Showing papers in "Transactions of the American Nuclear Society in 1964"

Fatigue-design basis for zircaloy components

Abstract: General methods have recently been developed for low-cycle fatigue design. The required basic strain-controlled data for both unirradiated and irradiated Zircaloy–2, −3, and −4 were obtained for te...

A stable numerical solution of the reactor kinetics equations

Abstract: A numerical procedure for the integration of the reactor kinetics equation is developed. It has the property of being numerically unconditionally stable for all values of the reactivity or integrat...

Fuel properties and nuclear performance of fast reactors fueled with molten chlorides

Abstract: The characteristics of fast reactors having molten fuels consisting of uranium and plutonium trichlorides dissolved in alkali chlorides and alkaline-earth chlorides were studied. The study included...

Reactor pulsing in activation analysis

Abstract: For neutron activation analysis with very short-lived activities (t12 < 50 sec) improved limits of detection are obtained by irradiating with TRIGA reactor neutron pulses rather than with steady-state irradiations. These pulses give peak fluxes of about 4.5 × 1016 n/cm2·sec compared to 1013 n/cm2·sec at maximum steady-state operation. Pulse width at half maximum is 15 msec. Therefore, short-lived radioactivities generated by pulses are not limited by the saturation factor and the pulse produces 50 times as much one-second half-life activity as can be generated by irradiation to saturation activity at maximum steady-state flux. Sensitivity data are presented on a number of reactor fast-and thermal-neutron produced activities and the results are compared with theoretical predictions.

Modified p2 approximations to the neutron transport equation.

Abstract: : The steady-state neutron transport equation for slab geometry is expanded in Legendre polynomials. The expansion is truncated after the third term (P sub 2 equations) and then is modified in an attempt to reduce the truncation error. The resulting equations are, for many problems, a better approximation to the neutron transport equation than the P sub 2 equations or the standard diffusion equations. The method is extended to two and three dimensions by a simplified form of the spherical expansion to the neutron transport equation. Sample results are given. (Author)

Nuclear-thermionic lunar base power supply

Abstract: A nuclear powered direct energy converter system employing a cylindrical radiator spaced from the converter and particularly well suited for lunar applications. One embodiment is adapted to be positioned in a lunar crater which constitutes radiation shielding, while another is adapted to receive radiation shielding in the form of lunar material. Reflectors positioned at an angle with respect to the cylindrical radiator reflect thermal radiation received therefrom in an axial direction.