Safe-to-fail: Accident-tolerant fuel cladding

安全无故障：容灾燃料包壳

• 批准号: 580476-2022
• 负责人: Noel, JamesJJ
• 金额: $ 8.74万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Alliance Grants
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=747574
• 关键词: Safe; fail; Accident; tolerant; fuel

Conventional water-cooled nuclear reactors, including the current fleet of CANDU reactors and the small modular reactor (SMR) planned for construction at the Darlington nuclear power plant site, use uranium oxide fuel that is clad in protective tubes of a zirconium-tin alloy called Zircaloy. However, during a severe loss-of-coolant accident (LOCA) in a reactor, the reaction of the Zircaloy with high-temperature steam can generate large volumes of hydrogen, a gas that is explosive when mixed with air. Such a scenario previously played out during the Fukushima-Daiichi reactor accident in 2011, resulting in multiple hydrogen explosions. A variety of "accident tolerant fuel" (ATF) concepts have been explored to help decrease or eliminate the risk of cladding-steam reactions leading to hydrogen explosions under severe LOCA conditions. Much of this research has focused on either applying a protective coating to the Zircaloy to decrease its reactivity with steam under severe LOCA conditions or replacing Zircaloy with a material that would not react so dangerously during an accident. Unfortunately, the current suite of coatings and replacements are not durable enough to withstand a LOCA without significant degradation. Since Canada is now preparing to build new SMRs, there is considerable value in building expertise in ATF cladding to match that of other leading countries, such as the USA, France, and China. This knowledge will be particularly valuable for government decision-making and regulatory oversight and licensing of SMR construction and operation. The European Parliament has recently mandated that all reactors implement ATFs approved by their respective country's regulators in order to qualify as "green energy" sources. Implementing such policy and regulatory decisions in Canada will require a robust domestic understanding of the various factors related to ATF cladding performance, established by studying existing ATF cladding concepts and developing novel Canadian solutions. This research program aims to develop novel ATF claddings and to perform fundamental studies on existing ATF cladding concepts meant to eliminate the potential for hydrogen explosions during a severe LOCA.

传统的水冷核反应堆，包括目前的 CANDU 反应堆和计划在达灵顿核电站建设的小型模块化反应堆 (SMR)，使用氧化铀燃料，该燃料包覆在称为“锆锡合金”的保护管中。锆合金。然而，在反应堆发生严重冷却剂损失事故 (LOCA) 时，Zircaloy 与高温蒸汽的反应会产生大量氢气，这种气体与空气混合时会发生爆炸。这种情况此前曾在2011年福岛第一核反应堆事故中上演过，导致多次氢气爆炸。人们已经探索了各种“事故容错燃料”（ATF）概念，以帮助减少或消除在严重 LOCA 条件下导致氢气爆炸的包壳蒸汽反应的风险。这项研究的大部分重点是在锆合金上应用保护涂层，以降低其在严重 LOCA 条件下与蒸汽的反应性，或者用在事故中不会发生如此危险反应的材料替代锆合金。不幸的是，目前的涂层和替代品套件不够耐用，无法承受失水事故而不发生明显退化。由于加拿大目前正准备建造新的中小型反应堆，因此建立 ATF 包壳方面的专业知识以与美国、法国和中国等其他领先国家相媲美具有相当大的价值。这些知识对于政府决策、监管以及中小型反应堆建设和运营的许可特别有价值。欧洲议会最近强制要求所有反应堆均执行各自国家监管机构批准的 ATF，以获得“绿色能源”来源的资格。在加拿大实施此类政策和监管决定需要通过研究现有的 ATF 包层概念和开发新颖的加拿大解决方案，对与 ATF 包层性能相关的各种因素有深入的了解。该研究计划旨在开发新型 ATF 包壳，并对现有 ATF 包壳概念进行基础研究，旨在消除严重 LOCA 期间发生氢气爆炸的可能性。