It is the purpose of this report to explain the bands and uses of a digital computer program for the calculation of steady state steam-water pressure drop and critical flow in pipes. The program has been coded for the IBM 709 computer. While so attempt has been made to obtain improved models of two-phase flow, it is believed that the numerical integration technique used in the code will permit more accurate calculation where pressure drops are large compared to the upstream pressure. The technique should lend itself readily to any improved correlations which appear in the future.

In formulating this general diffusion theory expression which represents the neutron balance in a nuclear chain reactor the following assumptions were made : (1) the medium through which the neutrons are diffusing has a low neutron capture cross section, (2) the region in which the flux distribute is being described is two or three mean free paths from strong sources and sinks or from a boundary. Certainly, is going to the lattice cell of a receptor, both of the above conditions are violated; fuel elements have a large absorption cross section and most lattice cells are only two or three mean free paths to is over-all sites

Describes the current prototype model of a linear amplifier, two-channel pulse-height analyser, two-channel count-rate meter, and count-rate difference detector for a gamma-ray spectrometer monitor developed to approach the above design criteria.