The presence of several homologous series of porphyrins have been demonstrated in some oil shale rocks, shale oils, and petroleums. However, the application of microanalytical techniques (i.e., mass spectrometry and gas chromatography) to structure determination has been limited due to the low volatility of the porphyrin components. The authors report the synthesis of several novel Si(IV) etioporphyrin I derivatives and the effects that their various additional silicon ligands have on porphyrin volatility as measured by gas chromatography at normal pressure.

Charge transfer associations are a well-established phenomena and a rather extensively investigated one also. Since the acceptor component of such complexes normally does not exist as a liquid under standard conditions, they wish to report on two organic liquids which function as acceptor components with suitable complimentary molecules. As indicated in Figure 1 (the presence of an extended shoulder in the spectra of the mixture), pentafluorobenzonitrile (PFBN) complexes with N,N,N{prime},N{prime}-tetramethyl-p-phenylenediamine (TMPD), with N,N-dimethylaniline (DMA), and with phenothiazine in cyclohexane. In addition, crystalline complexes of TMPN-PFBN and DMA-PFBN are obtained when the pure materials are mixed. These two organic bases also form solid complexes with hexafluorobenzene (HFB) when the materials are mixed in the pure state in a ratio of 1:1. However, new absorption bands are not detected in the spectra (in cyclohexane solutions) of mixtures of TMPD or DMA with HFB. When HFB is used as a solvent for TMPD or DMA, the solutions are visibly yellow. However, with time a reaction occurs as evident by the formation of a black precipitate. The solid complex formed between TMPD-PFBN, which is orange, was analyzed by a combination extraction and spectroscopic method and by vapor phase chromatography and found to contain a …

Economic and operational ground rules and their effects on fuel management are summarized, and examples showing the approach to typical fuel management problems are presented. The problems associated with in-core fuel management are also discussed, and the merits of various fuel cycling methods are evaluated. (D.C.W.)

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The application of an electronic data processing system to the unique combination of scientific and commercial data processing requirements of nuclear materials management is discussed. The organization and ilow of data from the plant through the data processing equipment to the final report are discussed. Included are topics concerned with the impact of conversion to electronic data processing on personnel, materials management costs, and on other plant organizations. Portions are devoted to programming systems and decision-making abilities of data processing equipment which make these systems readily adaptable to nuclear materials management. (auth)

The solubility of silver oxide on silver metal is not the same as that of the bulk oxide. The differences in solubility were investigated by shaking silver powder in deaerated solutions of various concentrations of ammonia and in buffers of ammonia and ammonium nitrate at a constant temperature of 25 deg C. These solutions were shaken in an atmosphere of N/sub 2/ in a stoppered bottle and in the absence of light. The concentration of silver ion in these solutions was measured potentiometrically and by using tagged silver ions. The NH/sub 3/ concentrations were obtained by titration of aliquots of these solutions to the methyl red end point with HCl both before and after shaking. Although several days elapsed between these titrations, the concentration varied less than 1% in all cases. (auth)

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A study was made of contact microradiographic techniques for the x-ray evaluation of tin specimens or selected small regions in large specimens. Extraneous absorbers such as air and the film holder were removed to permit the use of low-energy x rays, and high-resolution plates were used which permit magnifications up to 500x. Microradiographs are presented for graphite-coated uranium carbide particles, nickel screen, thin graphite section, and various fibrous materials. It is concluded that the contact microradiographic technique is a very useful tool. (D.L.C.)

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Monte Carlo (MC) calculations were made that show that an observed reactivity increase due to fuel rod bowing in the Sodium Reactor Experiment can be accounted for by the accompanying change in the thermal flux distribution. The questionable reliability of calculations with a simplified fuel element model that indicated the same relation prompted the MC calculations. Comparison with experimental results and results calculated by other means established the reliability of the MC calculations. (D.C.W.)

The variational method is applied to the monoenergetic time dependent transport equation to obtain a simple relation for the asymptotic decay constant in small pulsed assemblies. The results indicate that flat trial functions may be a reasonable representation of the flux distributions in the thin slab limit. This approach is superior to many of the usual transport approximations. (auth)

A method of operation developed for maintaining a minimum power peaking factor throughout the operating cycle of a power reactor is described. The basic operating principle for peaking factor minimization is presented, and its use in the design phase to compare and set design parameters and in the operational phase to establish control rod patterns is outlined. The method will (hopefully) increase the power density in the Big Rock Point Reactor. (D.C.W.)

A process for the production of seamless tungsten tubing is described. The process consists of the extrusion of sintered powder sleeves at elevated temperatures to sizes close to the final dimension. The tubing is finished by warm drawing. A size range of 0.100-in, diameter to 1 1/2-in. diameter has been fabricated. A preliminary evaluation of properties of the extruded tubes is given. (auth)

A digital computer program FLARE was developed for calculating the core reactivity and power distributions in the Big Rock Point Reactor. The calculations are restricted to a relatively coarse mesh, but good agreement was obtained in comparisons with operating data from the Kahl reactor. (D.L.C.)

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Approximately five years ago, the Safe, Secure Dismantlement program was started between the United States and countries of the Former Soviet Union (FSU). The purpose of the program is to accelerate progress toward reducing the risk of nuclear weapons proliferation, including such threats as theft, diversion, and unauthorized possession of nuclear materials. This would be accomplished by strengthening the material protection, control, and accounting systems within the FSU countries. This paper describes: the process involved, from initial contacting to project completion, for the physical protection upgrades now in place at the LNRC; the intervening activities; and a brief overview of the technical aspects of the upgrades.