THE DIFFERENTIAL METHOD TO MEASURE ONLY NEUTRON DOSE IN THE MIXED RADIATION FIELDS WITH NEUTRON AND GAMMA RADIATIONS

摘要

PURPOSE: A differential method for measuring only neutron dose in neutron and gamma mixed radiation field is provided to evaluate the combustion degree of nuclear fuel assembly after usage by dividing and simultaneously measuring the neutron dose and the gamma dose emitted from the surface of nuclear fuel assembly after usage and from an operating nuclear furnace and then by measuring only neutron. CONSTITUTION: A system for measuring neutron dose comprises a radiation measuring sensor(100), a pair of cables(200), a photoelectric converter(300), and a microprocessor(400). The radiation measuring sensor comprises a neutron measuring sensor(110) which absorbs and generates neutron, and a gamma-ray measuring sensor(120) which measures gamma-ray and generates visible ray. The cables are respectively connected to the neutron measuring sensor and the gamma-ray measuring sensor and transmit the visible rays generated from respective measuring sensor. The photoelectric converter changes the visible rays transmitted through the cables into electric signals. After the microprocessor obtains the neutron dose and gamma does from the electric signals and calculates the total dose, it calculates the neutron dose by subtracting the gamma dose from the total dose.