After several failures had occurred in the HRT leak detector system, several lengths of this tubing were removed for metallurgical examination. The tubing was of type 304 stainless steel and was 1/4" in diameter with a 0.065 wall. The tubing had been purchased as three different lots, the first in 45 ft. lengths and the other two as standards lengths. Tubing from the first lot was used primarily for the shield penetration and, therefore, sections of it are present in all lines of the system. It appears that chloride contamination entered the system in a portion of the first lot of tubing used for the shield penetration. The exact source of the chloride cannot be determined, but after considering the results and visiting the manufacturer's plant, it appears most likely the contamination was during the manufacturing process.

A system for concentrating uranyl nitrate solutions was designed and installed in the Thorex Pilot Plant. A total of 16,060 g of uranium was concentrated in the system in 68 batch runs. A total of 14,400 g total uranium (14.180 g U/sup 233/) was recovered as product suitable for shipment. Uranium loss to the evaporator condensate was 0.03% of the total uranium processed. The material balance across the system was 98.4%. The average concentration of uranium in the evaporator feed solution was 29 g/liter; the average concentration in the evaporated solution was 298 g U/liter and in the product solution was 199 g/liter. Radiation readings of bottles containing product solutions were taken with a hard-shell cutie pie immediately after each run, and these readings ranged from 35 to 1100 mr/hr. The radiation levels of the bottles of product solution shipped averaged 78 mr/hr. Bottles of product solution reading in excess of 300 mr/hr, maximum allowable for shipment. were reprocessed in the second-cycle solvent extraction system (Thorex) and reconcentrated. The products from seven runs had radiation levels in excess of 300 mr/hr at the time of concentration, or the activities had grown to that level by the time of shipment. The …

The Eyewash program, written by James H. Alexander and Nancy D. Given, provides solutions of reactor criticality problems in spherical geometry by means of the group diffusion method. It employs thirty lethargy groups (plus one thermal group) in nine regions. The input consists principally of specifying the geometrical scaling factor, boundaries and compositions of the various regions, and temperature level. The output includes the value of vc that would render the system critical, the relative fission density distribution, fissions, absorptions, and leakages in each lethargy group in each region, and, if desired, an edit of the flux at each space point, each lethargy, and an edit of the macroscopic cross sections for each lethargy, each region. OCUSOL-A is a minor modification and extension of Eyewash. It provides for the computation and editing, on the supervisory control typewriter, of the total absorptions in selected nuclides in the various regions. This information is useful in the computation of breeding ratios and the preparation of detailed neutron balances, and in the estimation of flux-averaged cross sections for use in estimating the rate of change of concentration of the various nuclides with burn-up. The program also provides for saving and transferring the final fission …

The in-plie slurry loop work is now being considered as a joint program between the PAR project and ORNL. It is proposed that PAR design, fabricate and test the in-pile loops and that ORNL operate the loops in-pile, dismantle the loops after irradiation and made the appropriate measurements to determine the radiation effects. This report gives the objects of the slurry in-pile program and outlines the facilities and operations required to execute ORNL's part of this program.

The radiolytic decomposition of tributyl phosphate has been show by burr to product gases, acids, and polymers. the acids that are formed can limit the usefulness of tributyl phosphate for the processing of radioactive materials. The study of acid formation on radiolysis therefor becomes important to us for the understanding of the mechanism of acid formation, the influence of added materials and the effect of the structure of organo- phosphorous compounds. Samples of purified esters have been irradiated in the ORNL cobalt source. Conclusions: (1) The formation of acid from tributyl phosphate during irradiation with cobalt gamma rays involves a mechanism that is not a primary step. Evidence has been obtained for a secondary reaction that is minimized by the presence of certain compounds. (2) Toluene acting as an inhibitor for radiolytic formation of acid may indicate the usefulness of an aromatic hydrocarbon diluent in processing. (3) The aromatic hydrocarbon, when phenyl, was not effective when it was part of the molecule. (4) First tests revealed that dibutyl butyl-phosphonate produced less acid the TBP and may warrant further consideration for process application.

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

The feasibility of determining particle sizes in the submicron range by employing an activation analysis - centrifugation method has been demonstrated. It is believed that this method is now applicable to the analysis of thorium oxide for submicron particles. The same techniques are, in most instance, usable in determining particle sized in other sample materials.

To supply information about the several letdown valves which have been in HRT service, a typical valve plug examined by the Metallurgy Section confirms the belief that chemical attack on the Stellite #6 was occurring. It appears that most of the corrosion was due to rinse solutions, since this phenomenon has not been noted on letdown valves in the HRT Mockup where over 90% of the operating time has been with UO2SO4 solutions.

The horizontal and vertical power distribution for a 5 x 7 fuel element loading of the TSR is presented. (auth)

Chloride-induced stress-corrosion cracking has been encountered in the Homogeneous Reactor Test during the preliminary testing. The rector is constructed of austenitic stainless steels. It is unique in that it will operate at 250 to 300 C with an aqueous uranyl sulfate solution fuel containing 200 to 500 ppm of dissolved oxygen. The cracking has occurred in a secondary system used for detecting leaks in the flanged joints of the primary systems and in the grooves of flanges in the primary systems. Tubing used in the leak-detection system was found to be contaminated with chloride introduced during manufacture.

.Recalculations were made of HRT cell pressures in the event of a simultaneous rupture of the reactor core vessel and the fuel and blanket heat exchangers. These calculations will be applicable after the replacement fuel heat exchanger is installed. The pressure rise in the cell is plotted as a function of time. A maximum cell pressure of 34 psig is achieved ~7 sec after rupture.

Several compatibility test of various materials in contact in sodium under 500 psi pressure were conducted for 716 hr at 1500 F. Of the diffusion couples studies, the Inconel-beryllium system showed the largest amount al alloying. The reaction between molybdenum and beryllium resulted in the formation of two compounds, both of which were severely cracked in several areas. The molybdenum-INOR #8, and the INOR #8p type 316 stainless steel interfaces showed little if any alloying.

A promising nonaqueous process for the recovery of uranium from spent fuel elements is under development at Oak Ridge National Laboratory. This process consists of dissolution of the fuel element in a fluoride melt by hydrofluorination at 600 to 700°C, direct fluorination with fluorine for the production and volatilization of UF6, with further decontamination of the product UF6 from fission product activity being secured in a NaF absorption-desorption step. Good decontamination is obtained in the fluorination step due to the low volatility of most of the fission product fluorides. An over-all decontamination factor greater than 106 with adequate uranium recovery has been demonstrated in laboratory scale tests using a double bed procedure for the NaF step. A pilot plant has been constructed for testing the process with various heterogeneous fuel elements. The engineering and operational features of the pilot plant are described

A method was developed for calculating shield induced gamma radiation escaping through openings in a biological shield. The method was applied to the HRT and the results indicated that the contribution to the dose from induced activity in the HRT shield was around 0.1 r/hr and was insignificant in comparison to to other mechanisms contributing to the escape of gamma rays through shield openings.

A simplified method was developed for calculating wall-scatter gamma radiation escaping through a shield opening. The method was applied to the HRT and the results showed that next to the line of sight contribution, scattering of the wall of the shield opening was the main contribution to the dose at the rear edge of the shield. Design charts were prepared that give the dose as a function of the gamma source location with the reactor cell.

The friction characteristics of a full-scale straight-tube model of the ART fuel-to-NaK heat exchanger were determined experimentally. The presence of the spacers resulted in a transition to semi-turbulent flow at a Reynolds modulus of 350. this semi-turbulent flow persisted up to a Reynolds modulus of 5,000. The circumferential spacers were found to contribute slightly more than the radial spacers to the pressure loss in the heat exchanger.

An estimate has been made of the gamma radiation levels at access holes in the HRT Shielding when the plugs have been removed to service or maintain the reactor. In every case the radiation level at the holes was greater than the maximum permissible exposure rate of 0.3 roentgens per week. The radiation through the holes can be attenuated to some extent by flooding the reactor cell up to the flange to be disconnected. However, shielding would still be required and it is more practical to provide a small additional shield thickness to compensate for the moderate attenuation that could be gained from flooding.

The assembly of a second thorium oxide slurry corrosion test facility, loop BS, has been completed and 2010 hr of operation on slurry have been logged. This second test loop has proved satisfactory from an .operational standpoint. Corrosion data and operational observations are given for six thorium oxide slurry runs made at 300 C in 100A pump loops BS and CS. A new development model of the rotator for an in-pile slurry toroid is described.

In an elastic collision the neutron loses part of its kinetic energy to the nucleus with both the kinetic and momentum of the system being conserved. However, for many elements the scattering is not isotropic in the center-of-mass system at the higher neutron energies. Many of the present reactor multigroup codes include anisotropic scattering at the high neutron energies, while many others assume isotropic scattering at all energies. In order to consider some of the effects of including anisotropic scatting, reference is made t the multigroup equation generally assumed for the slowing-down density.

General considerations involving the transportation of irradiated fuel and radioactive wastes are reviewed. It is assumed that many reactors will supply feed to a few large multipurpose chemical plants which ultimately send radioactive waste to a few disposal sites. General economic considerations of irradiated fuel reprocessing, economic aspects of the nuclear economy complex, growth predictions of the nuclear power economy in the U.S., general requirements for the shipment of fuel and waste, regulations applicable to fuel shipment, and permissible radiation levels are discussed.

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.

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.

The dose of ionizing radiation received by passengers and crew members traveling on commercial airlines which transport radioisotopes is of interest to all persons who travel the airways frequently. Tariff regulations permit the air transport of 40 units of radioactive materials where one unit represents a quantity of radioisotopes which when packaged delivers a dose rate of one mr/hr at a distance of one meter from the center of the package. Using five different types of commercial aircraft, shipments of radioisotopes were simulated and dose levels determined at various locations in the aircraft under conditions normal to commercial travel. The survey indicates that the tariff regulations should be amended giving consideration to the type of aircraft involved.

For various reasons it is not possible to leave the uranium or other nuclear fuel in a power reactor until all of it has been "burned up" by fission. In the case of liquid fuel (homogeneous) reactors a small part is continuously bled out, purified and returned. In the case of solid fuel reactors, fuel elements are periodically removed, reprocessed and the "unburned" fuel put back into service. In both cases the purification produces wastes which contain radioactive fission products and transuranic elements, and it is with the disposal of these wastes that we are concerned. For technical reasons, we will limit our consideration to the wastes from the processing of solid fuel elements, and from the processing of the very similar solid "blanket" elements in which fissionable fuel is made from non-fissionable isotopes of uranium and thorium by interaction with neutrons in the outer regions of the nuclear reactor.