ML17334A913

Responds to NRC 850826 Ltr Re Violations Noted in Insp Repts 50-315/85-13 & 50-316/85-13.Corrective Actions:Plant Walkdown Will Be Initiated to Identify & Seal Conduits Open at Both Ends That Penetrate Fire Barrier

ML17334A913
Person / Time
Site:	Cook
Issue date:	09/13/1985
From:	Alexich M INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
AEP:NRC:0692AG, AEP:NRC:692AG, NUDOCS 8510070314
Download: ML17334A913 (10)

Text

INDIANA 8 M IC H I G AN ELEC TRI C COM PA N Y P.O. BOX 16631 COLUMBUS, OHIO 43216 September 13, 1985 AEP:NRC:0692AG Donald C. Cook Plant Unit Nos. 1 and 2 Docket Nos. 50-315 and 50-316 License Nos. DPR-58 and DPR-74 PENETRATION FIRE SEALS INSIDE CONDUITS Mr. James G. Keppler U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137

Dear Mr. Keppler:

This letter is in response to Mr. C. J. Paperiello's letter dated August 26 985 which transmitted Inspection Report No. 50-315/85013(DRS);

50-316/ 5013 DRS) and to a request by Mr. J. Streeter of your staff.

Specifica y, we were requested to identify why we have concluded that we have complied with our licensing basis and are not required to provide additional fire seals inside electrical conduits.

It has always been our understanding that the licensing basis for the plant required silicone sealing outside of conduits penetrating fire barriers, but that. additional sealant inside the conduits was not, necessary.

A review of the then-applicable Standard Review Plan (SRP) and Branch Technical Position (BTP) does not show that sealing both inside and outside of conduits is required. Those standards focused on maintaining the integrity of fire barriers, which are penetrated by, among other things, piping or electrical conduits. The standards required the use of a sealant which would reestablish a barrier with an equivalent fire rating by sealing around the penetrating piping or conduits at the barrier. Consistent with those standards, we do not believe that we committed to seal the inside of penetrating conduits, and have been unable to find any documentation of such a commitment.

NRC's fire protection Safety Evaluation (SE), based in part on an NRR inspection of the in-place fire protection measures, and Region III inspections of the penetration fire stops, support our understanding of the licensing basis for conduit fire barrier penetrations.

The attachment to this letter addresses the pertinent parts of the SRP, the BTP, the SE and supporting documentation, and the Region III inspection reports, all of which support our belief that we had adequately complied with the requirements for fire barrier conduit penetrations.

Our Specification DCCFP101QCN was revised in 1982 to require conduits penetrating fire barriers to be sealed both inside and outside to reflect

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Mr. James G. Keppler AEP:NRC:0692AG newer industry practices. Since this exceeded the licensing basis requirement, our revised specification for internal conduit sealing was not made retroactive.

We continue to believe that we have fulfilled our licensing obligations for penetration fire stops and that no commitment was made to seal inside of conduits. However, we agree the safety of the plant would be further enhanced by sealing certain open ended 'conduits. An open ended conduit is one in which the contained cables exit the conduit into nonenclosed air space and do not directly enter into a metal enclosure such as a junction box. Therefore, we plan to initiate a plant walkdown to identify any conduits that penetrate a fire barrier, and are open at both ends. Though no commitment has previously been made to do so, we are planning to add one seal to those conduits with two open ends and no present internal seal.

This document has been prepared following Corporate procedures which incorporate a reasonable set of controls to insure its accuracy and completeness prior to signature by the undersigned.

Very truly yours, I

M.. A xich ~~~~<g)'0~

Vice President cm Attachment cc: John E. Dolan W. G. Smith, Jr. Bridgman R. C. Callen G. Bruchmann G. Charnoff NRC Resident Inspector Bridgman

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1. Safet Evaluation (SE) dated Jul 31, 1979 a~ The SE identified the following guidance documents which were used to establish the bases for licensing the D. C. Cook Plant in the area of penetration fire seals:

0 Standard Review Plan (SRP) NUREG-75/087, Section 9.5-1 dated May, 1976, including Branch Technical Position (BTP) APCSB 9.5-1 Appendix A, dated August 23, 1976. 0 Our response to Appendix A to the BTP 9 '-1, dated January 31, 1977. 0 Additional information requested by the NRC staff. .Our response (dated October 27, 1977) to NRC questions (dated July 11, 1977).

b. The SRP, page 9.5.1-26 paragraph (j) states in part: "Floors, walls, and ceilings enclosing separate fire areas should have minimum three-hour fire rating. Penetrations in these barriers, including conduits and piping, should be sealed or closed to provide fire resistance rating at least equal to that of the barrier itself."

The SRP, page 9.5.1-28, paragraph 3(d) states in part: "Cable and cable tray penetration of fire barriers (vertical and horizontal) should be sealed to give protection at least equivalent to the fire barrier." c~ Appendix A to BTP 9.5-1, page 15 for Plants Under Construction and Operating Plants, paragraph (j) states in part: "Floors, walls and ceilings enclosing separate fire areas should have minimum fire rating of three hours. Penetrations in these fire barriers, including conduits and piping, should be sealed oi closed to provide a fire resistance rating at least equal to that of the fire barrier itself.. . The fire hazard in each should be ~ evaluated to determine barrier requirements. If barrier fire resistance cannot be made adequate, fire detection and suppression should be provided...." Our response to Appendix A to BTP 9.5-1, page 33, states in part: "All openings for cable, pipe, and ductwork in these walls, floors, and ceilings have been sealed with foamed in place silicone...."

d. NRC Question 9, dated July 11, 1977 states in part: "Substantiate the fire resistance capability of the following items by verifying that their construction is in accordance with a particular design 1 of 3

I I ~~ that has been fire tested, and identify the design and test method used and acceptance criteria....

c. fire barrier penetration seals....

(3) Other pipe or conduit openings justify the lack of seals where they are not provided in fire rated barriers." Our response dated October 27, 1977 to Question 9.c(3) states: "There are no openings in what we consider fire rated barriers which have not been sealed."

e. The SE, page 2, states in part: "All licensees were requested to:

(1) compare their fire protection programs with the new guidelines; and (2) analyze the consequences of a postulated fire in each plant area. The results of these actions as applied to D. C. Cook, Units 1 6 2, are discussed below. "We have, with the assistance of our fire protection consultants,* reviewed the licensees'nalysis and visited both Units 1 and 2 to examine the relationship of safety related components, systems, and structures to combustible materials and associated fire detection and suppression systems.... The SE, page 13, states in part: "The penetration fire stops are provided to prevent the movement of fire from one area to another along the electrical cables which run through these fire areas. Silicone foam poured in and around the cable trays and conduits where they penetrate fire barriers make up the penetration fire stops. "The licensees have cited applicable generic test data for the penetration fire stops which show that the silicone foam material in this application provides a three-hour fire resistance to an ASTM E-119 type fire exposure. "During .our site visit we saw many of the penetration fire stops which had been installed in Unit 1. Subsequently, we learned that some penetration fire stops being installed for Unit 2 were (identical] to those designs that had been tested.... The SE, page 14, states in part: "We conclude that the penetration fire stops which are in place provide sufficient protection from the unbounded spread of fire along We base this conclusion on our knowledge of ASTM E-119 electrical'ables. fire tests including those cited by the licensees which substantiate the fire resistive ability of penetration fire stops constructed with silicone foam."

2. NRC Region III Ins ections of Penetration Fire Sto s

a. Report 050-315/75-01 for inspections dated January 7-9, 1975.

Section 2 states in part: "The licensee stated that all silicone 2 of 3 I I seals were installed in the Donald C. Cook Plant by. Brand Industrial Services, Incorporated (BISCO) .... During his tour of the plant, the (NRC] inspector did not observe any missing or damaged fire barriers...." Report 050-316/77-17 dated September 21, 1977. Section III, paragraph 3.e. states in part: "The Region III inspector observed BISCO personnel working on penetrations identified as trace numbers 302-003-1, -2, and -3 in the cable spreading room...." Report No. 050-315/77-25; 050-316/77-35,for inspections dated December 6-8 and 19-22, 1977. Pages 3 and 4 paragraph g states in part: "In the company of Operations Quality Control Coordinator, the [NRC] inspector made a tour of the following areas examining.... penetration areas requiring special sealing materials.... (1) Control room (including all cabinet interiors) (2) Control room cable spreading room (3) Switchgear rooms (4) Switchgear room cable spreading areas (5) Cable tunnels (6) Diesel generator rooms (7) Various areas of the Auxiliary Building and Turbine Building All penetration areas inspected were adequately sealed with approved and accepted sealant materials...." Report 050-315/78-08; 050-316/78-03 for inspections dated February 14-16 and March 8, 1978. Page 4 states in part: "(Closed) Item D.5, Attachment to License DPR-74, Fire barriers in cable spreading area below control room... All areas requiring the installation of fire barriers appeared to be completed. The inspector did not observe any area which required the installation of a fire barrier...." 3of3 4 t W v