The lack of control rod capacity in the reactors with nine rods is causing significant production losses. The present control system, which functioned satisfactorily at a 300 MW equilibrium power level, is unable to counteract the larger startup reactivity transient effects at the current high power levels. This lack of strength causes the power level to be restricted during startup. The control system is also not flexible enough to prevent outages for the discharge of temporary poison. (1) A method of obtaining the required supplementary control strength and flexibility has been conceived. (2) and equipment developed for this purpose. The purpose of this test. (3) was to demonstrate the operational feasibility of the special front and rear face equipment which was designed to permit the routine charging and discharging of poison slugs at selected process tubes during periods of reactor operation. This report presents the data, results and conclusions obtained from the trial use of this equipment.

Report discussing the progress of various research projects by members of the Mathematics Panel at Oak Ridge National Laboratory for the quarter ending April 30, 1952.