Transition from conventional analog technology to advanced digital technology is a global trend, and commercial and research reactors are increasingly using digital instrumentation and control (I&C) systems. However, common cause failures (CCFs) of the digital platform are significant issues. In this paper, we proposed a potential solution for such CCFs by implementing a digital hybrid model that combines two different platforms, programmable logic controller (PLC) and field programmable gate array (FPGA). PLCs have been used for decades, while FPGAs are comparatively new in nuclear safety-grade I&C systems. The digital hybrid model was compared with an analog model and individual digital models for each platform in terms of the results using fault tree analysis and generic failure rate database. The quantitative improvements of the proposed digital hybrid model were demonstrated for a reactor protection system.

从传统的模拟技术到先进的数字技术的过渡是全球趋势，并且商业和研究反应堆越来越多地使用数字仪器和控制（I＆C）系统。但是，数字平台的常见原因故障（CCF）是重大问题。在本文中，我们通过实现将两种不同平台（可编程逻辑控制器（PLC）和现场可编程门阵列（FPGA））相结合的数字混合模型，为此类CCF提出了一种潜在的解决方案。PLC已经使用了数十年，而FPGA在核安全级I＆C系统中相对较新。使用故障树分析和通用故障率数据库，根据结果将数字混合模型与模拟模型和各个平台的单个数字模型进行了比较。