June 29, 2007
The Honorable A. J. Eggenberger
Defense Nuclear Facilities Safety Board
625 Indiana Avenue, NW, Suite 700
Washington, DC 2004-2941
Dear Mr. Chairman:
The purpose of this letter is to report the conclusion of the Office of Environmental Management (EM) review of site procedures and safety bases mechanisms for using the 25 rem evaluation guideline (EG) to satisfy Commitment 8.9.1 of the Department of Energy Implementation Plan, for Defense Nuclear Facilities Safety Board Recommendation 2004-2, Active Confinement Systems, July 2006.
The EM Federal and Contractor communities understand that the value of 25 rem Total Effective Dose Equivalent (TEDE) is not to be used as a 'hard’ pass/fail level as 25 rem TEDE is not considered an acceptable public exposure, but a value indicative of a low risk of latent health effects and virtually no risk of prompt health effects. The community also understands that solely for classification of safety controls, unmitigated releases are to be compared against the EG to determine whether they challenge the EG, not if they exceed the EG. This is required due to the fact that consequence calculations can be highly assumption driven with known uncertainty in the evaluation methodologies.
EM has reviewed procedures generated by EM Field Organizations and their Contractors for evaluation and selection of Safety Class Systems, Structures, and Components (SSCs) and found them and their implementation consistent with this philosophy. In addition, I issued interim guidance on July 18, 2006, which emphasized that this philosophy, consistent with Appendix A of DOE-STD-3009, be utilized for selection of Safety Class SSCs for new EM facilities until the new DOE-STD-1189 is published.
In order to verify field application, EM has reviewed selection of Safety Class SSCs during Integrated Safety Management Program Assessments conducted at Idaho, Savannah River, and Oak Ridge. These reviews to date have shown that processes in the field are consistent with their procedures. EM will continue to emphasize the appropriate selection and development of controls, including Safety Class SSCs, during our regularly scheduled assessment activities.
If you have any comments or feedback, please call me at (202) 586-0738 or Mr. Dae Y. Chung, Deputy Assistant Secretary for Safety Management and Operations, at (202) 586- 5151.
Inés R. Triay
Chief Operating Officer for