TY - GEN
T1 - Development of regulatory guidance for risk-informing digital system reviews
AU - Arndt, Steven A.
PY - 2006
Y1 - 2006
N2 - In 1995, the U.S. Nuclear Regulatory Commission (NRC) issued the Probabilistic Risk Assessment (PRA) Policy Statement, which encourages the increased use of PRA and associated analyses in all regulatory matters to the extent supported by the state-of-the-art in PRA and the data. This policy applies, in part, to the review of digital systems, which offer the potential to improve plant safety and reliability through such features as increased hardware reliability and stability and improved failure detection capability. However, there are presently no universally accepted methods for modeling digital systems in current-generation PRAs. Further, there are ongoing debates among the PRA technical community regarding the level of detail that any digital system reliability model must have to adequately model the complex system interactions that can contribute to digital system failure modes. Moreover, for PRA modeling of digital reactor protection and control systems, direct interactions between system components and indirect interactions through controlled/supervised plant processes may necessitate the use of dynamic PRA methodologies. This situation has led the NRC to consider developing performance based rather than prescriptive regulatory guidance in this area. This paper will discuss the development of this guidance and some preliminary concepts.
AB - In 1995, the U.S. Nuclear Regulatory Commission (NRC) issued the Probabilistic Risk Assessment (PRA) Policy Statement, which encourages the increased use of PRA and associated analyses in all regulatory matters to the extent supported by the state-of-the-art in PRA and the data. This policy applies, in part, to the review of digital systems, which offer the potential to improve plant safety and reliability through such features as increased hardware reliability and stability and improved failure detection capability. However, there are presently no universally accepted methods for modeling digital systems in current-generation PRAs. Further, there are ongoing debates among the PRA technical community regarding the level of detail that any digital system reliability model must have to adequately model the complex system interactions that can contribute to digital system failure modes. Moreover, for PRA modeling of digital reactor protection and control systems, direct interactions between system components and indirect interactions through controlled/supervised plant processes may necessitate the use of dynamic PRA methodologies. This situation has led the NRC to consider developing performance based rather than prescriptive regulatory guidance in this area. This paper will discuss the development of this guidance and some preliminary concepts.
UR - http://www.scopus.com/inward/record.url?scp=34047121437&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:34047121437
SN - 0894480510
SN - 9780894480515
T3 - 5th International Topical Meeting on Nuclear Plant Instrumentation Controls, and Human Machine Interface Technology (NPIC and HMIT 2006)
SP - 828
EP - 835
BT - 5th International Topical Meeting on Nuclear Plant Instrumentation Controls, and Human Machine Interface Technology (NPIC and HMIT 2006)
T2 - 5th International Topical Meeting on Nuclear Plant Instrumentation Controls, and Human Machine Interface Technology (NPIC and HMIT 2006)
Y2 - 12 November 2006 through 16 November 2006
ER -