PY-CEI-NRR-0278, Responds to NRC Re Criteria for Sealing Inside Electrical Conduit 4 Inches or Less in Diameter.Test Data Demonstrates That Sealing Matls Effectively Prevent Transmission of Hot Gases/Smoke Through Conduit

Responds to NRC Re Criteria for Sealing Inside Electrical Conduit 4 Inches or Less in Diameter.Test Data Demonstrates That Sealing Matls Effectively Prevent Transmission of Hot Gases/Smoke Through Conduit

ML20128B610
Person / Time
Site:	Perry, Harris
Issue date:	06/26/1985
From:	Edelman M CLEVELAND ELECTRIC ILLUMINATING CO.
To:	Youngblood B Office of Nuclear Reactor Regulation
References
PY-CEI-NRR-0278, PY-CEI-NRR-278, NUDOCS 8507030301
Download: ML20128B610 (4)

Text

.. -

T s31. ys p

~

r; 23 < ! ! j r; p p ii(1,nj~

u r g-s; {.,: T, iio Ote y J i ,

, L c.c

j i_. [sj ,o, p g.seMV.

• t. s t ;.1 . r ,m .isL v-. .

P.o. BOX 5000 - CLEVELAND, oHlo 44101 - TELEPHONE (216) 622-9800 - lLLUMINATING BLDG. - 55 PUBLICSQUARE Sewing The Best Location in the Nation MURRAY R. EDELMAN VICE PRESIDENT NUC MA R June 26, 1985 PY-CEI/NRR-0278 L Mr. B. J. Youngblood, Chief Licensing Branch No. 1 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Perry Nuclear Power Plant Docket Nos. 50-440; 50-441 Fire Protection CMEB BTP 9.5-1 Section C.5.l(3), Penetrations

Dear Mr. Youngblood:

We have evaluated your letter of June 10, 1985 addressing the Perry Nuclear Power Plant criteria established in PY-CEI/NRR-0234 L for sealing inside electrical conduit 4 in. or less in diameter according to BTP CHEB 9.5-1, Section C.5.a(3). Your letter indicated you could not accept our sealing criteria as presented and suggested three alternatives were open for resolving the conduit penetration sealing issue. We are currently pursuing both alternatives (2) and (3) outlined in your letter which will result in the submittal of additional information augumenting our current criteria.

Test data presently available demonsrates the physical properties of our sealing materials to effectively prevent the transmission of hot gases / smoke through conduit sealed at one end (hot side) with approximately 9" of Bisco type sealant. Additional test data will be developed for typical con-figurations at PNPP to support our position and respond to the NRR alternative No. 2.

We are also examining in depth oer unsealed conduit / wall arrangements in conjuction with fire protection features in order to present our fire hazards analysis as discussed in your alternative No. 3. It is our intent to provide you with a sample package of additional justification; that is a fire hazard analysis for a given fire barrier using our sealing criteria. This information will be supplied to you by July 15, 1985.

1

{700 ,-

hhj7030301850626 i o p ADOCK 05000400 PDR

. . s i

B. J. Youngblood June 26, 1985 PY-CEI/NRR-0278 L i'

1 In an effort to determine the potential for the passage of hot gas and smoke I and to take adequate steps to limit this problem, the previously submitted j j criteria had been developed. Our criteria was established in a format that was j j simple and clear for implementation / monitoring with our contractors by '

establishing sealing criteria on a wall basis. This assures compatibility with I our FPER Appendix R fire wall identification and provides for a generic fire a

hazards analysis on a wall bases. Our additional information will support this approach.

This letter also is being submitted to identify our positions on BTP CMEB 9.5-1 Section C.S.a(3) interpretation and to elaborate on our previous FPER commitment for penetration sealing pursuant to BTP APCSB 9.5-1. CEI would like j to clarify that our FPER statements which did not address Section C.5.1(3) for i the special case of sealing inside electrical. conduit:

l l A. Our statements on pages 5-16 and 5-19 in Section 5 of our FPER l Revision 3 "All penetrations to these fire areas are sealed or l dampered to maintain the continous 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> fire resistance rating" and l " Cable penetrations in fire barriers are sealed consistent with fire barrier resistance requirements" were not commitments to seal inside l'

conduit. These statements are found in the FPER comparision table responding to BTP APCSB 9.5-1 Section D.1.(J) and D.3.(d),

respectively. These sections of BTP ACSB 9.5-1 did not provide any i' requirements for sealing inside conduit. Our statment/ commitment was I q a general statement related to sealing around cable trays, pipe and i other similar penetrations for maintaining the fire rated integrity of the barrier containing these penetrations.

The requirement for a 3 hr. rating on penetration seals' involves sealing around conduit trays and pipes passing through the

penetration. This is demonstrated by the descriptions of the rated

! penetration assemblies listed in the U. L. Building Material Directory. The rated systems do not require sealing inside the conduit as part of the described assemblies. The present penetration sealing program at Perry is being done using a system configuration tested by a recognized laboratory, in accordance with ASTM 119 as described in the FPER. This system does not require sealing inside conduits as part of the 3 hr. rating.

2 A significant effort has been expended at the PNPP site to seal around penetrations for compliance with BTP APCSB 9.5-1. The present PNPP penetration sealing program meets the commitments made in the 4

FPER. It provides a level of protection equivalent to other fire j barrier features such as fire doors and standard fire dampers. ,

, i

o

.- (

Mr'. B. J. Youngblood June 26, 1985 PY-CEl/NRR-0278 L B. Your letter of June 10, 1985 addresses sealing conduit to prevent flame, radiant energy, smoke or hot gases ftom being transmitteed through the interior of electrical conduit and references Generic Letter 85-01.

The concern raised in BTP CMEB 9.5-1 Section C.5.a(3) involves the potential for transmitting smoke and hot gasses through the fire barrier. This is a separate concern from the integrity of the barrier.itself and would occur through any minor opening such as allowable gaps at the top of fire doors, and the non smoke control type fire dampers used as part of the fire barrier.

Generic Letter 85-01 8.8 addresses the concerns for unsealed openings in fire barriers. This states that such openings should not permit

. flame radiant _ energy, smoke and hot gas to pass through the barrier.

Although flame and radiant energy could be potential problems for larger openings in the barriers such as unsealed vent openings, incomplete walls, etc., that is not the case for openings 4 inches or less in diameter. Generic Letter 85-01 references BTP CMEB 9.5-1 which uniquely specifies protection for sealing inside conduit 4 in.

or less in diameter, as follows:

" Openings inside conduit 4 inches or less in diameter should be sealed at the fire barrier unless the conduit extends at least 5 feet on each side of the barrier and is sealed either at both ends or at the fire barrier with non-combustible material to prevent the passage of smoke and hot gases."

In summary, our positions are as follows:

(1) Our referenced FPER commitment for penetration sealing addressed sealing outside cables, cable trays, pipe, etc. for preventing flame spread and maintaining the fire wall integrity and did not address sealing inside conduit.

(2) The requirement for sealing inside conduit 4 in. or less in diameter is a new criteria established in BTP CMEB 9.5-1 and was not a part of BTP APCSB 9.5-1 which was the original basis for in our licensing process. BTP APSCS 9.5-1 established criteria for maintaining the integrity of the fire wall with which CEI has complied.

(3) Section C.5.1.(3) of BTP CMEB 9.5-1 specifically addresses hot gas

'and smoke when considering sealing inside conduit 4 in. or less diameter as a special case. It does not require preventing the passage of flame or radiant energy through conduit. This position is supported by Generic Letter 85-01.

(4) Our present sealing criteria is a justifiable approach to preventing the passage of hot gas or smoke through conduit less than 4 in. in diameter in areas where safe shutdown could be impaired.

~ .-

Mr. B. J. Youngblood June 26, 1985 PY-CEI/NRR.-0278 L

< We look forward to meeting with you on this subject and finalizing a sealing criteria. We are currently sealing conduit penetrations according to the existing CEI criteria and will review these modificatons upon reaching a final agreement. As indicated in our May 3, 1985 letter (PY-CEI/NRR-0234 L) completion of this activity will be scheduled prior to exceeding 5% power for

! Unit 1.

i' If you have any questions, please feel free to call.

Very truly yours, Murray R. Edelman Vice President Nuclear Group MRE:nj c cc: Jay Silberg, Esq.

I John Stefano (2)

J. Grobe J. Ulie, Region III i

i B

i

_.___ _ _ _ _ . _ _ _ _ _ . _ _ _ _ . . _ . _ _ _ _ _ _ _ _ _ _ . . _ _ _ _ _ _ _ _ _ .