ML20248L794
| ML20248L794 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 06/08/1998 |
| From: | Cruse C BALTIMORE GAS & ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9806110362 | |
| Download: ML20248L794 (10) | |
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l Curut.Es 11. Cnust Dahimore Gas and Elect.ic Cornpany Vice Pcesident Cahert Cliffs Nuclear Power Plant
. . Nucinr Energy 1650 Calve t Cliffs Parkway Lushy. Maryland 23657 410 495-4455 BSE JureS,1998 U. S. Nuclear Regulatory Ccmmission Washington, DC 20555
.A'ITENTION: Dc.cument Control Desi.
SUBJECT:
Calvert Cliffs Nuclear Power Pitmt U nit Nos.1 & 2; Docket Nos. 50-347 & 50-318 Request for Relief from Certair ASME Code Requirements for Inservice
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Pursuant to 10 CF.R Part 50, Paragraph 30.55a(a)(3)(i), llaltimore Gai and Electric Company hereby proposes alternatives to cert. tin requirements of Section XI of the American Society of Mechanical Engineers (ASME) Boiler ar'd Pressure Vessel (B&PV) Cc le (1992 Edition,1992 Addenda).
In the Federal Register, dated August 8,1996 (61 FR a1303), the Nuclear Regulatory Cornmission amended its regulations to incorporate by reference the A iME B&PV Code, Section XI,1992 Edition, through the 1992 Addenla of Subsections IWE and IWL Subsectian IWE gives the r quirernents for inservice inspection of Class hlC (Metallic Containment components) and the mevillic liner of C;! ass CC (Concrete Containment compcc.cnts). Subsection IWL gis :s the requirements for inservice inspection of Class CC. Calvet Cliffs' containmem vessels are ungn?uted, post-tensioned concrete structures with metallic liners.
Details concerd.ng; the requested relief are provided in Attichmr nts (1) throul,h (3).
Attachment (1), requests relicf from ASME B&PV Code, Section XI,1992 Eduion,1992 Addenda, Tile IWE-220-1, Examination Category E-D, item msnbers E5.10, " Seals," and E5.20, ' Gaskets,"
which require a visual examination of m:tci containment seals and gaskets. Ext.mination of most seals and gaskets reyaires the joints to be disassembled. Cortninment seals and gaskets are proven adequate through leak v_te testing rerformed in accordance with 10 CFR Part 50, Appendix J.
Attechment G), requests relief from ASME B&PV Co.:le, Section XI,1992 Edition,1992 Addenda, suba#de IWE-2420 'fiuccessive Inspections," paragraph (b), which requires that repaired areas be !
examined during the nest inspection period. Repairs restare the component to full Code compliance and 980611CG52 900608 PDR ADOCIA 05(HX1317 W'
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Document Control Desk June 8,1998 Page 2 to an acceptable condition for continued service. Therefore, successive examinations should not be .
required for repaired areas.
Attachment (3) requests relief from ASME B&PV Code, Section XI,1992 Edition,1992 Addenda, subarticle IWA-2210, " Visual Examination," which lists requirements for minimum i'lumination and maximum direct examination distance of Class CC components under paragraphIWL-2310, " Visual Examination and Personnel Qualification." When remotely performing the visual exa ninations required by Subsection IWL, Paragraph IWL-2510, the maximum direct examination distance specified in -
TableIWA-2210-1 may be extended, and the minimum illumination requirements specified in TableIWA-2210-1 may be decreased provided the techniques are qualified to detect the required conditions and indications.
Calvert Cliffs Nuclear Power Plant is a participant in the Electric Power Research Institute project for the preparation of a generic IWE/IWL Program and Guide. Calvert Cliffs Nuclear Power Plant is submitting the relief request regarding the remote visual examinations as the lead plant in this project and, therefore, requests expedited Nuclear Regulatory Commission review. The IWE/lWL Program and Guide project needs timely approval of the relief request to allow the individual utilities to prepare IWE/IWL program plans prior to implementing the new Code requirements. The first inspection period of the first inspection interval for Calvert Cliffs' IWE/lWL Program starts September 9,1998. We request approval of all the relief requests prior to this date.
Should you have questions r<grding this matter, we will be pleased to discuss them with you.
Very truly yours,
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CHC/JKK/bjd Attachmcats (1) Relief Request El, " Seals and Gaskets" (2) Relief Request E2," Successive Examinations After Reair" (3) Relief Request L1, " Remote VT of Class CC" cc: R. S. Fleishman, Esquire H. J. Miller, NRC ,
J. E. Silberg, Esquire . Resident Inspector, NRC . {
S. S. Bajwa, NRC R. I. McLean, DNR .l A. W. Dromerick, NRC J. H. Walter, PSC l
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1 ATTACHMENT (1) 1 l
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SEALS AND GASKETS !
RELIEF REQUEST NO.E1 l
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Baltimore Gas and Electric Company Calvert Cliffs Nuclear Power Plant June 8,1998
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ATTACHMENT (1) i SEALS AND GASKETS l
=l RELIEF REQUEST NO. El l SYSTEM (SVCOMPONENT(S) FOR WHICH RELIEF IS REOUESTED l
'Ilis relief request applies to the following components that incorporate seals and gaskets as the containment pressure boundary:
- Electrical penetrations fitted with flexible metal seal assemblies; )
1 Air lock door seals, including door operating mechanism penetrations that are part of the 4 containment pressure boundary; e Containment penetrations and valves whose design incorporates resilient seals, gaskets, or sealant compounds; and
. Doors with resilient seals or gaskets except for seal-welded doors.
.CDDE REQUIREMENTS FOR WHICH REIII:F iS REOUESTED Seals and gaskets of Class MC (Metallic Containment) pressure-retaining components, Examination Category E-D, item Nos. E5.10 and E5.20 of IWE-2500, Table IWE-2500-1, American Society of Mechanical Engineers (ASME), Boiler and Pressure Vessel (B&PV) Code, Section XI,1992 Edition, 1992 Addenda, as amended by 10 CFR 50.55a. IWE-2500, Table IWE-2500-1, requires that seals and gaskets on air locks, hatches, and other devices receive a type VT-3 visual examination, as described in ASME XI, IWA-2213, once each interval to ensure containment leak-tight integrity.
PROPOSED ALTERNATIVE I The leak-tightness of the listed seals and gaskets will be test ~l in accordance with 10 CFR Part 50, Appendix J.
BASIS FOR 11EIIFF Title 10 CFR 50.55a was amended in the Federal Register (61 FR 41303) to require the use of the ASME B&PV Code, Section XI,1992 Edition,1992 Addenda, when performing contai unent examinations.
The penetrations discussed below are part of the containment examination:
. Electrical penetrations; Two types of electrical peaetruan assemblies are used: canister and unitized header. All electrical penetration anemblies are fabricated and tested in accordance with the ASME B&PV Code, Section III, Nuclear Vessel Code. The canister type is inserted in a nozzle of suitable diameter integral with the Containment Structure and field welded on the inside end. The unitized header type is welded to the nozzle on the outside end. These seals and gaskets cannot be inspected without the disassembly of the penetration to gain access to the seals and gaskets.
All penetration assemblies are currently leak tested in accordance with 10 CFR Part 50, Appendix J, Option B.
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- Air lock door seals, including door operating mechanism penetration, which are part of the containment pressure boundary; The Personnel and Err. rgency Air Locks utilize an inner and outer door with gasket surfaces to ensure leak-tight integrity. These air locks also contain other gaskets and seals, such as the handwheel shaft seals, electrical penetrations, blank flanges, and equalizing pressure l'
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ATTACHMENT (1) )
I SEALS AND GASKETS I RELIEF REQUEST NO. El connections, which require disassembly to gain access to the gaskets and seals. Both cccess ass?mblies are ?urre itly leak tested in accordance with 10 CFR Part 50, Appendix J, Option B.
- Containment penetrations and valves whose design incorporates resilient seals, gaskets, or sealant compounds; Containment purge blind flanges, fuel transfer tube blind flanges, and other penetration terminations contain gaskets and seals, which require disassembly to gain access to the gaskets and seals; these penetrations are currently leak tested in accordance with 10 CFR Part 50, Appendix J, Option B.
- Doors with resilient seals or gaskets except for seal-welded doors; The equipment hatch is a single door, utilizing a double gasket to ensure leak-tight integrity.
The equipment hatch is currently leak tested in accordance with 10 CFR Part 50, Appendix J, Option B.
The visual examination of seals and gaskets requires that the joints and valves, which are proven adequate through Appendix J leak rate tests, be disassembled. For the electrical penetrations, this involves a pre-maintenance Appendix J leak rate test, disconnecting cables at electrical penetrations if enough cable slack is not available, disassembly of the joint, removal and examination of the sealt and gaskets, reassembly of the joint, reconnecting the cables if necessary, post-maintenance testing of the cables, and then a post-maintenance Appendix J leak rate test of the penetration. For the Containment Personnel and Emergency Air Locks, blind flanges, and the equipment hatch, the work required would be similar except for the disconnecting, rccer.necting, and testing of cab!cs. This imposes the risk that l equipment could be damaged. If disassembly were not required, the VT-3 inspection of expos,ed surfaces !
of seals and gaskets would provide less assurance than that provided by the 10 CFR Part 50, Appendix J leak rate test.
Seals and gaskets are not included as part of the containment pressure boundary under current Section 111 Code rules [NE-2110 (b)], the Code under which Calvert Cliffs Nuclear Power Plant was constructed.
When the air locks and hatches containing these materials are tested in accordance with 10 CFR Part 50, Appendix J, degradation of the seal or gasket material is revealed by an increase in the leakage rate. In this case, corrective measures are applied and the component retested. Repair or replacement of seals and gaskets is not subject to Code (1992 Edition,1992 Addenda) rules in accordance with ASME B&PV Code, Section XI, Paragraph IWA-4111(b)(5).
Relief is requested in accordance with 10 CFR 50.55a(a)(3)(i). Testing the seals and gaskets in accordance with 10 CFR Part 50, Append'x J, provides adequate assurance of the leak-tight integrity of the seah, and gaskets.
IMPLEMENTATION SCHEDULE The IWE Program Plan, of which this relief request is a part, will be implemented the first period of the first inspection interval for IWE; September 9,1998 to September 9,2001.
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SUCCESSIVE EXAMINATIONS AFTER REPAIR RELIEF REQUEST NO.E2 l
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Baltimore Gas and Electric Company Calvert Cliffs Nuclear Power Plant June 8,1998 l
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ATTACHMENT (2) l SUCCESSIVE EXAMINATIONS AFTER REPAIR RELIEF RE8Y ' NO. E2 SYSTEM (SVCOMPONENT(S) FOR WHICH REI1FF IS REOUESTED l
This relief request applies to all Class MC (Metallic Containment) components and metallic liners of I Class CC (Concrete Containment) components.
l CODE REQUIREMENTS FOR WHICH RELIFF IS REOUESTED l' American Society of Mechanical Engineers (ASME), Boiler and Presnre Vessel (B&PV) Code, Section XI, 1992 Edition, 1992 Addenda, Paragraph IWE-2420(b) states: "When component examination results require evaluation of flaws, evaluation of areas of degradation, or repairs in accordance with IWE-3000, and the component is found to be acceptable for continued service, the areas containing such flaws, degradation, or repairs shall be reex mined during the next inspection period listed in the schedule of the inspection program of IWE-2411 or IWE-2412, in accordance with Table IWE-2500-1, Examination Category E-C."
PROPOSED ALTERNATIVE Reliefis requested from the requirement of Paragraph IWE-2420(b) to perform successive examinations after repairs are made, examined, and the component returned to service. Repairs will be performed in accordance with IWA-4000, to restore the component to its original condition.
BASIS FOR RELIEF Title 10 CFR 50.55a was amended in the Federal Register (61 FR 41303) to require the use of the ASME {
B&PV Code, Section XI,1992 Edition,1992 Addenda, when performing containment examinations.
'Ibe purpose of a repair is to restore the component to an acceptable condition for continued service in accordance with the acceptance standards of Article IWE-3000. When making repairs, paragraph IWA-4150 requires the owner to conduct an evaluation of the suitability of the repair, including l consideration of the cause of failure.
Repairs are performed in accordance with IWA-4000, the intent of which is to use the construction code to restore the component to its original condition. If the examination after a repair indicates that the repair has restored the component to an acceptable condition, successive examinations are not warranted.
If the post-repair examination indicates the repair was not suitable, then the repair does not meet Code requirements and the component is not acceptable for continued service; further repair work would be necessary. Neither Paragraphs IWB-2420(b), IWC-2420(b), nor IWD-2420(b) require that a repair be l subject to successive examination requirements. Additionally, if the repair area is subject to accelerated degradation, the repair would still require augmented examination in accordance with ,
(- Table IWE-2500-1, Examination Category E-C. i I~ Reliefis requested in accordance with 10 CFR Part 50.55a(a)(3)(i). Repairing components to restore the l component to its original condition provides adequate assurance of the integrity of the repair.
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IMPLEMENTATION SCHEDULE The IWE Program Plan, of wnich this relief request is a part, will be implemented the first period of the first inspection interval for IWE; September 9,1998 to September 9,2001.
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i ATTACHMENT (3) -
RELIEF REQUEST NO. L1 l
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Baltimore Gas and Electric Company l
Calvert Cliffs Nuclear Power Plant June 8,1998
ATTACHMENT (3)
RELIEF REQUEST NO. L1 I SYSTEM (S)/ COMPONENT (S) FOR WHICH REllFF IS REOUESTED This relief request applies to the exterior portion of Calvert Cliffs Nuclear Power Plant's Units 1 and 2 Containment Buildings fabricated of concrete. The concrete portion of both Units I and 2 Containment Buildings are subject to the rules and requirements for Inservice Inspection of Class CC (Concrete Containment) components, Examination Category L-A, Concrete, item Ll.11, as applicable to IWL-2310," Visual Examination and Personnel Qualification," and 1WA-2210," Visual Examinations."
CODE REQUIREMENTS FOR WHICH REIJFF IS REOUESTED American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (B&PV) Code, Section XI,1992 Edition,1992 Addenda, requirement IWL 2310, " Visual Examination and Personne!
Qualification," and IWA-2210, " Visual Examinations," require specific minimum illumination and maximum direct examination distance for all concrete surfaces.
PROPOSED ALTERNATIVE Perform the concrete surface inspection remotely as required by Subsection IWL, Paragraph IWL-2510, extending the maximum direct examination distance, and reducing the minimum illumination requirements specified in Table IWA-2210-1.
BASIS FOR RFTJFF Title 10 CFR 50.55a was amended in the Federal Register (61 FR 41303) to require the use of the ASME B&PV Code, Section XI,1992 Edition,1992 Addenda, when performing containment examinations. In I
addition to the requirements of Subsection IWL, the rulemaking also imposes the requirements of ASME B&PV Code, Section XI,1992 Edition,1992 Addenda, Subsection IWA for minimum illumination and maximum direct examination distance of Class CC components, specifically for the examination of concrete under Paragraph IWL-2510.
In accordance with IWA-2210, when remotely performing the visual examinations required by S :bsection IWL, Paragraph IWL-2510, using remote techniques, the maximum direct examination distance specified in Table IWA-2210-1 may be extended, and the minimtn illumination requirements specified in Table IWA-2210-1 may be decreased. The change in examination and illumination requirements are allowed provided the remote examination procedure is demonstrated to resolve the required test chart characters in Table IWA-2210-1. In lieu of the using the Table IWA-2210-1 test chart characters, the Responsible Engineer will use a combination of character- and workmanship-based ,
samples to determine the resolution required to ensure that indications of interest are detectable. The 1 Responsible Engineer will also identify the minimum size for indications ofinterest. For remote visual examination, the procedure and equipment to be used will be demonstrated capable of resolving these minimum indications to the satisfaction of the Responsible Engineer and the Inspector. The record of demonstration will be available to the regulatory authorities.
In order to conform with Section XI, IWA-2000 requirements for visual examination, Subsection IWL referenced type VT-1 and VT-3 examinations, as described in ASME XI, IWA-2211 and -2213, ,
respectively, but designated them VT-lC and VT-3C to signify that these were examinations of a i concrete structure. The original VT-1 and VT-3 examinations in Subsection IWA were designed for use on metal surfaces. Flaw detection on metal surfaces requires the ability to resolve a much smaller 1
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ATTACHMENT (3)
RELIEF REQUEST NO. L1 indication than that required on concrete due to the small grain size of a meul surface in comparison to I. the much larger grain size of a poured concrete surface. The visual examination requirements for illumination levels and examination distances preclude the ability to demonstrate that the remote visual examination is equivalent to direct visual examination when performing examinations of concrete surfaces. The visual examination of a concrete Containment is intended to uncover indications of significant conditions over a large area in a generally bemgn environment. i i l In subsequent editions of the ASME Code, the requirements for a VT-lC examination have been replaced with a " detailed visual examination," and the requirements fer a VT-3C examination have been replaced with a " general visual examination." The general visual examination of a concrete surface is performed under the direction of the Responsible Engineer to indicate the general structural condition of the containment. IWL-2000 references American Concrete Institute ACI-201.1 R-68 for guidelines used to determine concrete deterioration and distress. If the general visual examination detects any deterioration, the detailed visual examination is performed, again under the direction of the Responsible Engineer, to determine the magnitude and extent of the deterioration. Also, alternative lighting and resolution requirements have been added to later editions of Subsection IWL to be used in lieu of the requirements oflWA-2000.
Relief is requested in accordance with 10 CFR 50.55a(a)(3)(i). Inspecting the concrete surfaces using increased distances and decreased illumination requirements, approved by the Responsible Engineer, will still allow the detection of flaws of a size sufficient to present a structural problem with the concre'.e .
IMPIIMENTATION SCHFDULE The IWL Program Plan, of which this relief request is a part, will be implemented the first period of the first inspection interval for IWL; September 9,1998 to September 9,2001.
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