DEVELOPMENT OF THE UNDER-WATER BURNUP MEASURING SYSTEM FOR A SPENT PWR FUEL ASSEMBLY

摘要

The under-water burnup measuring system was developed at KAERI to determine the burnup profile of spent nuclear fuel assembly. It is important to provide useful data for the critical safety analysis and the safeguard of an advanced spent fuel management process. The measuring system consists of the HPGe gamma-ray detector, collimators, down tube and electronic equipment. In this study, the burnup of a spent nuclear fuel assembly discharged from Nuclear Power Plant in Korea was determined and the results were verified by the chemically determined burnup. As a result, nondestructively determined burnup values showed a good agreement with the chemically obtained results within 6 % error. And a cooling system of HPGe detector was modified for solving the problem of LN_2 supply in the pool area.