From abstract: "This report describes the overall loop design and the means by which this design was developed. These include critical facility measurements, analog computer calculations, hydraulic and heat transfer computations, and the construction and operation of an out-of-pile mock-up loop to determine the dynamic characteristics of the loop."

"Short-range order coefficients were measured at 300 and 400°C for iron-aluminum alloys containing 14.8, 18.2, and 20.0 atomic per cent aluminum. These alloys exhibited a strong preference for unlike near neighbors. The short-range order was greater at the lower temperature and increased as the Fe 3Al composition was approached."

From Introduction: "The recent acceptance by physicists and chemists of new values for the fundamental constants and the continued demand for expanded and convenient tables prompted the recomputation and preparation of this volume. The authors have tried to incorporate this work a number of the more desirable features of the above-cited works, particularly with respect to their use in calculations involving: Thermodynamic properties of gases; specific heats, electrical and thermal conductivity of solids; and molecular structure and spectroscopy of diatomic and polyatomic molecules. It is the hope of the authors that formal character of this publication will insure a more adequate notice and dissemination than was accorded the earlier works, thereaby reducing the probability of still further duplication of effort."

"Theoretical calculations have been carried our for the two ordering phases which occur in the FeAl system. The statistical treatment involves first and second neighbor interaction parameters as well as a magnetic interaction between first neighbor iron atoms. The phase diagram and the amount and type of long range order for slowly cooled alloys are calculated. Further calculations include short range order for the disordered phase at three compositions and two temperatures. As expected, the short range order increases as a critical temperature is approached either in composition of in temperature."

The following document describes the usage of the LRL 9-ZOOM code, a neutron diffusion theory reactor code for the IBM 709. The code has been modified to solve configuration of a series of stacked cylindrical disks, designating a new geometry case.

Applications of sheathed (metal) thermocouples may require in many instances, the insertion of the thermocouple thermal junction into an area that must be hermetically sealed to the outside. This same area usually contains highly reactive heat transfer medium such as an eutectic alloy of sodium and potassium of sodium alone. When fissionable materials are being irradiated, fission products that are driven off would also be present and must be contained under varying temperatures and pressures.

The Plutonium Recycle Test Reactor is heavy water moderated with a heavy or light water reflector contained by a complex aluminum vessel called a Calandria. ( See Figure 1). Construction of this vessel started in August, 1958, at a large West Coast vendor's plant and was completed at Hanford in December, 1959. The fabrication problems associated with a high integrity welded aluminum vessel were generally unrealized prior to this period. This report covers the fabrication of the Calandria and lists recommendations for improving the design and reducing the cost.

This semiannual progress report and future reports will be published as two documents to permit a wider distribution of the unclassified material. The report numbers are assigned in sequence so that the two reports will fall together when filed by report number.