TY - GEN
T1 - Digital I&C system categorization method for use in informing nuclear power plant failure data analysis and risk analysis
AU - Arndt, S. A.
AU - Waterman, M. E.
PY - 2008
Y1 - 2008
N2 - The proliferation digital system in safety critical applications has lead to the need to model these systems, both qualitatively and quantitatively in formal evaluations including system risk analysis and deterministic evaluations. Nuclear power plants are in the process of replacing the existing analog instrumentation and control (I&C) systems with digital technology. This paper will discuss the development of a digital system categorization methodology that will be used for two primary proposes, first to provide input to digital system operational experience evaluation, and to support and inform development of on-going digital system regulatory guidance. This paper will review digital systems categorizations or classifications methods that have been developed in the past to look at digital system design methods, based on both function design and intended use. A three-attribute categorization strategy will be described in the paper that can be used for classifying digital safety systems. The first attribute, digital system complexity, would be based on the amount and complexity of internal interactions and an overall digital system size and complexity index. The second attribute, digital system interactions/inter-conductivity, on the amount and type of coupling of the system has with the process it is interactive with. The attribute measure would be with how the digital system under study interacts with other systems and process parameters within the plant and how important accurately assessing these interactions are to the system safety. The third attribute would be digital system importance. This attribute measure would look at both traditional risk important measures, such as component risk achievement worth, and how important the system is for maintaining defense-in-depth concepts.
AB - The proliferation digital system in safety critical applications has lead to the need to model these systems, both qualitatively and quantitatively in formal evaluations including system risk analysis and deterministic evaluations. Nuclear power plants are in the process of replacing the existing analog instrumentation and control (I&C) systems with digital technology. This paper will discuss the development of a digital system categorization methodology that will be used for two primary proposes, first to provide input to digital system operational experience evaluation, and to support and inform development of on-going digital system regulatory guidance. This paper will review digital systems categorizations or classifications methods that have been developed in the past to look at digital system design methods, based on both function design and intended use. A three-attribute categorization strategy will be described in the paper that can be used for classifying digital safety systems. The first attribute, digital system complexity, would be based on the amount and complexity of internal interactions and an overall digital system size and complexity index. The second attribute, digital system interactions/inter-conductivity, on the amount and type of coupling of the system has with the process it is interactive with. The attribute measure would be with how the digital system under study interacts with other systems and process parameters within the plant and how important accurately assessing these interactions are to the system safety. The third attribute would be digital system importance. This attribute measure would look at both traditional risk important measures, such as component risk achievement worth, and how important the system is for maintaining defense-in-depth concepts.
KW - Categorization
KW - Digital systems
KW - Probabilistic risk assessment
UR - http://www.scopus.com/inward/record.url?scp=84876492831&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:84876492831
SN - 9781622765775
T3 - 9th International Conference on Probabilistic Safety Assessment and Management 2008, PSAM 2008
SP - 1041
EP - 1046
BT - 9th International Conference on Probabilistic Safety Assessment and Management 2008, PSAM 2008
T2 - 9th International Conference on Probabilistic Safety Assessment and Management 2008, PSAM 2008
Y2 - 18 May 2008 through 23 May 2008
ER -