Neutron CT technique was applied to the quantitative measurement of the key parameters of nuclear fuel rods at China Advanced Research Reactor(CARR).The sample of dummy nuclear fuel rod was rotated in 180°range,and 900neutron projections were obtained.The 3-D neutron Neutron CT technique was applied to the quantitative measurement of the key parameters of nuclear fuel rods at China Advanced Research Reactor (CARR). The sample of dummy nuclear fuel rod was rotated in 180 ° range, and 900neutron projections were. The 3-D neutron