A general program has been written to plot curves on the Oracle curve plotter. A description of the code and complete instructions for preparation of input tapes and operation of the code are given. The code tape is available from the Mathematics Panel or from the author.

A general program has been written to plot curves on the Oracle curve plotter. The supplement includes changes to slow down some of the loops and minimize the possibility of read-around errors and changes to handle special cases.

Increasing temperature in an aqueous liquid system results in a decrease in liquid density and an increase in vapor density. When level is measured by the differential pressure method, temperature increase results in a decrease in the effective span f the instrument and a shift in zero. When the instrument reference leg is uncompensated, both zero and span shifts occur with the effects being most pronounced at the high levels. When the reference leg is compensated, zero shifts are eliminated (instrument zero is at 100% level for this type installation). For control purposes at levels above 50% of full level, the compensated reference leg installation will give the best results. For measurement of levels below 50%, the uncompensated installation is best. As errors in level indications will be produced, in either type installation, by temperature, pressure and steam withdrawal (power) effects, the placement of taps should be such as to place the normal or control level in the region of 50% indicated level.

A qualitative theory for cake formation in ThO2 slurries is presented. The sphere formation which occurs in "Standard" slurry can be explained on the same basis. The irregular and unpredictable yield strength is easily fitted into the theory. On the basis of this theory, the writer has been led to the conclusion that only colloidally stable slurries, or slurries with crystallites or comminution-resistant particles which are large enough to overcome colloidal effects (probably larger than 0.1u) can be used with assurance in the ThO2 reactor system. This conclusion holds for 300 gm/kg slurries as well as for more concentrated mixtures.

A study of the degree and effects of radiation damage to the motor winding of the HRT 400-! canned motor circulating pumps was made. With the gamma flux estimate and the available radiation damage data, the effective life of the stator windings was estimated to be about one year, for normal operation of the pump and motor.

Data are presented for all toroid runs which circulated aqueous thorium oxide slurries between Aug, 1054, and October, 1956. In addition, a tabulation of the properties of numerous thoria preparations is presented.

Run SM-2 was run to determine whether a sulfated ThO2 slurry could be handled in a hydrodynamic system similar to the HRT test blanket. It was found that the ThO2 concentration circulating in the pipes was consistently 50% or less of the expected concentration based on the quantity of the oxide changed. The run lasted 1730 hours. It was terminated because of a slurry leak a few days before a shutdown had been scheduled. Severe erosion was found in the pump impeller and flow nozzle . Chloride concentration high enough to cause concern over possible stress corrosion cracking occurred on several occasions in the pressurizer.

The feasibility of improving the mechanical properties at 1700-1800°F of oxidation-resistant Fe-Al-Cr alloys by means of a refractory dispersion has been explored. A literature search was conducted, preliminary experimental determinations of properties of the alloy and its oxides were carried out, and certain mathematical relations between dispersion characteristics and metallurgical variables were derived. The results indicate that the alloys can be strengthened sufficiently by using a dispersion with an interparticle spacing of about 2-3 µ. High-temperature native oxides of the Fe-Al-Cr alloy consist largely of Al2O3 and in theory would serve as a satisfactory second phase.

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 method for water treatment has been developed for corrosion protection in the steam-water cycle of Homogeneous Reactor Experiment No. 2. The use of potassium phosphates for pH control, hydrazine for oxygen removal, and limitation of chlorides in the boiler water to less than 1 ppm has resulted in trouble-free operation of the steam system from December 1957 to December 1960.

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.

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).

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.

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

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).

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.

The general solution to the basic differential equation d^4w/dy^4 +4w= -4f(y) is transformed from the primary form treated in most texts to an alternate form in which each integration constant corresponds to one edge condition at y=0. The relationships between the integration constants of the two forms are derived and the values for the transformed functions are tabulated. The particular solution is derived in general and given in unique form for various functional forms of f(y). Matrix notation is used throughout the derivations; however, a knowledge of matrix theory is not need for application of the results.

In a gas-cooled reactor operating at very high power density the thickness of the reflector may be determine by the requirement that the steel pressure vessel be protected from an excessive dose of fast neutrons, rather than by the usual requirements of neutron economy and power distribution. It is important the the reflector not be made thicker than necessary, since an increase in pressure vessel diameter can result in a marked increase in cost, as well as a decrease in the permitted gas pressure level.

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.

In analyzing stresses, deflections, and forces in piping and certain structural systems, it is useful to have a set of equations giving the deflections at any point of a curved beam in terms of the various loads acting on the beam. This technical report presents the deflection equations for a curved circular-arc beam of variable length. The cases treated include in-plane and out-of-plane bending due to forces and moments applied to the end of the beam in three principal directions, and uniformly distributed loads applied along the beam in these three directions. Deflections were calculated by the strain energy method using Castigliano's theorem.

A falling ball viscometer under development at ORNL, employing a flow system and an electromagnetically operated dash-pot pump, was evaluated for possible use with aqueous ThO2 slurry systems under reactor irradiation. Interchangeable check valve inserts were designed and fabricated to investigate several pump designs. Magnetic flux concentrations which originally prevented circulation of the ferritic stainless steel viscometer ball through the electromagnetic pump were eliminated by substitution of iron-magnetic stainless steel inserts. Viscosity was correlated through a logarithmic plot of the dimensionless Reynolds number vs. Froude number with the ratio of ball diameter to tube diameter as a parameter. The relation is linear in the laminar flow region.

The distillation method (Argonne Sampler) for the analysis of sodium oxide in NaK was used to calibrate a plug indicator. The description of the equipment, procedure, and experiences with the Argonne Samplers are presented in great detail to aid future users of this method. Although this method is not very precise, it has been thoroughly checked out and is recommended as a standard means for sampling and analysis for oxide in liquid metal systems. (auth)

It is concluded that an excess of O2 must be added to the HRT fuel circulating stream in amounts sufficient to recombine the D2 in dead-end lines and serve as corrosion protection.