Investigation on the heat resistance of neutron shielding materials for reactor cavity

Abstract

BackgroundHigh temperature neutron shielding of the reactor cavity in the third generation nuclear power plant requires a high temperature resistant shielding material, but there is no suitable material that meets the design requirements in the market.PurposeThis study aims to develop a high temperature resistant neutron shielding material for the needs of nuclear engineering, and investigate its heat resistance.MethodsFirst of all, high temperature resistant phenyl silicone resin and phenyl hydrogen silicone oil were used as matrix materials, and boron carbide powder was taken as neutron absorber. A high temperature neutron shielding composite was prepared by the matrix materials and boron carbide powder. Then, the heat resistance of the composite and the effect of different phenyl content were investigated in details. The thermal weight loss and off-gases mechanisms of the neutron shielding material were studied by thermogravimetric analysis combined with gas chromatography and mass spectrometry (TGA-GCMS) method. The long-term thermal aging behavior of the materials was explored by thermal aging oven, and the outgassing environment of the material was measured at ~500 ℃.ResultsThermo gravimetric analysis (TGA) results show that the thermal weight loss of the composite decreased gradually with the increase of phenyl content, and the 5% weight lost decomposition point is at the high temperature of 487 ℃. After 500 h thermal aging at 300 ℃, the total weight loss of the composite is less than 10%.ConclusionThe shielding material prepared and tested in this study has good thermal resistance and stability. It provides a kind of neutron shielding material with excellent heat resistance for nuclear energy and other radiation shielding fields, and is expected to be further applied in engineering.

Keywords

• neutron shielding material
• high temperature resistance
• reactor cavity
• phenyl silicone resin