Development and test of spent fuel verification system using a scintillating glass fiber

Spent fuel verification by non-destructive assay has been implemented for safeguards purpose using various radiation detectors such as a gas type detector, a semiconductor detector and so on. However, due to the severe circumstance of spent fuel storage such as high temperature, high radiation intensity and difficult to access area, the applicable radiation detectors and measurement techniques are restricted. A scintillating glass fiber has been known to have a good radiation hardness and physical properties for high temperature and humidity. In order to verify spent fuels stored in difficult to access area, we designed a spent fuel verification equipment using a scintillating glass fiber. Gamma and neutron sensitivity were tested to optimize the measurement system. The field test was performed at Wolsung NPP (nuclear power plant) pond storage area. The measurement result was compared to the simulation result using MCNP and ORIGEN-ARP codes. From the comparison result, it was known that a SGF verification system can be used as a spent fuel bundle identifier as well as in item counting.