PNNL

Mr. Toyooka is an engineer with a BS in mechanical engineering. He has over 20 years of experience working as a safety and risk analyst and design engineer. He has experience in hazard analysis, accident analysis, authorization basis development, risk assessment, and system engineering. He has performed hazard and accident analyses for U.S. Department of Energy facilities. He has supported the development of standard technical specifications for the U.S. Nuclear Regulatory Commission (NRC). He has supported risk assessments for hydroelectric facilities.

• Process hazard analysis
• Risk assessments
• Safety analysis
• Accident analysis
• Technical safety requirements
• Safety basis development

• BS, Mechanical Engineering, Washington State University, 2002

• 2009 - Outstanding Performance Award, RPL Upgraded 325 Building Safety Basis Documents
• 2010 - Outstanding Performance Award, PDCF Project
• 2013 - Outstanding Performance Award, WTP Documented Safety Analysis Development

2012

• Unwin, S. D., P. P. Lowry, and M Y . Toyooka. 2012. "Reliability Models Of Aging Passive Components Informed By Materials Degradation Metrics To Support Long-Term Reactor Operations." Nuclear Science and Engineering 171, no. 1:69-77. PNNL-SA-78802.

2011

• 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.

2010

• 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, Washington. Mannheim:International Association for Probabilistic 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

• 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.