A THEMATIC APPROACH TO SYSTEM SAFETY

Sandia National Laboratories (Sandia) has refined a process for develo ping inherently safer system designs based on methods used by Sandia t o design detonation safety into nuclear weapons. The process was creat ed when Sandia realized that standard engineering practices did not pr ovide the level of safety assurance necessary for nuclear weapon opera tions, with their potential for catastrophic accidents. A systematic a pproach, which relies on mutually supportive design principles integra ted through fundamental physical principles, was developed to ensure a predictably safe system response under a variety of operational and a ccident based stresses. Robust, safe system designs result from this t hematic approach to safety, minimizing the number of safety critical f eatures. This safety assurance process has two profound benefits: the process avoids the need to understand or limit the ultimate intensity of off-normal environments and it avoids the requirement to analyze an d test a large array of accident environment scenarios (e.g., directio nal threats, sequencing of environments, time races, etc.) to demonstr ate conformance to all safety requirements.