Penn State University TRIGA Reactor Digital Reactivity Computer: Development and Testing

A digital control rod reactivity computer (DRC) has been developed using commercially available software (National Instruments LabView) for use to determine control rod worth curves for the Penn State University TRIGA research reactor. For low-worth reactivity steps, use of the prompt-jump approximation to the point kinetics equations enabled rapid calculation of rod reactivity insertions and minimized measurement noise effects. In contrast, use of the In-Hour method (an historically-effective way of determining control rod reactivity) would take several hours, compared to 30 min with the DRC for a complete control rod worth curve. All of the data acquisition, reactivity calculations, and integral control rod worth curve fitting are performed in LabView, which additionally provides for development of the graphical user interface. Results demonstrate the LabView DRC developed provides a platform for these measurements that calculates accurate control rod reactivity measurements in significantly less time than the historically accepted In-Hour method.