[DEPUTY SECRETARY LETTERHEAD]
January 23, 2002
The Honorable John T. Conway
Chairman
Defense Nuclear Facilities Safety Board
625 Indiana Avenue, NW
Washington, D.C. 20004
Dear Mr. Chairman:
Thank you for your November 5, 2001, letter regarding design requirements related to Emergency Operations Centers (EOCs).
As you noted, Los Alamos National Laboratory (LANL) designed the EOC for Performance Category 2 seismic design requirements. LANL addressed the possibility of more severe earthquakes, such as that defined as the design basis for the Plutonium Facility (Performance Category 3 Design Basis Earthquake), by enhancing the structural reinforcement for the EOC and by supplementing EOC capability via a mobile command center. This system of EOCs is intended to handle all credible seismic emergencies at LANL.
As you requested, we have evaluated the adequacy of our directives regarding the design of EOCs and the adequacy of associated functional and operational requirements. Specifically, we have reviewed DOE Orders, Guides, and Standards related to seismic design of facilities and Emergency Management Systems. Our Emergency Management Systems directives discuss the need for alternate EOCs if the primary EOC is not available. Alternate operating locations provide a means to continue emergency critical functions should the primary location suffer damage, become inaccessible, or require evacuation. The DOE seismic design directives give guidance to our contractors to apply more stringent seismic design if the safety function for the specific situation mandates.
Additionally, our seismic design directives point out that the design process shall consider the potential damage and failure of structures, systems, and components due to both direct and indirect effects, including common cause effects and interactions. To strengthen this concept, we will revise DOE Standard 1021, Natural Phenomena Hazards Performance Categorization Guidelines for Structures, Systems, and Components reinforcing the concept that system interaction may be between one facility and another facility.
Your letter and the enclosed trip report also discuss some additional work needed to ensure that the LANL TA-18 flood retention structure performs as intended in the event of significant flooding. Specifically, this additional work is related to erosion control and testing of the concrete strength of the dam. Our Los Alamos Area Office and LANL are in the final stages of executing this additional site work, and results of this work will be provided to your staff upon completion.
Sincerely,
Francis S. Blake