Skip to Main Content U.S. Department of Energy
Risk and Decision Sciences

Stephen Unwin

Stephen Unwin

Pacific Northwest National Laboratory
PO Box 999
Richland, WA 99352

Biography

Dr. Unwin's career has centered on the development of uncertainty and risk-analytic methodologies, their application to multi-domain problems of national and commercial importance, and the founding of businesses on those capabilities. He has developed methods and models for risk-informed decision-making that continue to be applied in numerous sectors, including nuclear energy, oil & gas, power grid infrastructure, renewable energy, national security, climate adaptation, the chemical process industries, and the fossil energy sector. Before joining Pacific Northwest National Laboratory (PNNL) in 2006 he founded Brookhaven National Laboratory's Safety Integration Group, SAIC's Risk & Reliability Management Division, Battelle's Integrated Risk Management Group, and Unwin Company - Integrated Risk Management, which is a continuing risk management resource to commercial and government clients. He served as the PNNL Nuclear Market Sector Manager with oversight of all PNNL programs for the commercial nuclear power industry, the US Nuclear Regulatory Commission and the US Department of Energy’s Office of Nuclear Energy. In his current role he oversees risk management programs in PNNL’s Energy & Environment Directorate. He holds a bachelors degree in physics from Imperial College, London and a doctorate in theoretical physics from the University of Manchester, UK.

Education and Credentials

  • Ph.D., Theoretical Physics, University of Manchester, U.K., 1980
  • B.Sc., Physics (First Class Honors), Imperial College of Science and Technology, University of London, U.K., 1977

Awards and Recognitions

  • Awarded United States flag by the National Aeronautics and Space Administration "in recognition of contributions made to the Ulysses mission launched October 6, 1990."
  • Awarded a Certificate of Appreciation by the U.S. Nuclear Regulatory Commission "in recognition of [Dr. Unwin's] outstanding contribution to NUREG-1150 resulting in a significant advancement in the state of technology of probabilistic risk analysis and a major contribution to the Nuclear Regulatory Commission's severe accident program."

PNNL Publications

2018

  • Veeramany A., G.A. Coles, S.D. Unwin, T.B. Nguyen, and J.E. Dagle. 2018. "Trial Implementation of a Multihazard Risk Assessment Framework for High-Impact Low-Frequency Power Grid Events." IEEE Systems Journal 12, no. 4:3807-3815. PNNL-SA-124609. doi:10.1109/JSYST.2017.2737993

2016

  • Veeramany A., G.A. Coles, S.D. Unwin, T.B. Nguyen, and J.E. Dagle. 2016. Trial Implementation of the High-Impact, Low-Frequency Power Grid Event Risk Framework to Support Informed Decision-Making. PNNL-25667. Richland, WA: Pacific Northwest National Laboratory. Trial Implementation of the High-Impact, Low-Frequency Power Grid Event Risk Framework to Support Informed Decision-Making
  • Veeramany A., S.D. Unwin, G.A. Coles, J.E. Dagle, W. Millard, J. Yao, and C.S. Glantz, et al. 2016. "Framework for Modeling High-Impact, Low-Frequency Power Grid Events to Support Risk-Informed Decisions." International Journal of Disaster Risk Reduction 18. PNNL-SA-115402. doi:10.1016/j.ijdrr.2016.06.008

2015

2013

  • Holmes A.E., L.H. Sego, B.M. Webb-Robertson, H.W. Kreuzer, R.M. Anderson, S.D. Unwin, and M.R. Weimar, et al. 2013. An Approach for Assessing the Signature Quality of Various Chemical Assays when Predicting the Culture Media Used to Grow Microorganisms. PNNL-22126. Richland, WA: Pacific Northwest National Laboratory. An Approach for Assessing the Signature Quality of Various Chemical Assays when Predicting the Culture Media Used to Grow Microorganisms
  • Unwin S.D., K.I. Johnson, W.J. Ivans, and P.P. Lowry. 2013. "A PROPOSED METHOD FOR ESTIMATING FAILURE RATES OF DEGRADED PASSIVE COMPONENTS IN THE NRC SIGNIFICANCE DETERMINATION PROCESS." Transactions of the American Nuclear Society 109, no. 1:2049-2050. PNNL-SA-99179.
  • Unwin S.D., P.W. Eslinger, and K.I. Johnson. 2013. "ROBUSTNESS OF DECISION INSIGHTS UNDER ALTERNATIVE ALEATORY/EPISTEMIC UNCERTAINTY CLASSIFICATIONS." In International Topical Meeting on Probabilistic Safety Assessment and Analysis (PSA 2013), September 22-27, 2013, Columbia, South Carolina, 1, 569-580. La Grange, Illinois:American Nuclear Society. PNNL-SA-95332.

2012

2011

  • Coles G.A., S.D. Unwin, G.M. Holter, R.B. Bass, and J.E. Dagle. 2011. "Defining resilience within a risk-informed assessment framework." International Journal of Risk Assessment and Management 15, no. 2/3:171-185. PNNL-SA-75420. doi:10.1504/IJRAM.2011.042115
  • Paulson P.R., T.E. Carroll, C. Sivaraman, P.A. Neorr, S.D. Unwin, and S.S. Hossain. 2011. "Simplifying Probability Elicitation and Uncertainty Modeling in Bayesian Networks." In Proceedings of the 22nd Midwest Artificial Intelligence and Cognitive Science Conference (MAICS 2011), April 16-17, 2011, Cincinnati, OH, edited by S Visa, A Inoue and AL Ralescu, 114-119. Madison, Wisconsin:Omnipress. PNNL-SA-77781.
  • Unwin S.D., A. Sadovsky, E.C. Sullivan, and R.M. Anderson. 2011. Risk-Informed Monitoring, Verification and Accounting (RI-MVA). An NRAP White Paper Documenting Methods and a Demonstration Model for Risk-Informed MVA System Design and Operations in Geologic Carbon Sequestration. PNNL-20808. Richland, WA: Pacific Northwest National Laboratory. Risk-Informed Monitoring, Verification and Accounting (RI-MVA). An NRAP White Paper Documenting Methods and a Demonstration Model for Risk-Informed MVA System Design and Operations in Geologic Carbon Sequestration
  • Unwin S.D., P.P. Lowry, and M.Y. Toyooka. 2011. "A Methodology Supporting the Risk-Informed Management of Materials Degradation." In Proceedings of the 2011 American Nuclear Society Winter Meeting and Nuclear Technology Expo, October 30-November 3, 2011, Washington DC. La Grange Park, Illinois:American Nuclear Society. PNNL-SA-80413.
  • Unwin S.D., P.P. Lowry, M.Y. Toyooka, and B.E. Ford. 2011. "DEGRADATION SUSCEPTIBILITY METRICS AS THE BASES FOR BAYESIAN RELIABILITY MODELS OF AGING PASSIVE COMPONENTS AND LONG-TERM REACTOR RISK." In Proceedings of the ASME 2011 Pressure Vessels & Piping Conference (PVP2011), July 17-21, 2011, Baltimore, Maryland, Paper No. PVP2011-58073. New York, New York:ASME. PNNL-SA-78798.
  • Unwin S.D., P.P. Lowry, R.F. Layton, M.B. Toloczko, K.I. Johnson, and S.E. Sanborn. 2011. Physics-Based Stress Corrosion Cracking Component Reliability Model cast in an R7-Compatible Cumulative Damage Framework. PNNL-20596. Richland, WA: Pacific Northwest National Laboratory. Physics-Based Stress Corrosion Cracking Component Reliability Model cast in an R7-Compatible Cumulative Damage Framework
  • Unwin S.D., P.P. Lowry, R.F. Layton, P.G. Heasler, and M.B. Toloczko. 2011. "Multi-State Physics Models of Aging Passive Components in Probabilistic Risk Assessment." In International Topical Meeting on Probabilistic Safety Assessment and Analysis (PSA 2011), March 13-17, 2011, Wilmington, North Carolina, 1, 161-172. La Grange Park, Illinois:Amercian Nuclear Society. PNNL-SA-76893.
  • Unwin S.D., R.H. Moss, J.S. Rice, and M.J. Scott. 2011. Characterizing Uncertainty for Regional Climate Change Mitigation and Adaptation Decisions. PNNL-20788. Richland, WA: Pacific Northwest National Laboratory. Characterizing Uncertainty for Regional Climate Change Mitigation and Adaptation Decisions

2010

  • Anderson R.M., A.E. Copping, F.B. Van Cleve, S.D. Unwin, and E.L. Hamilton. 2010. Conceptual Model of Offshore Wind Environmental Risk Evaluation System. PNNL-19500. Richland, WA: Pacific Northwest National Laboratory. Conceptual Model of Offshore Wind Environmental Risk Evaluation System
  • Anderson R.M., S.D. Unwin, and F.B. Van Cleve. 2010. Identification and Prioritization of Analysis Cases for Marine and Hydrokinetic Energy Risk Screening. PNNL-19535. Richland, WA: Pacific Northwest National Laboratory. Identification and Prioritization of Analysis Cases for Marine and Hydrokinetic Energy Risk Screening
  • Sanfilippo A.P., R.M. Riensche, S.D. Unwin, and J.P. Amaya. 2010. "Bridging the Gap between Human Judgment and Automated Reasoning in Predictive Analytics." In 10th International Probabilistic Safety Assessment & Management Conference - PSAM10, June 7-11, 2010, Seattle, WA. Mannheim:International Association for Probabilistic Safety Assessment & Management. PNNL-SA-71894.
  • Unwin S.D., P.P. Lowry, and M.Y. Toyooka. 2010. "A New Class of Risk-Importance Measures to Support Reactor Aging Management and the Prioritization of Materials Degradation Research." In 10th International Probabilistic Safety Assessment & Management Conference - PSAM10, June 7-11, 2010, Seattle, WA. Mannheim:International Association for Probabalistic Safety Assessment & Management (IAPSAM). PNNL-SA-70455.
  • Unwin S.D., P.P. Lowry, and M.Y. Toyooka. 2010. "COMPONENT DEGRADATION SUSCEPTIBILITIES AS THE BASES FOR MODELING REACTOR AGING RISK." In 2010 Pressure Vessels & Piping Conference (PVP 2010): Pressure Vessel Technology for Energy Challenge, Paper No. PVP2010-25750. New York, New York:American Society of Mechanical Engineers. PNNL-SA-71292.

2009

  • Riensche R.M., P.R. Paulson, G.R. Danielson, S.D. Unwin, R.S. Butner, S.M. Miller, and L. Franklin, et al. 2009. "Serious Gaming for Predictive Analytics." In AAAI Spring Symposium on Technosocial Predictive Analytics. Menlo Park, California:Association for the Advancement of Artificial Intelligence (AAAI). PNNL-SA-62908.
  • Sanfilippo A.P., A.J. Cowell, E.L. Malone, R.M. Riensche, J.J. Thomas, S.D. Unwin, and P.D. Whitney, et al. 2009. "Technosocial Predictive Analytics in Support of Naturalistic Decision Making." In NDM9: Proceedings of the Ninth International Conference on Naturalistic Decision Making, June 23-26, 2009, London, United Kingdom, edited by BLW Wong. Swindon:British Computer Society. PNNL-SA-63558.
  • Unwin S.D., and B.A. Fecht. 2009. "Consumer Choice and Dempster-Shafer Models of Threat Prioritization for Emerging Dual-Use Technologies: Their Application to Synthetic Biology." Defense & Security Analysis 25, no. 1:37-52. PNNL-SA-59853.
  • Unwin S.D., and T.E. Seiple. 2009. Risk D&D Rapid Prototype: Scenario Documentation and Analysis Tool. PNNL-18446. Richland, WA: Pacific Northwest National Laboratory. Risk D&D Rapid Prototype: Scenario Documentation and Analysis Tool
  • Unwin S.D., P.P. Lowry, and M.Y. Toyooka. 2009. "Informing Reactor Aging Management by Extended Risk Methodology." Transactions of the American Nuclear Society 101, no. 1:1047-1048. PNNL-SA-66915.
  • Wong P.C., L.R. Leung, N. Lu, M.J. Scott, P.S. Mackey, H.P. Foote, and J. Correia, et al. 2009. "Designing a Collaborative Visual Analytics Tool for Social and Technological Change Prediction." IEEE Computer Graphics and Applications 29, no. 5:58-68. PNNL-SA-64416. doi:10.1109/MCG.2009.92
  • Wong P.C., L.R. Leung, N. Lu, M.L. Paget, J. Correia, W. Jiang, and P.S. Mackey, et al. 2009. "Predicting the Impact of Climate Change on U.S. Power Grids and Its Wider Implications on National Security." In AAAI Spring Symposium on Technosocial Predictive Analytics, SS-09-09, 148-153. Menlo Park, California:AAAI Press. PNNL-SA-62199.

2008

  • Unwin S.D., B.A. Fecht, and T.M. Bergsman. 2008. "Business Metrics of Laboratory Space Utilization." Facilities 26, no. 9/10:366-373. PNNL-SA-56942.

Risk and Decision Sciences

Additional Information