ML20215C614

Forwards Clarifications to SER (NUREG-1002),Section 9.5.1 Re Fire Protection Program for Review

ML20215C614
Person / Time
Site:	Braidwood
Issue date:	11/26/1986
From:	Hunsader S COMMONWEALTH EDISON CO.
To:	Harold Denton Office of Nuclear Reactor Regulation
References
RTR-NUREG-1002 2438K, NUDOCS 8612150281
Download: ML20215C614 (3)

Text

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• [< ~ } 7COmmORWGelth Edleen One Fast Nanonal Plaza. CNea00. lilinois k ',~' J Address Reply to: Post Omoe Box 767 Nd CNca0o. lilinos 60000 0767 November 26, 1986 Mr. Harold R. Denton Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC. 20555

Subject:

Braidwood Units 1 and 2 Fire Protecticn Program Nhc Docket Nos. 50-456 and 50-457

Reference:

(a) NUREG-1002, Safety Evaluation Report, Supplement No. 2, dated October, 1986 (b) September 22, 1986 A.D. Miosi letter to H.R. Denton 4

(c) September 29, 1986 A.D. Miosi letter to H.R. Denton (d) August 4, 1986 A.D. Miosi letter to H.R. Denton

Dear Mr. Denton:

In Section 9.5.1, of reference (a), the NRC staff provided their evaluation of the Braidwood Fire Protection Program.

Commonwealth Edison has reviewed this section and has the clarifications that are included in Attachment "A".

These are being forwarded to you at this time for your review so that appropriate corrections can be made in the next Safety Evaluation Report Supplement.

Please direct any questions concerning this matter to this office.

One signed original and fifteen copies of this letter and the attachment are provided for your review.

Very truly yours, R

([

S. C. Hunsader fyd.

Nuclear Licensing Administrator

/klj att.

Stevens goh cc: J.

2nu 1 i

ATTACHMENT A

1. Section 9.5.1.4 on page 9-2 of Reference (a) states in part:

"However, by letter dated September 22, 1986, the applicant committed to install sprinklers at the hatchway opening before exceeding 5% of rated power. Additionally, draft curtains will be added to the hatchway no later than 6 months after fuel load. As an alternative to draft curtains, the applicant proposed to cover the hatchway with steel plates that are caulked into place, before exceeding 5% of rated power."

Contrary to this statement References (b) and (c) provided the following commitment: " Commonwealth Edison Response - CECO will use one of several options for this hatchway. The options are: (1) New Sprinklers will be added at the hatchway opening prior to exceeding 5% power and draft stops will be added to the hatchway no later than 6 months a"ter Fuel Load. (2) The hatchway will be covered by steel plates that are caulked into place prior to exceeding 5% power."

This response applios to the hatchways at elevations 426' and 364' of the Auxiliary Building (items K-3 and K-18, respectively from the Braidwood FP audit).

Commonwealth Edison has chosen to implement option #2, and as such will only be installing steel plates to cover the hatchways.

Sprinkler systems will not be installed around these hatchways as stated in Reference (a). The installation of steel plate to cover these hatchways is consistent with other installations of a similar design throughout the plant. As noted in the second paragraph on page 9-2 of Reference (a) approval has been previously given to use unrated steel hatch covers in lieu of fire-rated construction in several floor / ceiling assemblies on the basis that the steel cover would form a continuous noncombustible barrier against the vertical propagation of smoke and hot gases.

2. Section 9.5.1.4 on page 9-4, (paragraph 2) of Reference (a) describes the physical conditions concerning the separation of the redundant charging pumps and cubicle coolers on elevation 364' of the Auxiliary building. As a part of that paragraph it is stated that: "This cubicle is separated from the remaining portion of the fire area by masonry walls, and all pipe and cable penetrations there are sealed with a fire rated material."

At Braidwood Station all pipe and cable penetrations through the wall are sealed with radiation seals. While these radiation seals employ materials and construction details that are similar to fire seals, they do not have a 3-hour fire barrier rating.

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3. Section 9.5.1.4 on page 9-4, (paragraph 3) of Reference (a) describes a situation in the containment where the eight reactor coolant system hot-leg temperature instrumentation cables have a minimum, horizontal separation of approximately 15 feet (Deviation C.6 on page AS.8.30-1 of the Fire Protection Report). It is pointed out in this paragraph that Reference (d) provided a response to this concern by committing to protect one division of cables with a 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> fire barrier in such a manner as to achieve the minimum separation distance required by Section C.S.b(2)(b) of BTP CMEB 9.5-1.

Subsequent to that letter Commonwealth Edison implemented a design change to rero?te one division of Reactor Coolant System hot leg temperature instrumentation cables so that redundant divisions of the cables would be separated by a minimum horizontal distance of 52 feet. This separation is now comparable to that for other system cables inside containment as described in other Appendix R deviations. This change was pointed out during the NRC Fire Protection audit of Braidwood with the understanding that formal documentation would be filed in Amendment 9 to the Fire Protection Report.

4. Section 9.5.1.'4 on page 9-5 (paragraph 2) of Reference (a) references the essential service water system (ESW) tower fans.

There are no ESW tower fans at Braidwood Station. Any reference to this in the B/B Fire Protection Report Amendment #7 will be deleted in Amendment #9 to the Fire Protection Report.

5. Section 9.5.1.4 on page 9-6 (paragraph 1) of Reference (a) references valves "05X162-A,B,C, and D". This appears to be a typographical error. The correct valve numbers are OSX162-A,B.C, and D.

6. In Section 9.5.1.5 on page 9-12 of Reference (a) concerning Fire Protection for the control Room it is stated that: "Pending installation of smoke detectors in the main control console, the adequacy of the smoke-detection system in the control room is considered open."

Commonwealth Edison had previously evaluated the need for the installation of smoke detectors in the main control console and does not have the installation of any smoke detectors pending for this application. Commonwealth Edison submitted information to the NRC in Reference (c) concerning the duct smoke detectors that are installed to detect fires for the main control panels. As summarized in Reference (c) the design employed to monitor for main control room panel fires is conservative and will provide the function desired (i.e., smoke detection and alarm). By utilizing ionization type duct smoke detectors we are assuring that fires will be detected in its incipient stage before a major fire can develop.

Given the nature of the combustibles in the panels, mainly IEEE-383 rated cable, an incipient fire will be quickly detected prior to the spread of fire to the surrounding cables. We believe that our design clearly meets the intent of the NRC guidelines to promptly i detect fires within the main control room panels. l 2438K

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