Nuclear measurements for type 3 replacement cores for SM-1, SM-1A and PM-2A CE-3

Description and results are given of an experimental program to evaluate the effect of utilizing Type 3 (SM-2) replacement cores in existing Army field plants SM-1, SM-1A, and PM-2A. SM-2 mockup fuel elements similar in composition to Type 3 fuel elements were employed to determine startup characteristics of Type 3 cores in SM-1, SM-1A, and PM-2A core configurations. Measurements include comprehensive power distribution, temperature coefficients, initial critical bank positions, control rod calibrations, critical rod configurations, and material coefficients, all obtained under cold and clean core conditions. The 45-element SM-1 and SM-1A configurations with SM-2 mockup fuel elements contain 36.4 kg U235 and an estimated 67.9 g B/sup 10/, while the 37-element PM-2A configuration with SM-2 mockup elements contains 30.0 kg U 235 and an estimated 56 g B10. (auth)