This memorandum discusses slug rupture frequency which appears to be a factor that may limit the power level of C Pile. Since additional exposure of Group 8 uranium slugs has increased the available information on the behavior of material similar to that which will be charged into C Pile, a review of this tube power limitation has been made. Utilization of additional data has been possible by use of the revised method of calculating rupture rates discussed in reference (2).

The test established that a practical orifice selecting device can be made and used to control the water flow rate to a process tube at either of two accurately calibrated rates with no loss of accuracy in flow measurement. With the selector tested, there was no flow restriction during the orifice transition. The pressure fluctuations during the change were small in magnitude, and caused no operational problem. The test demonstrated that orifice selection is feasible from operating other factors justify their use.