In connection with the development of in-line analytical equipment for monitoring pH, gamma activity and uranium concentration in process streams, experiments and tests were carried out during the past year and a half in the Metal recovery Plant on a pH monitor for the hydrogen ion concentration in neutralized waste, a continuous gamma activity monitor on the RCU, an automatic photometer for uranium in RAF, and an automatic polarograph for uranium in RAW. This letter is written to present up-to-date diagrams of the equipment used, outline briefly the studies conducted and the main conclusions regarding design and operability of the equipment, and present material which will supplement that included in the previous reports on theses instruments.

The decontamination of the present Hanford reactors involves a once-through cleaning operation. Considerable interest has been shown in determining the feasibility of this once-through technique for cleanup of certain portions of the NPR system. This is the second interim report of a series that covers tests performed in the 242-B Single Pass Flow Facility. The first was distributed in January, 1960.