ML17312B338

Summary of 970219 Meeting W/Aps Re Thermo-Lag Issues.List of Meeting Attendees & Viewgraphs Encl

ML17312B338
Person / Time
Site:	Palo Verde
Issue date:	03/27/1997
From:	Thomas C NRC (Affiliation Not Assigned)
To:	NRC (Affiliation Not Assigned)
References
NUDOCS 9703280297
Download: ML17312B338 (87)

Text

UNITED STATES NUCLEAR REGULATORY COMMlSSION WASHINGTON> D.C. 2055&4001 Mar ch 27, 1997 LICENSEE:

Arizona Public Service Company FACILITY:

Palo Verde Nuclear Generating Station

SUMMARY

OF MEETING HELD ON FEBRUARY 19,

1997, TO DISCUSS THERMO-LAG ISSUES On February 19, 1997, the NRC staff met with representatives of Arizona Public Service Company to discuss Thermo-Lag issues.

Persons attending the meeting are listed in Attachment I:, and the viewgraphs presented at the meeting are listed in Attachment 2.

During the meeting, the licensee established management involvement in resolving the Thermo-Lag issues.

The licensee demonstrated that it has made measurable progress towards overall resolution of the Thermo-Lag issues.

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example, the licensee has verified installation techniques and important barrier parameters, completed a post-fire shutdown reanalysis, reevaluated and revised the fire hazards

analysis, completed engineering evaluations of barrier configurations, designed barrier upgrades, upgraded about 10 percent of the required barriers, and developed and applied an ampacity derating evaluation methodology.

This methodology is based on a cable loading diversity factor, which provides a means of increasing ampacity margins in cables.

The NRC staff will review the licensee's methodology for acceptability.

As part of its design-basis reconstitution effort at Palo Verde Nuclear Generating Station (PVNGS), the licensee re-evaluated the Unit I power cables with regard to ampacity margins and as-built conditions.

Cable ampacity was determined on the basis of the as-built physical installation and routing at PVNGS.

This reevaluation will give assurance that ampacity issues, including derating for the application of the Thermo-Lag 330-1 fire protection material, will not result in cable installations that would lead to adverse thermal conditions.

The licensee anticipates that the Thermo-Lag evaluation it performed on Unit I will bound Units 2 and 3.

The licensee stated that if the Unit I evaluation does not bound Units 2 and 3, calculations will be performed specifically for Units 2 and 3 following completion of the Unit I evaluation.

The licensee described its corrective action plan and schedule for resolving th Thermo-Lag issue at

PVNGS, as discussed in Generic Letter 92-08, "Thermo-Lag 330-1 Fire Barriers."

The licensee stated that only 3,400 square feet of the total 44,500 square feet of Thermo-Lag at PVNGS wi'.1 be maintained to meet NRC fire protection requirements.

These fire barriers will be upgraded by September 1997 to achieve a fire resistance rating of I hour.

Compensatory measures will remain in place until the corrective actions are completed.

The

'censee will no longer credit the installed 3-hour-rated Thermo-Lag to meet NRC fire protection requirements.

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'he licensee discussed why Thermo-Lag corrective actions scheduled for completion in 1996 were rescheduled.

The licensee stated that evaluation of the applicability of the ampacity calculation for Unit 1 to Units 2 and 3 is scheduled to be completed by the end of December 1997.

During the next refueling outage, some Thermo-Lag will be removed from the remote shutdown rooms for each unit; Unit 1 will be completed in the spring of 1998 during its refueling outage.

The majority of the Thermo-Lag at PVNGS will be left in place and will be maintained as a balance-of-plant system with no inspection requirements.

On the bas.i's of the information presented in its submittal of December 31,

1996, as supplemented during the meeting, the staff concluded that the licensee has been and will continue to make progress towards the overall resolution of the Thermo-Lag issues at PVNGS and that the new completion schedule is reasonable.

ORIGINAL SIGNED BY Charles R.

Thomas, Project Manager Project Directorate IV-2 Division of Reactor Projects III/IV Office of Nuclear Reactor Regulation DISTRIBUTION: (Hard'opy)

Docket File OGC PUBLIC'CRS PDIV-2 Reading Docket Nos.

STN 50-528, STN 50-529 and STN 50-530 Attachments:

1.

List of"Attendees 2.

Viewgra'phs Ci cc w/atts:

See next page E-Mail SCol 1 ins/FMiragl i a MBiamonte RZimmerman '.,

AHowell, RIV JRoe

DKirsch, RIV

.. EGAl'Jenkins

,WBateman 'Qualls

CThomas, EConnell

,JCliffor'd TEaton

- -EPeyton."

LTran DRoss l

"C",~ Copy'without enclosures "E" ~ Copy'with enclosures "N" ~ No copy t

I P

l DOCUMENT NAME:THERMO.LAG To receive a copy of this document, fn'dicate'in'~the box:

The licensee performed an engineering evaluation of the combustibility of the 700 square feet of Thermo-Lag used inside" the containment as a radiant energy heat shield and concluded that the, temperatures required for combustion of the material would not be reached.

The staff expressed concern about the licensee's methodology for resolving the use of Thermo-Lag as a radiant energy heat shield inside the containment because Thermo-Lag is combustible.

This aspect of the corrective action plan is the subject of a request for additional information sent to the licensee on January 21, 1997.

OFFICE PM PDIV-2 LA PDIV-2

SPLB EELB NAME CThomas tlh Pe ton TMarsh JCalvo DATE 03/

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The'licensee performed an engineering evaluation of the combustibility of the 700 square feet of Thermo-Lag used inside the containment as a radiant energy heat shield and concluded that the temperatures required for combustion of the material would not be reached.

The staff expressed concern about the licensee's methodology for resolving the use of Thermo-Lag as a radiant energy heat shield inside the containment because Thermo-Lag is combustible.

This aspect of the corrective action plan is the subject of a request for additional information sent to the licensee on January'1, 1997.

The licensee discussed why Thermo-Lag corrective actions scheduled for completion in 1996 were rescheduled.

The licensee stated that,evaluation of the applicability of the ampacity calculation for Unit 1 to Units 2 and 3 is scheduled to be completed by the end of December 1997.

During the next refueling outage, some Thermo-Lag will be removed from the remote shutdown rooms for each unit; Unit 1 will be completed in the spring of 1998 during its refueling outage.

The majority of the Thermo-Lag at PVNGS will be left in place and will be maintained as a balance-of-plant system with no inspection requirements.

On the basis of the information presented in its submittal of December 31,

1996, as supplemented during the meeting, the staff concluded that the

. licensee has been and will continue to make progress towards the overall resolution of the Thermo-Lag issues at PVNGS and that the new completion schedule is reasonable.

Docket Nos.

STN 50-528, STN 50-529 and STN 50-530 harles R. Thomas, Project Manager Project Directorate IV-2 Division of Reactor Projects III/IV Office of Nuclear Reactor Regulation Attachments:

1.

- List of Attendees 2.

Viewgraphs cc w/atts:

See next page cc w/encl:

Hr. Steve Olea Arizona Corporation Commission 1200 W. Washington Street

Phoenix, Arizona 85007 Douglas Kent Porter Senior Counsel Southern California Edison Company Law Department, Generation Resources P.O.

Box 800

Rosemead, California 91770 Senior Resident Inspector USNRC P. 0.

Box 40

,Buckeye, Arizona 85326 Regional Administrator, Region IV U. S. Nuclear Regulatory Commission Harris Tower

& Pavillion 611 Ryan Plaza Drive, Suite 400 Arlington, Texas 76011-8064

Chairman, Board of Supervisors ATTN:

Chairman 301 W. Jefferson, 10th Floor Phoenix; Arizona 85003 Hr'. Aubrey V. Godwin, Director Arizona Radiation Regulatory Agency 4814 South 40 Street

Phoenix, Arizona 85040 Hs. Angela K. Krainik, Manager Nuclear Licensing Arizona Public Service Company P.O.

Box 52034

Phoenix, Arizona 85072-2034 Hr. John C. Horne, Vice President Power Supply Palo Verde Services 2025 N. Third Street, Suite 220 Phoenix, Arizona 85004 Mr. Robert Burt Los Angeles Department of Water

& Power Southern California Public Power Authority 111 North Hope Street, Room 1255-B Los Angeles, California 90051 Hr. David Summers Public Service Company of New Mexico 414 Silver SW, 80604 Albuquerque, New Mexico 87102 Mr. Bob Bledsoe Southern California Edison Company 14300 Mesa Road, Drop D41-SONGS San Clemente, California 92672 Hr. Robert Henry Salt River Project 6504 East Thomas Road Scottsdale, Arizona 85251 Terry Bassham, Esq.

General Counsel El Paso Electric Company 123 W. Hills El Paso, Texas 79901 Hr. James H. Levine Executive Vice President, Nuclear Arizona Public Service Company Post Office Box 53999

Phoenix, Arizona 85072-3999

f o I

Attachment 1

MEETING WITH ARIZONA PUBLIC SERVICE PALO VERDE THERMO-LAG ISSUE ETTEN ANCE Il T.

FEBRUARY 19 1997 Arizona Public Service William Ide Scott Bauer Frank Garrett Rodney Wilferd Harvey Leake Scott Koski NRC Phill squalls Ed Connell Tanya Eaton Ronaldo Jenkins Linh Tran Charles Thomas NEI Fred Emerson

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EETING WITH ARIZONA PUBLIC SERVICE ALO V RDE THERMO-LAG ISSUE VIEWGRAPHS EBRUARY 9

1997

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pP'esen a ion 0 PVNGS Thermo-Lag Project Status February 19, 1997 LTLAGNRCl.PPT

nro UC iOn 0 APS has technically resolved a majority of Thermo-Lag Issues.

I With Few Exceptions, Corrective Actions Willbe Complete by 4th Quarter 1997 0 Purpose of Today's Meeting Is to Describe Issue Resolution and Remaining Actions

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I Introduction 0 Summary of Thermo-Lag InstaIlations 1 Quality Assurance Considerations I Fire Endurance Considerations I Combustibility Considerations I Seismic Considerations 0 Ampacity Design Basis Reconstitution 0 Conclusion

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nsa aion ec ni ue FILLIN CORNERS AND BUTTJOINT WITHTHERMO-LAG TROWEL GRADE TIE STRESS SKIN FLANGES TOGETHER ANDBEND INWARD THERMO-LAGTROWEL GRADE SKM COAT BUTTJOINT BETWEEN PREFABRICATED PANELS, STRESS SKINFLANGES STITCHED PREFABRICATED THERMO-LAGPANEL 18 GA. TIE WIRE CONTINUOUS STRESS SKIN 1/4" MAX r:r c

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uai ssurance onsi era ions I Installation Techniques 0 Material Consistency I Weight/Density

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0 Verified Important Barrier Parameters

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ire n Urance onsi era ions 0 Performed Appendix R Reanalysis I Qualified Remaining Fire Barriers t Evaluated Fire-Proofing on HVAC and Cable Tray Supports Fire Damper Qualification Penetration Seal Integrity

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Credited Fire Induced LPP Barrier 2%

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a Different Compliance 5trategy H Manual Operator Actions

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~ Upgrades to be Completed 3rd Quarter 1997 Compensatory Measures Remain

Fire-Proofing on HVAC and Cable Tray Supports I Supports for Appendix R Raceways are Protected 1 Other Supports Are Not Required to be Protected Fire Dampers Penetration Seals

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ro ec ion or ire am er uaiica ion 0 Fire-Proofing OriginallyInstalled for Dampers In Gypsum and Plaster Walls I UL 555 Subsequently Revised 0 PVNGS Has Verified Installed Dampers Are Qualified Without Fire-Proofing UL 555 Vendor Guidance Supported By 1-Hr and 2-Hr Duct Tests 0 Defense-In-Depth Fire Protection Features

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roecion or ene ra ion ea n e ri t Penetration Seals Qualified in Accordance with ASTME119 4 Fire-Proofing OriginallyInstalled to Minimize Sagging of Cable Trays Which Could Compromise Penetration Seal Integrity 0 Defense-In-Depth Addresses Concern 0 Integrity ofPenetration Seal is Maintained Without Crediting Fire Proofing

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eeva Ua e ire azar na sis 0 Performed Extensive Walkdowns 0 Evaluated Additional Contribution ofThermo-Lag to Combustible Loading I 50 Fire Zones Affected 9 Fire Zones Elevated from Low to Moderate Classification 1 Fire Zone Elevated From Moderate to High Classification (Thermo-Lag to be Removed) 0 Existing Fire Protection Features Are Sufficient

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eeva Ua e en ix evia ions I Reviewed Deviations Using Revised Combustible Loading I 7 Appendix R Deviations Required Further Evaluation MinimalEffect 0 Abilityto Achieve and Maintain Safe Shutdown Assured

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~ Smoke Detectors

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~ Hose Stations

~ Fire Kxtingnishers

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Hot Gas Layer Evaluation Low Fire Loading in Each Fire Zone 0 Qualitative Evaluation Concluded Temperatures Required for Combustion Would Not Be Reached 0 Additional Analysis Performed to Confirm Qualitative Analysis

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m aci verview 0 Original Design Cable Sizing I Design Basis Reconstitution - Ampacity 0 Evaluation Methodology 0 Available Ampacity 0 Thermo-Lag Screening Criteria 0 Ampacity Margin 0 Results

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e e ec ion izin 0 Accepted industry practices ICKA 0 Conservatism 25% design margin Ambient temperature criteria

~ Class 1E: 60'C

~ Non-Class 1E: 50'C or 60'C 4 Deratint factors applied for special conditions

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asis econs i u ion I Reevaluated cable thermal capability Cables in Cable Trays

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~ Covered

~ Fire Stop

~ Thermo-Lag Cables in Conduits

~ Thermo-Lag

e Ine onserva IYe ssum ions I Actual ambient < standard criteria 50 - 60'C 0 Use of available design margin 1 Diverse cable loading reduces overall heating Method as described in IKEKpaper Replaces "watts-per-foot" method

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o en ia ro em reas I 14 Non-Class 1K Tray Sections 9 Sections - Revise T-Lag coverage assumptions

~ As-BuiltThermo-Lag coverage < 5% ofsection 5 Sections - Revise load current assumptions

~ Miscellaneous Local Fire Protection Panels

~ Boric Acid Heat Trace Control Panel

~ MSSS Penetration Coolin Fans

~ Balance ofPlant Instrumentation Power Supplies

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~ Operability Evaluation Completed

~ Cable Life Issue Vs. Operability Concern Remove Thermo-Lag Next Refueling Outage

I Large Ampacity Margins in PVNGS Design I Incorporated into Design Basis Calcs I Conservative Engineering Assumptions 0 Conservative T-Lag Screening Criteria I Based on Empirical Test Results

m acl en ems 0 Resolve Ampacity Margin Deficiencies 14 Non-1E tray sections 0 VerifyUnit 1 Bounds Units 2 dt 3 0 Remove I-Lag Where necessary Remote Shutdown Panel Room 10 8

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verview o ermo-a ro ec 0 Extensive Resources Invested in Evaluating PVNGS Thermo-Lag Installations I Compensatory Measures willRemain in Place UntilUpgrades are Completed l Materials Used to Address Technical Concerns Represent PVNGS Material 0 Fire Endurance Issues Addressed Using Appendix R Reanalysis and Upgrades

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emainin c lons 0 Upgrade Credited Thermo-Lag Enclosures by Sept. 30, 1997 I Complete Final Ampacity Analysis of Non-Class 1E Cable Tray Sections and Determine Corrective Actions I Remove One Thermo-Lag Enclosure Per Unit During Next Refueling Outage I VerifyUnit 1 Ampacity Evaluations Bound Unit 2 4 3 by June 30, 1997