August 17, 2016

Followup Audit on Sandia National Laboratories' Nuclear Weapons Safety Program

As part of its nuclear explosive and weapon surety program, the National Nuclear Security Administration (NNSA) is required to incorporate design features that minimize the possibility of accidental or inadvertent nuclear explosive detonation.  According to Sandia, weapon systems have deviations from an ideal nuclear safety design and/or implementation.  These deviations, termed “nuclear safety soft spots,” can be associated with nuclear safety-related design or implementation attributes, or with the technical basis underlying these attributes based on Sandia’s principle-based approach to assured nuclear safety design.  

In July 2008, the Office of Inspector General reported that Sandia’s Safety Assessment had identified 23 high priority nuclear weapons safety issues, now called nuclear safety soft spots, for which there were either no plans to resolve the issues or plans were incomplete (Sandia National Laboratories Nuclear Weapons Safety Program, DOE/IG-0799).  We also found that Sandia management had not resolved disagreements between Sandia’s Surety Assessment, Engineering, and Analysis Center and Weapon Systems Engineering on the need to address the identified soft spots.  In addition, Sandia did not have a formal tracking system to identify actions taken, or planned, to address the soft spots or provide the rationale for opting not to address them.  

Our followup audit on Sandia’s management of weapons safety issues determined that Sandia officials had taken action to improve the management of nuclear weapons safety soft spots.  In particular, Sandia had developed a process for tracking all soft spots using general engineering documents that contain the agreed-upon prioritized soft spots and their dispositions for each weapon system.  In addition, Sandia had formalized its process to resolve disagreements related to nuclear weapons safety.  We also found that Sandia management had considered soft spots in the design and development activities for the B61-12 Life Extension Program and W88 Alteration 370 and had plans to mitigate or eliminate a number of the soft spots associated with the legacy B61 and W88 systems.  Sandia continues to work on addressing soft spots by gaining new knowledge through studies, tests, and analyses.  

However, we also noted an issue that warrants management’s attention.  We found that Sandia had not fully implemented its formal tracking system for soft spots.  This occurred primarily because the project that Sandia established in 2011 to improve the formal tracking system has languished for several years without a defined scope or firm completion date.  As a result, the information that is needed to make informed decisions about safety improvements in future weapon refurbishment programs may not be readily accessible to Sandia management and weapon system engineers in the formal tracking system.  In addition, concerns about employee turnover and the resulting loss of institutional knowledge further highlight the importance of maintaining this information for stockpile management activities.

Topic: National Security & Safety