Critical mass information applied to purex and recuplex design

Some time ago, a series of experiments (the P-11 project) were conducted to determine the critical mass of plutonium in variously sized and shaped vessels and with various solution concentrations. These experiments were rather general in nature, hence, it is necessary to interpret the data to the specific critical mass problems of interest in separation processes. The design of new continuous flow separation processes calls for even further extrapolations of these data to vessel geometries far from the range of present experimental knowledge. The purpose of this report is to review for reference the estimates used in the design of the critically safe portions of Purex and Recuplex. This report is compiled for engineering use in approximate design; however, any design of vessels involving criticality hazards will be reviewed by the Critical Mass Group