XXXX measurements in a pilot-scale poison tank using radiotracer technique.

@entity9725 @entity5497 @entity1054 @entity27742
UNASSIGNED: Various types of systems are used to control the reactivity and shutting down of a nuclear reactor during emergency and routine shutdown operations. Injection of @entity9725 solution (borated water) into the core of a reactor is one of the commonly used methods during emergency operation. A pilot-scale poison tank was designed and fabricated to simulate injection of @entity9725 poison into the core of a reactor along with coolant water. In order to design a full-scale poison tank, it was desired to characterize flow of liquid from the tank. @entity1054 ( @entity27742 ) measurement and analysis was adopted to characterize the flow dynamics. Radiotracer technique was applied to measure @entity27742 of aqueous phase in the tank using @entity5497 -82 as a radiotracer. @entity27742 measurements were carried out with two different modes of operation of the tank and at different flow rates. In Mode-1, the radiotracer was instantaneously injected at the inlet and monitored at the outlet, whereas in Mode-2, the tank was filled with radiotracer and its concentration was measured at the outlet. From the measured @entity27742 curves, mean residence times (MRTs), dead volume and fraction of liquid pumped in with time were determined. The treated @entity27742 curves were modeled using suitable mathematical models. An axial dispersion model with high degree of backmixing was found suitable to describe flow when operated in Mode-1, whereas a tanks-in-series model with backmixing was found suitable to describe flow of the poison in the tank when operated in Mode-2. The results were utilized to scale-up and design a full-scale poison tank for a nuclear reactor.
