ML20153B881

Safety Evaluation Accepting Request for Relief from Certain Requirements of ASME Boiler & Pressure Vessel Code,Section Xi,For Plant,Unit 2

ML20153B881
Person / Time
Site:	Fermi
Issue date:	09/18/1998
From:	NRC (Affiliation Not Assigned)
To:
Shared Package
ML20153B865	List: ML20153B861 ML20153B881
References
NUDOCS 9809230275
Download: ML20153B881 (16)

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% UNITED STATES j NUCLEAR REGULATORY COMMISSION o+ WASHINGTON, D.C. 30006 0001 i

3AFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REQUESIS FOR REllEF FOR THE FIRST 10-YEAR INTERVAL INSERVICE l

INSPECTION NONDESTRUCTIVE EXAMINATION PROGRAM DETROIT EDISON COMPANY FERMI 2 DOCKET NO. 50-341 l

1.0 INTRODUCTION

The technical specifications for Fermi 2 require that the inservice inspection (ISI) of the American Society of Mechanical Engineers (ASME) Code Class 1, 2, and 3 components shall be performed in accordance with Section XI of the ASME Boiler and Pressure Vessel Code (the Code) and applicable addenda as required by 10 CFR 50.55a(g), except where specific written i relief has been granted by the Commission pursuant to 10 CFR 50.55a(g)(6)(i).  !

10 CFR 50.55a(a)(3) states that attematives to the requirements of paragraph (g) may be used, when authorized by the NRC, if (i) the proposed attematives would provide an acceptable level of quality and safety or (ii) compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.

Pursuant to 10 CFR 50.55a(g)(4), ASME Code Class 1,2, and 3 components (including supports) shall meet the requirements, except the design and access provisions and the pre-service examination requirements, set forth in the ASME Code,Section XI, " Rules for

' inservice inspection of Nuclear Power Plant Components," to the extent practical within the limitations of design, geometry, and materials of construction of the components. The regulations require that inservice examination of components and system pressure tests conducted during the first 10-year interval and subsequent intervals comply with the requirements in the latest edition and addenda of Section XI of the Code incorporated by reference in 10 CFR 50.55a(b) 12 months prior to the start of the 120-month interval, subject to the limitations and modifications listed therein. The applicable edition of Section XI of the Code for the Fermi 2 first 10-year ISI interval is the 1980 Editibn through Winter 1981 Addenda.

. By letter dated April 16,1998, as supplemented by letters dated June 19 and July 27,1998, the licensee proposed attematives contained in requests for relief Nos. RR-A1, A16, A17, A18, A19, A20, A21, A22, A23, and A24 for Fermi 2. The July 27,1998, letter withdrew request for relief RR A1. The NRC granted requests for relief RR-A17, A19, A20, A21, and A22 in a letter and safety evaluation dated August 25,1998. This safety evaluation addresses only RR-A16, A18, and A24. The licensee has indicated it plans to revise request for relief RR-A23 and resubmit it

!( in the future. The staff will review the revised request for relief when it is received.

! 9809230275 980918 PDR ADOCK 05000341 l

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2.0 EVALUATION The staff, with technical assistance from its contractor, the Idaho National Engineering and Environmental Laboratory, has evaluated the information provided by the licensee in support of the licensee-proposed alternatives contained in requests for relief Nos. RR-A16, A18, and A24 l

for Fermi 2. Based on the results of the review, the staff adopts the contractor's conclusions and recommendations presented in its technical letter report.

2.1 Raouest for Relief RR-A16 2.1.1 Licensee Prooosal Section XI of the Code, Table IWA-4700(a) requires that a system hydrostatic test be performed in accordance with lWA-5000 after repairs by welding on the pressure-retaining boundary. In accordance with 10 CFR 50.55a(a)(3)(i), the licensee proposed to use Code Case N-416-1, "Altemative Pressure Test Requirement for Welded Repairs or installation of Replacement items by Welding, Class 1,2, and 3." The licensee stated:

Code Case N-416-1 cllows for the performance of test at nominal operating pressure l in lieu of a hydrostatic pressure test required by IWA-4000 providing the following p requirements are met:

(a) NDE [non-destructive examination) shall be performed in accordance with the methods and acceptance criteria of the applicable Subsection of the 1992 Edition of Section Ill.

l (b) Prior to or immediately upon retum to service, a visual examination (VT-2) l shall be performed in conjunction with a system leakage test, using the 1992 Edition of Section XI, in accordance with paragraph IWA-5000, at nominal operating pressure and temperature.

(c) Use of the Code Case shall be documented on the NIS-2 form.

l The NRC has indicated the intention to accept this Code Case in Draft Regulatory Guide (RG) DG-1050, issued February 1997. A supplementary requirement to perform additional surface NDE on the root-pass layer of butt and socket welds

! where the surface examination method is selected for Class 3 components is included.

Fermi will use the Code Case with this additional stipulation of DG-1050 until it is approved by the NRC and incorporated into RG 1.147. At that time, this relief request will expire and Fermi will use the Code Case as approved by the NRC.

'2.1.2 ' Staff Evaluation i The licensee proposes to implement the alternative to hydrostatic pressure tests contained in

Code Case N-416-1 for Code Class 1,2, and 3 repairs / replacements. In addition, the licensee will supplement the pressure test with an additional surface examination on the root pass layer of Class 3 repair / replacement welds or welded areas.

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l l* l Code Case N-416-1 specifies that NDE of the welds be performed in accordance with the applicable subsection of the 1992 Edition of Section Ill. This Code Case also allows a VT-2

l. visual examination to be performed at nominal operating pressure and temperature in conjunction with a system leakage test, in accordance with paragraph IWA-5000 of the 1992 L Edition of Section XI. The staff compared the system pressure test requirements of the 1992 Edition of Section XI to those of the 1989 Edition cf Section XI, the latest Code edition referenced in 10 CFR 50.55a, and found that:

l The test frequencies and pressure conditions are unchanged; j -

The hold times either remained the same or increased;

• The terminology associated with the system pressure test requirements for all three  !

Code classes has been clarified and streamlined; and '

The NDE requirements for welded repairs remain the same.

Hydrostatic testing only subjects the piping components to a small increase in pressure over the design pressure and, therefore, does not present a significant challenge to pressure boundary integrity. Accordingly, hydrostatic pressure testing is primarily regarded as a means to enhance leak detection during the examination of components under pressure rather than as a measure of the structuralintegrity of the components.

Following welding, the Code requires volumetric examination (depending on wall thickness) of repairs or replacements in Code Class 1 and 2 piping components, but only requires a surface examination of the final weld pass in Code Class 3 piping. There are no ongoing NDE requirements for Code Class 3 components except for VT-2 visual examination for leaks in conjunction with the 10-year hydrostatic tests and the periodic pressure tests. However, the staff finds that the examinations required by Code Case N-416-1 are commensurate for Class 3 l systems when (1) a surfa'ce examination is performed on the root pass layer of butt and socket welds, and (2) a system pressure test at nominal operating pressure is performed.

Considering the previous acceptance of Code Case N-416 by the NRC and the supplemental surface examination on the root pass for Class 3 systems, the staff concludes that the licensee's proposed alternative will provide an acceptable level of quality and safety. Therefore, the licensee's proposed alternative, to ute Code Case N-416-1 with a supplemental surface examination on the root pass layer of butt and socket welds, is authorized pursuant to L 10 CFR 50.55a(a)(3)(i). The use of the Code Case is authorized for the current interval or until such time as the Code Case is published in a future revision of RG 1.147 (" inservice inspection Code Case Acceptability - ASME Section XI, Division I"). At that time, if the licensee intends to continue to implement this Code Case, the licensee should follow all provisions in Code Case N-416-1 with limitations issued in RG 1.147, if any.

2.2 Reauest for Relief RR-A18 2.2.1 Licensee Prooosal Section XI of the Code, IWA-2300, requires that personnel performing VT-2 and VT-3 visual examinations be qualified in accordance with comparable levels of competency as defined in l

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ANSI N45.2.6. Addition ally, the examination personnel shall have natural or corrected near l distance acuity, in at le ist one eye, equivalent to a Snellen fraction of 20/20. For far vision, l l personnel shall have natural or corrected far distance visual acuity of 20/30 or equivalent. In  ;

accordance with 10 CFR 50.55a(a)(3)(i), the licensee proposed to use Code Case N-546,

" Alternative Requirements for Qualification of VT-2 Examination Personnel,Section XI, i Division 1." The licensee stated-Code Case N-546 provides the following alternative qualification rules for personnel l i

such as licensed and nonlicensed operators, local leak rate personnel, system j engineers, and inspection and nondestructive examination personnel.  !

1 (a) The individual must have at least 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> plant walkdown experience such as l that gained by licensed and nonlicensed operators, local leak rate personnel, system engineers, and inspection and nondestructive examination personnel.  ;

l (b) At least 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> of training on Section XI requirements and plant specific l procedures for VT-2 visual examination will be completed.

(c) Vision test requirements of lWA-2231 (1995 Edition) will be satisfied.

In addition, the following actions will ensure consistent quality in the performance of examinations. 3 1

1. Records of the training and qualifications specified in Code Case N-546 will be provided and maintained in accordance with the Fermi written practice.

2. Visual examination will be conducted in accordance with specific written procedures.

3. Visual examination procedures will provide for a documented independent review and evaluation of test results.

The use of Code Case N 546 will eliminate the need to qualify VT-2 examination personnelin the same manner as NDE personnel. VT-2 requires no special knowledge of technical principles, it is simply an inspection for evidence of leakage. l No special skills or technical training are required in order to observe water dripping from a component or bubbles forming on a surface wetted with a leak detection solution Therefore, qualification in accordance with the provisions of the Code Case will not present an reduction in quality or safety. In fact, it will facilitate the qualification of those personnel most familiar with the walkdown of plant systems.

2.2.2 Staff Evaluation j The Code requires that VT-2 visual examination personnel be qualified to levels of competency l

comparable to those identified in ANSI N45.2.6. The Code also requires that the examination personnel be qualified for near and far distance vision acuity. In lieu of the Code requirements, the licensee proposed to implement Code Case N-546 for personnel performing VT-2 visual examinations. This Code Case includes the following requirements:

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1. At least 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> plant walkdown experience, such as that gained by licensed and nonlicensed operators, local leak rate personnel, system engineers, and inspet 'n and NDE personnel.

2. At lenst 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> of training on Section XI requirements and plant-specific procedures for VT-2 visual examination.

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3. Vision test requirements of IWA-2321,1995 EdiVon.

The qualification requirements in Code Case N-546 are not significantly different from those for VT-2 visual examiner certification. Licensed and nonlicensed c.perators, local leak rate personnel, system engineers, and inspection and NDE personnel typically have a sound working I knowledge of plant components and piping layouts. This knowledge makes them acceptable l candidates for performing VT-2 visual examinations. I As part of the proposed alternative, and in addition to the requirements contained in Code Case j N-546, the licensee will (1) use procedural Duidelines for consistent, quality VT-2 visual examinations, (2) verify and maintain records of the qualification of persons selected to perform VT-2 visual examinations, and (3) perform independent reviews and evaluations of leakage by a i person (s) other than those that performed the VT-2 visual examination. Based on a review of l Code Case N-546 and the additional actions that will be taken by the licensee, the NRC staff l finds that the proposed alternative to the Code requirements will provide an acceptable level of quality and safety. Therefore, the licensee's request to implement Code Case N-546 with the l additional actions is authorized pursuant to 10 CFR 50.55a(a)(3)(i). The use of this Code Case is authorized for the current interval at Fermi 2, or until the Code Case is approved for general use by reference in RG 1.147. After that time, the licem,ee must follow the conditions, if any, specified in the RG.

2.3 Reouest for Relief RR-A24 2.3.1 Licensee Procosal The Code requires surface and volumetric examination of Class 1 and 2 longitudinal piping welds for Examination Categories B-J, C-F-1 and C F-2, Items B9.12, C5.12, C5.22, C5.52, and C5.62. The Code requires surface examination of Class 1 and 2 longitudinal piping welds for items 89.22, C5.42 and C5.82. The examination volume / surface area includes 2.5 times the pipe thickness at the intersection with circumferential welds that must be examined. In accordance with 10 CFR 50.55a(a)(3)(i), the licensee proposed to use Code Case N-524,

" Alternative Examination Requirements for Longitudinal Welds in Class 1 and 2 Piping." The licensee stated:

Code Case N-524 allows for the examination of the intersecting longitudinal weld in the zone required by the circumferential weld as follows:

(a) When only a surface examination is required, examination of longitudinal piping welds is not required beyond those portions of the welds within the examination boundaries of the intersecting circumferential welds.

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1 6 1 (b) When both surface and volumetric examination are required, examination of l longitudinal piping welds is not required beyond those portions of the welds I l within the examination boundaries of intersecting circumferential welds j provided the following requirements are met:

(1) Where longitudinal welds are specified and locations are known,

l. examination requirer,'ents shall be met for both transverse and parallel i flaws at the intersection of the welds and for that length of longitudinal weld within the circumferential weld examination volume; (2) Where longitudinal welds are specified but locations are unknown, or the existence of longitudinal welds is uncertain, the examination requirements shall be met for both transverse and parallel flaws within the entire exarnination volume of intersecting [circumferential) welds.

Longitudinal welds are fabricated during the product form manufacturing process under controlled shop conditions. This results in high quality welds with even stress l distribution.

l The welds were subjected to full radiography and pressure testing in accordance with ASME Section Ill.

l There has been no history of degradation of longitudinal seam welds beyond the  ;

! zone of the intersecting circumferential weld. When cracking does occur, such as iCSCC [intergranular stress corrosion cracking] in austenitic stainless materials, it initiates and will be evident in the zone of the circumferential weld. The absence of significant longitudinal weld problems is evidenced by ASME Code Case N-524, l which has been tentatively approved without restrictions in Draft Guide DG 1050.

This Code Case has been approved at other nuclear facilities...and was incorporated into the 1995 Addenda of ASME Section XI.

Because Code Case N-524 eliminates examination of the longitudinal weld beyond the intersection with a circumferential weld, use of N-524 can significantly reduce examination time requirements, thus reducing the cost of such examinations and unnecessary radiation exposure to examination personnel. In addition to the man-rem savings obtained by reduced examination time, additional radiological benefits can be realized due to the significant reduction of dose and effort associated with removing / reinstalling insulation and interferences (component supports) and preparing the welds for examination.

2.3.2 Staff Evaluation l Section XI of the Code requires the examination of longitudinal welds for the length of 2.5 times l the pipe thickness for Class 2 piping welds. These lengths are measured from the intersection

! with the circumferential weld. The licensee's proposed attemative is to examine only the

! portions of longitudinal weld contained within the examination area of the intersecting

circumferential weld. This attemative is contained in Code Cass N-524, which the staff has l previously found acceptable for use at other facilities.

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Longitudinal welds are produced during the manufacture of the piping, not in the field as are circumferential welds. Consequently, the welds are fabricated under the strict guidelines specified by the manufacturing standard, which provides assurance of structuralintegrity. These welds have also been subjected to the preservice and initial inservice examinations, which provide additional assurance of structuralintegrity. No significant loading conditions or material degradation mechanisms have become evident to date that specifically relate to longitudinal seam welds in nuclear plant piping. The most critical region of the longitudinal weld is the portion that intersects the circumferential weld. Since this region will be examined during the examination of the circumferential weld, the licensee's alternative provides an acceptable level of quality and safety. Therefore, in accordance with 10 CFR 50.55a(a)(3)(i), the licensee's proposal to implement Code Case N-524 is authorized. The use of the Code Case is authorized for the current inter /al at Fermi 2, or until such time as the Code Case is published in a future revision of RG 1.147. At that time, if the licensee continues to implement this Code Case, the l licensee should follow all provisions in Code Case N-524, with any conditions specified in the RG.

3.0 _C_QNCLUSION The staff has reviewed the licensee's submittals and concludes that for requests for relief j RR-A16, A18 and A24, the licensee's proposed alternatives to the Code requirements provide an acceptable level of quality and safety. Therefore, the staff concludes that the licensee's proposed alternatives contained in these requests for relief are authorized pursuant to 10 CFR 50.55a(a)(3)(i).

The alternatives contained in these requests for relief (the use of Code Case N-416-1 for RR-A16, Code Case N 546 for RR-A18, and Code Case N 524 for RR-A24) are authorized for the current interval or until such time as the Code Cases are published in a future revision of RG 1.147. At that time, if the licensec intends to continue to implement these Code Cases, the licensee should follow all provisions of the Code Cases with the limitations issued in RG 1.147, if i any.

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Principal Contributor; T. McLellan

. Date: September 18, 1998

Attachment:

Technical Letter Report f

TECHNICAL LETTER REPORT ON THE FIRST 10-YEAR INTERVAL INSERVICE INSPECTION r1EQUESTS FOR RELIEF EQB DETROIT EDISON FERMI 2 DOCKET NUMBER: 50-341

1. INTRODUCT!ON By letter dated April 16,1998, the licensee, Detroit Edison, submitted ten requests for relief from the requirements of the ASME Code,Section XI, for the Fermi 2 first 10-year inservice inspection (ISI) interval. The licensee requested expedited review of Request for Relief Nos. RR-A17, RR A19, RR-A20, RR-A21 and RR-A22, which were evaluated in a separate report. This report contains the evaluations of the remaining requests for relief, namely, Request for Relief Nos. RR-A1, A16, A18, A23 and RR-A24. In a letter dated June 19,1998, the licensee provided additional information in response to a Nuclear Regulatory Commission (NRC) request for additionalinformation (RAl). By letter dated July 27,1998, the licensee provided additional clarification for Requests for Relief RR-A21 and RR-A22, and withdrew Request for Relief RR-A1. Per correspondence with the Fermi 2, NRC Project Manager on August 31,1998, Request for Relief RR-A23 will be revised and resubmitted by the licensee for evaluation at a later date. Therefore, Request for Relief RR A23 is not included in this review. The Idaho National Engineering and Environmental Laboratory (INEEL) staff's evaluation of the subject request for relief is in the following section.

2. EVALUATION The informabon provioed by Detroit Edison in sup' port of these requests for relief from Code requirements has been evaluated and the bases for disposition are documented below. The Code of record for the Fermi 2, first 10-year ISI interval, which began January 1988, is the 1980 Ecition through Winter 1981 Addenda of Section XI of the ASME Boiler and Pressure Vessel Code.

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2.1 Reauest for Relief RR-A1. Examination Cateaorv B-A. Items B1.11. B1.21. 81.22 and B1.30. Reactor Pressure Vessel FM.LWalds Note: Request for Relief RR A1 was withdrawn by the licensee by letter dated July 27,1998.

' 2.2 ~ Raouest for Relief RR-A18. Use of Code Case N-416-1. Altemative Pressure Test -

Reauirement for Welded Renairs or Installation of Renlacement items bv Welding, Class 1. 2. and 3.Section XI. Division 1 Code Reauirement: Section XI, Table IWA-4700(a) requires that a system hydrostatic test be performed in accordance with IWA 5000 after repairs by welding on the pressure-retaining boundary. .

Licensee's Pronosed Afternatiy.s: In accordance with 10 CFR 50.55a(a)(3)(i), the licensee proposed to use Code Case N 4161, Alternative Pressure Test Requirement for Welded Repairs or Installation of Replacement items by Welding, Class 1, 2, and

.3. The licensee stated:

" Code Case N 416-1 allows for the performance of test at nominal operating pressure in lieu of a hydrostatic pressure test required by IWA 4000 providing the following requirements are met:

(a) NDE shall be performed in accordance with the methods and acceptance criteria of the applicable Subsection of the 1992 Edition of Section Ill.

(b) Prior to or immediately upon return to service, a visual examination (VT-2) shall be performed in conjunction with a system leakage test, using the 1992 Edition of Section XI, in accordance with paragraph IWA-5000, at nominal operating i pressure and temperature.

(c) Use of the Code Case shall be documented on the NIS-2 form.

"The NRC has indicated the intention to accept this Code Case in Draft Regulatory Guide DG-1050, issued February 1997. A supplementary requirement to perform additional surface NDE on the root pass layer of butt and socket welda where the surf ace examination method is selected for Class 3 components is included.

" Fermi will use the Code Case with this additional stipulation of DG 1050 until it is approved by the NRC and incorporated into Regulatory Guide 1.147. At that time, this relief request will expire and Fermi will use the Code Case as approved by the NRC."

3 Licensee's Basis for Prooosed Alternative (as stated):

" Code Case N 416-1".

Evaluation: Section XI of the Code requires a system hydrostatic test to be performed in accordance with IWA-5000 after repairs by welding on the pressure-retaining boundary. The licensee proposes to implement the alternative to hydrostatic pressure tests contained in Code Case N-416-1 for Code Class 1,2, and 3 repairs / 1 replacements, in addition, the licensee will supplement the pressure test with an additional surface examination on the root pass layer of Class 3 repair / replacement welds or welded areas.

Code Case N-4161 specifies that nondestructive examination (NDE) of the welds be performed in accordance with the applicable subsection of the 1992 Edition of Section Ill. This Code Case also allows a VT-2 visual examination to be performed at nominal operating pressure and temperature in conjunction with a system leakage test, in accordance with paragraph IWA 5000 of the 1992 Edition of Section XI.

Comparison of the system pressure test requirements of the 1992 Edition of Section XI to those of the 1989 Edition of Section XI, the latest Code edition referenced in 10 CFR 50.55a, shows that:

• The test frequencies and pressure conditions are unchanged;

• The hold times either remained the same or increased;

• The terminology associated with the system pressure test requirements for all three Code classes has been clarified and streamlined; and

• The NDE requirements for welded repairs remain th6 same.

Hydrostatic testing only subjects the piping components to a smallincrease in pressure over the design pressure and, therefore, does not present a significant challenge to

! pressure boundary integrity. Accordingly, hydrostatic pressure testing is primarily l regarded as a means to enhance leak detection during the examination of components under pressure rather than as a measure of the structuralintegrity of the components.

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4 Following_ welding, the Code requires volumetric examination (depending on wall i thickness) of repairs or replacements in Code Class 1 and 2 piping components, but only requires a surface examination of the final weld pass in Code Class 3 piping, j There are no ongoing NDE requirements for Code Class 3 components except for VT-2 visual examination for leaks in conjunction with the 10-year hydrostatic tests and the l- periodic pressure tests. However, the INEEL staff believes that the examinations required by Code Case N-416-1 are commensurate for Class 3 systems when 1) a surface examination is performed on the root pass layer of butt and socket welds, and

2) a system pressure test at nominal operating pressure is performed.

, Considering the previous acceptance of Code Case N-416 by the NRC and the 1

supplemental surface examination on the root pass for Class 3 systems, it is concluded that the licensee's proposed alternative will provide an acceptable level of quality and safety. Therefore, it is recommended that the licensee's proposed alternative, to use Code Case N-416-1 with a supplemental surface examination on the root pass layer of butt and socket welds, be authorized pursuant to 10 CFR 50.55ala)(3)(i). The use of the Code Case should be authorized for the current interval or until such timo as the Code Case is published in a future revision of Regulatory Guide 1.147. At that time, if the licensee intends to continue to implement this Code Case, the licensee should follow all provisions in Code Case N-4161 with limitations issued in Regulatory Guide 1.147, if any.

2.3 Reauest for Relief RR-A18. Use of Code Case N 546 A/temative Reou/rements for Qualification of VT-2 Examination Persc R %ction XI. Division 1 Code Reauirement: Section XI, IWA-2300, requires tilat personnel performing VT-2 and VT-3 visual examinations be qualified in accordance with comparable levels of competency as defined in ANSI N45.2.6. Additionally, the examination personnel shall have natural or corrected .1 ear distance acuity, in at least one eye, equivalent to a l Snellen fraction of 20/20. For far vision, personnel shall have natural or corrected far i

distance visual acuity of 20/30 or equivalent.

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. Mcynsee's Prooosed Alternative: in accordance with 10 CFR 50.55a(a)(3)(i), the licensee proposed to use Code Case N 546, Alternative Requirements for Qualification of VT-2 Examination Personnel,Section XI, Division 1. The licensee stated:

" Code Case N 546 provides the following alternative qualification rules for personnel such as licensed and nonlicensed operators, local Isak rate personnel, system engineers, and inspection and nondestructive examination personnel.

(a) The individual must have at least 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> plant walkdown experience such as that gained by licensed and nonlicensed operators, local leak rate personnel, system enginesis, and inspection and nondestructive examination personnel.

I (b) At least 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> of training on Section XI requirements and plant specific 1 procedures for VT 2 visual examination will be completed.  !

L (c) Vision test requirements of IWA-2231 (1995 Edition) will be satisfied.

"In addition, the following actions will ensure consistent quality in the performance of examinations. 1

1. Records of the training and qualifications specified in Code Case N-546 will be i provided and maintained in accordance with the Fermi written practice.

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2. Visual examination will be conducted in accordance with specific written )

procedures. l l 3. Visual examinatbn procedures will provide for a documented independent review l and evaluation of test results."

Licen;ee's Basis for Prooosed Alternative (as stated):

"The use of Code Case N-546 will eliminate the need to qualify VT-2 examination personnelin the same manner as NDE personnel. VT-2 requires no special knowledge of technical principles, it is simply an inspection for evidence of leakage. No special skills or technical training are required in order to observe water dripping from a l componant or bubbles forming on a surface wetted with a leak detection solution.

Therefore, qualification in accordance with the provisions of the Code Case will not I

present an reduction in quality or safety, in fact, it will facilitate the qualification of those personnel most familiar with the walkdown of plant systems."

Evaluation: The Code requires that VT-2 visual examination personnel be qualified to l levels of competency comparable to those identified in ANSI N45.2.6. The Code also requires that the examination personnel be qualified for near and far distance vision acuity. In lieu of the Code requirements, the licensee proposed to implement Code

! Case N 546 for personnel performing VT-2 visual examinations. This Code Case h includes the following requirements:

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l* 1. Ai least 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> plant walkdown experience, such as that gained by licensed and

, nonlicensed operators, local leak rate personnel, system engineers, and inspection and nondestructive examination personnel.

L 2. At least fou'r hours of training on Section XI requirements and plant specific o

l procedures for VT-2 visual examination.

L L 3. Vision test requirements of IWA-2321,1995 Edition.

The qualification requirements in Code Case N 54f) are not significantly different from

(-

those for VT-2. visual examiner certification. Licensed and nonlicensed operators, local leak rate personnel, system engineers, and inspection and nondestructive examination personnel typically have a sound working knowledge of plant components and piping layouts. This knowledge makes them acceptable candidates for performing VT 2 visual examinations.  ;

l In addition to meeting the requirements contained in Code Case N-546, the licensee -

has committed to use procedural guidelines for consistent, quality VT-2 visual examinations, verify and maintain records of the qualification of persons selected to perform VT-2 visual examinations, and perform independent reviews and evaluations of

, leakage by a person (s) other than those that performed the VT-2 visual examination.

-Based on a review of Code Case N 546 and the additional commitments made by ths licensee, the INEEL staff believes that the proposed alternative to the Code

requirements will provide an acceptable level of quality and safety. Therefore, it is recommended that the licensee's request to implement Code Case N-546 with the additional commitments be authorized pursuant to 10 CFR 50.55a(a)(3)(i). The use of this Code Case should be authorized for the third interval at Fermi 2, or until the Code a Case is approved for general use by reference in Regulatory Guide 1.147. After that

. timei the licensee must follow the conditions, if any, specified in the regulatory guide.

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7 2.4 Reauest for Relief RR-A23. Examination Cateoorv B-J. Item B9.11 and B9.12. Class 1 Pinino Welds Note: Per correspondence with the Fermi 2, NRC Project Manager on August 31, 1998, Request for Relief RR-A23 will be revised and resubmitted by the licensee for evaluation at a later date. Therefore, Request for Relief RR-A23 is not included in this l

review.

2.5 Reouest for Relief RR A24. Use of Code Case N 524. A/ternative Examination Reauirements for Lonoitudinal Walds in Class 1 and 2 Pinino.Section XI. Division 1 i

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! Code Reautrement: Examination Categories B-J, C F-1 and C F-2, items 89.12, C5.12, C5.22, C5.52, and C5.62, require surface and volumetric examir.ation of Class 1 and 2 longitudinal pipin0 welds, items B9.22, C5.42 and C5.82 require surface examination l

of Class 1 ano 2 longitudinal piping welds. The examination volume / surface area l includes 2.5t at the intersection with circumferential welas required to be examined.

Licensee's Procosed Alternative

In accordance with 10 CFR 50.55a(a)(3)(i), the licensee proposed to use Code Case N-524, Altemative Examination Requirements for Longitudinal Welds in Class 1 and 2 Piping. The licensee stated:

" Code Case N 524 allows for the examination of the intersecting longitudinal weld in

!. the zone required by the circumferential weld as follows:

(a) When only a surface examination is required, examination of longitudinal piping welds is not required beyond those portions of the welds within the examination boundaries of the intersecting circumferential welds.

(b) LWhen both surface and volumetric examination are required, examination of  ;

longitudinal piping welds-is not required beyond those portions of the welds within l- the examination boundaries of intersecting circumferential welds provided the l D following requirements are met:

g (1) Where longitudinal welds are specified and locatinns are known, examination requirements shall be met for both transverse and parallet flaws at the intersection of the welds and for that length of longitudinal weld withing the circumferential weld examination volume;

(2) Where longitudinal welds are specified but locations are unknown, or the j existence of longitudinal welds is uncertain, the examination requirements

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shall be met for both transverse and parallel flaws within the entire examination volume of intersecting circumferential welds."

Licensee's Basis for Pronosed Alternative (as stated):

" Longitudinal welds are fabricated during the product form manufacturing process under controlled shop conditions. This results in high quality welds with even stress distribution.

"The welds were subjected to full radiography and pressure testing in accordance with ASME Section Ill.

( "There has been no history of degradation of longitudinal seam welds beyond the zone I

of the intersecting circumferential welds. When cracking does occur, such as IGSCC in austenitic stainless materials, it initiates and will be evident in the zone of the circumferential welds. The absence of significant longitudinal weld problems is l evidenced by ASME Code Case N-524, which has been tentatively approved without l restrictions in Draft Guide DG 1050. This Code Case has been approved at other nuclear facilities and was incorporated into the 1995 Addenda of ASME Section XI.

"Because Code Case N-524 eliminates examination of the longitudinal weld beyond the l intersection with a circumferential welds, use of N 524 can significantly reduce

! examination time requirements, thus reducing the cost of such examinations and

! unnecessary radiation exposure to examination personnel, in addition to the man-rem savings obtained by reduced examination time, additional radiological benefits can be realized due to the significant reduction of dose and effort associated with removing / reinstalling insulation and interferences (component supports) and preparing the welds for examination.

Evaluation: ASME Section XI requires the examination of longitudinal welds for the

- length of 2.5 times the pipe thickness for Class 2 piping welds. These lengths are measured from the intersection with the'circumferential weld. The licensee's proposed l

alternative is to examine only the portions of longitudinal weld contained within the examination area of the intersecting circumferential weld. This alternative is contained l in Code Case N-524, A/temative Examination Requirements for Longitudinal Welds in Class 1 and C/ ass 2 Piping, which has previously been found acceptable for use at other f acilities.

Longitudinal welds are produced during the manuf acture of the piping, not in the field as are circumferential welds. Consequently, the welds are fabricated under the strict guidelines specified by the manufacturing standard, which provides assurance of i structuralintegrity. These welds have also been subjected to the preservice and initial

inservice examinations, which provide additional assurance of structuralintegrity. No significant loading conditions or material degradation mechanisms have become evident l

to date that specifically relate to longitudinal seam welds in nuclear plant piping. The

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most critical region of the longitudinal weld is the portion that intersects the circumferential weld. Since this region will be examined during the examination of the circumferential weld, the licensee's alternative provides an acceptable level of quality and safety. Therefore, in accordance with 10 CFR 50.55a(a)(3)(i), it is recommended that the licensee's proposal to implement Code Case N-524 be authorized. The use of l

the Code Case should b6 authorized for the current interval or until such time as the Code Case is published in a future revision of Regulatory Guide 1.147. At that time, if the licensee continues to implement this Code Case, the licensee should follow all provisions in Code Case N-524, with conditions specified in the Regulatory Guide.

3. CONCLUSION The INEEL staff has reviewed the licensee's submittals and concludes that for Requests for Relief RR-A16, RR-A19, and RR-24, the licensee's proposed alternatives to the Code requirements provide an acceptable level of quality and safety. Therefore, it is recommended that these proposed alternatives be authorized pursuant to 10 CFR 50.55a(a)(3)(i). Requests for Relief RR A1 and RR A23 were withdrawn by the lit;ensee in a letters dated July 27,1998 and August ??.1998, respectively.

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