July 13, 2005
The Honorable A. J. Eggenberger
Defense Nuclear Facilities Safety Board
625 Indiana Avenue, N. W., Suite 700
Washington, D.C. 20004-2901
Dear Dr. Eggenberger:
Thank you for your June 1, 2005, letter supporting the ongoing Hanford Tank Farms Corrosion Expert Panel and laboratory studies on Double-Shell Tank (DST) corrosion, and the new data that you referenced on vapor space corrosion. The Expert Panel is assessing the feasibility of designing accelerated testing methods for pitting and stress corrosion cracking (SCC) in environments comparable to the DST vapor exposure.
The U.S. Department of Energy’s Office of Environmental Management (EM), the Office of River Protection, and the CH2M HILL Hanford Group, Inc., reviewed the ongoing laboratory testing at CC Technologies in Columbus, Ohio, on June 7, 2005. Your staff also attended this review and their input is appreciated. The accelerated SCC testing in simulated waste to date has some promising results. However, extensive testing is still required before this information can be reliably used to more effectively manage tank operations and safety controls.
A September meeting is being scheduled for EM to provide the requested briefing to the Defense Nuclear Facilities Safety Board. It is anticipated that additional laboratory results and a path forward will be available at that time making the briefing more complete. EM will continue to update your staff on the laboratory testing results and technical direction.
If you have any further questions or concerns, please contact me at (202) 586-7709 or Mr. Dae Y. Chung, Director, Office of Licensing, at (301) 903-3968.
Charles E. Anderson
Principal Deputy Assistant Secretary
for Environmental Management