Application of neutron monitors to process control in Recuplex. Status report

A program was. initiated early in 1957 to develop a neutron monitor capable of detecting plutonium (Pu) concentration in process vessels in Recuplex. This followed an earlier application by Finished Products Operation and Research and Engineering of neutron monitoring to powder counting which had been successful and was being regularly used. The process vessel monitoring was to be done by the ``in tank probe`` method, utilizing the monitored solution as its own-moderator, and detecting the resulting slow and thermal neutrons with boron trifluoride (BF{sub 3}) type proportional counters. This report is intended to present the history of the Recuplex program; a summary of the development work to date; the current status of the monitoring system; and the immediate plans for future installations and work. This report is intended as a design guide for presently scheduled and future monitor installations in Recuplex and elsewhere of the types herein described. The report also includes calibration curves for both D-11 tank and H-3 column monitors, schematic representation of all installations, manual switching panel circuit diagram, pre-amplifier circuit diagram, probe well designs, and Kl-2 instrument tank design