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.

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).

Calculations indicate that the proposed shielding arrangement will give a dose rate at the surface of the water tank of about 100 mrem per hr., practically all gammas. This is adequate for transportation and handling, but if the radiation actually proves to be this high, a storage location isolated from normal working areas must be provided. The isolation area need not be large, however, since the calculated dose rate at 10 feet from the shielded sources is only 3.5 mrem pr hr. For the short time required to transfer the source from the water tank into the reactor the Pb carrier alone will provide sufficient shielding. At one meter from the source shielded by the Pb carrier, the dose rate is estimated to be 170 mrem per hr., with neutrons contributing he major part. With reasonable care, the operations should be carried out without excessive exposures. The results of the calculations are summarized.

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.

This technical report presents an overview of nuclear reactor maintenance to be used in planning a nuclear reactor. There are certain basic maintenance fundamentals that are common to all types of reactors that may be' incorporated in a power producing facility. Basically, there are only two types of maintenance procedures. The direct type, which is common to conventional steam plants, may be used in some areas where the radioactivity is low enough. In most parts of the plant, maintenance will of necessity be remote due to the high level of radioactivity. For simplicity of description in this report all reactor types are divided into two general classes: solid fuel types and circulating fuel types. The report lists nine types of reactor power plant types with advantages and disadvantages maintenance-wise of each.