[DOE LETTERHEAD]

October 1, 2002

The Honorable John T. Conway
Chairman
Defense Nuclear Facilities Safety Board
625 Indiana Avenue, NW, Suite 700
Washington, D.C. 20004-2901

Dear Mr. Chairman:

The purpose of this letter is to respond to your September 9, 2002, letter detailing the results of the Defense Nuclear Facility Safety Board staff review of the Waste Feed Delivery (WFD) transfer system at the Hanford Site. The U.S. Department of Energy shares your concern over waste slurry characterization analysis uncertainties and the need to prevent transfer line plugging.

CH2M HILL Hanford Group, Inc. has conducted research and testing to characterize the properties of the waste slurry to support the design process. Uncertainties from this work require resolution to complete validation of the final design basis. A technical evaluation has been initiated to confirm that existing analysis and assumptions support the current design basis. Pending the outcome of this evaluation, additional analysis and experimental testing may be required. The evaluation will consider actual Hanford and Savannah River Site experience in waste slurry transfers. This evaluation is planned for completion by December 31, 2002.

The evaluation and subsequent analysis and/or additional testing will provide assurance that the resulting WFD transfer system design basis will fulfill mission requirements for safe and reliable flow of high-level waste slurry. The Office of River Protection staff will keep your staff apprised on the technical evaluation and subsequent analysis and/or testing requirements.

Sincerely,

Jessie Hill Roberson
Assistant Secretary for
Environmental Management

cc: Mr. Mark Whitaker, S-3.1