[DOE LETTERHEAD]
National
Nuclear Security Administration
October 31,
2005
The Honorable
A. J. Eggenberger
Chairman
Defense Nuclear Facilities Safety Board
625 Indiana Avenue, NW.
Suite 700
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.
Sincerely,
Doug Abbott
Director
Office of Nuclear Weapons Stockpile
Defense Programs
cc:
K. Fortenberry, DNFSB
A. Matteucci, DNFSB
M. Whitaker, DR-1
S.
Erhart, PXSO