This report considers the theoretical evaluation of a system for gaining increased control strength and increased control lifetime and presents a theoretical model which is applicable to conventional multigroup diffusion theory.

Stability tests are to be made in the VBWR (boiling water reactor). The tests are of three types: steady state measurements, rod oscillator tests, and transient tests.

The power of nuclear track research emulsion as a fast neutron dosimeter is examined in the exposure of a human phantom to PuBe neutrons. Semiautomatic track scanning and high-speed data analysis obviate the major disadvantages of this dosimeter, and allow the following basic information to be obtained without a serious cost in time: the rulative proton recoil energy spectrum, the absolute differential proton track den sity spectrum, and the average proton recoil energy at various locations in the phantom. From this are calculated the total absorbed local tissue doze due is proton recoils, the local thermal neutron intensity, and that portion of the tissue doze due to thermal [formula] tracks.

Pulse-amplitude discriminators are useful in nuclear counting to separate signals of greater amplitude from a background of unwanted or noise signals of lesser amplitude. As used here, the term "fast" implies circuits capable of responding to pulses between a nanosecond and a microsecond in duration. An ideal discriminator would produce for any incoming signal whose amplitude is greater than a threshold bias level, an output pulse of constant amplitude, duration, and delay with respect to the input signal, regardless of the incoming duration and rate; and for signals less than the threshold, zero output.

"A survey of the current theoretical picture of plasma containment in cusped magnetic configurations is presented together with a mention of the points of contact which exist or might soon be made to exist with experiment. A theory of containment was developed which is applicable to the whole range of plasma densities from a tenuous plasma in an essentially vacuum magnetic field to a fully developed plasma which completely excludes the magnetic field from its interior. Also presented are cursory accounts of the situation with regard to stability, cyclotron radiation, and methods of creating this type of plasma configuration."

"Design and fabrication techniques were improved so that the large area image intensifier now performs well in image intensifier systems for photographing nuclear tracks. Two successful samples meeting most of the objectives were completed and started in circulation among members of the AEC Image Intensifier Committee for evaluation in systems to record nuclear tracks. Except for a reported long decay in the P-15 phosphor performance was quite good. Resolution, gain, and background requirements were met. Magnification was still high (1/6.5 compared to a design objective of 1/8) but can be lowered to 1/8 by a straightforward mechanical change. Evaporated layers of thallium activated rubidium and cesium iodide were improved and further evaluated. Improved control of color and persistence was obtained. Efficiency as high as 1/3 that of P-11 phosphor was obtained in some samples. The current test series confirmed earlier results that an increase in cesium iodide content shifts the emission spectrum towards the yellow. Burn-resistance and light output was poorer for the cesium enriched phosphors while decay time was decreased.

Abstract; This technical report describes the changes in the SM-1 incurred by the experiment, Core Temperature and Flow Instrumentation (Task XIV), and evaluates the possible hazard involved in these changes. Temperature and flow measurements will be taken on a Task XIV instrumented stationary fuel element, instrumented control rod fuel element and other selected points in the SM-1 core to provide data on the core steady state and transient performance. The hazards evaluation consists of a nuclear evaluation, thermal and hydraulic analysis, description of tests to be performed, and discussion of containment integrity and maximum accident considerations.

Abstract: This technical report describes the changes incurred in the SM-1 by the insertion of the SM-1 Core II and special components. The special components consist of impact specimens, a boron gradient rod, SM-2 elements, a PM-1-M element, and high burnup SM-1 Core I elements. The change in hazards, due to operation of SM-1 with Core II and the special components is evaluated. The analysis indicates there is no change in hazards.

Abstract: This technical report contains a description and results of a second series of critical experiments performed on the SM-2 core mock-up, as additional to the first series of experiments reported in APAE No. 54. The SM-2 core mock-up contains 36.4 kg U-235 and and estimated 67.9 gm B-10. The equivalent diameter and the active height are about 22 in.; the metal-to-water volume ration is 0.344. Data is presented on activation, reactivity, and stuck rod measurements. All measurements were conducted on the open seven control rod array employing 38 stationary fuel elements. Activation measurements consisted of neutron flux measurements using uranium fission foils for relative power distribution studies, the effect of flux suppressors on reducing power peaks, blocked coolant channel measurements, and gamma ray dose distribution. Reactivity measurements were performed to determine the effect f flow divider, flux suppressors and stimulated high temperature and pressure operation; b-10 loading in the SM-2 core; and core material coefficients. For the later, the worth in cents per gm or cents per cc was determined at simulated temperature of 510 degree F for B-10, U-235, stainless steel, and void. Stuck rod measurements were made to obtain an indication of the criticality margin in the …

Abstract: Hydrodynamic flow studies were conducted on a full scale model of the SM-2 reactor vessel and core. Test fluid was water at 200 psi and 200 degree F. Test facilities, model, and instrumentation design are discussed. Flow distribution in the stationary fuel elements, lattices, and control rods of the second pass was investigated. Pressure losses through the various core components were measured and are compared with calculated values. Observed over-all pressure drop was 71 feet of water at 200 degree F, 31% higher than predicted, part of which was due to presence of instrument leads. Element to element flow distribution varied approximately +-8% from pass average. Channel-to-channel stationary element flow distribution varied approximately +-10% from element average and control rod flow distribution varied from +-8.9% to +-6.4 and -11.6% depending upon rod locations. These variations exceed the original goals of a +-10% and +-12% combined deviation for stationary and control rod elements respectively, but are satisfactory in relation to thermal design. There was no indication of unsatisfactory structural performance of any components under hydrodynamic loadings up to 130% of design values. The test program was terminated after determining flow distribution in the reference core design, omitting any work on …

Abstract: "The electron paramagnetic resonance (EPR) of color centers in additively colored KCl crystals is measured to observe the effects of optical bleaching at room temperature. Earlier measurements on the F-center are confirmed and the susceptibility is measured at 78 and 300 deg K over five decades of power, including the very low power region. The width and the saturation properties of the individual multiplets are studied in detail and the technique of making EPR measurements on inhomogeneously broadened lines is discussed. A calculation is presented which shows that a slight departure from a Lorentzian multiplet shape can account for the saturation data. The bleached crystals show a resonance which has a width of 35 gauss and a different rate of saturation than the F- center. This resonance is associated with the B-band which appears in the optical absorption."