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 …

To determine the maximum permissible concentration (MPC) of a radionuclide which may be ingested or inhaled with exceeding accepted levels of exposure tot he human body, it is necessary to know the average normal concentration of the natural element in the various tissues of the body. Any element may be ingested or inhaled as the element or as a compound. Although nearly all elements have been observed in living tissue, few quantitative observations had been made before 1950. Preliminary studies showed that individual variations in concentration of all elements were very wide and that geographical variations for certain elements occurred. Collection of tissues from autopsies in 9 cities has been done as of February 1957.

All tissues included in this report were received from Miami, Florida and the majority are from Jackson memorial Hospital. They were collected, ashed and analyzed according to the methods described in ORNL-CF-57-2-2. The average value of the concentration for each element in a tissue is the average of the concentrations in only those samples of the tissue which contained the element. For example, if, of 25 lives analyzed, only 10 contained lead, the average for lead in liver is the average of those 10 values. For those tissues in which an element does not appear in every sample, the lowest value is reported as less than the limit of sensitivity of the method for that element in that tissue. For the elements, cesium, lithium and rubidium, the ash was a composited ash sample for each particular tissue. As an example, in lieu of analyzing 20 individual aortas, only on composited aorta as was analyzed.

The heat transfer and fluid friction characteristics have been determined for a liquid flowing parallel to the tube bundle of a heat exchanger consisting of one hundred and two 1/16-inch O.D. tubes arranged in a delta or triangular array. These results may be expressed by empirical equations.

Results of previous toroid tests with 28 micro 1600 fired ThO2 spheres are analyzed. Four possible explanations for the essentially zero attack rates are offered and discussed: peculiar motion of toroids or some unknown wall effect; rotational hydrodynamic forces cushioning the particle impact; the bed was not in suspension and not sliding over the walls of the toroid; round particles are not as erosive to oxide film surface as sharp pointed particles.

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.

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.