球床模块式高温气冷堆中的炭材料

摘要

Compared with the long use of carbon materials in human history,the debut of carbon materials in the Chicago Pile-1 nuclear reactor took place only 70 years ago. Since then,carbon materials have played important roles in nuclear reactors,especially in high temperature gas-cooled reactors (HTRs) because of their many excellent properties. As the most promising candidate for Generation Ⅳ reactors,a demonstration plant for HTRs,an HTR pebble-bed module(HTR-PM) is currently under construction in China. In the HTR-PM,carbon materials act as the core structural material,reflector,fuel matrix,moderator,and thermal and neu-tron shields. Because the dimensions and properties of the carbon are generally influenced by the high temperature and neutron irradi-ation in the HTR-PM,there are rigorous requirements for their performance. Since the precursor materials such as cokes and natural graphite,and the subsequent forming method play a critical role in determining the structure,properties and performance of the ma-terial under irradiation,a judicious selection of the raw materials and forming method is required to obtain the desired structure and properties. This paper introduces the detailed property requirements of different carbon materials in the HTR-PM and their fabrication processes. In addition,the current status and future commercialization of the HTR-PM in China and abroad are presented. In order to meet the requirement of full local production in a commercial HTR, long-term considerations such as the sustainable and stable supply of the raw materials, optimization of the manufacturing process in the local production of nuclear graphite for structural graphite and graphite pebbles, and the stable production and reduced cost of the precursor materials are discussed. Finally, current progress and future arrangements for the irradiation testing of Chinese nuclear graphite at the Oak Ridge National Laboratory(USA) are presented. This manuscript is intended to act as a reference for carbon material producers who intend to develop nuclear graphite and carbon materials for use in future commercial HTRs. Meanwhile,a great deal of information introduced in the manuscript is also useful for scientific researchers of carbon materials.%与人类使用炭材料的悠久历史相比,炭材料在核反应堆的首秀却只是发生在70多年前.凭借其优良的综合性能,炭材料在核反应堆特别是高温气冷堆(HTR)中发挥了重要作用.作为第四代核反应堆候选堆型中最有希望的代表,中国的球床模块式高温气冷堆(HTR-PM)目前正在建设中.在HTR-PM中,炭材料扮演着堆芯结构材料、反射层、燃料基体、慢化剂、热和中子屏蔽材料等多重角色.由于炭材料的尺寸和性能受高温和中子辐照的影响,因此对于在HTR-PM中使用的炭材料的各项性能都有着严格的要求.本文详细介绍了HTR-PM中各种炭材料的性能及其制造工艺的要求,并简要介绍了HTR-PM当前的现状和未来的商业化发展.此外为满足未来高温气冷堆商用核电站的全面国产化需求,对生产核级石墨和石墨粉的主要原材料如焦炭和天然鳞片石墨未来的长期稳定供应进行了展望.最后简要介绍了目前正在美国橡树岭国家实验室入堆进行辐照试验的国产核级石墨的现状和未来的辐照试验计划.本文旨在为有志于研发用于未来商用高温气冷堆核电站中的炭材料的生产厂家提供参考,文中提及的大量信息对于炭材料的科研人员也很有借鉴意义.