The purpose of this document is to describe the design and construction of a full-scale, electrically-heated model of a 19-rod PRTR fuel element for use in heat transfer experiments.

Iron containing approximately 0.01 wt. % carbon was quenched from 700°C and irradiated in the BNL reactor at 57°C for various lengths of time. The rate of decay of the Snoek internal friction peak was observed at 57°C after irradiation. After a 4-hour irradiation the rate of decay of the peak was one order of magnitude faster than the rate of decay in an unirradiated specimen. Longer irradiation times up to 48 hours caused no further acceleration of the decay rate. This observation implies that in the irradiated specimens there are ten times more precipitation nuclei than in the unirradiated specimens. This is confirmed by electron microscope studies which also show a factor of ten greater concentration of precipitate particles in specimens irradiated for 5 hours at 57°C as compared to an equivalent unirradiated specimen. Electron microscope studies also show that longer irradiation times do not increase further this number of precipitates. Although these experiments clearly demonstrate the enhancement of nucleation by neutron irradiation, it is not known why the incipient nuclei created by irradiation times of longer than 5 hours do not form observable precipitate particles.

Two methods for measuring target efficiencies are briefly discussed. The second method puts an upper bound on the efficiency and permits observation of instantaneous efficiency, thereby aiding location of losses. Measurements agree well with conventional radiochemical values.

The reactor equipment cell is expected to be completed by February 15. While filled with water, the tank was inspected for leaks, and the few leaks found will have been repaired by February 15. All orders for construction materials placed prior to this quarter have been received. New requisitions issued during the quarter total $16,000. Work orders were issued, and fabrication of all low-pressure-system components was begun in the ORNL shops. The thermal shield around the reactor vessel was specified as a 2-ft-thick cylindrical concrete wall. With this shield, the fast-neutron flux in the equipment area will be reduced to 7 x 109 neutrons/cm2/sec, the slow flux to 4 x 107 neutrons/cm2/sec, and the gamma intensity to less than 105 r/hr. The possible blast effects from a rupture of the pressure vessel were studied and are judged to be sufficient to justify the inclusion of a 1.5. to 2-in.-thick blast shield around the pressure vessel. The blast shield eliminates the danger of damaging the leak tight equipment-cell liner. Pressures in the reactor equipment cell, as a result of vessel failure, were calculated in order to arrive at a safe design pressure for the reactor equipment cell. For the case of …

The development of ionic methods for the determination of corrosion products in the highly radioactive Homogeneous Reactor (HR) fuels has been of major interest in the work of the Ionic Analyses Laboratory. Methods for the spectrophotometric determination of aluminum and for the polarographic determination of iron in HR fuels have been developed. The polarographic determination of molybdenum in uranyl sulfate solutions was studied. A polarographic method for the determination of zinc was developed. A fluorometric method for the determination of microgram amounts of fluoride was studied. Three organic reagents were investigated as precipitants for microgram quantities of zirconium in HR fuel. The automatic photometric titration technique was applied to the determination of thorium and of sulfate. A method was developed for the ionexchange separation and potentiometric titration of cobalt. The ultraviolet absorption spectra of technetium and rhenium were studied.

A method of determining enclosure pressure in the event of a reactor rupture is presented and a sample calculation is shown. This method was used in calculating the design pressure of the Dresden Nuclear Power Station enclosure.

This report is an amendment to the Preliminary Hazards Summary Report (1) and the Operating Procedures and Emergency Plans (5) for the Dresden Nuclear Power Station, submitted to the United States Atomic Energy Commission on September 3, 1957, and June 5, 1958, respectively.

In the HRP Welding program, a major part of the welding and fabrication, and some of the testing, is performed using an inert atmosphere. the use of the inert gas consumable arc welding process and dry box welding or other work in a dry box comes within this category. Since much of the work in the project make use of, or requires, inert atmospheres, a general discussion follows of the methods used, description of equipment, processes, quality of atmospheres, purity requirements, kinetics of metal-gas reactions, and the proper application of the equipment and methods use din obtaining the desired results.

General considerations involving the transportation of irradiated fuel and radioactive wastes are reviewed. It is assumed that many reactors will supply feed to a few large multipurpose chemical plants which ultimately send radioactive waste to a few disposal sites. General economic considerations of irradiated fuel reprocessing, economic aspects of the nuclear economy complex, growth predictions of the nuclear power economy in the U.S., general requirements for the shipment of fuel and waste, regulations applicable to fuel shipment, and permissible radiation levels are discussed.

Specifications are presented for cleanliness during installation of piping and equipment in the High Level Volatility Laboratory, Bldg. 4507.

The object of the work done during the month of June has been to assure that deposition of chemically pure chromium metal by gas plating, both by itself, or as a component of nickel-chronium and/or other alloys.

To obtain a better understanding of the mechanism involved in scaling behavior of zirconium, kinetic studies were made of the weight pickup in air after the following pretreatments; (1) exposure to oxygen or nitrogen, (2) exposure to air, oxygen or nitrogen and removal of the resulting surface compounds.

A study was made of a method for the flame photometric determination of iron. In Part I of this report, the flame emission spectrum of iron, measured by means of a Beckman Model DU spectrophotometer with a flame attachment, is compated to that measured with an ORNL high-sensitivity, recording, single-beam instrument, in order to determine which instrument is best suited for this application. Although it was found that the Beckman product has the higher resolving power over the wavelength region of 360 to 400mu, it does no posses the sensitivity or ease of operation of the ORNL instrument. On this basis, the ORNL flame spectrophotometer is used in subsequent tests. After selecting the best-suited instrument for the flame photometric determination of iron, it was necessary to establish the optimum operating conditions for this particular method. These conditions are described in Part II.

Preliminary measurements of the corrosion of titanium were made in 13 M HNO3-0.05 M fluoride using 0.1 M H3BO3 as a liquid and vapor phase complexing agent. Titanium Ax-55 was attacked at average rates of 0.58 and 0.33 mils/month in the liquid and vapor. In dissolver solutions containing 0.5 and 1.0 M titanium, all rates were less than 0.1 mils/month.

The solution of the monoenergetic Boltzmann equation in an infinite homogeneous, nonmultiplying medium with linearly anisotropic scattering and an isotropic plane source is given and compared with the corresponding solution for isotropic scattering. The effective source strength for the asymptotic flux turns out to be the same as that for isotropic scattering to first order in Σa/Σ.

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 description of the thick-target neutron yields from the D(t,n)He4 and the D(d,n)He3 reactions is calculated as a function of the energy of the bombarding particles. For 60-kev particles the ratio is 108. I increases to 168 at 100 Kev and to 194 for 120-kev particles. A qualitative discussion of the yields from various deuterium target leads to the conclusion that the greatest yield would come from the target which has the lowest stopping cross section per deuterium atom.

The definition of the Lebesgue integral is used to develop a numerical integration method in which the integral is evaluated directly from a contour plot of the function. It is useful in working from weather maps, potential surfaces, etc., but was particularly designed to assist in reducing blast diffraction space-time diagrams to simple, meaningful quantities.

The purpose of the test was to determine the responses of the plant when subjected to load transients exceeding the design magnitudes, and to determine the maximum load changes, positive or negative, that the plant can sustain. The reactor plant responded satisfactorily to all load transients. The only limits exceed were the pressurizer high and low level alarm points. The magnitude of the transients and the time required for the plant to return to equilibrium was dependent upon the size of the the load change. The pressurizer spray was effective in reducing reactor coolant pressure positive surges; however, this resulted in larger negative surges than when the spray valve was closed.

"The effects of radiation emission on the motion of electrons in high energy synchrotrons are analyzed. The damping rates and quantum excitation of the three principal modes of oscillation are derived for strong focusing and constant gradient accelerators. Methods for correcting the radiation effects for strong focusing accelerators are discussed."