Reactivity Coefficient Measurement of Buckling

: The current series of exponential measurments on light water moderated, slightly enriched uranium rod lattices is intended to provide typical reactor parameters for such assemblies in the clean, cold state. So far, extrapolating to operational conditions in a going power reactor (with fission production buildup, high temperature, structural poisons, partial fuel burnout, Pu buildup, etc.) must be done by calculations which are first made to predict the clean, cold results correctly. Of course, it is desirable to make such estimates of the predicted behavior as sound as possible. In order to provide some experimental basis for predicting the effect of 25 burnup and 49 buildup, we are planning to supplement our present work with measurements in assemblies fueled partly by Pu. We intend to measure as many quantities as possible, hoping to get critical masses, and to find ont pertinent details of the neutron economy.