Report discussing the mechanics of X-Ray and COMBO computer programs.

Abstract; SM-1 Reactor Core I Rearranged and Spiked, and Core II with Special Components were analyzed under various off-design conditions to induce nucleate boiling. The steady state code, STDY-3, written for the thermal analysis of pressurized water cores, was employed for the analysis. The code performs a complete steady state parallel channel thermal analysis for both nominal and hot channels. Thermal characteristics of individual elements were investigated while changing the parameters of primary pressure or inlet temperature to introduce the phenomenon of nucleate boiling in the the core. Reduction of system pressures to 1000, 800, and 600 psia and increasing core inlet temperatures to 465 and 500 degree F were studied as the means to induce boiling in the core. This analysis indicates that SM-1 Core I Rearranged and Spiked can be safely operated at the reduced pressure of 910 psia without introducing extensive boiling in the core. SM-1 Core II with Special Components can be operated at 800 psia or at an inlet temperature of 500 degree F at 1200 psia.

Abstract: This technical report analyzes gamma dose rate and neutron measurements in their relation to the SM-1 shield design and is a continuation of previous shielding measurements and analyses reported in APAE-35 and APAE-35 Supplement 2. The data reported herein are spent fuel element and rod drive pit gamma dose rates. An analysis of gamma dose rates off the core midplane is presented and compared with test data.

From summary: "A superposition model is developed to predict the critical heat flux in forced convection flow. The model is applied to available experimental results in boiling water flows and good agreement is obtained between the model and test data over the multitude of geometries, flow rates, pressures, and fluid enthalpies tested to-date."

From introduction: "Evaluations to determine cause of fuel rods breakage following irradiation."

The subject of this report is the generalized computer program written to solve problems involving steady fluid flow through heterogeneous, partially-saturated porous media.