Quarterly progress report discussing activities related to the Vallecitos Boiling Water Reactor (VBWR) and related facilities.

Work performed during the quarter is summarized by: direct measurement of fission gas pressure, loop operations, performance of UO2 fuel, UO2 grain growth and melting studies.

A research program is being conducted to obtain experimental data in the irradiation of plutonium-enriched fuel to confirm a theoretical model for predicting isotopic composition and reactivity changes in plutonium-enriched, light-water-moderated reactors. Quarterly progress: Forty-six fuel pellet faces have been auto-radiographed. These faces have been prepared from twenty-three pellets by making an exposure before and after the removal of an additional ten mils of fuel. A substantial number of large "hot spots" continue to appear. The largest spot so far observed was 44 mils long, 20 mils wide, and of the order of 20 mils thick. This spot has a PuO2 concentration which varied from 70% on the periphery to 100% at then center. There is some evidence that the segregated regions are elongated with their long axes perpendicular to the direction of the pressing of the green pellet. Determination of the size and concentration distribution is continuing. The EPITHERMOS code now seems to be operating correctly. A test problem for a typical water lattice converged in eleven iterations. The computation of the spectrum for a pure water medium gave results which agreed very well with the expected 1/E spectrum. At the end of the quarter, the program fuel element …

Work performed during the quarter is summarized by direct measurement of fission gas pressure, loop operations, performance of UO2 fuel.

In early 1961 a Target Fabrication Center was established at Oak Ridge National Laboratory to carry out the routine preparation of a wide variety of targets and to provide research and development support to the target program. Although most of the effort concerned enriched stable isotopes, both normal and radioactive materials are also handled. With the aid of rolling mills, resistance-heat and electron-bombardment vacuum evaporation, presses, and electroplating equipment, targets of elements and compounds are prepared which cover a broad range of thicknesses and sizes, in both supported and self-supporting forms. Thicknesses vary from a few micro-inches to dimensions limited in many cases only by the amount of material available. Although there are certain limitations imposed by the chemical reactivity, the development effort is supporting targets of most elements and compounds.

The analyzer can be operated either internally or externally. The 10 ma germanium discriminator is quiescently biased to 8.5 ma in its low-voltage state. An input signal current of 3.5 ma or more triggers it to its high voltage state. This triggers the oscillator. The oscillator signal is buffered and mixed in the bridge modulator with the reference radiofrequency signal from the cyclotron. The low-frequency beat note from the bridge modulator is squared up and passed to the beat zero univibrator which generates 0.7 mu sec signals each time the beat note passes through zero from positive to negative. The trailing edge of the beat zero univibrator is employed to terminate the time-of-flight measurement and to control the servo measurement. Drawings are included. (M.C.G.)

As reported in the previous Progress Report (December 16, 1959) a stock solution of Th 230 was prepared from pitchblende. Pulse height analysis of this solution indicated the presence of only Th 230 (93%), Th 227 (5%), Th 232 (1%), and Th 228 (1%). This solution was used to make up synthetic thorium solution of various concentration. These synthetic solutions were analyzed to establish a chemical yield for the procedure. Neither the precision nor the chemical yield of the procedure were considered to be satisfactory. In the next report period, we hope to complete the testing of the thorium procedure, both with regard to chemical yield and precision, as well as to determine decontamination factor from radium, uranium, and polonium. To do this, pure solutions of polonium, radium, and uranium will be prepared. The polonium and radium will be processed from pitchblende while the uranium will be made by purifying reagent grade uranyl nitrate.

Applications of radioisotopes in the preparation of labeled drugs are reviewed. Among the applications described are the preparation of carbon-14- labeled cardiac glycosides, and the biosyinthesis of carbon-14-labeled digitoxin, morphine, colchicine, atropine, podophyllotoxin, and nicotine. The fate and metabolism of many of these drugs were traced. Radiochemical procedures were developed for the synthesis of pure compounds of pharmacological interest labeled with carbon-14, sulfur-35, and tritium. Investigations were made on the phenomena of drug penetration into the central nervous system. Publications during the period are listed. (C.H.)

SNAP II is the designation for a nuclear auxiliary power unit, designed primarily for utilization in the WS117L satellite vehicle. The SNAP II system consists of a reactor heat source, a mercury Rankine engine, and an alternator. Dynamic analysis of the power conversion system was conducted utilizing a comprehensive analog computer simulation. Feasibility of a parasitic load control for numerous system disturbances was demonstrated. This analysis was performed under a subcontract to to Atomics International as part of the Atomic Energy Commission Contract No. AT(11-1)-GEN-8.

The report covers work performed during the period December 1, 1959 through December 31, 1959. The general objectives of the program of "Studies of Reactor Containment" are to accomplish theoretical and experimental investigations of the loads to which external containment structures for nuclear reactors are subjected in the vent of a violent incident at the reactor core, the evaluation of methods of reducing that loading, and the study of the response of and design criteria for external containment structures as a result of such loading. Progress of technical effort during the report period is summarized for each of the eight tasks of the program..

The overall scope of the program encompasses both research into the physical parameters involved in the collection of airborne radioactive particles and the development, fabrication and calibration of balloon-borne sampling equipment to enable the precise determination of stratospheric particle concentration and particle size distribution.

Two Zircaloy-clad capsules (GKH-14-19,20) containing two compacts each of high density PuO2-UO2 mixed crystal oxides were shipped to the MTR in December 2, 1958. The compacts contain 0.026 a/o PuO2, have densities of 91 percent of the theoretical value, and will generate the same specific power as an Al-1.8w/o Pu alloy rod of the same diameter would produce. Two capsules (GKH-14-21,22) have been prepared and contain three compacts each of low density, about 65 percent of the theoretical value, PuO2-UO2 mixed crystal oxides. It is tentatively planned to ship the last two capsules during January 1959.

A six-inch diameter "O" ring from the HRT Mockup was examined metallographically after 2452 hours exposure to uranyl sulfate solution at 300C. surface defects, except for cold work defects were found only in areas exposed to uranyl sulfates. Defects found were pits, transgranular cracks, surface cracks, and grain attacks.

The polymerization of vinyl monomers can be initiated by heat, ultraviolet radiation, and various catalysts. More recently, ionizing radiation has been shown to effectively initiate vinyl polymerization. However, polymerization in the solid state by ionizing radiation is not reported in the literature, although several papers have been published that describe briefly the thermal polymerization of divinyldiphenyl, Leuch's anhydride and in greater detail the peroxide catalyzed polymerization of acetaldehyde. The purpose of this note is to describe some experiments which demonstrate that crystalline acrylamide undergoes polymerization upon irradiation with γ-rays from an intense Co-60 source. Below its melting point the monomer shows little or no tendency to polymerize thermally.

The Hanford Remote Pipetter has developed into a very useful tool for routine pipetting by semi-skilled non-technical personnel. Radiation exposure to the operators has decreased to normal background levels as proper shielding exists between the sample and the operator. The results achieved by the pipetter have demonstrated its flexibility and simplicity of operation.

Abstract: "Dissolution of carnotite in several readily liquefiable gases, including ammonia, sulfur dioxide, chlorine, and nitrogen dioxide, was found to be negligible, even in the presence of uranium complexing agents. No low-boiling liquids have been found which will dissolve carnotite directly. Treatment with various sulfur chloride will convert carnotite to a form soluble in water or in certain organic solvents. Also, carnotite can be readily dissolved in HCl-acidified ethanol, methanol, or acetone. Amenability tests on nine western ores with HCl-methanol solvent indicated that uranium extractions greater than 90 per cent could be obtained if sufficient acid was used to insure some free acidity in the pregnant liquor. Temple Mountain and Sinbad-Muddy River ores were exceptions to this, uranium extractions being only about 50-60 per cent. Vanadium extractions were invariably lower than uranium extractions. Chemical analyses are presented for nine western ores."

From abstract: "Operation of the 86-inch cyclotron has been continuous except for a three-day interruption caused by a water leak inside the vacuum chamber; monthly output has averaged over 210,000 [mu]a-hr; the average continuous (168-hour week) beam power has been approximately 5.5 kw; and the energy of the beam has been determined to be ~19.4 Mev. No changes due to radiation damage have been detected in Inconel tubes containing UF4-NaF-KF eutectic which were irradited in the 96-inch cyclotron with power inputs up to ~415 watts/cc. The major components of the 63-inch cyclotron have been fabricated and are being tested as the machine is being assembled. On the 22-inch cyclotron a radius-wise examination of the fine structure of the proton beam reveals definite proton orbits. Several grams of very pure uranium 235 have been prepared; the chemical recovery for first-stage separation of U 236 has been established as 97%; and facilities for laboratory-scale separation of plutonium isotopes are being prepared."

"This report covers mainly the work completed since the last interim report, HNL Log No. 0-4714. This report includes results from studies of the rare earth distribution in bismuth-uranium and fused chloride and studies of fused chloride behavior."

From abstract: "The reaction between hydrogen and oxygen with the aid of various catalysts (especially platinum on aluminua) has been studied, and the operating variables such as flow rates, space velocity, temperature, and gas composition have been examined rather extensively. It has been found that hydrogen and oxygen in stoichiometric proportions and mixed with either steam or helium may be made to react to the extent of 99.5% or greater at space velocities up to 30,000 hr-1, or even higher, at temperatures from 100[degrees] to 900[degrees]C, and with mixtures ranging from less than 1% hydrogen to mixtures containing 12% hydrogen and 6% oxygen. Richer mixtures, including undiluted electrolytic gas (H2 + 1/2 O2) have been used with catalysts less active than platinum (e.g. copper, silver, nickel and V2O5) but here the gas mixture is explosive and care must be taken to prevent explosions. The thermal reaction between hydrogen and oxygen diluted with steam has also been investigated at temperatures between 500[degrees] and 800[degrees]C."

This report follows an investigation made on the welding of Ames thorium by the inert-gas-shielded tungsten-arc process as the first part of a program on the joining of thorium. This program is part of a broader research program to develop the technology of thorium.

A report describing a the results of a fluorimetric and volumetric method for the determination of fluoride. This method was developed for the determination of ionizable fluorine in gases in the range of 1-500ppm. This method was chosen because the determination depends on the generation of a color rather than the bleaching effect or on a change of color.

A report of research work intended for the development of a process for the separation and subsequent purification of radium from the K-65 (pitchblende) residue.

A search for gamma-ray activities with period 1-100 msec from thermal neutron fission of U235 gave negative results. 0.43 +- 0.03 sec was the shortest observed. The period of B12 was found to be 27 +- 3 msec. The cyclotron beam was pulsed to supply 1-10 msec neutron bursts. coincidence scintillation deters were employed.

From introduction: "The purpose of this report is to summarize some of the information obtained to date on the distribution of the uranium in the mineral phases of the phosphate rocks and shale."