[DOE LETTERHEAD]
May 21, 2004
The Honorable John T. Conway
Chairman
Defense Nuclear Facilities
Safety Board
625 Indiana Avenue, NW, Suite
700
Washington, DC 20004-2901
Dear Mr. Chairman:
The purpose of this letter is to
provide a response to concerns identified by your letter of March 23, 2004. The Defense Nuclear Facilities Safety Board (DNFSB)
asked how the Department of Energy (DOE) will ensure the Bechtel National, Inc.
(BNI) proposed
methodology for developing requirements for fire resistance for structural
steel used in Waste Treatment and Immobilization Plant (WTP) facilities
receives adequate review and comment through a peer review process, consistent with the process that would
be expected of any consensus code requirement. The DNFSB further requested DOE to discuss why
the proposed methodology should be used in lieu of recognized methods already
in use in the fire protection and structural
engineering communities, and address any potential structural or
safety impacts on the WTP facilities.
This letter and the enclosed
response address the DNFSB questions. As noted in the DNFSB’s letter, the
BNI methodology for justifying a reduction
in fire resistance ratings of structural steel was still evolving when the
DNFSB letter was issued. As discussed in the enclosed
response, a revised methodology has been proposed that is significantly
different than the methodology previously discussed with DNFSB staff. Specifically, BNI does not intend to use the
performance-based approach of performing heat transfer analyses coupled with
limiting temperature criteria from British Standard BS 5950-8:2003, Structural use of steelwork in building,
to determine the
response of structural columns to fire effects. Instead, BNI will use qualitative analyses to
determine the adequate protection requirements set and controls. BNI believes that the structural steel elements
in the WTP process buildings may be adequately protected from postulated fire
events by the existing automatic fire suppression system (wet pipe sprinkler
system) and the installation of additional sprinkler heads located to protect
the lower portions of structural steel columns from the effects of postulated
worst-case fires. However, the potential
need for fire-resistance coating will be evaluated as part of the equivalency approach. The qualitative analyses will include
consideration of room heights, sprinkler actuation set points, and multiple
fire magnitudes. The project Preliminary
Fire Hazard Analysis reports will be revised accordingly. This approach for protecting WTP structural steel
does not involve the development of an ad hoc fire protection code or standard.
Rather, the equivalency provisions of
the International Building Code, 2000 Edition, and DOE Standard DOE-STD-1066-97
will be used.
DOE will retain the services of
an independent technical expert knowledgeable of the building code, National
Fire Protection Association standards, and DOE requirements to perform an
independent technical review of the BNI analyses and conclusions. The independent technical review will assess
the use of active systems and passive systems. From this information and the revised BNI equivalency
methodology, DOE will determine the structural steel fireproofing requirements
for the W'I'P. The results of this
review will be provided to the DNFSB.
Thank you for meeting with us on
May 18. I realize that the Board has
continuing concerns regarding the WTP and we have scheduled a follow-on meeting
on June 2. As a result, we may need to provide
refinements to this response.
If you have further questions,
please call me at (202) 586-7709 or Ms. Patrice Bubar, Deputy Assistant
Secretary for Integrated Safety Management and Operations Oversight, at (202)
586-5151.
Sincerely,
Jessie Hill Roberson
Assistant Secretary for
Environmental Management
Response to DNFSB Letter