Effect of Gd on neutron absorption properties and electrochemical corrosion behavior of Zr-Gd alloy in boiling concentrated HNO3  

作　　者：Cheng-Jie Du Xiao-Gang Hu Ping-Yi Guo Xiao-Long Pan Jin-Ping Wu 

机构地区：[1]School of Materials Science and Engineering,Jiangsu University of Science and Technology,Zhenjiang 212100,China [2]Xi’an Rare Metal Materials Institute Co.,Ltd,Xi’an 710016,China

出　　处：《Nuclear Science and Techniques》2023年第3期40-51,共12页核技术（英文）

基　　金：supported by the National Natural Science Foundation of China (Nos.52201021 and 52101099);Key Research and Development Program of Shaanxi (2021GY-249,2021GY-233);Natural Science Basic Research Program of Shaanxi (No.2020JC-50);Shaanxi Provincial Natural Science Youth Foundation (2022JQ-410).

摘　　要：A Zr-Gd alloy with neutron poisoning properties and resistance to boiling concentrated HNO3 corrosion was developed based on a corrosion-resistant Zr-702 alloy to meet the demand for neutron shielding in the closed-loop treatment of spent fuel and the nuclear chemical industry.In this study,1 wt.%,3 wt.%,5 wt.%,7 wt.%,and 9 wt.%Zr-Gd alloys were designed and fabricated with Zr-702 as the control element.The electrochemical behavior of the Zr-Gd alloys in boiling concentrated HNO3 was investigated,and the neutron shielding effect on plate thickness and Gd content was simulated.The experimental results demonstrate that the corrosion resistance of the alloy decreased slightly before~7-9 wt.%with increasing Gd content;this is the inflection point of its corrosion resistance.The alloy uniformly dissolved the Gd content that could not be dissolved in the Zr lattice,resulting in numerous micropores on the passivation coating,which deteriorated and accelerated the corrosion rate.The MCNP simulation demonstrated that when the Gd content was increased to 5 wt.%,a 2-mm-thick plate can shield 99.9%neutrons;an alloy with a Gd content≥7 wt.%required only a 1-mm-thick plate,thereby showing that the addition of Gd provides an excellent neutron poisoning effect.Thus,the corrosion resistance and neutron shielding performance of the Zr-Gd alloy can meet the harsh service requirements of the nuclear industry.

关 键 词：Zr-Gd alloy Boiling concentrated HNO3 Electrochemistry Neutron shielding MCNP 

分 类 号：TG146.414[一般工业技术—材料科学与工程] TL24[金属学及工艺—金属材料]