A cross section tape has been prepared containing data for elements of most interest for aqueous homogeneous reactor multigroup diffusion calculations involving combinations of 150, 200, 240, 260, and 280°C temperatures. This tape permits multigroup analysis of a reactor in which two or more regions are at different temperatures.

A multiple controller system for a single process is formulated in block diagram form. It is shown that for the general case of n controllers and one type of cross coupling, the system equations can be reduced to the standard forms of servomechanism theory. The effects of failure in individual controllers are examined, and it is demonstrated that the system shows considerable promise for both reliability and maintenance without process interruption.

THOROBRED is an IBM-704 code for the calculation of nuclear and economic characteristics of two-region homogeneous reactors operating on a U-Th fuel cycle in the steady state. The major input variables are reactor dimensions, power level, thorium concentration, chemical and purification systems cycle times, corrosion rates, fraction of Pa loss, and nuclear and economic data. The output includes equilibrium isotope concentrations, neutron balance, and a breakdown of fuel cost. Running times are normally less than one minute per case.

The equilibrium and maximum override values for xenon and samarium poisoning have been computed using the recently issued effective cross sections of C. H. Westcott. Values are given as a function of specific power, neutron temperature, and epithermal flux content.

A review of helium sources, availability, consumption, and future production capacity indicates that the helium consumed in the operation of 100 helium-cooled reactors for 300-Mwe power plants over a 20-year period will run no more than a few per cent of the helium consumed in the U. S. in the next 25 years and less than 1% of the helium that is to be stored during that period under the helium conservation act of 1960 (Public Law 86-777).

Analyses are generally made at the ORR with a view toward determining the surface temperatures of fuel plates.

A listing and description is given of the experiments associated with the HFIR Critical Experiment-2. The primary experiments concern the reactivity of the bare core, reactivity worth of "gray" control plates, core-power distribution, reactivity. The secondary experiments concern the reactivity of the fuel, and the reactivity worth of a "partial" gray plate.

The absorption in lead of Bremsstrahlung X radiation from a Sr^90 TiO3 pellet in the proximity of Hastelloy "C" was measured. The tenth value layer of the more energetic components of the X-ray continuum was determined to be 1.60 inches.

A carrier containing 138.99 liters of solution, uranium concentration 202.04 g/liter with an isotopic concentration of 97.3% U-233, was prepared for shipment. The total uranium was 28,062 +/- 60 g (95% confidence level) and the U-233, 27,305 +/- 66 g (95% confidence level).

Simulated reactor fuel solutions were circulated at temperatures as high as 365°C in a small titanium pump loop. A hydroclone separator separated heavy phases formed at high temperatures. As the temperature of the solution was increased beyond the two-liquid-phase temperature (327°C), the salt concentration of the light phase decreased and the acid concentration increased. The mole ratios of uranium to sulfate, uranium to copper, and uranium to nickel in the light phase decreased in the same proportion in the temperature range of 330 to 365°C. Corrosion of titanium and Zircaloy-2 specimens was insignificant during the relatively short exposure periods.

Startup accident and pump run-down on the ORR have been simulated on the Reactor Controls Analog Facility. At full flow the 150% level scram (45 Mv) easily terminates the startup accident before the metal temperature gets above 180°F. For very low flows typical of criticality runs, temperature coefficients turn the excursion before it reaches 150% of full power, and temperatures climb to boiling, a potentially hazardous condition. (This same behavior can occur at full flow is the power is increased to the point where the level scram must be set above 50 Mw).

A nonnuclear explosion involving an evaporator occurred in a shielded cell in the Radiochemical Processing Pilot plant at Oak Ridge National Laboratory. Plutonium released from the processing cell contaminated areas in the pilot plant building and nearby streets and building surfaces. The explosion is considered the result of rapid reaction of nitrated organic compounds formed by the inadvertent nitration of about 14 liters of a proprietary decontaminating reagent.

Measurements of the interfacial tension between water and tributyl phosphate solutions were made for application to the analysis of Marengoni effect in solvent extraction. A 24 hr flame calcination run to product Th02 particles yielded 40% as product and 54% collected from the furnace walls and from a coarse particle trap. The elution rates of uranyl ion from Dowex 21K using sodium nitrate could be approximated by assuming apparent diffusion coefficients of 1.67 x 10^-7 and 1.18 x 10 ^-7 cm^2/sec, respectively for 960µ and 820µ resn while the corresponding apparent coefficients using sodium chloride were 1. 78 x 10^-7 and 1.27 x 1-^-7 cm^2/sec. The reacting surface of ThO2 Universal Match Co. pellets was determined as a function of fraction dissolved. The lead scews and companion nuts from both the multipurpose saw and dejacketing machine were coated with a baked on lubricant. In Zirflex decladding studies using 4.5 M NH4F - 0.5 M NH4NO3, the average dissolution rate of Zircaloy-2 was decreased only 10% when the overhead condensate was withdrawn and 1.0 M NH4OH was added to maintain the volume.

This study was designed to determine how swaging stainless steel over unground pellets will affect the integrity of fuel rods, and to find maximum pellet diameter variation that can be tolerated.

Four methods of rebunching protons within Brookhaven's AGS are discussed. The first method involving switching off the old r-f and switching on the new r-f simultaneously with the new r-f increasing adiabatically seems impractical. Two other methods utilize gradual removal of the old r-f voltage and introduction of the new r-f voltage, or the reverse. Removal of the old r-f voltage followed by introduction of the new seems to give the best results. Several phase diagrams are included. (D.C.W.)

This article presents data on the effects of gamma radiation on the physical properties of a number of different classes of plastics materials of construction which were screened to determine their capabilities and limitations for service in applications where ionizing radiation exists. The irradiations were carried out in air at ambient temperature at normal atmospheric pressure to various gamma radiation doses up to 1*10^9 r depending upon the stability of the materials to radiation exposure. The different classes of materials and materials within a class are compared.

Figures 1 and 2 summarize total decay energies for the four radioactive series. The alpha-decay energy obtained by measuring the energy of the alpha particle leading to the ground state includes the energy of the recoil nucleus. The curve shown in figure 3 defines in broad outline the conditions and regions of alpha instability. A great deal more is to be learned from a more detailed examination of the region where alpha radioactivity is prominent. Of great value to the experimentalist is that he is able to predict alpha energies, and the agreement between predicted and measured values often serves as a criterion for isotopic assignment. A number of systems for correlating alpha decay energies have been employed, and that perhaps most widely used is illustrated in figure 4. Here the isotopes of each element on a mass number vs. energy plot are joined, resulting in a family of curves which over a wide region comprise a series of nearly parallel lines.

The guiding center motion and the adiabatic invariants of charged particle trajectories in electromagnetic fields are treated in this review. General and specific theories of charged particle motion are also reviewed.

This paper reports the chemical and physical properties of the NTA film packet. It correlates with these properties the response of this packet to neutrons of various energies. In this correlation the concept of the track unit is introduced as a basic unit for reporting film-packet response.

"A comparison of the grafting of a 2:1 molar mixture of methacrylic acid and styrene to both polypropylene film and fabric using CO60 source and electron accelerator as sources of ionizing radiation is made on the basis of mutual or simultaneous grafting and post-irradiation grafting.

"Evacuated electrical oscillating cavities frequently are found to exhibit a strong loading due to electron (or iron) multiplications, the so-called multipactor effect. This effect tends to prevent the buildup of dee voltage in cyclotrons. In conventional cyclotrons driven from external oscillators having their own resonant tank circuits the difficulties are usually slight, but in cyclotrons using a simple dee system as the tank circuit difficulties are encountered in getting the oscillator to break into full oscillation."

"The ion source used for hydrogen and deuterium ions in the variable energy cyclotron at the University of Rochester is of the hooded arc type. For the past year it has been operating with a new feature which has greatly improved its performance. The new feature is a magnetic mirror built into the upper end of the arc hood by a simple insertion of a steel bearing ball 1/8" in diameter. The magnetic field gradient near the ball provides a magnetic mirror action on electrons moving up the arc channel toward the ball, reflecting may of them."

"This paper deals with the Riemann function for linear hyperbolic systems of first-order equations. the leading term in the singularity of the Riemann function is determined and interpreted. In addition to equations with distinct characteristics, certain equations with multiple characteristics are treated."

This program was established to develop new information concerning the mechanism of diffusion of fission gases (krypton and xenon) through UO2 and UC. The work was to concentrated on measurements of diffusion rates in unirradiated materials in the temperature range of 1000°C to above 2000°C, these determinations being important to the projected use of refractory fuel materials in high-temperature, high-burnup reactors.