ABSTRACT Proponents of high temperature gas cooled reactors argue that the reactor type is inherently safe and that severe accidents with core damage and radioactive releases cannot occur. The argument is primarily based on the safety features of the special form of the fuel. This paper examines some of the assumptions underlying the safety case for high temperature gas cooled reactors and highlights ways in which there could be fuel failure even during normal operations of the reactor; these failures serve to create a radioactive inventory that could be released under accident conditions. It then describes the severe accident scenarios that are the greatest challenge to high temperature gas cooled reactor safety: ingress of air or water into the core. Then, the paper offers an overview of what could be learned from the experiences with high temperature gas cooled reactors that have been built; their operating history indicates differences between actual operations and theoretical behavior. Finally, the paper describes some of the multiple priorities that often drive reactor design, and how safety is compromised in the process of optimizing other priorities.

中文翻译：

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涉及球床高温反应器的事故情景

摘要 高温气冷堆的支持者认为，这种反应堆类型本质上是安全的，不会发生堆芯损坏和放射性泄漏的严重事故。该论点主要基于特殊形式燃料的安全特性。本文审查了高温气冷反应堆安全案例的一些假设，并强调了即使在反应堆正常运行期间也可能出现燃料故障的方式；这些故障有助于产生可在事故条件下释放的放射性存量。然后描述了对高温气冷反应堆安全构成最大挑战的严重事故情景：空气或水进入堆芯。然后，该文件概述了可以从已建成的高温气冷反应堆的经验中学到的东西；它们的操作历史表明实际操作和理论行为之间存在差异。最后，本文描述了经常推动反应堆设计的多个优先事项中的一些，以及在优化其他优先事项的过程中如何损害安全性。