Year
2003
Abstract
A radiation probe system composed of two PM tubes, two passive fiber cables(PFC) and one optical fiber scintillator(OFS) was designed to be used for in spent fuel verification. We initially designed the OFS/PFC1/PMT1 system, in which the OFS emits light by radiation interaction and the PFC1 conveys the light to the PM tube which converts the light to an electric current, to measure the radiation intensity in the local area. However in a high radiation field, such as a spent fuel storage area, PFC also generates unnegligible light which has to be corrected for accurate measurement. In order to eliminate the PFC signal, a second compensating PFC(PFC2) was connected to a second PM tube(PMT2), and the PFC2/PMT2 was parallely positioned in the first OFS/PFC1/PMT1 system. By subtracting the PFC2/PMT2 current from the OFS/PFC1/PMT1 current, an accurate radiation measurement in local area could be achieved. The measured current from the optical fiber radiation probe system shows good linearity with a gamma dose rate and a neutron flux. Due to the thin and flexible structure, and good radiation hardness, the optical fiber radiation probe system is recommended for use as a spent fuel verifying system.