Higher operating levels in the 100 Area piles have caused alarming increases in pile effluent activity and pressure drop through the process tubes. Projected additional increases in power level may not be possible unless the problems of film formation and pile effluent activity are overcome. Although a solution to these problems is not the responsibility of the Power Division, we do not have an interest in seeing that any proposed solution meets the test of operational practicability. Consequently, this was written in order that pertinent water treatment information may be readily available.