Explanation

A ternary alloy of silver, indium and cadmium. neutron absorbing material. Hafnium is a very effective control materials, but it is very expensive. silver-indium-cadmium alloy was developed as a substitute for hafnium. The control efficiency of silver -15% indium -5% cadmium is equivalent to that of hafnium, and it is widely used in the control of pressurized water reactors. Physically, the control materials should have high neutron absorption performance, and change as little as possible during its life. The thermal neutron absorption cross section of cadmium is very large, and the absorption cross section of its daughter is very small, so the burning loss is very fast. The thermal neutron absorption cross-sections of silver and cadmium are not large, but they have strong resonance absorption peaks in the superheat neutron region, and these absorption peaks do not overlap. This compensates for the low absorption capacity of cadmium for epithermal neutrons, and the complementary effect of the three elements gives it the same control ability as hafnium. The addition of indium improves the corrosion resistance of silver cadmium alloy. The determination of composition shall not only consider the manufacturing process, but also the composition change caused by nuclear transformation, such as silver transformation to cadmium, and indium transformation to tin. In addition, the selection of alloy composition should also take into account the mechanical strength and processing properties. Silver -15% Indium -5% Cadmium alloy has high thermal conductivity and is insensitive to temperature inhomogeneity caused by reactor power distribution inhomogeneity.

Classification