Use of hazard assessments to support risk-based decision making in the US Department of Energy Stockpile Stewardship (SS-21) Program

This paper summarizes the nuclear explosive hazard assessment activities performed to support the US Department of Energy (DOE) Stockpile Stewardship (SS-21) Integrated Safety or ``Seamless Safety`` program. Past practice within the DOE Complex dictated the use of a significant number of post-design/ fabrication safety reviews to analyze the safety associated with operations on nuclear explosives and to answer safety questions. These practices have focused on reviewing-in or auditing-in safety vs incorporating safety in the design process. SS-21 was proposed by the DOE as an avenue to develop a program to ``integrate established, recognized, verifiable safety criteria into the process at the design stage rather than continuing the reliance on reviews, evaluations and audits.`` The cornerstone of the SS-21 design process is the hazard assessment, which is performed concurrently with process and tooling design. The hazard assessment is used as the key management tool to guide overall risk management associated with the nuclear explosive activity through supporting risk-based decisions made with respect to process design