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October 7, 1999NOC-AE-000653 |

File No.: G09.16 |*

10CFR50.55a j

|U. S. Nuclear Regulatory Commission i

Attention: Document ControlDesk )'

Washington, DC 20555

South Texas Project .

Units 1 and 2 ,

Docket Nos. STN 50-498, STN 50-499 )Request for Relief from ASME Boiler and 1

Pressure Vessel Code Section XI Requirements |

$tief Request RR-ENG-IWE-01)l

In accordance with the provisions of 10CFR50.55a(a)(3)(i), the South Texas Project requestsrelief from ASME Section XI code requirements of Table IWE-2500-1 for -VT-3 visualexamination of seals and gaskets on airlocks, hatches, and other devices required to assurecontainment leak-tight integrity. This request is applicable to the first IWE inservice inspectioninterval of Units 1 and 2. The attached relief request describes a proposed alternative to affectedportions of Subsection IWE that the South Texas Project believes will provide an acceptablelevel of quality and safety.

The attached relief request includes a discussion of the basis and justification for the reliefrequest and an implementation schedule.

The South Texas Project requests Nuclear Regulatory Commission review and approval of thisrelief request by February 28,2000.

If there are any questions, please contact either Mr. C. A. Murry at (361) 972-8285 or me at(361) 972-8757. I

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J. J. SheppardVice President,

g'30 Engineering & Technical Services !

PLW -

Attachment: Request for Relief from ASME Boiler and Pressure Vessel Code Section XIi

Requirements (Relief Request RR-ENG-IWB-01) p,

'h |9910200050 991007PDR ADOCK 05000498 1

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NOC-AE-000653File No.: G09.16Page 2

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Ellis W. Merschoff Jon C. WoodRegional Administrator, Region IV Matthews & BranscombU. S. Nuclear Regulatory Commission One Alamo Center ;

. 611 Ryan Plaza Drive, Suite 400 106 S. St. Mary's Street, Suite 700Arlington, TX 76011-8064 San Antonio, TX 78205-3692

Thomas W. Alexion Institute of Nuclear PowerProject Manager, Mail Code 13H3 Operations - Records Center

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U. S. Nuclear Regulatory Commission 700 Galleria ParkwayWashington, DC 20555-0001 Atlanta, GA 30339-5957

Cornelius F. O'Keefe Richard A. RatliffSr. Resident Inspector Bureau of Radiation Controlc/o U. S. Nuclear Regulatory Commission Texas Department of HealthP. O. Box 910 1100 West 49th Street -

Bay City, TX 77404-0910 Austin, TX 78756-3189

J. R. Newman, Esquire D. G. Tees /R. L. BalcomMorgan, Lewis & Bockius Houston Lighting & Power Co.1800 M. Street, N.W. P. O. Box 1700Washington, DC 20036-5869 Houston,TX 77251

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M. T. Hardt/W. C. Gunst Central Power and Light CompanyCity Public Service A'ITN: G. E. Vaughn/C. A. JohnsonP. O. Box 1771 P. O. Box 289, Mail Code: N5012San Antonio,TX 78296 .Wadsworth,TX 77483 I

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A. Ramirez/C. M. Canady U. S. Nuclear Regulatory CommissionCity of Austin Attention: Document Control Desk

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Electric Utility Department Washington, D.C. 20555-0001721 Barton Springs RoadAustin,TX 78704

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NOC-AE-000653File No.: G09.16Page 1 of 3

SOUTH TEXAS PROJECT, .

UNITS 1 & 2'

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REQUEST FOR RELIEF FROM ASME BOILER A.NDPRESSURE VESSEL CODE SECTION XI REQUIREMENTS

(RELIEF REOUEST RR-ENG-IWE-01)

Reference Code: ASME Boiler and Pressure Vessel Code, Section XI,1992 Edition through1992 Addenda

A. Components for Which Exemption is Requested:

(a) Name and Identification Number: Seals and gaskets of Class MC pressure-retainingcomponents

(b) Function: Ensure leak-tight integrity for Class MC containment components:airlocks, hatches, and other devices.

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(c) Class: ASME Code Class MC

B. Code Requirement from Which Relief is Requested:

ASME Boiler and Pressure Vessel Code Section XI Code, Table IWE-2500-1Examination Category E-D, requires VT-3 visual examination of seals and gaskets onairlocks, hatches, and other devices required to assure containment leak-tight integrity. -

C. Basis for Relief from Code Reauirements:

The design configuration of the connections incorporating the subject seals and gasketsprecludes visual examination of the seals and gaskets without disassembling theconnection. Disassembly of a connection poses the risk of equipment damage, while aVT-3 visual examination would not by itself ensure a leak-tight connection afterreassembly of the connection.

. The containment penetrations discussed below contain seals and gaskets subject to theVT-3 visual examination requirements:

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Electrical Penetrations |

Electrical penetrations use a header plate attached to a containment penetrationnozzle flange with a double set of o-rings between the header plate and flangeface. Modules through which electrical conductors pass are installed in theheader plate. |

One module type, manufactured by ' Westinghouse, uses multiple o-rings (four perassembly) to assure leak tight integrity. A second type, manufactured by Conax,uses. compression fittings. Both types utilize sealant compounds internal to themodule to insulate and seal the electrical connectors. The o-ring seals are

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NOC-AE-000653 |File No.: G09.16 |

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completely inaccessible; however, there is an internal space between the o-ring,s* '

to permit periodic leak rate tescing. The Conax compression fittings are alsoinaccessible withcut: disassembling the component. Each penetration is I

- pressurized with dry nitrogen to maintain and monitor integrity and to prevent )intrusion of moisture into the penetration. |

Personnel. Eauipment. and Emergency Escane Hatch PenetrationsThe Personnel, Equipment, and Emergency Escape Hatches utilize doublegasketed doors to ensure leak-tight integrity. These hatches also contain other

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grskets and seals in such applications as: )handwheel shafts,e

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* ' electrical penetrations, )-

blank flanges, I*

viewport gaskets, and ie

pressure equalization connections.e.

. lGaskets and seals in these applications are inaccessible without disassembling thecomponent. Double gaskets and seals are used with provision made for Type Btesting for leak tightness in accordance with 10CFR50 Appendix J.

If the connections are disassembled, leak-tight tests are required to be performed bothbefore and after maintenance activities. For electrical penetrations, this involves:

A pre-maintenance Appendix J test;*

De-termination of cables c.t electrical penetrations if enough cable slack is not i*

available;.Disassembly of the joint;*

Removal and examination of the seals and gaskets;*

Re-assembly of the joint; -*

Re-termination of the cables if necessary:'

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Post-maintenance testing of the cables; and*

Post-maintenance Appendix J testing of the penetration.*

The work required for the containment hatches is similar except for de-termination, re-termination, and t,esting of cables.

D. Alternative Reaulistnia; -

. Seals and gaskets (for containment integrity are Type B tested for leak-tightness inaccor6nce with 10CFR50, Appendix J. Appendix J Type B testing of the subjectpenetrations is' performed at least once each inspection interval.

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E. 1 Justification for Granting Relief:

As required by 10CFR50.55a(a)(3)(i), the proposed alternative provides an acceptablelevel of quality and safety. Appendix J Type B testing provides adequate assurance cf

. the leak-tightness of the connections. Type B tests include measurement of leabge fromcontainment penetrations whose design incorporatcs resilient seals, gaskets 'r sealantcompounds, and electrical penetrations fitted with flexible metal seal, assemblies.Consequently, VT-3 nsual examinations are not necessary to ensure that'containmen'tpenetrations are leak-tight.

For those penetrations that are routinely disassembled, a Type B test is required uponfinal assembly and prior to star -up: Because the Type B test will assure the leak.-tight:

integrity of containment penetratinns, performing a visual examination will not increasethe level of quality or safety.

Visual examination of the seal or gasket is not necessary to identify degradation of thematerial. When penetrations containing seals and gaskets are Type B tested inaccordance with 10CFR50, Appendix J, degradation of the seal or gasket material wouldbe revealed by an increase in the leakage rate. Corrective measures would be applied andthe component re-tested.

ASME Section XI,1992 Edition,1993 Addenda, recognizes that disassembly of joints toperform these examinations is not warranted. Note 1 in Examination Category E-D wasmodified in the 1995 Edition of ASME Section XI to state that seal ~d or gasketed

. connections need not be disassembled solely for serformance of visual examinations. Inaddition,' the requirement to examine seals and gaskets has been removed fromSubsection IWE of the 1998 Edition of ASME Section XI.

F. Implementation Schedul ;t

The South Texas Proba requests the . Nuclear Regulatory Commission approve this reliefrequest by February 28,2000, so that it can be implemented during the first InspectionInterval for the IWE Program.

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