Acknowledgment

The sodium ion electrode can also be used to indicate steam entrainment in the extraction samples. Starting with a low flow, the voltage indicated by the ion analyzer is noted. The sample flow rate is then increased, while monitoring the ion analyzer. The voltage will remain constant as long as only water is being sampled. A change in voltage indicates steam entrainment, and the sample flow rate should be decreased. From this discussion it can be seen that completely adequate instrumentation is available for implementation of the sodium tracer technique. I t should be noted that the high-quality spectrophotometer is not an uncommon instrument, since it is found in most PWR plants. Summary The ease and practicability of using nonradioactive sodium as a tracer in testing saturated steam turbine-generators in PWR cycles has been demonstrated. The ability to obtain a series of consistent samples has been demonstrated. The suitability of modern flame spectrophotometers for determination of sodium content has been proven. New ways of using a tracer to deter-mine moisture relationships within the turbine cycle have been identified. The authors intend to pursue other applications of the sodium tracer method and ultimately to conduct a fullscale test in ac-cordance with the new ASME Interim Code