Abstract: "The thermal and electrical conductivities of a series of Pu-Al alloys have been determined in the range 0.12 atomic percent Pu. The conductivities are approximately proportional to the volume of free aluminum."

This technical report presents results of nuclear plate work carried out to determine the neutron energy distribution inside the Los Alamos fast reactor. Most of the distributions which were investigated are valid over the energy region from 0.4 to 6 Mev. The results show that at the center of the reactor pot about 65% of the neutrons are located below 1 Mev in a rather narrow energy region which has a maximum in the neighborhood of 0.5 to 0.6 Mev. Above 2 Mev the energy distribution is similar to that of a plutonium fission neutron spectrum, i.e. the spectrum decreases exponentially, diminishing by a factor of 10 in intensity over an energy range of about 4 Mev. The leading geometry of the reactor pot does not seem to appreciably affect the spectrum at the center of the pot. However, spectra determined outside the pot can be significantly altered by the particular viewing geometry employed to examine the neutrons coming from the center of the reactor.

Uranium can be rolled from cast metal or forged ingot to sheet satisfactory for cupping, deep drawing, and similar fabrication procedures by a combination of hot breakdown in the neighborhood of 600 deg C and warm finishing at 225 to 325 deg C. Sheet may also be obtained by hot rolling alone and by warm rolling alone. However, it is difficult to secure a uniform, controlled grain size by hot rolling only and warm rolling is time consuming because of the limited reduction per pass obtainable. The combination of hot and warm rolling afforded best and most practical method to secure good quality sheet in the quantity required. The percent reduction by hot working does not appear to be critical, but at least 60% warm reduction is desirable to obtain complete and controlled grain size by recrystallization with high ductility and strength properties. Except for research investigation, rolling of uranium below 225 deg C is not recommended. In the temperature range considered (below 225 deg C), reduction is difficult and must be limited to one to two percent if edge cracking is to be avoided. Hot rolling of unplated uranium from the as-cast or as-forged surface is recommended, using a …