BVY-92-115, Responds to NRC Bulletin 92-001 Supplement 1 Failure of Thermo-Lag Fire Barrier Sys to Maintain Cabling in Wide Cable Trays & Small Conduits Free from Fire Damage. Temporary Fire Detection Installed

Responds to NRC Bulletin 92-001 Supplement 1 Failure of Thermo-Lag Fire Barrier Sys to Maintain Cabling in Wide Cable Trays & Small Conduits Free from Fire Damage. Temporary Fire Detection Installed

ML20106A991
Person / Time
Site:	Vermont Yankee
Issue date:	09/24/1992
From:	Murphy W VERMONT YANKEE NUCLEAR POWER CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
BVY-92-115, IEB-92-001, IEB-92-1, NUDOCS 9209300199
Download: ML20106A991 (4)

Text

.Va'Rk1ONT YANKEE

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j nat. s on. m en Q_,/ *>7at1 Septembsr 24,1992 BVY 92-115 l

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I U.S. Nuclear Regulatory Commission I ATTN: Dncement Contrel Desk Washington, D.C. 20555 l Referencas-. (a) License No. DPR 28 (Docket No. 50-270  ;

(b) NRC Bdletin 92-01, Failure of Thermo-Lag 330 Fire Barrior System to Maintain Cabling in Wide Cable Trays and Small Condults Free From Fire Damage, dated 6/24/92 (c) Memo, W.H. Rasin (NUMARC) to NUMARC Administrative Points of Contact, NRC Meeting with NUMARC on Thermo-Lag Fire Barrier issue, datet' 7/8/92 (d) Letter, VYNPC to USNRC, BVY 92 092, dated 7/24/92 (e) NRC Bulletin 92 01 Supplement 1, Failure of Thermo-Lag 330 Fire Barrier to Perform its Specified Fire Endurance Function, dated 08/28/92 (t) Letter, P.M. Sears (USNRC) to W.P. Murphy (VYNPC). Response to NRC Bulletin 92-01, Failure of Thermo-Lag Fire Barrier System to Maintain Cabling in Wido Cable Trays and Small Conduits Free From Fire Damage, dated 9/8/92

Subject:

HRC Bulletin 92-01 Supplement 1 " Jsponse to Reference (f).

Dear Sir:

On Friday evening. August 28,1992, Vermont Yankee received a copy of Reference (e), which expanded the applicability of Thermo-Lag 330 (R) concems to include all conduits, trays, walls, ceilings, and equipment enclosures. Reference (e) further required all nuclear facilities utilizing this material to implement immediately upon recuipt, the appropriate compensf tory measures as if the fire barriers were inoperable, and to provide, within 30 days of receipt, a written notification describing whether Thermo-Lag barriors were installed and what actions would be taken to ensure or restore fire barrier integrity.

Earlier, discussions had been held between Vermont Yankee and NRC staff regarding compeasatory actions instituted subsequent to the r_eceipt of Reference (b). Reference f) detailed some of the issues ralbec' during these discussions and requested that Vermont Yankee address these issues in this response. This letter is submit'ed as our response to NRG Bulletin 92-01 Supplement 1 and the issues raised in Reference (f).

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VERMONT YANKEE NUCLEAR FOWER CORPOR ATION U.S. Nuclear Regulatory Commission September 24,1992

- Page 2 IMMEDIATE CORRECTIVE ACTIONS:

After evaluation of the information contained in Bulletin 92-01 Supplement 1, two additional 4-inch conduits were added to the scope of Vermont Yankee Thermo Lag applications requiring compensatory measures.

As an interim rneasure, an hourly fire watch was established for the 4 inch conduits immediately upon receipt of Supplement 1. This fire watch was also temporarily expanded to cover the 3-inch conduit identified in Reference (b) at this time.

Temporary fire detection was installed in the area of the 4-inch conduits. This detection alarms at a local fire panel and in the Control Room.

ANALYSIS:

A more detalled review of this specific Thermo-Lag 330 application at Vermont Yankee has subsequently been performed for the 4-inch conuuits. The following are the results of this review:

The two 4" conduits are wrapped with Thermo-Lag 330 in a 3-hour configuration and located in the hallway between the Reactor Building and the Control Building. The conduits housa the power cabins for the motor control conter supplying Division Sll safe shutdown toads, such as the RCIC-15 valve emergency feed, " A" Core Spray l'jection valves, " A" Torus Spray / Torus Cooling valves and the "A" Residual Heat Removal heat exchanger service wat1r outlet valve.

Considered in our evaluadon of appropriate compensatory measures were the following:

l a) Temporary fire detection was installed in the area of the 4 inch conouits to alert the Control Room in the unlikely event of a fire in the area.

j b) No ignit!an sources are present noar the location of the 4-inch conduite i

c) The 4 inch conduits are located in a hallway with frequent personnel traffic and which contains minimalin situ and transient combustible loading.

During a telecon on August 31,1992 between VY and NRC, the hourly walkdown of the areas, in concert with the installation of temporary fire detection was determined to be sufficient to ensure that these conduits are edequately protected until permarent resolution to the Thermo-Lag issues are identified.

RESPOi4SE TO REFERENCE (f);

Vermont Yankee's review of Reference (f) revealed the following items requiring resporse; (1) Page 1, Paragraph 3 : Vermont Yankee Technical Spo,ifications are silent with regard to fire j' barriers.

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VERMONT YANKEE NUCLE AR POWER CORPORATION U.S. Nuclear Regulatory Commission  !

September 24,1992 l Page .3 l l

The Vermont Yankee Technical Specific ations state the following in regard to fire barriers: l 3.13.E Vital Fire Barrier Penetration Fire Seals l

1. Except as specified b Specification 3.13.E.2 below, vital fire barrier penetration seats protecting the Reactor Building Control Room Building, and Dies '

Generator Rooms shall be intact.

2. From and after the date a vital fire barrier penetration fire seal is not intact, a continuous fire watch shall be established on at least one side of the affected penetration within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.

4.13.E Vital Fire Barrier Penetration Fire Seats

1. Vital fire barrier penetration seals shall be verified to be functional by visual inmetion at least once per operating cycle and following any repair.

(2) Page 1, Paragragh 3 : Vermont Yankee should submit a Technical Specificatior' revision whir.1 covers fire barriers.

In heu of a Technical Specification revision, Vermont Yankee will procedurally implement controls on the Appendix R fire barriers such that a continuous fire watch on any degraded fire barriers would be established immediately and remaM in place until the condition is resolved or further analysis justifies alternative compensatory measures.

(3) Page 2, Paragraph 1 : Vermont Yankee's planned use of cameras as a compensatory measure.

Upon weipt of Supplement 1 to NRC Bulletin 92-01 Vermont Yankee immediately instituted a 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> fire watch on the two 4-inch conduits located in a hallway between the reactor building and the control building. This 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> fire watch was also temporarily extended to cover the 3" conduit discussed in Reference (b). Givon these changes and recognizing that the NRP was not entirely satisfied with Vermont Yankee's response to the original bulletin, Vermont Yankee requested a telecon with the appropriate NRC personnel to explain our response to Supplement 1. During this telecon, held on August 31,1992, Vermont Yankee explained that a 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> fire watch had been initiated for all (3) conduits which contain safe shutdown wiring and are wrapped with Thermo-lag 330. We also explained that we were in the process of installing temporary fire detectica in the area of the 4-inch conduit. This fire detection was installed and operable by September 1,1992.

During the August 31, 1992 conversation Vermont Yankee further stated that we were evaluating .astar : in of television cameras with the intent that we would justify reducing the fire watch frequency from once per hour to twice per shift. The NRC suggested that VY should

- coordinate its evaluation, relating to the use of television cameras, with the indu3try via NUMARC, and risvelop a consistent industry position on the matter. The NRC indicated that they would prefer to deal with one position rather than many individual, varying, plant positions.

Therefore, no consideration is currently being given to the use of television cameras.

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VERMONT YANKEE NUCLEAR POWER CORPORATION U.S.- Nuclear Regulatory Commission September 24,1992 Page 4 i

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SUMMARY

The Thermo-Lag 330 fire barrier material in question, is utilized to a very limited extent at Vermont Yankee. We believe we have appropriately addressed the issue with the information currently available to the industry. Vermont Yankee is aware of and an active sponsor of the industry program being coordinated by NUMARC to establish a test database, develop guidance for applicability of tests, develop generic installation guidance and consider /coordina.e additional testing as appropriate.

Vermont Yankee plans to follw these activities and continue efforts to evaluate options f ar addressing this issue on a longer term basis.

We believe that the actions described above are responsive to your concerns; however, should you have any further questions, please do not hesitate to contact us.

Very truly yours, Vermont Yankee Nuclear Power Corporation f it Warren P. Mgrphy mm Senior Vice P, resident, pegions 4

cc: USNRC Region i Administrator USNRC Resident inspector - VYNPS USNRC Project Manager - VYNPS William H. Rasin. NUMARC

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8 SALLY A. SANDSTRUM

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NOTARY PUBUC <

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STATE OF VERMONT )  %'!NDHAM COUNTY, VERMONT 2 $

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My Term Expdes ~.Mo/r .-

y 6 Jvb E W ' msf ,.Ssf4J-Then personally appeared before me, Warren P. Murphy, who, being duty sworn, d$ Sthty that he is Ser{gMVipe President Operations, nf Vermont Yankee Nuclear Power Corporation, that ne is duly authorized ib foregoing document in the name and on the benatf of Vermont Yenkee tfiefin tgreMents Nuclear Power therein are true to the best of his knowledge and behef.

JanG A.A L Sally A. S'andstrum, Notary Pubbc 14dn My Cammission expires February 10,1995

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