Safety quality classification test of the sealed neutron sources used in start-up neutron source rods for Qinshan Nuclear Power Plant

According to the regulations listed in the GB4075, the safety quality classification tests have been carried out for the neutron sources. The test items include temperature, external pressure, impact, vibration and puncture, Two dummy sealed sources are used for each test item. The testing equipment used have been examined and verified to be qualified by the measuring department which is admitted by the National standard Bureau. The leak rate of each tested sample is measured by UL-100 Helium Leak Detector (its minimum detectable leak rate is 1 x 10-10Pa·m3·s-1). The samples with leak rate less than 1.33 x 10-8 Pa·m3·s-1 are considered up to the standard. The test results show the safety quality classification class of the neutron sources have reached the class of GB/E66545 which exceeds the preset class