ML20106C035

Responds to Suppl 1 to NRC Bulletin 92-001, Failure of Thermo-Lag 330 Fire Barrier Sys to Perform Sepcified Fire Endurance Function. One Addl Fire Barrier Declared Inoperable on 920831 & Compensatory Measures Established

ML20106C035
Person / Time
Site:	Monticello
Issue date:	09/28/1992
From:	Parker T NORTHERN STATES POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
IEB-92-001, IEB-92-1, NUDOCS 9210060018
Download: ML20106C035 (5)

Text

.

l Northern States Power Company 4' ' Niconet Mall M, iapolis, Minnesota $54011927 Te.,; phone (612) 330-5500 September 28 1992 10 CFR Part 50, Section 50,54(f)

US Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C.

20555 MONTICELLO NUCIXAR GENEPATINC PIANT Docket No. 50-263 License No. DPR-22 Response to NRC Bulletin 92-01 Supplement 1, " Failure of Tnermo-Lag 3S0 Fire Barrier Systcm to

[

Perform Its Specified Fire Endurance Function" to this letter provides our rasponse to NRC Bulletin 92-01 Supples.m i 1, " Failure of Thermo-Lag 330 Fire Barrier System to Perfc,rm Its Spectiled Fire Endurance Function" Attachment I also provides the information necessary to satisfy Technical Specification 3.13.G.2, which requires that a special report he submitted to the Commission when an inoperable penetration fire barrier cannot be restored to operable status within 14 days.

Please contac us if you require additional inforttation.

/

/

/

Mt4 pl n

Thomas M. Parker Manager Nuclear' Support Services cc:

Regional Administrator-II., NRC NRR Project Manager, NRC Resident Inspector, NRC State of Minnesota, Attn: Kris Sanda i Silberg Attachments: Affidavit to the US Nuclear Regulatory Commission :

Response to NRC Bulletin 92-01 Supplement 1 9210060018 920928

/

l ll PDR-ADOCK 05000263 y

PDh

.m 4

UNITED STATES NUCLEAR REGULATORY COMMISSION NORTHERN 'TATES POWER COMPANY MONTICELLO NUCLEAR GENERATING PLANT DOCKET NO. 50 263 Respor.se to NRC Bulletin 92-01 Supplement 1, " Failure of Thermo-Lag 330 Fire Barrier System to l

Perform its Specified Fire Enduranco Function" Northern States Power Company, a Minneaota corporation, hereby provides the luformation requested by NRC Bulletin 92-01 Supplement 1, " Failure of Thermo-Lag 330 Fire Barrier System to Perform Its Specified Fire Endurance Function",

Pursuant to 10 CFR 50. 54(f). Answers t-: the specific questions as'eed by the bulletin are provided in attachment 1 to this submittal.

Thia letter contains no restricted or other defense information.

NORTHERN S ES OMPANY J

By s

id

'Ih'omas M Parker

~

Manager Nuclear Support SetJices on this.Nf d day of b p N de v

/?e9 b before me a notary public in and for said County, personally appeared Thomas M Parker, Manager Nuclear Support Services, and being first duly sworn acknowledged that he is authorized to execute this document on behalf of Northern States Power Company, that he knows the contents thereof, and that to the best of his knowledge, information, and belief the statcments made in it are true and that it is not

-interposed for delay.

(

/

-y ht!

hh eam!<W 7

f

/

//

= =, =,.,, = _.

f NOTARYPUDUC M:NNEGOTA JUDY L.KU,PPSRicg ANOKA ColWTY Wy Commusen Expkes Sept 29. tsar

• N N wwwwwu,w.'.

i Page 1 PESPONPLTO NRC BU1J2IJE 92-01 SUPPLEMENT 1 DACKGROMUR; On June 24, 1992, an advance copy of NRC Bulletin 92-01 " Failure of -Thermo Lag 330 Fire Barrier System to Maintain Cabling in Wide Cable Trays and Stall Conduits Free From Fire Damage" vas received at Monticello.

Based on an evaluation of the information contained in this bulletin, one fire barrier was declared inoperable on June 24, 1992 and compensatory measures were established.

On August 31, 1992, an advance copy of NRC Bulletin 92-01 Supplement-1

" Failure of Thermo-lag 330 Fire Barrier System to Perform Its Specified Fire Endurance Function" was received.

This supplement required that each licenseo submit a written response to questions concerning usage of Thermo-Lag at erch facility.

Based on an evaluation of the information contained n this bulletin suppicment, one additional fire barrier was declared inoperable on August 31, 1992 and compensatory measures were established.

Technical Specification 3.13.G.2 requirea, in part, that if an inoperable penetration fire barrier cannot be restored to operable status within 14 days, a special report must be submitted to the Commission-outlining the causa of the inoperability and the plans and schedule for restoring the barrier to Operable status.

The barriers declared inoperable on June 24, 1992 and August 31, 1992 remain inoperable at this time, therefore, the Technical Specification requirement for a special report applies, BULLETIN RESfpNSE..

ll With respect to NRC Bulletin No. 92-01 Supplement 1, we provide the following information:

l Bulletin 92-01 Supplement 1 Requested Actions:

"Each licensee who has installed Thermo-lag 330 fire barriers must-

. inform the NRC in writing within 30 days of receiving this bulletin-supplement, whether or not it has taken the'(following) actions.":

j l.

.For those plants that use either 1-or 3-hour pre-formed Thermo-Lag -

l "1.

330 panels and conduit shapes, identify the areas of the plant which have Thermo-tag 330' fire barrier material installed and determine the plant areas which use this material for the protection and separation of the safe shutdown capability."

L l

--e a

r

~ -. - - - - -.. -

Attachment.l.

Page 2

- Egyponse: As reported in our July 24, 1992 response to Bulletin 92-_01, Monticello presently uses Thermo-Lag 330 Fire Barrier Systems in ons. fire area.

There is approximately 35 fret of barrier on one i :h conduit and 35 feat of barrier on four inch conduit.

Both of these barriers are used to ensure safe r:.httdown ecpability during a 10 CFR part 50, Appendix R fire.

P "2.

In those plant areas in which Thermo-Lag fire barriers are used in raceways, valls, ceilings, equipment enclosures, or other areas to protect cable trays, conduits, or separate redundant safe shutdown functions, the licensae should Implement, in accordance with plant procedures, the appropriate compensatory meneures, such as ftre watches, consistent with those that would be implemented by either the plant technical specifications or the operating license for an inoperable fire barrier. These compensatory measurcs should remain in place until the licenses can declare the fire barriers operable on the basis 2 appli tr.ble tests which demonstrate successful 1-or 3-hour barrier performance."

b ; inn The barrier protecting the on.e inch conduit was declared inoperable per Bulletin 92 01.

A continuous fire watch was posted until a fire detection system with remote alarm was. installed, at which time a once per hour roving firo watch covering che af fected area.was implemented per the Plant Technical Specification for Penetration Fire Barriers (Technical Specification 3.14.G ')).

Per riulletin 92-01 Supplement ', the barrier protecting the four inch conduit l

was declared inoperable on August 31, 1992.

2ince the one inch and four inch barriers are located within one foot of each other for their entire length, the previously installed fire detection and alarm system. continued to provide adequate coverage The once per hour roving fire warch established for the one' inch barrier was expanded to include the four inch barrier, If the detection syst.em in this. area becomes inoperable, a continuous fire watch will be reestablished per the fechnical Specifications.

"Where ftre barriers ata declared inoperable, the licensee is required to describe the measures being taken to ensure or restore fire barrier operability.

These measures should be consistent with actions taken in response to Bulletin 92-01."

i i

i

.,-.~_..-.e_

..~.

m 9

Page 3

Response

Our plan to restore the one anc four inch ccnduit; fire barriers to operable status is corposed of two parallel efforts.

First, a Design Change hos been initiated to replace'the inoperabic fire barriers or reroute the affected conduits so that they do not require fire barrier wraps. Second, actions to restore fire barrier operability are be3ng developed through an industry program being coordinate.d through NUMARC. - This program will include-establishment _of a. test database, development of guidance for applicability of tests, development of generic installation guidance, and consideration of-_.

additional testing as appropriate. We will apply the results of one of_these efforts, as appropriate, to the inoperable conduit fire barriers. These measures are-consistent with actions taken in response to Bulletin 92 J1.

ADDITION /W_ltRQEMATlpN TO SATISFY TECHNICAL SPECIFICATION REPORTIEG REOUIREMENTS:

With respect to the report re.,uired by Technical 3pecification 3.14.G.2, the following additional information is provided:

1 Gouse of Inonerability; The fire barriers w.re decTered inoperable as a result of the information'provided in NRC Bulletin No. 92-01 and Supplement 1 concerning the failure or Thermo-Lag 330 fire barrier systems during endurance testing.

Plans and Schedule for Restarine Barrier to Operable _ Status:

Our plans for restoring the inoperable fire barriers are discussed in the bulletin response above.

The barriers will be restored to operability by the end-of our 1993 refueling outage.

Note that in our letter of July 24, 1992 on this subject, indicated this action would be complete by March 31 1993.

That date was we selected because it represtnted the projected completion date-for the:1993 refueling outage, which is when the work will be performed.

Since that time, the outage start date has been moved back approximately 3 weeks. We-have therefore revisert the commitment completion date to reflect the fact-it is dependent on the outs.e schedule.

b F

k'

..4-,e

. m4

---

m--

,,y m

-.v

~

o-

-