating in air at temperatures in excess of the melting point results in the release of a large portion of the radioactivity. On the other hand, a moderate amount of heating in air or steam sufficient only to melt a specimen results mainly in the partial volatilization of the rare gases; the halogens, iodine and bromine; and the alkali metals, cesium and rubidium. In the presence of air or water vapor, strontium and other fission products are not released. At trace concentration of fission products, slow melting of the APPR plate at 1525 C in air or steam effected the release of 50 percent of the rare gases, 33 percent of the iodine, 9 percent of the cesium and traces of strontium. After 25% burn-up, the cesium value increased to about 60 percent. Aluminum alloy of the MTR type, also at trace concentration, upon melting at 700 C released up to 2 percent of the iodine, 10 percent of the rare gases, and negligible portions of other fission products. Zirconium alloy of the STR type after 15 percent burn …

Various nuclear characteristics of two-region spherical homogeneous reactors have been computed in order to provide information for the design of HRE-3. Equilibrium isotope concentrations were established using an ORACLE code, and a two-group model was used to obtain critical concentrations and flux distributions. Breeding ratio is plotted as a function of reactor size, blanket thorium concentration, and other design and operating parameters, and the time required for a demonstration breeding is discussed. Tables of results, including neutron balances, are given for selected reactors. a number or relations are presented for estimating the effects of fission products, copper, corrosion products, H2O, and the core tank on breeding ratio.

The gamma dose rate in the motor region of the HRT fuel circulation pump was measured with the pump scroll full of radioactive solution. Extrapolation of the data to the solution activity expected in the pump under normal operation gives a dose rate well below that which would result in excessive gas production in the stator can within the life of the pump. The above dose rate does not include the effects of fast neutrons from the fuel solution or of the general cell radiation level in the vicinity of the pump. It appears that the possibility of gas production in the stator from the cell background radiation is sufficiently great to warrant the installation of a shield around the outside of the motor end of the fuel circulating pump.

This compilation includes the following subjects: (1) Spectroscopic studies, (2) Neutral carbon in the vacuum carbon arc, (3) Anode effects, doppler blast effects, and stark broadening, (4) Neutrals in the high-current carbon arc; (5) Photon breakup of N2 in the high-current carbon arc, (6) Ion density in the high current carbon arc, and (7) Recombination cross-section for fast hydrogen ions and slow electrons. Minor revisions have been made in the subject memoranda in incorporating them in the compilation.

Tests have been completed on a combination heater-cooler unit for use in in-pile loops designed to operate in beam hole HN-1 of the ORR facility. The unit is designed to use air-water mixtures as the coolant. the coolant flows through a spiral of 3/8-inc. diameter tubing cast in aluminum around the 3/8-in. IPS loop pipe. four 1000-w calrod-type electric heating elements are cast into the aluminum, along with the cooling coils to provide loop heating.

The new and as yet unsolved problems introduced by the production of large quantities of fission products and radioactive isotopes from fission or neutron capture present mankind a most complex technical, economic, and political problem. On one hand, the possibility of using the fission process to produce energy from an unexploited and abundant natural source is emerging from large programs of research and development. We are also beginning to see the promise of use of particulate and electromagnetic radiation for the good of man. On the other hand, we are presented with the problem of controlling the dangerous products of fission for periods of time measured in terms of many hundreds of years, periods longer than the effective tenure of any political state in history. We must not only devise ways of protecting ourselves in the present and for our lifetime but, in addition, we must establish the basic technical, social, and administrative control of vast quantities of artificial radioactivity that must remain effective for at least ten to twenty lifetimes.

A method has been developed for the determination of total sulfur in fluoride salts using the methylene blue procedure. Reduction of sulfate to hydrogen sulfide is achieved through the use of a new reducing mixture consisting of stannous chloride dissolved in concentrated phosphoric acid. The new mixture is effective on microgram amounts of sulfate and offers a major advantage over the red phosphorous reducing mixtures in that larger samples may be taken for analysis. The procedure has been applied to fluoride salts containing from 1 to 500 ppm of sulfur. The coefficient of variation the method is 10 percent.

The compositions of the compounds and fused salt mixtures referred to in the ANP project by numbers are given.

The results of a machine calculation of a modified Fanning-friction-factor Hedstrom plot for Hedstrom numbers from 0 to 10(10) are presented in graphical and tabular form.

Nickel is more susceptible to mass transfer in a 100hr non-isothermal dynamic corrosion system than is Inconel when exposed to a NaCl-MgCl2-UCl3 (50.0-33.3-16.0 mole %) bath at a hot zone temperature 1800 F. No nickel mass transfer was observed in a 500-hr test at 1350 F, but Inconel showed some attack under these conditions. Inconel mass transfer was observed in both tests, being more severe at the higher temperature. On the bases of these preliminary tests, it appears that nickel is a more satisfactory container than Inconel for the chloride bath at temperatures in the region of 1350 F. The chromium is more susceptible to selective leaching from Inconel at 1800 F during a short 100-hr test (0.26% Cr in bath) than in a 500-hr test (<0.001% Cr in bath) at a lower temperature (1350 F ).

A new and rapid method for the liquid-liquid extraction of uranium and plutonium from hydrochloric acid solution is based on the use of tri(iso-octyl)amine dissolved in xylene or methylisobutylketone. Uranium and/or plutonium are separated from thorium, alkalis, alkaline earths, rare earths, zirconium, niobium, ruthenium and other elements which do not form anionic species under the conditions described. The technique may be used for either tracer or macro quantities of uranium. Several practical applications of the method for the separations chemist are proposed.

On May 23, 1957, a visit was made by the writer to the Selas Corporation of American in Dresher, Pennsylvania. The purpose of the visit was to discuss further investigations into methods of tubesheet brazing by direct heating. Original work along these lines has been carried out at ORNL and is covered by a memo (CF-57-4-57) to W.D. Manly, dated April 16, 1957, and entitled : Investigation of Tubesheet Brazing by a Method of Direct Heating.

In a reactor system the principal components affect by slurry properties are the blanket vessel, pressurizer, heat exchanger, and dump tant. The particular properties that affect the operation of these components are: caking, degree of flocculation, foaming, and slime formation. these properties are related to the characteristics of compounds in a reactor system through experience gained in the operation of slurry loops. It is pointed out that the optimum slurry for one component may not necessarily be the optimum for another.

The HRT mockup was shut down February 16, 1957 after operating for 576 hours on high concentration uranyl sulfate. At this time, all corrosion samples in the system were removed and replaced, and the wire extending thought the letdown hear exchanger was removed of examination.

A spectrophotometric method for the determination of cerium with Tiron (disodium-1,2-dihydroxybenzene-3,5disulfonate) was applied to the determination of cerium in samples which contain uranium and zirconium. The cerium-Tiron complex in solutions of pH 8 or greater exhibits an absorption maximum of 500 mu . This reagent does not react with any other lanthanide element. The interference of iron, uranium, and zirconium was eliminated by extracting these interfering elements with a solution of trioctylphosphine oxide in cyclohexane. (auth)