| 摘要: |
| 目的 防止乏燃料包壳与容器的性能退化，需在乏燃料装入贮运容器之后，执行干燥除湿程序，并回填氦气以构建惰性气体环境，故深入探讨了乏燃料贮运容器干燥技术相关的关键问题。方法 通过规范调研确定容器干燥准则，按非结合态水和结合态水2个类别估算残余水量，基于残余水自身及其分解产物研究其对贮运安全性的影响，并分析真空干燥系统以及强制氦循环干燥系统2种主要干燥系统的特点。结果 在干燥过程中，容器须遵循包壳温度控制准则和最终干燥度准则;残余水以未结合态和结合态2种形态存在，其残余量的估算值分别约为50 mL和18 mL~1.8 L。残余水可能通过包壳氧化、芯块氧化、包壳吸氢、可燃气体产生、水性腐蚀等机制对乏燃料贮运安全性产生影响。真空干燥系统由于结冰和热工安全性，其干燥效率受到限制;而强制氦循环干燥系统消除了容器及管路中冰形成的可能，通过强制对流热传递保持乏燃料处于较低温度。结论 强制氦循环干燥系统可缩短干燥时间，减少职业辐照剂量，可靠保障乏燃料热工安全，在高燃耗乏燃料贮运场景中更具优势。 |
| 关键词: 残余水 包壳温度 干燥度 强制氦循环 |
| DOI：10.19554/j.cnki.1001-3563.2025.07.028 |
| 分类号: |
| 基金项目:国家电力投资集团有限公司科研项目(KY-B1-2020-HN-05) |
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| Dry Technology for Spent Fuel Transport and Storage Containers |
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WENG Chenyang, HUANG Shangqing, LIAO Jiaqi, SHAO Changlei, LIU Yongjun, LI Lei
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(Shanghai Nuclear Engineering Research and Design Institute Co., Ltd., Shanghai 200233, China)
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| Abstract: |
| After the spent fuel is loaded into the storage container, the drying and dehumidification procedure must be performed and the helium gas should be backfilled to build an inert gas environment, to prevent the performance degradation of the fuel cladding and container, so the work aims to discuss the key issues related to the drying technology of the spent fuel storage container. The drying criteria of the container were determined through standard research, the residual water quantity was estimated according to the two categories of the unbound water and the bound water, and the effect of the residual water and its decomposition products on the storage and transport safety was studied, and the characteristics of vacuum drying and forced helium circulating drying systems were analyzed. In the drying process, the container must follow the cladding temperature limit and dryness criteria. The residual water existed in both unbound and bound states, and the estimated residual value was about 50 mL and 18 mL to 1.8 L respectively. Residual water might affect the safety of storage and transport of spent fuel through mechanisms such as cladding oxidation, fuel pellet oxidation, cladding hydrogen absorption, combustible gas generation and aqueous corrosion. The drying efficiency of the vacuum drying system was limited due to the icing and thermal safety problems. The forced helium cycle drying system eliminated the possibility of ice formation in the container and pipeline, and kept the spent fuel at a low temperature by forced convective heat transfer. The forced helium cycle drying system can shorten the drying time, reduce the occupational radiation dose, reliably guarantee the safety of fuel heat, and have more advantages in the storage and transport scenario of high burning fuel. |
| Key words: residual water cladding temperature dryness forced helium cycle |
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