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The development and testing of a demonstration brushless alternator for the ML-1 mobile nuclear power plant is described. The brushless concept was selected after it became apparent that a conventional power generator could not satisfy the ML-1 weight and size requirements. The demonstration alternator fabricated and tested under this program did not meet all performance specifications; the efficiency was low and the unit could not be operated for significant periods of time without overheating. However, a large body of useful data was accumulated during the extensive development program. Of special interest are data on the rotor and stator design, the cooling requirements and on the distribution of eddy current losses. Analysis of the data indicates that a brushless alternator, only slightly larger and heavier than was specified for the ML-1, could be developed with a modest additional effort.

Evidence is presented which points to (at least) two bound forms of bacteriochlorophyll present in chromatophores of Rhodospirillum rubrum, both of them readily converted to unbound bacteriochlorophyll (abs. max. 770 mu) when the chromatophores are extracted with acetone or ethanol. Controlled oxidation of the chromatophores with Ir(IV) or with Zn(II) and ferricyanide preferentially destroys the more strongly absorbing pigment (abs. max. 880 mu) but brings about only a slight decrease in the magnitude of the photoinduced absorption changes at 810 and 792 mu. Such oxidations yield a new pigment, absorbing at 715 mu in the aqueous preparation and, more strongly, at 680-684 mu when the pigment is extracted into organic solvents. This pigment is formed irreversibly and is therefore different from the material formed by photooxidation of chromatophores. Its visible spectrum and the spectrum of the material formed from it by acidification suggest that it is a chlorophyll-like substance, possibly derived from bacteriochlorophyll by (two-electron) oxidation of one of the dihydropyrrole rings to a pyrrole ring. Directions are given for separation of this pigment from other colored compounds present in the oxidation mixtures.

The recently completed 25-inch hydrogen bubble chamber combines excellent picture quality with a fast operating cycle. The chamber has a unique optical system and is designed to take several pictures each Bevatron pulse, in conjunction with the Bevatron rapid beam ejection system. At present the chamber operates twice per Bevatron pulse. The general features of the chamber constructiosn are shown in Figs. 1 and 2. The chamber is ten inches deep at the narrowest point. The magnet is of conventional water cooled design and in present operation produces a vertical field of 18.5 kgauss. With suitable generators it has produced a field of 22.8 kgauss. The most important new features are discussed below.

Phosphorus pentoxide reacts with ether to form bicyclo-tetraphosphate ester (II), cyclotetraphosphate ester (III), isocyclotetraphosphate ester (IV), and tetraphosphate ester (V). Phosphorus n.m.r. measurements show the content of the mixtures. The so-called 'ethyl metaphosphate' (Langheld ester) is a mixture of III (50% to 45%), IV (36% to 25%), and V (14% to 30%).

The decay kinetics of the photo-induced absorbance changes in red and green algae are very sensitive to the wavelength of the actinic 11ght. A four to twofold increase in half-decay time is noted in going from short wavelength (550-650 mu) to long wavelength (> 700 mu) excitation. The slow decay ratios, produced by long wavelength light can be enhanced with a steady background of short wavelength light. A relationship between initial decay rates and 02 evolution rates is described. This relationship allows a direct correspondence between these spectroscopic studies and the 'red-drop' and 'enhancement' experiments of Emerson.

Program 3 of Operation BREN consisted in a study of the performance of biological shields composed of various arrangements of steel, water, and borated polyethylene in spherical, cubical, and parallelepipedal geometries. Studies were also made of the radiation levels within concrete-lined and -capped pits, 4 ft in dia and 8 ft deep. The principal radiation source was the ORNL Health Physics Research Reactor, an unshielded, unreflected, 90 wt % U-10 wt % Mo, cylindrical bare-metal assembly. It was supported at heights ranging from 27 to 1500 ft by a hoist car riding outside of a 1527-ft-high steel tower. A 1200-curie Co/sup 60/ gamma-ray source, similarly supported, was substituted for the reactor for some measurements. The work reported includes measurements of fast-neutron and gamma-ray dose rates and thermal-neutron fluxes in air and within the various shields, using the reactor source, measurements of gamma-ray dose rates in air from the Co/sup 60/ gamma-ray source, and measurements of gamma-ray pulse-height spectra within the pits, also employing the Co/sup 60/ source. 8 refs., 33 figs., 29 tabs.

A number of burnout tests have been run subsequent to the publication of the burnout equations in DP-355 and DP-725. The range of variables was extended in these tests and the burnout heat flux was measured. This memorandum presents a modified empirical equation, which correlates the new data, for use in the design of fuel assemblies for the HWCTR. We expect to submit this material for a journal publication within the next quarter.

Operation of the present accelerator is summarized and plans for a new injection system and additional machine modernization are described. Research results of both experimentalists and theorists are reviewed in very brief summaries; references are provided. (RWR)

Information is presented concerning coated fuel particle development and evaluation; burnup capabilities of Y/sub 2/O/sub 3/-stabilized UO/sub 2/ and stabilized fuel - BeO matrix materials; high-temperature studies of substoichiometric urania and urania solid solutions; high-temperature carbides and borides research; and high-flux reactor materials gaseous fuels research.

The altitudes and times of ablation have been determined for the SNAP-10A, SS-316 vessel wall reentering under various conditions. The results are confined to one typical location on the reactor and to one typical reentry trajectory. The location is the side wall of the vessel and the trajectory is the one used in NAA-SR-8303.

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Work was continued on the development of a process for the gasification of bituminous coal with heat from a nuclear reactor. Major objectives of the project are: (1) develop and test components for a gas-cooled reactor system that can heat gases to 2000/sup 0/ to 2500/sup 0/F; (2) investigate coal gasification methods compatible with this system; and (3) develop an exchanger that can utilize high-temperature heat to gasify coal or heat chemical process streams. During the past year, work was concentrated on the design, construction and installation of a fluidized-bed gasifier in the high-temperature heat system. Design of the fluidized-bed gasifier was based on information obtained from laboratory and pilot-scale gasifiers. The gasification chamber, a length of 6-inch, schedule 80 stainless steel pipe, is fitted with ten 1/2-inch Hastelloy-X tubes running lengthwise. Hot helium flowing through the 1/2-inch tubes provides heat for the gasification of the steam-fluidized char in the 6-inch pipe. Helium leaving the gasifier generates the superheated steam required for gasification. Fabrication and installation of the gasifier was completed and shakedown runs started. In the gasifier, the heat-exchanger tubes will be heated to 1900/sup 0/F in a mixture of the corrosive gases, including H/sub 2/, CO, CO/sub 2/, …

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The Hanford graphite-moderated reactors have an enclosed gas circulation system to maintain control of the composition of gas atmosphere in the graphite stack. This investigation was undertaken to answer several questions concerning the generation and release of Carbon-14 in the operation of these graphite moderated reactors. The principle question was: Will an increase in the nitrogen content of the reactor atmosphere increase the release of Carbon-14 sufficiently to create a health hazard. Other questions were: (1) What are the main sources and the main release routes. (2) How much does carbon-14 build up in the graphite in the reactor stack. and (3) Is the total release of carbon-14 to the atmosphere sufficient to enhance the /sup 14/C levels in the vegetation surrounding the reactors.

Cerium sulfate purified by D2EHPA in Semiworks can be precipitated by adjusting pH to between 1 and 2 in tank 6 with 50% caustic. The solution can then be transferred through tank 1 to tank 67, where sodium bisulfate is added to make the solution 0.5M sulfate. A stoichiometric amount (mole for mole) of 50% caustic is added to just neutralize the sodium bisulfate. The precipitate is digested one hour at 60 C, then filtered.

This report details activities of the N-Reactor Department during the month of September 1964.

Newly developed multidimensional gamma-ray spectrometric counting techniques permit the direct measurement of twelve fallout radionuclides on air filters. Observed concentrations of Be{sup 7}, Na{sub 22}, Mn{sup 54}, Co{sup 60}, Y{sup 88}, Zr{sub 95}Nb{sup 95}, Ru{sup 106}, Sb{sup 124}, Sb{sup 125}, Cs{sup 134}, Cs{sup 137} and Ce{sup 144} during the past two and a half years help explain the origin and fallout rates of the trace radionuclides in air. 14 refs., 1 tab.

This document details activities of the N-Reactor Department during the month of February 1964.

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This report details activities of the Irradiation Processing Department during the month of May 1964.