锆合金包壳二次氢化破损模拟方法研究  

Simulation method for secondary hydriding breakage of zirconium alloy cladding

作　　者：马雁[1] 张智鑫 陈嘉威 MA Yan;ZHANG Zhixin;CHEN Jiawei(North China Electric Power University,Beijing 102206,China)

机构地区：[1]华北电力大学,北京102206

出　　处：《核技术》2022年第4期67-73,共7页Nuclear Techniques

基　　金：国家科技重大专项(No.2019ZX06004009)资助。

摘　　要：压水堆燃料锆包壳管一旦出现破口,流入包壳内的水会在内外壁压差的作用下闪蒸为水蒸汽,在包壳管内壁引发锆水反应,使包壳管内壁由于大量吸氢而产生破损,称为二次氢脆。为了模拟压水堆一回路运行工况与锆包壳管的二次氢脆发生过程,通过理论强度计算与热工验证,自主设计锆合金包壳管二次氢脆实验堆外模拟装置,并针对ZIRLO合金包壳管开展双热源模拟实验。该装置实现了在一回路工况水平下的长期稳定运行,模拟结果显示ZIRLO合金管内外壁氧化并生成沿轴向自下而上浓度增加的氢化物。表明该装置解决了窄缝空间热分层现象带来的影响,可模拟包壳管二次氢脆过程中的一次破口失水、冷却水闪蒸及间隙蒸汽腐蚀行为,验证了该装置技术手段可行性。[Background] When the fuel zirconium cladding tube of pressurized water reactor(PWR) breaks, the water flowing into the cladding will flash into water vapor under the action of the pressure difference between the inner and outer surface. The inner surface of the tube is damaged due to a large amount of hydrogen absorption,which is known as secondary hydriding embrittlement. [Purpose] This study aims to simulate the operating conditions of the first circuit of a PWR and the occurrence of secondary hydrogen embrittlement in zirconium clad tubes. [Methods] Through theoretical strength calculations and thermal engineering verification, a Zirconium alloy clad tube secondary hydrogen embrittlement experimental off-heap simulator was independently designed and implemented. Then the dual heat source simulation experiments ware conducted for ZIRLO alloy clad tube. [Results]Unit operation and experimental results show that unit achieves long-term stable operation at the one-loop condition level, and the inner and outer walls of ZIRLO alloy tubes oxidize and generate hydrides with increasing concentration along the axial direction from the bottom up. [Conclusions] The off-heap simulator device of study solves the impact of thermal delamination in narrow seam space, and can simulate the water loss in primary breach, cooling water flash and interstitial steam corrosion behavior in the secondary hydrogen embrittlement process of the pressurized water reactor cladding tube, which verifies the feasibility of the technical means of the device.

关 键 词：锆包壳 二次氢脆 堆外模拟装置 氧化 氢化物 

分 类 号：TL99[核科学技术—核技术及应用]