**\[DOE LETTER HEAD\]**

**NATIONAL NUCLEAR SECURITY ADMINISTRATION**

December 21, 2007

The Honorable A. J. Eggenberger

Chairman

Defense Nuclear Facilities Safety Board

625 Indiana Avenue, NW, Suite 700

Washington, DC 20004-2901

Dear Mr. Chairman:

In a letter dated August 18, 2006, former Administrator Brooks responded
to your request for information regarding the National Nuclear Security
Administration\'s (NNSA) plans for handling the staging, assessment, and
disposition of a damaged U.S. Nuclear Weapon and Improvised Nuclear
Device (IND). In subsequent meetings between Defense Nuclear Facilities
Safety Board (DNFSB) representatives and my office, the DNFSB requested
additional information on NNSA\'s plans for preparing the G-Tunnel for
the limited possibility that it will be used for the disposition of an
IND.

The NNSA has determined that the G-Tunnel does not meet the definition
of a nuclear facility for Department of Energy Emergency
Response-identified specific operations and will no longer treat the
Tunnel as such. The NNSA will carefully balance the limited probability
of an interdicted IND scenario with the benefits of G-Tunnel upgrades
and the costs associated with implementation. With the limited
possibility that the G-Tunnel will be used in the disassembly of an IND
and uncertainties surrounding the circumstances of such use, it is our
intent to address appropriate life safety and mission-related facility
upgrade issues that are prudent to pursue.

> \- NNSA will continue to prepare for the potential use of the G-Tunnel
> for the disassembly and technical nuclear forensics support of an IND.
> The alacrity of the side-by-side disassembly and forensics operations
> will be of paramount priority, given the critical nature to national
> security of such an activity. Several life safety upgrades have been
> identified for the G-Tunnel that will require significant investment.
> The life safety issues are identified in the \"Facility Safety Plan
> for U12g Tunnel\" (Enclosure 1). We will continue to assess these
> upgrades to determine the proper scope and prioritization.

-   It will also be prudent to pursue improvements that will enhance the
    ability of the facility to complete any assigned mission and improve
    the overall safety for operations involving an IND. A program of
    evaluating potential facility upgrades to determine the relative
    contribution to the mission completion capability has been
    initiated. The benefit of each upgrade with respect to carrying out
    the facility mission will be evaluated. The \"White Paper on
    Evaluating Proposed U12g Facility Upgrades\" (Enclosure 2) describes
    how facility hazards will be analyzed.

We will continue to analyze the hazards of the G-Tunnel and develop
appropriate controls, conduct interagency drills and exercises, and
implement specific upgrades to the G-Tunnel to improve both the overall
safety posture and the ability of the facility to support a successful
mission outcome. We believe these actions are in keeping with the
G-Tunnel\'s mission to serve as a non-nuclear training and transitional
facility that *may,* in an extremely unlikely event, under emergency
circumstances, be used for the disposition of an IND.

Beginning in Fiscal Year 2008, the NNSA has established a six-year
funding profile to address these infrastructure upgrades. The actual
length of time to complete these upgrades will, of course, be dictated
by the actual costs. The schedule is to complete the cost and
risk/benefit assessment on the issues identified in the Documented
Safety Analysis Implementation Plan by April 2008. At that time, a
comprehensive project plan will be developed that addresses both life
safety and facility safety upgrades and prioritizes potential
improvements based on the cost and risk reduction they would provide.

Hopefully, the aforementioned synopsis of NNSA\'s plan to move forward
with the G-Tunnel improvements clarifies your understanding. We will
continue to work with the

DNFSB as we move forward with our plans for the G-Tunnel.

If you have any questions please contact Mr. Thomas Black, Director,
Office of National Technical Nuclear Forensics on 301-903-7314.

Sincerely,

***Joseph J. Krol***

***Associate Administrator for***

***Emergency Operations***

[Enclosures](http://www.hss.energy.gov/deprep/2007/AttachedFile/TB07D21d_enc.HTM)

cc: Gerald Talbot, NSO

James McConnell, NA-2.1

Laura Tomlinson, NSO

Thomas Black, NA-45