ML20064H498

Forwards Util Most Recent Submittal to NRC on Thermo-Lag Fire Barriers,Per Obligation to Keep Licensing Board Apprised of New Info Potentially Relevant to Matters Being Adjudicated

ML20064H498
Person / Time
Site:	Diablo Canyon
Issue date:	03/09/1994
From:	Repka D Public Service Enterprise Group, WINSTON & STRAWN
To:	Bechhoefer C, Kline J, Shon F Atomic Safety and Licensing Board Panel
References
CON-#194-14777 OLA, OLA-2, NUDOCS 9403180029
Download: ML20064H498 (9)

Text

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WINSTON & STRAM[go FREDERICK H WIN 5'fDN (18511866) 1400 L STREET. N W. . cHCAGO OFFCE SILAS H STRAWN (1891-194,,) WASHINGTON. D.C. 20005 3502 U$k ld Ml )9 '3ll WEST WACMER DalvE CHecAQQ ILUNOfS 606M (202) 371 5700 0FFICE OF SECRFin' ~,, m , o,,c, ,

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(202) 371-5726 March 9, 1994 Charles Bechhoefer, Chairman Frederick J. Shon Administrative Judge Administrative Judge Atomic Safety and Licensing Atomic Safety and Licensing Board Board U.S. Nuclear Regulatory U.S. Nuclear Regulatory Commission Commission Washington, DC 20555 Washington, DC 20555 Jerry R. Kline Administrative Judge Atomic Safety and Licensing Board U.S. Nuclear Regulatory Commission -i Washington, DC 20555 Re: Pacific Gas and Electric Co. (Diablo Canyon Nuclear Power Plant, Units 1 and 2), Docket Nos. 50-275-OLA. 50-323-OLA (Construction Period Recanture)~ '

Dear Administrative Judges:

Mindful of our obligation to keep the Licensing Board apprised of new information potentially relevant to matters being adjudicated,V attached is a copy of Pacific Gas and Electric Company's most recent submittal to the NRC on Thermo-Lag fire barriers. As stated on page 1 of the submitta), PG&E had previously committed to remove Thermo-Lag used in containment as a radiant energy heat shield. PG&E has now decided to remove all remaining Thermo-Lag installations, including those credited as a V Hgg Duke Power Co. (William B. McGuire Nuclear Station, Units 1 and 2), AII.B-14 3 , 6 AEC 623, 625 (1973).

9403180029 940309 O PDR ADOCK 05000275 O PDRr }

WINSTON & STRAWN March 9, 1994 Page 2 fire barrier. As stated on page 4, the replacement of the credited fire barriers will be completed by December 31, 1994.

Very truly yours, DA-David A. Repka C ~

Counsel for Pacific Gas and Electric Company Attachment cc: Service List i

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'f 217195 Pacific Gas and Electric Company . 77 Beale Street. Room 1451 Gregory M.Rueger P.O. Box 770000 Senior Vice President and San Francisco.CA 94177 - GeneralManager 415/973 4684 Nuclear Power Generabon Fax 415/973-2313 February 14,1994 PG&E Letter No. DCL-94-034 U.S. Nuclear Regulatory Commission RECEIVED

!? _y ATTN: ' Leonard J. Callan FEB 181994

$? @ Washington, D.C. 20555 1 CHRISTOPHER j. WARNER ,

Re: Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 Diablo Canyon Units 1 and 2 Respor.sa to l1cque::: for Addit:ona!Information Regarding Generic Letter 92-08 Gentlemen:

The NRC letter dated December 21,1993, " Request for Additional Information Regarding Generic Letter 92 08, 'Thermo-Lag 330-1 Fire Barriers,' Pursuant to 10 CFR 50.54(f) - Diablo Canyon, Units 1 and 2," ,

was received by PG&E on December 29,1993, and required a response within 45 days from the date of receipt. PG&E's response to this request for additional information is enclosed.

Sincerely, ,

i AM.y Gregory M. Rueger -

Subscribed end sworn to before Attorneys for Pacific Gas this 14th day of February 1994. and Electric Company Howard V. Golub Christopher J. Warner

L C n* ) A (if , ,  %.9 Rosa W. Schoening, Notar[Public Christopher J. harner i omCIAL SEA 1. h cc

Mary H. Miller Kenneth E. Perkins Fanmumannmununnuum.un..u ROSA W. 5CHOENING NOTARY PUBUC CAUFORNIA E i

Shen R. Peterson crn a, coum or san rnAncisco E Diablo Distribution . My commi.um cxpires umn 2o.1995 i emumuuuuuumuuuuuuumuuuuuums Enclosure 4 1

5003S/ALN/2232

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. l PG&E Lett:r No. DCL-94-034 2.17195 ENCLOSURE RESPONSE TO REQUESTFOR ADDITIONAL INFORMA TION REGARDING GENERIC LETTER 92-08 The NRC letter dated December 21,1993, " Request for AdditionalInformation Regarding Generic Letter 92-08, 'Thermo-Lag 330-1 Fire Barriers,' Pursuant to 10 CFR 50.54(f) - Diablo Canyon, Units 1 and 2," was received by PG&E on December 29,1993, and required a response within 45 days from the date of receipt.

PG&E has taken several actions with respect to Thermo-Lag in the interim between this response and our previous responses to Bulletin 92-01 (PG&E Letter No.

DCL-92-173, dated July 29, 1992) and its Supplement (DCL-92-208, dated September 28, 1992) and to Generic Letter (GL) 92-08 (DCL-93-090, dated April 16,1993). In DCL-93-090, PG&E noted that there were a total of fourteen areas where Thermo-Lag was installed, of which in eleven areas the Thermo-Lag was credited as a fire barrier to protect safe shutdown functions; there are now a total of eleven areas where Thermo-Lag is installed, of which in eight areas the Thermo-Lag is credited as a fire barrier to protect safe shutdown functions.

Specifically, the Thermo-Lag in Fire Area (FA) 30-A-5 (the Units 1 and 2 Intake Structure) was replaced by Pyrocrete, and the Thermo-Lag in FA 13 E/11-B-2 (the 107-foot elevation in the Turbine Building) was replaced by a 3-hour rated drywall system. Also, as noted in PG&E Letter No. DCL-93-109, dated April 30,1993, the Thermo-Lag used as a radiant energy heat shield in FA 9 (Unit 2 containment) was replaced with 3M fire barrier material. Consequently, these FAs are no longer listed in Table 1, "Thermo-Lag Installations." As further noted in DCL-93-109, the Thermo Lag in FA 1 (Unit 1 containment) is scheduled for replacement with 3M fire barrier material during the upcoming Unit 1 sixth refueling outage in the Spring of 1994.

In addition to the Thermo-Lag used as a radiant energy heat shield in the Unit 1 containment (Fire Area 1), PG&E has decided to remove the Thermo-Lag in the remaining ten FAs as weil, and to replace as appropriate the Thermo-Lag credited as a fire barrier by the present Appendix R fire hazards safe shutdown analysis to protect safe shutdown functions.

As discussed with Sheri Peterson and Steve West of the NRC on January 24 and 25,1994, pursuant to the decision to remove and replace all Thermo-Lag, PG&E need only respond to Parts I, V, and VI of the response for additional information, since the information requested by Parts 11,111, and IV would be necessary only if PG&E intended to qualify the existing Thermo-Lag for continued use. With these actions noted, PG&E's response to the December 21,1993, request for information follows.

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21'7195

1. Thermo Lag Fire Barrier Configurations and Amounts item 1 of this Part requires descriptions of the Thermo-Lag barriers used to:

a. meet 10 CFR 50.48 or Appendix R to 10 CFR Part 50

b. support an exemption from Aopendix R

c. achieve physicalindependenca of electrical systerns

d. meet a condition of the plant operating license

e. satisfy licensing commitments.

The descriptions should include the intended purpose and fire rating of the barrier and the type and dimension of the barrier.

Item 2 of this Part requires submittal of an approximation of:

a. the total linear feet and square feet of 1-hour and 3-hour cable tray barriers l

b. the total linear feet of 1-hour and 3-hour conduit barriers

c. for all other fire barriers, the total square feet of 1-hour and 3-hour fire barriers

d. for all other barriers and radiant energy heat shields, item 2 requires i submittal of an approximation of the total linear or square feet of 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> or 3-hour barriers, as appropriate for the barrier configuration or type.

PG&E Resoonse i Thn infnrmation rnquested by item 1 to Part I is presented in Table 1 of this l enclosure.

In response to item 2, PG&E provides the following information. The following totals include the Thermo-Lag currently installed but no longer credited. Also, the following totals include the Thermo Lag used to wrap interferences (i.e., heat transfer commodities) in accordance with the guidelines of Thermal Science, incorporated: )

a. 0.0 total linear feet and 0.0 square feet of cable tray Thermo Lag barriers  !

I j

b. Approximately 550 total linear feet of 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> conduit Thermo-Lag barriers and 75 total linear feet of 3 hour3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> Thermo-Lag conduit barners  ;

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. 2,17195-

c. Approximately 212 square feet of 's-hour Thermo-Lag fire barriers (Junction boxes, conduit boxes, etc.) and 12 square feet of 3-hour Thermo-Lag fire barriers

d. 50 total linear feet of Thermo-Lag radiant energy heat shield conduit and 65 square feet of Thermo-Lag radiant energy heat shield barrier.

fl. Important Barrier Parameters As discussed in the introduction above, a PG&E response to this Part is not required.

Ill. Thermo-Lag Fire Barrier Outsicle the Scope of the NUMARC Program As discussed in the introduction above, a PG&E response to this Part is not required.

IV. Ampacity Derating As discussed in the introduction above, a PG&E response to this Part is not required. However, in PG&E's response to GL 92-08 (PG&E Letter No. DCL-93-090, dated April 16, 1993) PG&E stated that a preliminary review determined that sufficient margin for ampacity derating existed for all raceways enclosed in Thermo-Lag barriers, and that the margins would be reviewed and confirmed with respect to the results of ampacity testing obtained from the NUMARC test program. The review of the margins is complete and confirms that sufficient margin exists for the additional ampacity derating resulting from the Texas Utilities Electric Company and Tennessee Valley Authority test results. ,

V. Alternatives This Part requires a description of the specific alternatives for achieving compliance with NRC fire protection requiremerts in plant areas that contain Thermo-Lag fire barriers.

PG&E Resoonse i

PG&E has determined that the preferable route to compliance with NRC fire ,

protection requirements is to replace as appropriate the Thermo-Lag described '

in Table 1 of this enclosure with other fire barrier materials.

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VI. Schedules This Part requires submittal of an integrated schedule that addresses the overall corrective action schedule for the plant. This schedule should address:

a. implementation and completion of corrective actions and fire barrier upgrades for fire barrier configurations within the scope of the NUMARC program b .' implementation and completion of plant-specific analysis, testing, or alternative actions for fire barriers outside the scope of the NUMARC program.

PG&E Resoonse PG&E will complete replacement of the Thermo-Lag described in Table 1 as appropriate with other fire systems by December 31,1994. Compensatory measures will be maintained as appropriate for each Thermo-Lag installation until its replacement is complete.

Vll. Sources and Correctness of Infortnation This Part requires that the sources of the information provided in response to the NRC request be described (for example, from plant drawings, quality assurance documentation, walkdowns, or inspections) and how the accuracy and validity of the information were verified.

PG&E Resoonse PG&E verified the information provided in response to Part I by plant walkdowns.

5003S Table 1 217195 THERMO-LAG INSTALLATIONS Purpose / Fire Type and Dimension Compensatory Fire Area (FA)/

Rating Actions Fire Zone (FZ)

1. FA 3-BB 1-hour fire barrier (with One 3" o conduit; Hourly Fire Watch the exception of two box made from pre-(Unit 1 Containment Penetration Area) conduits and boxes formed panels for that Appendix R one 1" o conduit; reanalysis shows no boxes made from longer to be necessary pre-formed panels for compliance) for 4 junction boxes and 3 pull boxes

2. FA 3-CC 1-hour fire barrier Two 3" o conduits; Hourly Fire Watch boxes made from (Unit 2 Containment Penetration Area) pre-formed panels for 5 junction boxes and 4 pull boxes

3. FZ 3-L N/A (formerly One 4" o conduit; N/A considered a 1-hour box made from pre-(85 Foot Elevation Auxiliary Building) fire barrier; Appendix R formed panels for reanalysis shows 1 Junction box barrier not necessary for compliance)

4. FA 4-B 1-hour fire barrier for Two 4" o conduits Hourly Fire Watch (Access Control) one of the conduits; N/A for the other 3-hour fire barrier on the basis of Appendix R reanalysis that shows this second barrier to not be necessary for compliance.

5. FA 5-A-4 1-hour fire barrier One 2" @ conduit Hourly Fire Watch (Unit 1480 V Switchgear Room)

6. FA 5-B-4 1-hour fire barrier One 2" o conduit Hourly Fire Watch (Unit 2 480 V Switchgear Room) 5003S 5-

n 3 c ;I 21'7135 -

Table 1 (Con'd)

THERMO-LAG INSTALLATIONS 1 Purpose / Fire Type and Dimension Compensatory Fire Area (FA)/ Actions Fire Zone (FZ) Rating 1-hour fire barrier Two 2" $ conduits Continuous Fire -

7. FA 22-C (Unit 2 Diesel Watch, or Portable o Generator Corridor)

Fire Detection System with Hourly Fire Watch 1-hour fire barrier Thermo- Hourly Fire Watch  ;

8. FA 10 Lag /Pyrocrete (Unit 1 - 12 kV Switchgear Room) Barrier 1-hour fire barrier Thermo- Hourly Fire Watch

9. FA 20 Lag /Pyrocrete .;

(Unit 2 - 12 kV '

Switchgear Room) Barrier Radiant energy heat 2 - 1.5" 9 conduit; 5 N/A

10. FA 1 (Unit 1 junction boxes Containment) shield N/A (formerly 2 - 2" c conduit; 2 N/A

11. FZ 19-A (Unit 2 85 Foot Elevation Turbine considered a 3-hour Junction boxes Building) fire barrier; Appendix R '

reanalysis shows barrier not necessary [

for compliance) e f

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