[DOE LETTERHEAD]
National Nuclear
Security Administration
February 15, 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:
As you know, the Department has identified the
Pit Disassembly and Conversion Facility (PDCF) as a pilot facility in its revised Implementation Plan (IP) for the Defense
Nuclear Facilities Safety Board (DNFSB) Recommendation 2004-2, Active
Confinement Systems. As part of the revised IP, the Department has completed a PDCF Ventilation System Evaluation
report, which was reviewed and approved by the Central Technical Authority of
the National Nuclear Security Administration. This report was provided to you on December 19,
2006.
The PDCF Ventilation System Evaluation identified three potential gaps, none of
which require mandatory resolution. However, one of these gaps concerning post accident indication of
filter break-through in the sand filter
was recommended for closure. To close
this gap, the PDCF design will be modified to
upgrade the sand filter exhaust sample
collection system to meet Performance Cntegory-3 Natural Phenomena Hazard criteria
and safety class emergency power requirements. The design will also be modified to include a sample collection point prior to the exhaust stack, with sampling components
located in the fan house. NNSA is committed to implementing these upgrades,
which have been incorporated into the PDCF technical baseline.
If you have any questions, please contact me or
have your staff contact Mr. Joe Olencz, PDCF Program Manager, at 202-586-4124.
Sincerely,
William H. Tobey
Deputy Administrator
For Defense Nuclear Nonproliferation
cc: Kenneth E. Baker, NA-20
Thomas Deters, NA-20
Ken Chacey, NA-26
Ken Bromberg, NA-26
Joe Olencz, NA-261
Katie Vogler, NA-26
Marty Newdorf, NA-261
Marggie Schwenker, NA-261
Garrett Smith,
NA-261
Ram Mukunda, NA-262
Rich Person, NA-262
Kenneth Sanders, NA-262
Bill Clark, NA-266
Robert Billue, NA-266
Sam Glenn, NA-266
Joanne D.
Lorence, HS-1.1
Mark B.
Whitaker, HS-1.1