The CRANK System—A Simple, Robust Apparatus for Measurement of Cherenkov Light at Open-Pool Reactor

Abstract

Recently, techniques for qualitative inspections of spent fuel using Cherenkov light have advanced the International Atomic Energy Agency’s ability to perform defect verification measurements following discharge of the fuel from the reactor. Unfortunately, these measurements are limited in their value for safeguards and nuclear material accountancy since they do not quantify the fissile material quantities and cannot characterize a reactor during operations. The Cherenkov Radiation Assay for Nuclear Kinetics (CRANK) system has been devised to quantify the fissile material in the Oregon State TRIGA Reactor (OSTR) during two or more reactor pulses through the measurement of Cherenkov light. The results from the OSTR experiments have shown that the CRANK system is capable of determining the ratio of reactor kinetics parameters (RKP) through the measurement of Cherenkov light in an assay of a research reactor capable of pulsing. There exists excellent agreement between the declared value of the RKP ratio in the OSTR Final Safety Analysis Report and four separate reactor pulse comparisons using the CRANK system. Future applications of the CRANK system can provide independent determination of a pulsing research reactor with an unknown RKP ratio.

Keywords:

• Reactor kinetics
• pulse
• Cherenkov light
• CRANK system, safeguards

Acknowledgments

The authors would like to thank the reviewers for their insightful comments and the OSTR reactor staff for their advice and assistance in accomplishing this work.