A Strategic Approach to Employ Risk-Informed Methods to Enable Margin Recovery of Nuclear Power Plants Operating Margins

Zhang, Hongbin; Szilard, Ronaldo; Hess, Stephen; Sugrue, Rosemary M

doi:10.2172/1514992

Cited by 6 publications

(4 citation statements)

References 9 publications

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“…The PRA results from the previous reliability analyses are supposed to provide different risk-significant accident scenarios for the multi-physics best-estimate plus uncertainty analysis. The capability has been built by different platforms such as the INL-developed LOTUS [88] and RAVEN [18] [19] .…”

Section: Integrated Risk Assessment Strategy For Digital Iandc Systemsmentioning

confidence: 99%

Uncertainty quantification and software risk analysis for digital twins in the nearly autonomous management and control systems: A review

Lin

Bao

Dinh

2021

Annals of Nuclear Energy

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Section: Integrated Risk Assessment Strategy For Digital Iandc Systemsmentioning

confidence: 99%

Uncertainty quantification and software risk analysis for digital twins in the nearly autonomous management and control systems: A review

Lin

Bao

Dinh

2021

Annals of Nuclear Energy

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Section: Risk Assessment Process For Diandc Systemsmentioning

confidence: 99%

Integrated Risk Assessment of Digital I&C Safety Systems for Nuclear Power Plants

Zhang¹,

Han²,

Shorthill³

et al. 2021

12th Nuclear Plant Instrumentation, Control and Human-Machine Interface Technologies (NPIC&HMIT 2021)

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Upgrading the existing analog instrumentation and control (I&C) systems to state-of-the-art digital I&C (DI&C) systems provides the foremost means to improve performance and reduce costs for existing light-water reactors (LWRs). However, qualification of digital technologies remains a challenge-especially the issue of software common cause failure (CCF), which has been difficult to address. Existing analyses of CCFs in I&C systems mainly focus on hardware failures. With the application and upgrading of new DI&C systems, design flaws could cause software CCFs to become a potential threat to plant safety, considering that most redundancy designs use similar digital platforms or software in their operating and application systems. With complex multi-layer redundancy designs to meet the single failure criterion, these I&C safety systems are of particular concern in U.S. Nuclear Regulatory Commission (NRC) licensing procedures. In 2019, the Risk-Informed Systems Analysis (RISA) Pathway of the U.S. Department of Energy's (DOE's) Light Water Reactor Sustainability (LWRS) Program initiated a project to develop a risk assessment strategy for delivering a strong technical basis to support effective, licensable, secure DI&C technologies for digital upgrades and designs. An integrated risk assessment for the DI&C (RADIC) process was proposed for this strategy to identify potential key digital-induced failures, implement reliability analyses of related digital safety I&C systems, and evaluate the unanalyzed sequences introduced by these failures (particularly software CCFs) at the plant level. This paper summarizes these RISA efforts in the risk analysis of safety-related DI&C systems at Idaho National Laboratory.

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“…It is noted that the term "safety margin" is used to ensure that the SSCs in an NPP can perform their intended functions under both normal and abnormal operating conditions [46]. The application of safety margins compensates for uncertainties in the phenomena and model data, as well as variability in the initial and boundary conditions associated with the analysis of events that can impact plant safety.…”

Section: Consequence Analysis Approaches 34mentioning

confidence: 99%

“…In addition, by providing a probabilistic evaluation, the results can be used to prioritize analyses to concentrate on those that have the highest likelihood of resulting in undesired consequences; thus, ensuring efficient use of resources. Therefore, in [46], a Risk-Informed Multi-Physics Best Estimate Plus Uncertainty (RI-MP-BEPU) framework was proposed to conduct comprehensive investigations of design basis requirements and their implementation through plant processes and systems (i.e., SSCs, maintenance, surveillance, testing, qualification and quality requirements of encompassed systems, technical specifications, limiting conditions of operations, etc.) to identify and recover margins associated with uncertainties and conservatisms of legacy licensing, design, and analysis.…”

Section: Consequence Analysis Approaches 34mentioning

confidence: 99%

An Integrated Risk Assessment Process for Digital Instrumentation and Control Upgrades of Nuclear Power Plants

Bao

Zhang

Thomas

2019

Self Cite

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Most of the existing nuclear power plants (NPPs) in the world rely on traditional analog instrumentation and control (I&C) systems for monitoring, control, and protection functions. With the industrial base largely moving to digital systems, the operation and maintenance of plants involves managing issues including lack of needed analog spare parts, increasing maintenance costs, and the loss of vendor support. Compared with existing analog I&C systems, digital I&C systems have significant functional advantages, such as reliable system performance in terms of accuracy and computational capability, high data handling and storage capabilities to fully measure and display operating conditions, and improved capabilities (e.g., fault tolerance, self-testing, signal validation, process system diagnostics). Therefore, the U.S. nuclear power industry has initiated the replacement of existing, aging analog systems with digital I&C technology, and is developing new designs for advanced plants using digital systems in integrated control rooms to provide modern control and protection systems. However, the qualification of digital I&C systems remains a challenge, especially the issue of software common cause failure (CCF), which has been difficult to address.Upgrading digital I&C (safety and non-safety-related) systems in existing NPPs within a cost-effective and regulatory acceptable way offers the foremost means of performance improvements and cost-reductions for existing NPPs. One key outcome of this project is to perform plant-specific risk assessment to provide a sustainable scientific support for enabling industry to balance the digital-related risks, costs, reliability, and safety.

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A Strategic Approach to Employ Risk-Informed Methods to Enable Margin Recovery of Nuclear Power Plants Operating Margins

Cited by 6 publications

References 9 publications

Uncertainty quantification and software risk analysis for digital twins in the nearly autonomous management and control systems: A review

Uncertainty quantification and software risk analysis for digital twins in the nearly autonomous management and control systems: A review

Integrated Risk Assessment of Digital I&C Safety Systems for Nuclear Power Plants

An Integrated Risk Assessment Process for Digital Instrumentation and Control Upgrades of Nuclear Power Plants

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