[DOE LETTERHEAD]
NATIONAL NUCLEAR
SECURITY ADMINISTRATION
February 20, 2003
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:
This letter is provided
as an interim response to your letter of December 27, 2002, regarding the
Highly Enriched Uranium Materials Facility (HEUMF) at the Y-12 National
Security Complex. Your letter noted
that, despite improvements to the design criteria document and the process for
identification of safety controls, persistent weaknesses discussed in the Issue
Reports enclosed with your letter require attention to assure an adequate
safety basis for the operation of the HEUMF facility. The National Nuclear Security Administration (NNSA) concurs with
many of the issues noted in the Issue Reports.
Subsequent to the
November 2002 HEUMF staff review, as part of the ongoing development of the
HEUMF Preliminary Documented Safety Analysis (PDSA) process, the control set
being developed to mitigate a large fire in the HEUMF continues to be
updated. One element of the control set
presently under investigation is the use of an active vented safety confinement
system vice the isolation (holdup) approach noted with concern in the staff
report. The analysis considers both
worker and public protection and potential Post Accident Recovery consideration
during the development of the System Safety Function and Functional
Requirements. A draft PDSA that
documents the updated contractor recommendation is scheduled for submittal to
NNSA for formal review in early April.
Additionally, the NNSA Site Office and Headquarters staff coordinate
informally on an ongoing basis with the contractor staff to maintain awareness
of the DSA progress, and to ensure that an appropriate set of design features
are included in the facility to address worker and public protection. We will also continue to keep your staff
apprised of developments in this matter.
Your letter noted
concerns with the types and physical characteristics of materials and the
technical standards and criteria for storage in the HEUMF. The current Y-12 site storage criteria, as
described in Y/ES-015/Rl dated May 2002, apply to Highly Enriched Uranium (HEU)
stored on an interim basis, as well as for indefinite or long-term storage up
to 50 years. The criteria for long-term
and interim storage from this document will be used for storing HEU metal,
metal alloys, and stable oxides in the HEUMF.
The solution or residue form of uranium is not an acceptable form of
storage in the HEUMF. The staff report
also noted concerns as to the type of storage containers that will be used for
material stored in the HEUMF. To
address a recent issue, which in part resulted from the fact that multiple types
of storage containers complicate criticality safety requirements and affect
operator conduct of operation performance, BWXT Y-12 is establishing a team to
develop a project plan for implementing a storage container architecture for
the Y-12 site.
The NNSA will
provide a report by March 27, 2003, as requested in your letter to identify and
provide status on specific actions being taken to address the issues noted in
your letter on HEUMF design and storage requirements. We will also continue the actions taken by NNSA and BWXT in
response to your March 2002 HEUMF letter, with our staff working closely with
your staff exchanging updates on issue resolution and project documentation as
it becomes available. We have found
this ongoing dialogue to be useful and beneficial.
If you have any
questions concerning our approach to responding to your letter, please contact
me or have your staff contact Mr. David E. Beck at (202) 586-4879 or Mr. Bill
Brumley at (865) 576-0752.
Sincerely,
Deputy
Administrator
for Defense
Programs