[DOE LETTERHEAD]

November 4, 2002

The Honorable Jessie Hill Roberson

Assistant Secretary for Environmental Management

U.S. Department of Energy

1000 Independence Avenue, SW

Washington, DC 20585-0113
Dear Ms. Roberson:

The staff of the Defense Nuclear Facilities Safety Board (Board) has completed a review of the Documented Safety Analysis (DSA) for the high-level waste Concentration, Storage, and Transfer (CST) facilities at the Savannah River Site. The CST DSA was prepared by the Westinghouse Savannah River Company to comply with Title 10 of the Code of Federal Regulations, Part 830 (10 CFR 830), Nuclear Safety Management, and was submitted to the Department of Energy's (DOE) Savannah River Operations Office for review and approval on June 27, 2002.

After reviewing the CST DSA, the Board's staff found that unmitigated accident scenarios were not adequately developed for several accidents involving the leakage or spill of high-level waste. The unmitigated accident analysis methodology used in the DSA improperly credits a number of operator actions for detecting and terminating waste release accidents. This methodology limits the calculated unmitigated consequences of an accident, and may not allow the proper selection of safety-class or safety-significant controls as necessary to adequately protect site workers and members of the public.

The Board believes that this approach is not in accordance with the guidance in the applicable DOE standard, DOE-STD-3009-94, Preparation Guide for U.S. Department of Energy Nonreactor Nuclear Facility Documented Safety Analyses. This standard states that unmitigated release calculations should represent a theoretical limit to accident consequences so that the physical release potential of a given process or operation can be conservatively estimated. A truly unmitigated analysis takes no credit for normal operating equipment or safety features.

The Board's staff also found that some values used as inputs for accident calculations may not be conservative and identified several other issues that merit further evaluation. The enclosed report summarizes the staffs observations relative to the CST DSA and is provided for your information.

On September 23, 2002, the Board issued a letter that discussed concerns with the improper implementation of safety analysis methodology at DOE defense nuclear facilities. Consistent with that letter, the Board believes that proper unmitigated or bounding accident analyses utilizing appropriately conservative input values should be included in the CST DSA. Such analyses allow the proper identification and selection of safety-class and safety-significant equipment and administrative controls. Any necessary equipment upgrades can then be prioritized on the basis of safety improvement, and a plan developed to ensure that the CST facilities can provide an adequate level of protection to site workers and members of the public for the remaining 20-30 years of facility life, as required by 10 CFR 830.

The Board would like to be briefed by appropriate representatives of DOE's Savannah River Operations Office and Westinghouse Savannah River Company in the next 30 days in response to the issues raised in the enclosed report.

Sincerely,

John T. Conway
Chairman

c: Mr. Mark B. Whitaker, Jr.

Mr. Jeffrey M. Allison

Enclosure