[DOE LETTERHEAD]

 

May 4, 2005

 

The Honorable A. J. Eggenberger

Acting Chairman

Defense Nuclear Facilities Safety Board

625 Indiana Avenue, NW

Suite 700

Washington, DC 20004-2901

 

Dear Dr. Eggenberger:

 

The Defense Nuclear Facilities Safety Board’s letter to Under Secretary Garman dated August 27, 2004, concerned the adequacy of Department of Energy (DOE) natural phenomena hazards design standards and the performance category designation for the conceptual seismic design of the Salt Waste Processing Facility (SWPF) at the Savannah River Site.  The Under Secretary responded to those concerns by letter dated October 13, 2004.  As part of that response, DOE committed to provide clarification and supplemental guidance on seismic design standards by January 31, 2005.  Enclosed is the draft interim revision (Section 6.1) to DOE G 420.1-2, Guide for the Mitigation of Natural Phenomena Hazards for DOE Nuclear and Nonnuclear Facilities.  A copy has also been provided to your staff for review and comment.  Once comments are resolved, it will be issued for interim use.

 

We also recognized that it would be beneficial to review recently approved-for-issuance, but not yet published, American Nuclear Society (ANS) 2.26, Categorization of Nuclear Facility Structures, Systems and Components for Seismic Design.  We formed a DOE-wide team to review this standard and report on its acceptability for use in DOE.

ANS 2.26 was based on existing DOE seismic standards in large part and we believed initially that ANS 2.26 could be used as the supplemental guidance that would address your seismic design issues.  As ANS 2.26 went through the ANS consensus process, it was revised from the original DOE seismic design standard and, in particular, how results from accident analyses will establish seismic design.  Therefore, a more comprehensive review will be required to determine if it will be suitable for DOE use.

 

A more comprehensive review of ANS 2.26 will take several months.  Given the stage of design for SWPF and other facilities in DOE, we believe it is prudent to issue supplemental guidance on seismic design standards at this time that address your concerns rather than await the results of the ANS 2.26 review.  We will work with your staff to revise the enclosed Guide and other DOE directives as our ANS 2.26 review progresses.

 

Sincerely,

 

John Spitaleri Shaw

Assistant Secretary for

Environment, Safety and Health

 

Enclosure

 

cc:

 

M. Whitaker, DR-1

P. Golan, EM-2

D. Chung, EM-24

J. Allison, SRS

J. Paul, NA-2

J. Kimball, NA-2