ML17311A747

Forwards Response to follow-up Request for Addl Info Re GL 92-08, Thermo-Lag 330-1 Fire Barriers

ML17311A747
Person / Time
Site:	Palo Verde
Issue date:	03/28/1995
From:	Stewart W ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
102-03297-WLS-S, 102-3297-WLS-S, GL-92-08, GL-92-8, NUDOCS 9504050105
Download: ML17311A747 (24)

Text

(ACCELERATEDRIDS PROCESSINC'OCKET g

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SUBJECT:

Forwards response to follow-.up.request for addi info re GL 92-08, "Thermo-Lag 330-1 Fare Barriers."

DXSTRXBUTION CODE: A029D COPIES RECEIVED:LTR ENCL SIZE:

TITLE: Generic Letter 92-008 Thermal-Lag 330 Fare Barrier

.REGULATORY INFORMATION DISTRIBUTION SYSTEM (RXDS)

P' ACCESSION'BR:9504050105 DOC.DATE: 95/03/28 NOTARIZED: NO FACIL:STN-50-528 Palo Verde Nuclear Station, Unit 1, Arizona Publi STN-50-529 Palo Verde Nuclear Station, Unit 2, Arizona Publi STN-50-530 Palo Verde Nuclear Station, Unit 3, Arizona Publi AUTH.NAME AUTHOR AFFILIATION STEWART,W.L.

Arizona Public Service Co. (formerly Arizona Nuclear Power RECIP.NAME 'ECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

NOTES:STANDARDXZED PLANT Standardized plant.

Standardized plant.

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C NOTE TO ALL"RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACTTHE DOCUMENTCONTROL DESK, ROOM P!-37 (EXT. 504-2083 ) TO ELIMINATEYOUR NAME'FROM DISTRIBUTIONLISTS FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUIRED:

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Arizona Public Service Company P.O. BOX 53999

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PHOENIX, ARIZONA85072-3999 WILLIAML. STEWART EXECUTIVEVICEPRESIDENT NUCLEAR 102-03297-WLS/SAB/NLT March 28, 1995 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station P1-37 Washington, DC 20555-0001

References:

1)

Letter dated December 28,

1994, from Roy P.

Zimmerman, Associate Director for

Projects, Office of Nuclear Reactor Regulation, USNRC, to William L. Stewart, Executive Vice President, Nuclear, APS 2)

Letter dated February 21, 1995, W. H. Rasin, NEI, to W. T. Russell, Director, Office of Nuclear Reactor Regulation, USNRC 3)

Letter dated December 22, 1994, from W. L. Stewart, Executive Vice President, Nuclear, APS, to USNRC

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Units 1, 2, and 3 Docket Nos. STN 50-528/529/530 Response to the Follow-up to the Request for Additional Information Regarding Generic Letter 92-08, Issued Pursuant to 10 CFR 50.54(f) on December 28, 1994 By letter dated December 28, 1994 (Reference 1), the NRC required that Arizona Public Service Company (APS), pursuant to 10 CFR 50.54(f), submit additional information regarding Generic Letter (GL) 92-08, "Thermo-Lag 330-1 Fire Barriers." The following information is provided as the response to this request.

APS is participating in the Nuclear Energy Institute (NEI) program, communicated to the NRC in Reference 2, to evaluate chemical composition as a means of addressing product consistency.

APS has sent fire barrier material samples taken from Palo Verde Nuclear Generating Station (PVNGS), Units 1, 2, and 3, to the NEI designated laboratory so that generic data on product composition can be developed by NEI. APS willaddress the need for additional sampling and chemical analysis based upon the results arid completion of the NEI program.

Reasonable assurance will be obtained that products purchased from Thermal Sciences Incorporated (TSI) and installed in PVNGS Units 1, nnncg" 9504050i05 950328 PDR ADOCK 05000528 P-PDR.

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U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Thermo-Lag 330-1 Response to Request for Additional Information Page 2 2, and 3, are representative of tested materials and configurations relied upon in order to perform fire endurance, ampacity derating, and combustibility evaluations.

APS has taken many actions, independent of the information and data supplied by TSI and independent of generic industry actions, which allow us to assess the applicability of generic data and information to the PVNGS Thermo-Lag 330-1 installations.

These actions include the following:

Destructive examinations'on a.sample basis of installations in each of the PVNGS units.

Extensive plant walkdowns, and visual inspections of as-built installations.

Interviews with original installers on installation techniques and practices.

Reviews ofinstallation documentation, QA documentation, and procedures.

W APS has performed destructive examinations ofThermo-Lag 330-1 installations primarily to document construction techniques and barrier parameters which could not be obtained via visual inspections.

APS has not performed and does not intend to perform a quantitative statistical sampling campaign for destructive examinations.

Examinations have been performed on barriers which are no longer credited for compliance to Appendix R commitments. These barriers were discussed in Section III.B.2of Reference

3. The installations were located in each PVNGS unit and installed during various times of construction of PVNGS, and are considered a representative sample of PVNGS installations.

At present, 15 configurations have been disassembled, inspected, documented on "as-built" field sketches, and the barriers'arameters have been analyzed.

These 15 configurations, which include ancillary Thermo-Lag on supports and intervening steel, comprise approximately 500 square feet ofThermo-Lag 330-1 material.

Individual panel thickness measurements were taken. There were no significant material deficiencies noted in the form of voids, cracks, or delaminations in the panels.

The installations are consistent with the construction methods described during interviews with craft personnel involved in the original installation of the Thermo-Lag 330-1 panels at PVNGS.

The method for verification of each important barrier parameter provided in Section II of the December 1993 Request for Additional Information, was annotated in Attachment D to the Reference 3 submittal. This information is again provided as an enclosure to this letter, and contains additional information on those barrier and cable parameters for which field verification or destructive examination was performed.

Since APS has relied

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U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Thermo-Lag 330-1 Response to Request for Additional Information Page 3 on TSI for information on the weight and density of Thermo-Lag 330-1 panels, further destructive examinations will be performed, as appropriate, by September 30, 1995, to evaluate panel weight and density.

APS has not established a specific sampling campaign to obtain this information, but to maximize plant safety, an emphasis will be placed on barriers which will be maintained in place or those that need to be reworked to meet generically tested configurations.

APS has qualitatively concluded that the potential failuie of Thermo-Lag in a seismic event will not adversely impact the functioning of any Seismic Category I plant feature.

Thermo-Lag 330-1 panels are secured in place with extensive use of mechanical fasteners, tie wires, and stress skin stitched with tie wire.

Based upon observations of destructive examinations performed to date, APS has concluded that in a seismic event Thermo-Lag 330-1 willcrack, chip, and crumble, but will not fail in a gross manner (i.e.,

detachment of panels or sections from raceways).

Quantitative mechanical properties of Thermo-Lag have not been used and are not required in evaluating Seismic Category 9 (Seismic 2 over 1) issues at PVNGS.

APS will review raceway seismic calculations following the aforementioned evaluation of panel weight and density.

APS has not verified the mechanical properties identified by the NRC in Reference 1

such as tensile strength, compressive strength, shear strength, and flexural strength.

The listed material properties are not required for evaluating the attributes of fire endurance rating, ampacity derating and combustibility of Thermo-Lag 330-1.

These attributes are determined from laboratory testing to Industry. Standards.

Product performance is based on the criteria outlined in each individual Industry Standard, which is independent of the mechanical property values.

-Reasonable assurance of product consistency (chemical composition) will provide assurance of product performance in these areas.

Should you have any questions, please contact Scott A. Bauer at (602) 393-5978.

Sincer y,

WLS/SAB/NLT/rv Enclosure cc:

L. J. Callan

, K. E. Perkins B. E. Holian K. E. Johnston

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STATE OF ARIZONA

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COUNTY OF MARICOPA )

I, E. C. Simpson, represent that I am Vice President - Nuclear Support, Arizona Public Service Company (APS), that the foregoing document has been signed by me on behalf of APS with full authority to do so, that I am familiar with the content of such document and its enclosure and that to the best of my knowledge and belief, the statements made therein are true and correct.

E. C. Simpson Sworn To Before Me This Day Of

, 1995.

Notary Public My Commission Expires MyCommission Expires June 12, 1997

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ENCLOSURE THERMO-LAG BARRIER INSTALLATIONAND CABLE PARAMETERS

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THERMO-LAG BARRIER INSTALLATIONAND CABLE PARAMETERS BARRIER PARAMETER 3.

DESCRIPTION Raceway orientation (horizontal, vertical, radial bends)

Conduit Junction boxes and lateral bends Ladder back cable tray with single layer cable fill Cable tray with T-section Raceway material (aluminum, steel)

Support Protection, thermal shorts (penetrating elements)

Airdrops OBTAINED Yes Yes Yes Yes Yes Yes Yes Yes VERIFIED (METHOD)

Yes (Note 1)

Yes (Note 3)

Yes (Notes 1 8 3)

Yes (Note 5)

Yes (Notes 1,3 8 5)

Yes (Note 3)

Yes (Notes 1 & 3)

Yes (Note 5)

SUMMARY

OF FIELD EVALUATIONS Field walkdowns performed on 100% of fire-rated raceways.

Field evaluations not required.

Field walkdowns performed on 100% of fire-rated raceways.

Fire endurance parameter only; cable tray protection no longer required, parameter no longer required.

Fire endurance parameter only; cable tray protection no longer required, parameter no longer required.

Field evaluations not required.

Field walkdowns performed on 100% of fire-rated raceways.

Fire'endurance parameter only; cable tray protection no longer required, parameter no longer required.

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BARRIER PARAMETER 10.

12.

13.

14.

15.

DESCRIPTION Baseline fire barrier panel thickness Preformed conduit panels Panel rib orientation (parallel or perpendicular to the raceway Unsupported Spans Stress skin orientation (inside or outside)

Stress skin over joints or no stress skin over joints Stress skin ties or no stress skin ties OBTAINED Yes Yes Yes Yes Yes Yes Yes VERIFIED (METHOD)

Yes (Notes 1,2 8 3)

Yes (Notes 1 8 4)

Yes (Note 2)

Yes (Note 1)

Yes (Notes 1 8 2)

Yes (Notes 1 8 2)

Yes (Note 2)

SUMMARY

OF FIELD

" EVALUATIONS Approximately 500 sq. ft. of

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Thermo-Lag was destructively examined.

Field walkdowns performed on 100% of fire-rated raceways.

Approximately 500 sq. ft. of Thermo-Lag was destructively examined.

Field walkdowns performed on 100% of fire-rated raceways.

Externally: field walkdowns performed on 100% of fire-rated enclosures.

Internally 500 sq. ft. of Thermo-Lag was destructively examined for information on utilization of internal stress skin.

Approximately 500 sq. ft. of Thermo-Lag was destructively examined including over 1300 linear feet of corner joints and approximately 120 individual butt joints.

Over 1300 linear feet of corner joints were evaluated.

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BARRIER PARAMETER DESCRIPTION OBTAINED VERIFIED (METHOD)

SUMMARY

OF FIELD EVALUATIONS 16.

17.

18.

19.

20.

21.

22.

Dry-fit, post buttered joints or pre-buttered joints Joint gap width Butt joints or grooved and scored Steel bands or tie wires Band/wire spacing Band/wire distance to joints No internal bands in trays Yes Yes Yes Yes Yes Yes Yes Yes (Note 2)

Yes (Note 2)

Yes (Note 2)

Yes (Note 2)

Yes (Note 2)

Yes (Note 2)

Yes (Note 5)

Approximately 500 sq. ft. of ~

Thermo-Lag was destructively examined including over 1300 linear feet of corner joints and approximately 120 individual butt joints.

Approximately 120 individual butt joints.

Approximately 120 individual butt joints.

Approximately 500 sq. ft. of Thermo-Lag was destructively examined.

Approximately 500 sq. ft. of Thermo-Lag was destructively examined.

Approximately 120 individual butt joints.

Fire endurance parameter only; cable ray protection no longer required, parameter no longer required.

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BARRIER PARAMETER 23.

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CABLE PARAMETER 4a.

DESCRIPTION No additional trowel material over sections and joints or additional trowel material applied.

No edge guards or edge guards DESCRIPTION Cable size and type (power, control, or instrumentation).

Cable jacket type (thermoplastic, thermoset) and materials Cable conductor insulation type (thermoplastic, thermoset plastic) and materials Cable fill OBTAINED Yes Yes OBTAINED Yes Yes Yes Yes VERIFIED (METHOD)

Yes (Notes 1 8 2) h Yes (Notes 1 8 2)

VERIFIED (METHOD)

Yes (Note 3)

Yes (Note 3)

Yes (Note 3)

Yes (Note 3)

SUMMARY

OF FIELD EVALUATIONS Field walkdowns performed on 100 % of fire-rated enclosures, 500 sq ft of Thermo-Lag was destructively examined to determine thickness of trowel material.

Approximately 500 sq. ft. of Thermo-Lag was destructively examined.

SUMMARY

OF FIELD EVALUATIONS Field evaluations not required.

Field evaluations not required.

Field evaluations not required.

Field evaluations not required.

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CABLE PARAMETER DESCRIPTION OBTAINED VERIFIED (METHOD)

SUMMARY

OF FIELD EVALUATIONS 4b.

Distribution of cables within the protected conduit or cable tray Proximity of cables to the unexposed (inside) surfaces of the fire barrier.

Presence of materials between the cables and.the unexposed side of the fire barrier material (for example, Sealtemp cloth, which is used in the NUMARC test specimens).

Cable operating temperature Temperatures at which the cables can no longer perform their intended function when energized at rated voltage and current.

~ No Yes Yes No No (Note 6)

No Yes (Notes 2 8 3)

Yes (Note 3)

No (Note 7)

, Approximately 500 sq. ft. of Thermo-Lag was destructively examined.

Field verification is not required.

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NOTES PERTAINING TO TABLE Note 1:

Note 2:

Verification is from field walkdowns to perform installation verification. Walkdowns were performed by Engineering with second party verification.

Field verification for each specific PVNGS installation was not performed.

However, the installation technique for generic enclosures was determiried by original installer testimony and verification of the testimony was performed utilizing destructive examination.

Note 3:

Note 4:

Verification is from design documentation.

PVNGS does not use pre-formed conduit panels.

This has been validated by field walkdowns, Specifications, and Purchase Orders.

Note 5:

PVNGS no longer credits Thermo-Lag 330-1 on cable trays to comply with commitments to 10 CFR 50, Appendix R.

Note 6:

Note 7:

PVNGS no longer credits Thermo-Lag 330-1 on cable trays.

Cables in conduits are random and the distribution of cables in conduit does not affect the applicability of fire endurance tests.

1 PVNGS will use the equipment qualification maximum temperature limitation for LOCA events for PVNGS'EEE 383 cable.

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