Abstract: This report describes the fabrication of elements for the OMRE third core loading.

From abstract: The vapor pressure determination of solid ThF4 has been completed. Experiments to determine the heat of formation of ThF4 by studying the reaction of ThF4 with SiO2 are described.

Introduction: On November 14, 1961, an environmental test program commenced on the first SNAP 10A system structure, S10A-PSM-1.

Abstract: this report discusses and summarizes all stress analysis done on the SNAP 10A system; it also mentions many of the structural tests which were accomplished.

Abstract: This report presents the results of the structural tests which were performed on the S10A-PSM-1A system to qualify the basic structural design for the anticipated launch environment.

Progress report for the Piqua Reactor Operations Analysis Program describing observations and analyses at the Piqua Nuclear Power Facility (PNPF). The program goals are to monitor operations and collect data in order to ensure that the plant's operation is safe, to improve design and performance, to evaluate the performance and lifetime of the plant's components and systems, to evaluate plant safety and safeguards, and to disseminate all information to the scientific community.

From abstract: "A chamber was constructed with three electrodes dividing the space into two regions of 800 c.c. The surfaces of one of these were coated with boron carbide. With opposite potentials on two electrodes, ion currents to the collecting electrode due to gamma rays were practically cancelled and ion currents due to alpha rays induced by slow neutrons were measured."

The construction and operation of a fission gas generator, containing about 25 grams of uranium in the form of a powder with a high specific surface, are described in detail. The purpose of the work discussed in this report was to examine the feasibility of producing, separating, and assaying samples of Xe135 in preparation for a proposed measurement of the neutron cross section of this isotope. Krypton and xenon are separated by selective adsorption on charcoal at reduced temperature while iodine is removed by charcoal sorption at room temperature.

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.

Abstract: Residual and fission gas release from UO2 were studied in the laboratory and in in-reactor experiments. Arc-fused powder and sintered pellets were used to determine the rate of evolution and types of residual gases as a function of temperature. Fission gas release was related to the average UO2 temperature and fission gas release calculations were made using the latest thermal conductivity values, isotopic half lives, and branching ratios available in the literature. The results obtained were compared with those available in the literature, and a satisfactory agreement was found among the groups of comparable data.

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. All program efforts have been temporarily deferred except for those associated with the irradiation of the program fuel element in the VBWR. The program fuel element was exposed to a burnup of 831 MWD/T during the quarter which brings the total to 3165 MWD/T. Applying the same scale factor between logged exposure and Ce-Cs analysis of the first fuel sample gives a corrected exposure of 3774 MWD/T.

Activities in a program to develop techniques in the use of pulsed neutron sources to measure shutdown parameters related to large thermal power reactors are reported. The development of pulsed neutron source techniques for large power reactors has led to a new theoretical model recently developed by E. Garelis and J.L. Russell, Jr. The theory is presently based on a bare, one-group model with m-delayed precursors and takes all spatial modes into account. Results indicate, however, that the application of this model is much broader. Experiments were designed and carried out to both verify this new theory and to demonstrate the performance of the experimental hardware in a large power reactor.

Preface; Subsequent to the analysis in the body of this report metallurgical developments indicated that it would not be feasible to build the APPR-1 Core II with the increased boron loading specified herein. At the time of the issuance of this report the Core II boron loading is to be the same as that for Core I. At the time of procurement of the core in the fall, if metallurgical developments warrant, the increased boron loading will be employed. The loading discussed in the body of the report and the first three appendices is that designed to meet the specifications outlined in the introduction. Appendix IV discusses changes in the loading to account for the various methods of employing boron.

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

Discussing the occurrence of Visible Uranium minerals in the Morrison Formation of the Nacimiento Mountains.

"The behavior of charged particles in a plasma-free cusp field, or in a cusp field where there is very little plasma, is studied. The numerical computations described may provide a valid picture of the behavior of particles outside such a body of plasma or in the early stages of creation of such a cusped plasma in the low- beta limit. The computations provide a striking illustration of orbits which neither have constant magnetic moment nor behave so irregularly as to defy explanation."

"An account is given of an extensive study of the A-2 Compiler System for the Remington Rand Univac digital computer. In particular, the following topics are discussed: application and performance of subroutines, segmenting, and introduction of subroutines to the library."