"An analysis is presented of the accidental release of activity following the operation of the NS "Savannah" at the New York Shipbuilding Corporation docks in Camden, New Jersey. Although a number of accidents are considered, the report is primarily concerned with the environmental activity levels and subsequent exposures which would result from the "maximum credible accident" (p. v).

This course on reactor controls is for the purpose of acquainting the student with some of the elementary considerations involved in setting up a control and safety system for a nuclear reactor. This material is the outgrowth of the notes prepared for the lectures on Reactor Controls given in the Oak Ridge School of Reactor Technologu. The lectures given by T. E. Cole in 1953-1955 are the basis of portions of the subject matter on reactor kinetics. Many suggestions and ideas contributed by E. R. Mann are included throughout almost every section. In addition, several members of the Oak Ridge National Laboratory, and of the Reactor Controls Department in particular, have provided information which has been included in these lectures notes.

The results of a parametric study on a gas cooled reactor are reported on herein. The system considered was a helium cooled, UO2 fueled arrangement with the fuel assemblies consisting of clusters of long cylindrical elements, each element covered b a stainless steel jacket. The axial power distribution was assumed to be a "chopped cosine" having an axial peak-to-average power 1.32.

An ion-exchange -- polarographic method was developed for the determination of iron(III) in Homogeneous Reactor Fuels. Copper, which interferes, is removed from the fuel by plating it onto a cadmium coil. Iron is oxidized to iron(III) by potassium permanganate, and the iron(III) is separated from interfering metal ions by ion exchange on a Dowex 1 resin column that is in the sulfate form. The iron(III) in the effluent is determined polarographically in 0.5 M sodium citrate solution as supporting electrolyte. A fairly well defined polarographic wave is obtained for the iron(III) → iron(II) reduction at a half-wave potential of approximately -0.15 v. vs. the S.C.E. The relative standard deviation of the data for 2 µg of iron(III) per ml of solution in the polarographic cell was 6.5%; for 10 µg of iron(III) per ml it was 0.6%.

This report is the result of a study to develop heat-resistant fin materials possessing a high thermal conductivity for air radiators. Since an economical and commercially feasible product was desired, the investigation was restricted primarily to a study of electroplated copper, clad copper, and copper alloys. Sheet material 0.008 to 0.010 in. thick was evaluated for fabricability and for metallurgical stability and thermal conductivity at 1500°F. From the results of the rests it was concluded that: (1) electroplates were unsatisfactory; (2) clad-copper fins possessing a thermal conductivity of 50% of that of copper are commercially feasible; (3) copper-aluminum alloys possessing a thermal conductivity approaching that of copper at 1500°F are possible. Service tests of clad copper and the copper-aluminum alloys indicate that the choice of materials will be dictated by the requirements of the radiator, since each presents some unique problems.

The ORNL 86-in. cyclotron is being modified to provide for deflection of the proton beam. It is expected that operation will be resumed late in the spring. Nuclear physics work was limited, for the most part, to interpretation of previously collected data and to making preparations for utilizing the deflected beam. It was found that for certain isotopes the production rates could be almost doubled by operating at a slightly reduced energy and a much larger current. With the use of the ORNL 63-in. cyclotron, the absolute values of the electron capture and loss cross sections for 26-Mev nitrogen ions were obtained. The angular distribution of the cross sections for elastic scattering of nitrogen by nitrogen was measured at energies from 13 to 22 Mev. A double-focusing 90-deg magnet is being planned for use in identifying stable reaction products from nitrogen-induced reactions. The major components of the revised 44-in. test cyclotron were assembled and are being tested. Consideration is being given to the use of these components, along with a new 20,000-oersted magnet and a shielded cyclotron room, and if the tests are satisfactory the Laboratory will have available a machine which will accelerate N5+ ions to 81 Mev.

Report discussing the progress of various research projects by members of the Mathematics Panel at Oak Ridge National Laboratory for the quarter ending April 30, 1952.

Technical report containing the detailed design of the equipment within the reactor shield, reviewed in 1950. Contains various summaries on engineering design and development, reactor physics, chemical studies, and corrosion.

Report documenting ongoing research and development carried out by the Instrumentation and Controls Division of the Oak Ridge National Laboratory.

Program written to perform polynomial least squares fits on the the IBM 7090 computer.

Report documenting the ongoing research and developments of the Oak Ridge National Laboratory's Homogeneous Reactor Project.

Report that describes the research and developments of the Nuclear Safety Research and Development Program of the Oak Ridge National Laboratory.

Thorium, a fertile material, is of interest to the Reactor Program in the production of U233. Thorium can be extracted and processed to a very pure bulk metal for fabrication into solid fertile elements. There are advantages, technical and economic, for using fabricated bulk thorium dioxide rather than the metal in some applications. It is the purpose of this paper to point out these advantages and to present briefly the technology related to fabrication, radiation damage and chemical processing of ThO2.

Activity and ionic impurity specifications are presented for Thorex thorium nitrate products. Two sets of specifications are given, one set for direct handling during refabrication of production reactor thorium metal slugs and the second for refabrication of future power reactor thorium metal elements by semi-remote technics. Consideration was given to the health hazard problems associated with each process step between the Thorex process and final refabricated source material in order to arrive at these specifications.

An estimate has been made of the gamma radiation levels at access holes in the HRT Shielding when the plugs have been removed to service or maintain the reactor. In every case the radiation level at the holes was greater than the maximum permissible exposure rate of 0.3 roentgens per week. The radiation through the holes can be attenuated to some extent by flooding the reactor cell up to the flange to be disconnected. However, shielding would still be required and it is more practical to provide a small additional shield thickness to compensate for the moderate attenuation that could be gained from flooding.

The criteria for selection of an HRT secondary refrigerant system refrigerant to replace Freon-11 are given. The properties of Amsco which make it desirable are tabulated and it is compared with triethyl phosphate (the second choice) and Freon-11.