Sealed-source applications

Abstract

Previous chapters have served to demonstrate the versatility of radioactive tracer techniques in investigating a wide range of plant problems. Case histories have amply demonstrated that in many situations the use of a tracer is not only the best solution but the only solution. However, useful as they are, radiotracer techniques suffer from one significant disadvantage: by definition, radioactive materials are injected into the plant and therefore become dispersed in the process material. In other words the process material becomes mildly contaminated with radioactive material. Of course, by careful choice of a tracer with short half-life, by exercising judgement over the amount of tracer injected and by ensuring that the radioactive material is diluted by the vastly greater volume of process material, the level of contamination, and therefore, the hazard, can be made negligibly small (Chapter 7). Nevertheless, each radiotracer investigation requires detailed prior planning. The logistics of carrying out the measurement need careful consideration and, additionally, one must invariably satisfy national or local environmental authorities that the proposed work is safe.