注锌对燃料包壳表面污垢沉积及硼析出的影响研究  

Effect of zinc injection on crud deposition and boron precipitation on fuel cladding surface

作　　者：廖家鹏 毛玉龙 阮天鸣 胡友森 金德升 厉井钢 陈忠村 LIAO Jiapeng;MAO Yulong;RUAN Tianming;HU Yousen;JIN Desheng;LI Jinggang;CHEN Zhongcun(China Nuclear Power Technology Research Institute Co,Ltd.,Shenzhen 518000,China)

机构地区：[1]中广核研究院有限公司,深圳518000

出　　处：《核技术》2023年第3期95-101,共7页Nuclear Techniques

基　　金：中国博士后科学基金面上项目(No.2021M703023);国家自然科学基金面上项目(No.52171085)资助。

摘　　要：反应堆一回路腐蚀产物在燃料包壳表面过冷泡核沸腾的作用下沉积于包壳表面,形成燃料污垢。一回路注锌被认为是抑制燃料包壳表面污垢沉积的重要途径之一。本文通过开展国产锆合金燃料包壳在不同锌浓度下的污垢沉积试验,研究在模拟核电站高温高压水环境中注锌对污垢沉积行为的影响,得到污垢沉积的锌浓度敏感性结果。冷却剂中的锌浓度越高,燃料包壳表面的烟囱状结构越不明显,污垢表面越平整,污垢沉积厚度越小,污垢内部镍铁比降低,硼析出量越少。当锌浓度增加至100μg·L^(-1),污垢内部有少量含锌物相析出。结果表明:当锌浓度在0~100μg·L^(-1)范围内时,一回路注锌能够显著抑制燃料包壳表面的污垢沉积。[Background]Under the condition of sub-cooled nucleate boiling(SNB),corrosion products in primary coolant of nuclear reactor will deposit on the outer surface of fuel cladding,which is commonly called fuel crud.Previous literature shown,zinc injection in primary coolant is an important method to inhibit the fuel crud deposition on the fuel cladding surface.[Purpose]This study aims to investigate the influence of zinc concentration on the behavior of fuel crud deposition,and eventually provide guidance for zinc injection in primary coolant of nuclear power plant.[Methods]The fuel crud deposition tests of domestic zirconium alloy fuel cladding in different zinc concentrations were carried out by using a self-made fuel crud deposition device.Tubular crud deposition test specimen with built-in heating unit was designed and prepared for simulation study.After the tests,stereo microscope(SM)and scanning electron microscope(SEM)were employed to observe the macro and micro morphology of fuel crud whilst the composition of of fuel crud was observed and analyzed by the energy dispersive spectroscopy(EDS)with SEM,and X-ray photoelectron spectroscopy(XPS)was used to analyze the contents of Zn and B elements in the crud phase and inside the crud.[Results]Observation results show that the chimney-like crud formed on the fuel cladding surface becomes less obvious with increasing the zinc concentration in the coolant and the crud surface becomes flatter.Simutabeously,the crud thickness,the ratio of Ni/Fe and the boron precipitation mass within the crud are decreasing with increase of the zinc concentration.When the zinc concentration increases to 100μg‧L^(−1),new Zn containing phases precipitate within the crud.[Conclusions]Within the zinc concentration of 0~100μg‧L^(−1),zinc injection in primary coolant of reactor can significantly inhibit the crud deposition on the fuel cladding surface.

关 键 词：压水堆 燃料包壳 污垢沉积 硼析出 注锌 

分 类 号：TL341[核科学技术—核技术及应用]