Summary: Transition boiling data was taken with an improved flow loop, to explore the influence of loop characteristics on rod temperature fluctuations the transition region was found to be much smaller than for comparable conditions with a different loop. Also the amplitude, and frequency of the temperature oscillations, were significantly less than before. These results indicate that loop characteristic and flow disturbance parameters play a prominent part in governing the transition temperature fluctuations. Additional two-rod transition boiling data are presented. The results include data taken at high wall temperature levels during a demonstration test at low steam qualities, and the effect of a change in rod spacing on heat transfer performance.

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: Project fuel fins irradiated to 1860, 3000, and 5300 MWD/T have been successfully sampled in the Radioactive Materials Laboratory. The samples have been dissolved and aliquots delivered to Chemistry for Mass Spectrometry and burnup determination. The first Stanford Pool Irradiation indicated that there was some inconsistency in the thermal flux and the near thermal epithermal flux. The experiment was repeated, increasing the number of foil wheel positions from two to three. The data from the second measurement are being reduced. The EPITHERMOS code modification has been completed. Comparisons between the results computed by the code and experimental data show much improved agreement. The metallographic photomicrographs of a polished half-pellet from rod F, irradiated to 5000 MWD/T, show structure very similar to that shown by the pellet from rod S, irradiated to 1860 MWD/T.

This paper summarized the work at ORNL in controlled-potential dc polarography since mid 1959 and states conclusion and viewpoints that have been reached in the course of this work. The following topics are discussed: (1) Potentiostatic Compensation for Polarographic Cell Resistance; (2) Time-Derivative DC Polarography; (3) Signal-to-Noise Ratio (S.N); (4) Resolution; and (5) DC Polarography in Non Aqueous Solvents and, Particularly, in Solvent Extracts.

The subject which I will discuss is the distorted - waves theory of direct reactions and its application to the study of nuclei. I shall mainly be concerned with a study of the reaction theory, its range of validity, and its ability to give quantitative information about nuclear structure.

The series of papers that we are about to discuss is primarily concerned, not as the first part of the session title indicates, with photochemistry of nucleic acids, but, as the second part indicates, with the biological implications of the photochemistry. We know that ultraviolet acts on nucleic acids in cells, and we know a good deal about the photochemistry of this interaction in vitro. The question we ask here is, which test tube reactions are of importance to the survival of the cell?

The quasi reference electrode ( Q.R.E. ) is a bright platinum wire or other inert conductor immersed directly in the solution; it may have a very small area. It is used instead of a true reference electrode but must be used with potentiostatic or other circuits that prevent the drawing of cell current through the Q.R. E. When used in appropriate situations, the results obtained by use of a Q.R.E. are like those obtained with a true reference electrode except for the lack of thermodynamic meaning of the Q.R.E. potential ; hence , this simple electrode is called a quasi reference electrode.

Abstract: Continued irradiation experience under the AEC - Euratom, UO2 High Performance Program provided five separate and distinct sets of data on UO2 thermal conductivity. Four of these results are expressed in terms of the value of the thermal conductivity. The first two of these measurements were applicable -- strictly -- to poly crystalline UO2. Recently, three additional sets of measurements have been obtained -- all pertinent to UO2 after the formation of large columnar grains. The extent of melting in the experiments on which the results are based ranges from slight, to greater than 70 percent of the fuel cross section. The conclusions from all of these thermal conductivity measurements considered together are: (1) The true value of the UO2 conductivity integral form 0 degrees C to melting (2805 - 15 degrees C) lies in the range from 90 to 96 W/cm. The most probable value is closer to 90 W/cm. To ensure no central melting and the associated clad swelling the maximum thermal performance level for solid pellet, UO2 fuel rods should not exceed 90 W/cm. (2) Any improvement in thermal conductivity due to the formation of large, columnar UO2 grains is small and not detectable within the …

The United States and the European Atomic Energy Community (Euratom), on May 29, and June 18, 1958, signed an agreement which provides a basis for co-operation in programs for the advancement of the peaceful applications of atomic energy. The work described in this report represents the Joint U.S.-Euratom effort. The over-all development program is designed to obtain the test data and operating experience necessary to eventually realize a 50 percent increase in the output of the Garigliano Nuclear Power Station located at Sessa Aurunca (Campania, Italy). One task is in progress: Task I - Data Logging and Computer System. The work on the other tasks is being planned and initiated.