National Nuclear Security Administration
October 31, 2005
The Honorable A. J. Eggenberger
Defense Nuclear Facilities Safety Board
625 Indiana Avenue, NW.
Washington, D.C. 20004
Dear Mr. Chairman:
Enclosed is a draft copy of the Technical Business Practice (TBP), "Hazard Analysis and Weapon Response," for your review and comment. The purpose of this TBP is to reflect the national laboratory and Pantex Plant interfaces associated with recent changes in the hazard analysis and weapon response process that resulted from the Value Streaming Analysis (VSA) effort conducted in mid-Fiscal Year 2005. The purpose of the VSA was to identify and improve areas of inefficiency in the hazard analysis and weapon response process and it included participants from the three national laboratories, National Nuclear Security Administration (NNSA), and Pantex Plant. Regarding the weapon response process, the VSA identified significant inefficiency in the existing practice of determining conditional weapon response probabilities for all scenarios no matter how insignificant or how similar they were to previously analyzed scenarios. The VSA identified a modification to the process to address hazards in a more systematic iterative manner. The modification includes a method to address hazards with lesser or known consequence through previous analysis on other programs using a standard set of weapon response rules in the form of thresholds and screening criteria. The Hazard Analysis Task Team (HATT), which includes laboratory and Pantex Plant members, can then utilize the set of rules to screen a large number of identified hazard scenarios. As part of the hazard analysis process, the Pantex Plant requests laboratory concurrence on the appropriate use of the rules via an Information Engineering Release. For the remaining scenarios, the HATT conducts an assessment to mitigate/eliminate the hazard via process and/or tooling changes or engineered/administrative controls. Hazard scenarios that were not mitigated or eliminated during this step are forwarded to the laboratories for formal assessment via the original method. The laboratories are then able to focus weapon response resources on a smaller more manageable set of hazard scenarios. In the resulting Hazard Analysis Report, each hazard scenario is still listed with the associated weapon response or screening rule.
The VSA results drove a change in the weapon response approach, which reduced the necessity to explicitly define expectations for the evaluation and documentation of weapon response as was indicated in the Recommendation 98-2 deliverable. In conjunction with this TBP, the NNSA is updating the Development and Production Manual, Chapter 11.8, "Integration of Weapon Response into Authorization Bases at the Pantex Plant," which serves as the requirements document for hazard analysis and weapon response. In the updated version of Chapter 11.8, the NNSA will still require that the laboratories have a formal process compliant with the Title 10, Code of Federal Regulations, Part 830, rule to evaluate weapon response requests from the Pantex Plant. Each laboratory has an internal process for evaluation of weapon response that includes deterministic/probabilistic modeling, expert elicitation using subject-matter experts, and review of existing test and analysis. The benefits of this approach result in consistency among programs and more streamlined and prioritized efforts for weapon response.
Please provide your comments no later than November 30, 2005. Should you have any questions, please call me at 202 586-1730 or have your staff contact Ms. Wendy Baca at 505-845-6340.
Office of Nuclear Weapons Stockpile
K. Fortenberry, DNFSB
A. Matteucci, DNFSB
M. Whitaker, DR-1
S. Erhart, PXSO