ML20235F214

Advises That Review of Fire Barrier Penetration Seal Fire Ratings Determined That Some Minor Changes in Order for Particular Seals,To Achieve Consistency Among & Between Ref Documents.Proposed Clarifications & Changes Listed

ML20235F214
Person / Time
Site:	Fort Saint Vrain
Issue date:	07/02/1987
From:	Warembourg D PUBLIC SERVICE CO. OF COLORADO
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
P-87241, TAC-54373, NUDOCS 8707130271
Download: ML20235F214 (3)

Text

O Pubiic service-  :=<=- -

2420 W. 26th Avenue, Suite 1000, Denver, Colorado 80211 July 2, 1987 Fort St. Vrain Unit No. 1 P-87241 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 Attention: Mr. Jose A. Calvo Director, Project Directorate IV Docket No. 50-267

SUBJECT:

Revisions to Fort St.

Vrain Penetration Seal Fire Ratings

REFERENCE:

1) PSC Letter, Lee to Johnson, dated 8/30/85 (P-85301)

2) PSC Letter, Warembourg to Calvo, dated 5/15/87 (P-87167)

3) PSC Letter, Fuller to Gammill, dated 11/13/78 (P-78182) l 4) PSC Letter, Fuller to Gammill, dated 10/13/78 (P-78167)

5) PSC Letter, Fuller to Denise, dated 9/19/77 (P-77194) ,

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6) NRC Letter, Denise to Fuller, dated 3/31/78 (G-78029)

Dear Mr. Calvo:

A review .of the Fort St. Vrain fire barrier penetration seal fire ratings has been recently performed to ensure they meet the requirements of the Fire Areas specified in the FSV Appendix R Evaluation (Ref. 1) and the recent changes in 'the Fire Protection Shutdown /Cooldown models (Ref. 2). This review has determined that .

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July 2, 1987 d

some minor changes are in order for particular penetration seals, 'to achieve consistency among and between the referenced documents.

Therefore, PSC proposes the following clarifications and changes:

1. There are numerous penetrations between floor levels in both the Reactor Building and the Turbine Building as well as penetrations in walls internal to the Reactor Building. Reference 3 states that both buildings have an open structure design concept with open steel floor grating, open' stairways and machinery and personnel access openings in walls and floors. Reference 4 states that penetrations within the Reactor Building and Turbine Building between floor levels are not sealed by nature of the open space design concept. As a result of this open space design, the Appendix R Evaluation (Ref.1) has designated the entire Reactor Building as a single Fire Area and the entire Turbine Building, except several separate rooms within the Turbine Building, as another single Fire Area.

Penetrations between floor levels in the Reactor Building and 1 Turbine Building and walls internal to the Reactor Building have been sealed, though there has been no regulatory requirement to do so. Based on References 3 and 4 and the 10 CFR 50 Appendix R 4 Evaluation, in which no reliance is placed on these floors in l both buildings and walls internal to the Reactor Building to )

provide fire barriers, PSC will not treat these penetration seals )

as rated fire barrier penetration seals.

The "J" wall congested cable area floor penetration seals in the Reactor Building and the "G" wall congested cable area floor  !

penetration seals in the Turbine Building are presently and will continue to be rated fire barrier penetration seals.

The exterior walls of the Reactor Building are not fire rated.

The wall separating the Reactor and Turbine Buildings is not a 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> fire rated wall as covered by an exemption request to 10 CFR 50 Appendix R in the FSV Appendix R Evaluation Report, Vol. 4.

2. The 1978 Fire Hazards Analysis identified the Access Control Bay as a separate Fire Area. The Appendix R Evaluation instead  ;

considers the entire Turbine Building as a single. Fire Area with i the exception of five specific rooms, which does not include the Access Control Bay. The Access Control Bay serves no safety function as a separate Fire Area. Therefore, penetration seals  !

in the Access Control Bay will not be treated as rated fire l

barrier penetration seals in the future.

3. The Auxiliary Electrical Equipment Room floor seals have been the subject of extensive correspondence concerning their design and rating, including References is and 6. These seals offer pressure

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i retention and some degree of fire resistance, but have never been tested to the specific requirements of ASTM E-119. The NRC has agreed in Reference 6, that conservative calculations have shown 1 that they will provide sufficient fire resistance for the service they are in. Therefore, these seals in the Auxiliary Electrical Equipment Room floor will remain unrated. These seals will be maintained as " gas tight" unrated fire seals and surveillance annually.

The design and configuration of all other penetration seals in Fire j Barriers designated in the Appendix R Evaluation are 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> fire rated, as tested and certified per ASTM E-119. These seals will i continue to be treated as such to ensure their continued 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> fire

! rating.

With the NRC's concurrence, these changes will be reflected in the Fort St. Vrain Fire Protection Program Plan, and appropriate FSV plant procedures. PSC is presently maintaining hourly fire watches on the above affected areas until NRC concurrence is received on this  ;

request. '

If you have any questions concerning this matter, please contact Mr.

M.H. Holmes at (303) 480-6960. j l

Very truly yours,

]

h W Warn ~b D. W. Warembourg Manager .

Nuclear Engineering Division '

DWW/RS/jw 1

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