An order of magnitude estimate was made to determine a minimum cost for 10% pure oxygen-17 when produced by a chemical exchange process. the calculations were based on separations factors of 1.03, 1.01, and 1.003. the cost of product was found to vary from $23 per gram for the large factor to $165 per gram for the smaller.

The measured pressure drop across the reactor core, with the sample holder in place, is 6.9 psi, more than twice the estimated value. Better estimates, based on more rigorous mathematical analysis, should be possible for future problems of this type. The 2% density difference which produced the relatively high velocity of approximately 1 fps, in this experiment, will result from a temperature difference of about 8 C. It is concluded that the bulk fluid temperature near the sample holder will be less than 8 C above the average temperature at the same elevation in the core.

The failure of the valve bellows would appear to be due to a combination of stress corrosion and crevice corrosion. Stress corrosion occurred as evidenced by the transgranular branched cracking found in the bellows and in the base which which was joined to the bellows. It seems probable that chlorides were present, which, along with the residual stresses present in the bellows assembly, created the necessary conditions for stress corrosion to occur. Crevice corrosion occurred probably due to heavy deposits of solids at the base of the bellows, which created a condition of oxygen impoverishment. While the crater in the base may have been related to a galvanic effect created by the gold gasket, the contour of the crater would suggest that the cause of the crater was due more to crevice corrosion.

In the HRP Welding program, a major part of the welding and fabrication, and some of the testing, is performed using an inert atmosphere. the use of the inert gas consumable arc welding process and dry box welding or other work in a dry box comes within this category. Since much of the work in the project make use of, or requires, inert atmospheres, a general discussion follows of the methods used, description of equipment, processes, quality of atmospheres, purity requirements, kinetics of metal-gas reactions, and the proper application of the equipment and methods use din obtaining the desired results.

One of the considerations in designing a flat plate fuel element is the resistance of the fuel plates, especially the outer plates in the fuel plate array, to deflection and permanent deformation as a result of pressure differentials. An investigation was recently initiated wit the objective of obtaining preliminary information on the APPR-type fuel element to determine the effect of pressure differentials on the outer plates in the fuel assembly. The APPR-1 fuel element consists of 18 flat composite stainless steel fuel plates, joined to grooved 50 mil thick type 304L stainless steel side plates by brazing with Coast Metals N. P. alloy.

Small Heat Exchanger ORNL #1, type SHE #2, was removed form test stand B after 2071 hours of operation. Thirty-five samples were removed form the entire heat exchanger. The corrosion found on the outside of the tubes exposed to the fluoride mixture ranged to a maximum depth of .004 inches; however, the frequency of occurrence along the tube wall was heavier at the NaK outlet header, which was the hottest area in the heat exchanger. The depth of attack observed on the fluoride side of this heat exchanger was uniform from header to header and did not exceed .004 inches.

Blake and his co-workers have shown that uranium and other elements can be extracted from acid solutions by various type of organo-phosphorous compounds. Early investigations in the laboratory have demonstrated the applicability of tri-n-alkyl phosphine oxides to the extraction of metal ions from acidic solutions for analytical purposes. This paper is concerned with a similar qualitative investigation of the extraction of metal ions with a di-alkyl phosphoric acid, di-2-ethylhexyl phosphoric acid (D2EPHA).

The fuel requirement of a heavy-water moderated, homogenous, power reactor were estimated for a variety of initial loadings, for both bath and continuous methods of fuel removal. This study considered a 12-ft spherical reactor, temperature 250 C, 500 Mw thermal power, 125 Mw electrical power capability, 0.8 load factor, and 4%/year inventory charges for U and D2O. The fuel shipping-and-processing charges were assumed to be $1/gm of fissionable fuel for the "batch" processed reactors, and $0.37/gm for the "continuous" processed reactors, Under these conditions, the minimum fuel costs associated with a 10-year 'batch" operating period were about 1.8 or 3.1 mills/kw-hr, if highly enriched U cost $15/gm or $20/gm, respectively. the analogous costs for the "continuous" processed reactor were about 1.6 and 2.6 mills/kw-hr, respectively.

The fact that material transport does occur under conditions of finite temperature difference in a flowing molten metal system was established. The rate mass transfer was thought to be either diffusion limited or solution rate limited. It is believed that the mass transfer of structural materials in Na or NaK systems is solution rate limited. The limiting process has not been qualitatively or quantitatively confirmed for the Inconel-Na or Inconel-NaK system. Increasing the maximum system wall temperature increases the amount of mass transfer, at least above 1300 deg F. The effect of the total temperature difference across the system on the amount of mass transfer was determined.

The circuits described herein and shown functionally in Fig. 1 are to be added to the HRT control circuit to provide control and protection for the revised HRT cooling water system. The circuitry will provide protection against excess pressure in the demineralized cooling water loop and cooling water activity, will initiate action to insure containment of activity in event of an explosion and will provide emergency cooling water from the tower basin when required.

Lewis in 1929 determined the thermal conductivity of beryllium metal for the first time. The next measurement reported in the open literature on the thermal conductivity of beryllium was by Powell in 1953. Measurements were also made by Grenell, Linebrink, and Johnson at Battelle Memorial Institute in 1947. Their values are in good agreement with those of Powell.

Thorium nitrate, recovered from irradiated thorium metal processed in the ORNL Thorex Pilot Plant, was converted to thorium oxide and then to the fluoride in one pilot-plant-scale and two laboratory-scale runs. Activity distributions, decontamination factors, and safety of the process are treated. (D.L.C.)

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 HRT leak detector system consists of four headers each of which are connected on one side to a common supply of pressurized water and on the other side by individual tubing to the ring grooves of approximately twenty flanges. There are two methods of detecting the loss of water that are particularly applicable to the HRT: (1) By the loss of pressure in a constant volume system; (2) By the measurement of flow from a constant pressure system. It was determined to investigate the second method which requires a flowmeter capable of measuring flows of .5 cc or less of water per hour. The experiment flowmeter constructed performed almost exactly as the design calculations predicted.

All tissues included in this report were received from Dallas, Texas and 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, 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.

Analytical expressions were obtained for the time behavior of fuel concentrations and fuel-feed rates in single-region, spherical, UO3-ThO2-D2O reactors.

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.