This is the second article on the Risk Analysis Screening Tool (RAST). Part I provides an overview of the RAST software and how it can be used when performing a Hazards Identification and Risk Analysis. This article will focus on one piece of equipment: an ammonia storage tank located within a densely populated university campus. For the storage tank, the relief valve vents outdoors at the height of a two‐story building with its release modeled as an outdoor release. The potential failure scenarios proposed by the RAST software confirmed the scenarios generated by the Process Hazards Analysis team. RAST can be used using minimum required inputs and general assumptions and default values within the software. The results are presented in this article along with an additional, similar case study on chlorine. The risk matrix and risk summary tabs give a visual presentation of whether the failure scenarios found by RAST are within an acceptable, tolerable risk. The user or company running the study may change the desired target frequency factor then work to achieve those figures through implementation of protective layers.

中文翻译：

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风险分析筛选工具 (RAST)：第二部分，使用 RAST 评估氨​​的释放

这是关于风险分析筛选工具 (RAST) 的第二篇文章。第 I 部分概述了 RAST 软件以及在执行危害识别和风险分析时如何使用它。本文将重点介绍一种设备：位于人口稠密的大学校园内的氨储罐。对于储罐，泄压阀在两层楼高的室外泄放，其泄放建模为室外泄放。RAST 软件提出的潜在故障场景证实了过程危害分析团队生成的场景。RAST 可以使用软件中所需的最少输入和一般假设以及默认值。本文中介绍了结果以及关于氯的其他类似案例研究。风险矩阵和风险摘要选项卡直观地显示了 RAST 发现的故障场景是否在可接受的、可容忍的风险范围内。运行研究的用户或公司可以更改所需的目标频率因子，然后通过实施保护层来努力实现这些数字。