[DOE
LETTERHEAD]
July 13,
2005
The Honorable A. J. Eggenberger
Acting Chairman
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.
Sincerely,
Charles E. Anderson
Principal Deputy Assistant
Secretary
for Environmental Management