ML20212E081

SER Accepting Third 10-yr Interval Insp Program Plan & Associated Requests for Relief for Plant

ML20212E081
Person / Time
Site:	Cooper
Issue date:	10/23/1997
From:	NRC (Affiliation Not Assigned)
To:
Shared Package
ML20212E074	List: L-96-034, TER on Third 10-Yr Interval ISI Program Plan:Nppd Cns ML20212E068 ML20212E081
References
NUDOCS 9711030046
Download: ML20212E081 (23)

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3* *a UNITED STATES j

• } NUCLEAR REGULATORY COMMISSION

• WASHINGTON, D.C. 306 4 0001 9 ,d 9*...

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION OF THE TH!fD TEN YEAR INTERVAL INSERVICE INSPECTION PROGRAM PLAN AliQ ASSOCIATED REQUESTS FOR RELIEF NEBRASKA PUBLIC POWER DISTRICT COOPER NUCLEAR STATION DOCKET NO. 50-298

1.0 INTRODUCTION

l The Technical Specifications (TSs) for Cooper Nuclear Station (CNS) state that the inservice inspection of the American Society of Mechanical Engineers (ASME) Code Class 1, 2 and 3 components shall be performed in accordance with Section XI c7 the ASME Boiler and Pressure Vessel (B&PV) Code and applicable addenda as required by 10 CFR 50.55a has been granted by the Commission pu(g),

rsuant to except 10 CFRwhere specific written relief 50.55a(g)(6)(1).

10 CFR 50.55a(a)(3) states that alternatives to the requirements of paragraph (g) may be used when authorized by the Nuclear Regulatory Commission (NRC),

if (i) the propo, sed alternatives would provide an acceptable level of quality and safety or ii compliance with the specified requirements would result in hardship or unu(sua)l difficulty without a compensating increase in the level o 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 or components and system pressure tests conducted during the first ten-year interval and subsequent intervals comply with the requirements in the latest edition and addenda of Section XI of the ASME Code incorporated by reference in 10 CFR 50.55a(b) twelve 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 ASME Code for the CNS third ten-year inservice inspection (ISI) interval is the 1989 Edition. The third ten-year interval began March 1,1996, and ends February 28, 2006..

j ENCLOSURE 1 9711030046 971023 PDR G ADOCK 05000298 PDR

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Pursuant to 10 CFR 50.55a(g)(5), if the licensee determines that conformance with an examination requirement of Section XI of the ASME Code is not i practical for its facility, information shall be submitted to the Comission in support of that determination and a request made for relief from the ASME Code roquirement. After evaluation of the determination, pursuant to 10 CFR 50.55a(g)(6)(1), the Comission may grant relief and may impose alternative requirements that are determined to be authorized by law, will not endanger life, property, or the comon defense and security, and are otherwise in the public interest, giving due consideration to the burden upon the l licensee that could result if the requirements were imposed.  !

In a letter dated October 18, 1995, the Nebraska Public Power District the licensee), submitted to the NRC its third ten-year ISI interval program (plan and associated requests for relief for CNS. The licensee submitted Revision 1 to its 151 program plan and associated requests for relief in its letter dated April 11, 1996. The licensee provided additional information in its letters dated April 11 and August 5, 1996, and February 7, 1997.

2.0 EVALUATION The staff, with technical assistance from its contractor, the Idaho National j Engineering Laboratory (INEL), has evaluated the information provided by the

, licensee in support of its Third Ten-Year Inservice Inspection Interval Program Plan, Revision 1, and associated requests for relief for CNS. Based on the information submitted, the staff adopts the contractor's conclusions and recommendations presented in the attached Technical Evaluation Report (TER).

Based on the staff's review of the licensee's Third Ten-Year Inservice Inspection Program, Revision 1, the staff determined that no deviations from regulatory requirements or comitments were identified. The staff's conclusions regarding the requests for relief contained in the licensee's third ten-year 151 program nisn are noted below.

The licensee withdrew Request for Relief RI-01 by its letter dated October 18, 1995.

Request for Relief RI-02, Revision 1: Section XI, IWA 2232 requires that ultrasonic examinations shall be conducted in accordance with Appendix 1.

Appendix 1, Paragraph I-2200 states that ultrasonic examination of vessel welds less than 2 inches thick and all piping welds shall be conducted in accordance with Appendix 111, as supplemented by Appendix 1. Appendix III, Paragraph !!!-3411 outlines the material specification requirements for calibration blocks. It requires calibration blocks to be fabricated from material of the same specification as the piping being joined by the weld. It also states that if material of the same specification is rot available, material of similar chemical analysis, tensile properties, and metallurgical structure may be used.

c The licensee has proposed as an alternative to the Appendix !!!, Paragraph 111-3411 requirements for calibration block material specifications to continue to use existing calibration blocks. The licensee has committed to compare the attenuation cf the calibration block and material velocity of the material being examined. The material specification documentation required by the 1989 Edition was not required by the original fabrication code; the original calibration blocks were fabricated based on P-number groupings. The procurement of new calibration blocks of the same material specifications would result in an unusual difficulty without a compensating increase in the level of quality and safety. The licensee has committed to com)are the attenuation of the calibration block and material velocity of tie material ,

being examined. This additional comparison will provide adequate assurance

-that the existing blocks will provide the proper ultrasonic calibration and sensitivity.

The staff has concluded that acquiring materials for new calibration blocks to satisfy current Code requirements is a hardship without a compensating increase in quality and safety. Therefore, the licensee's proposed alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(ii).

Request for Relief RI-03: The licensee has proposed as alternative to the Code-required volumetric examination of the inner radius sections for the head

' spray nozzle (N6A), head instrument nozzle (N6B), and head vent nozzle (M7) to perform a surface examination of the subject nozzle inner radius sections.

liie Code requires that the subject nozzle inner radius sections ba 100%

i volumetrically examined. However, because of the size and geometry of the reactor pressure vessel head nozzles, it is difficult to obtain a meaningful ultrasonic examination of the inner radius sections without the use of computer modeling and multiple, angle beam transducers. The licensee has proposed to perform a surface examination of the inner radius for the area labeled M to N as defined by Figure IWB-2500-7, in lieu of a volumetric examination. Boiling water reactor closure heads are typically unciad, and access to the subject nozzle inner radius section from beneath the reactor pressure vessel head is possible when located on the head stand during refueling. For the inner radii of these nozzles, inservice flaws will likely initiate on the vessel inside surface. The licensee's alternative, performing a surface examinatic on the inner radius section, will verify that flaw initiation at the nozzle inside radius is not occurring.

The staff concluded that the lice see's proposed inside surface examination, in lieu of a volumetric examination, will detect flaws initiating at the inner radius surfaces. Furthermore, the staff concluded that the licensee's proposed alternative provides an acceptable level of quality and safety.

Therefore, the licensee's proposed alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(1).

kequest for Relief RI-05: The Code, Section C , Examination Category C-A, item C1.30, requires a 100% volumetric exa6 ' ion of tubesheet-to-shell welds as defined by figure IWC-2500-2. The licensee v.uested relief from the Code-

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required volumetric examination of the Residual Heat Exchanger IA tubesheet-to-shell weld No. RHR-CA-3A and RHR Heat Exchanger IB, Weld No. RHR-CA-38.

Based on the geometry of the weld and associated component design, the staff has concluded that the Code-required examinations of the subject weld are impractical without redesign or disassembly of the component. As an alternative to the Code-required examination, the licensee will perform a VT-1 visual examination on the subject welds and the staff concludes that this '

alternative, in combination with the Code-required VT-2 visual uamination, provides reasonable assurance of operational readiness of the subject welds.

Therefore, relief from the Code-required volumetric examination is granted and the alternative imposed pursuant to 10 CFR 50.55a(g)(6)(1).

Request for Relief RI-06, Revision 1: The Code requirement Section XI, Table IWB-2500-1, Examination Category B-A, Items B1.11 and 81.12 requires that essentially 100% of all circumfr.rential and longitudinal reactor pressure vessel shell welds be volumetrically examined as defined in Figures IWB-2500-1 and IWB-2500-2. Items Bl.21 and B1.22 require that essentially 100% of the accessible length of all reactor pressure vessel circumferential and meridional head welds be volumetrically examined as defined in Figure IWB-2500-3.

The licensee requested relief from the Code-required 100% volumetric coverage of the following welds

HMB-BB-1. HMB-BB-2, HMB-BB-3, HMB-BB-4, HMB-BB-5, HMB-BB-6, VCB-BA-2, VLA-BA-1, VLA-BA-2, VLA-BA-3, VLB-BA-1, VLB-BA-2, VLB-BA-3, HMC-BB-1, VCB-BC-5-1, VCB-BC-5-2, and VCB-BC-5-3.

! The staff has determined that the licensee has not yet performed the examinations to determine actual coverages for compliance with the Augmented Reactor Pressuro Vessel Rule as required by the Code of Federal Regulations, 10 CFR 50.55a(g)(6)(ii)(A), issued September 8, 1992; therefore, relief is denied.

Request for Relief RI-07: The Code Examination Category B-H, Table IWB-2500-

. 1. Reactor Pressure Vessel Support Skirt to Bottom Head Weld, requires 100%

volumetric or surface examination, as defined by figures IWB-2500-13. -14, or

- -15, as applicable. The licensee proposed as an alternative to perform a surface examination of the areas A-B and C-D of the reactor pressure vessel support skirt weld.

Bat,ed on a review of the subject examination area, the staff determined that access to perform o surface examination of area C-D inside the support skirt is limited. The staff concluded that the licensee's proposed alternative to examine area C-D to the extent possible with an ultrasonic technique in combination with the Code-required surface examination of the weld area A-B outside of the support skirt, will provide reasonable assurance of weld integrity and thus provides an acca,otable level of quality and safety.

Therefore, the proposed alternative volumetric examination is authorized pursuant to 50.55a(a)(3)(i).

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5-Request for Relief RI-08: The licensee has requested to use the sample expansion criteria for additional examination areas provided in NUREG-0313.

This sample expansion methodology is a systematic approach to determine potential failure trends, since the sample is selected from components with similar characteristics. In addition, the structure of the NUREG-0313 scheduling criteria essentially doubles the nunber of welds susceptible to Intergranular Stress Corrosion Cracking (IGSCC) that receive volumetric examination during the 10-year interval, which tends to offset the smaller number of additional examinations that may be required if IGSCC is detected.

I Section XI, Paragraph IWB-2430 states that examinations that reveal indications exceeding acceptance standards shall be extended to the remaining i welds, areas, or parts included in the inspection item listing and scheduled I for examination during this and the subsequent period. NUREG-0313 states that for welds susceptible to IGSCC, an additional sample of the welds in the appropriate category (Categories A, B, or C) should be inspected. The additional sample should be approximately equal in number to the original sample and should be similar in distribution (pipe size, system, and location) to the original sample. The staff has found it acceptable to take Section XI credit for the augmented volumetric examinations performed in accordance with Generic letter (GL) 88-01 and NUREG-0313. Revision 2, provided that the Code-required surface examination is also performed.

The staff concludes that the licensee's proposed alternative, in combination with the Code-required surface examinations, will provide an acceptable level of quality and safety because the additional examination areas selected will more closely relate to the welds where IGSCC is detected, thus providing assurance of weld integrity. Therefore, the licensee's proposed alternative contained in Request for Relief RI-08 is authorized pursuant to 10 CFR 50.55a(a)(3)(i).

Request for Relief RI-09: Section ) >

agrgh IWA-2311(b), Appendix Vil ,

Ultrasonic Examination Personnel Qua) Alon Requirements, requires that the training, qualification, and certifit.. uf ultrasonic examination personnel shall also comply with the requirements specified in Appendix Vll. Appendix Vll states requirements for the employer's written practice, qualification of ultrasonic examiners, qualification records, and the minimum content of initial training courses for the ultrasonic examination method. The licensee requested relief from the Appendix Vil requirements for the qualification of nondestructive examination personnel for ultrasonic examination.

The licensee has proposed as an alternative to the Code to utilize ultrasonic examination personnel qualified in accordance with the requirements of IWA-2300, with the exception of IWA-231)(b). Additionally, personnel utilized to perform ultrasonic examinations on IGSCC susceptible welds will be qualified in accordarce with the latest EPRI guidelines.

Appendix Vil was incorporated in the 1988 Addenda to the 1986 Edition of ASME Section XI to enhance ultrasonic examination flaw detection. This appendix

. specifies administrative and examination qualification requirements. Although Appendices VII and Vlli both have requirements related to flaw detection in ultrasonic examinations, their concurrent implementa','on is not necessary.

Certain requirements of Appendix Vill may strengthen the efforts of Appendix Vil, but they are not necessary for its implementation.

The staff determined that the licensee has had sufficient time to develop an Appendix Vil program. Although Appendix Vill will further improve confidence in flaw detection, its implementation is not required at this time in conjunction with Appendix Vll. An Appendix VII program will increase quality and safety and is not considered impractical. ,

The staff concluded that compliance with the requirements of Appendix VII will enhance the overall quality of Code Section XI required volumetric examinations. Therefore, the licensee's request for relief is denied since i information has not been submitted to justify the authorization of an alternative pursuant to 10 CFR 50.55a(a)(3) or to grant relief per 10CFR50.55a(g)(6)(1).

Request for Relief RI-10: Section XI, IWA, IWB, IWC, and IWF-4000 (IWX-4000),

Repair Procedures, and IWA, IWB, IWC, and IWF-7000 (IWX-7000), Replacements, require that IWX-4000 provides the rules and requirements for repair of pressure-retaining Class 1, 2, and 3 components and their supports, and for the attachment of replacements to the system by welding or brazing, and IWX-7000 provides the rules and requirements for specification and construt. tion of items to be used for replacement.

The licensee has proposed as an alternative to the 1989 Code rules and requirements for repair of pressure-retaining Class 1, 2, and 3 components and supports defined by IWX-4000 and IWX-7000 to use the 1989 Edition of ASME Section XI, as a" ended by the 1989 Addenda, to govern Repair Procedures (IWX-4000) and Replacements (IWX-7000).

The 1989 Addenda to the Code provide ennancements or clarification to existing Code requirements. Based on a review of the changes in the 1989 Addenda to Section XI, the staff determined that the changes incorporated by the 1989 Addenda enhance and/or clarify the intent of the rules for the implementation of repair and replacement programs and plans. The changes appear to be primarily administrative in nature and do not alter the technical content of the Code rules. Therefore, the staff concludes that changes incorporated by the 1989 Addenda provide an acceptable level of quality and safety.

Therefore, the licensee's proposed alternctive is authorized pursuant to 10 CFR 50.55a(a)(3)(i).

Request for Relief RI-11: Section XI, IWB-2420 and IWC-2420, Successive Examinations of Class 1 and 2 Vessels Code Requirement-lWB-2420, Successive inspections, states:

"(b) If flaw indications or relevant conditions are evaluated in accordsuce with IWB-3132.4 or IWB-3142.4, respectively, and the

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component qualifier as acceptable for continued service, the areas containing such finw indications or relevant conditions shall be reexamined during the next three inspection periods listed in the schedule of the inspection programs of IWB 2410.

(c) If the reexaminations required-_by flaw indications remain essentiallyunchanged (b) abovefor reveal three that the successive inspection periods the com>onent examination -

schedule may revert to the orlginal sc)edule of successive inspections.

(d) For steam generator tubing, the successive examinations shall

, be governed by the plant Technical Specification."

IWC-2420, Successive inspections, states:

(b) If component examination results require evaluation of flaw indications in accordance with IWC-3000, and the component qualifies as conditionally acceptable for continued service, the area containing such flaw indications shall be re-examined during the next inspection period listed in the schedules of the inspection programs of IWC-2411 and IWC-2412.

"(c) If the reexaminations required by (b) above reveal that the flaw indications remain essentially unchanged for three e successive inspection periods, the component examination schedule may revert to the original schedule of successive inspections.'

f' The licensee requested relief from the ASME Section XI requirements for examining-flaws during successive periods and proposed the following alternative:

"As an alternate to IWB-2420 and IWC-2420, CNS will not perform successive examinations on vessel flaws which, through analysis, have been determined to originate from material manufacture or-fabrication provided:

a) The flaw-is characterized as subsurface in-accordance with IWA-3310(b);-

b) The NDE technique and evaluation which identified and characterized the flaw as originating from material manufacture or fabrication are

' documented in the flaw evaluation report; and c) The flaw has been determined to be acceptable for continued service in accordance with IWB-3132.4, or IWC-3122.4, and demonstrated-to have growth within acceptable limits until the next scheduled inspection, or the end of service life of the component."

I

4 The staff determined it :t for each examination that would result in successive examinations specific 'iformation to establish the position that the flaw is amanufacturIngdefectan.dwillnotgrowmustbedeveloped. The licensee is to only request relief from successive examinations only when flaw > that are detected can be verified as manufar.iuring defects based on the fabrication radiograph and/or the inservice flaw size correlates well with the fabrication or baseline examination. This information should be submitted to regulatory authorities for evaluation on a case by case basis. Based on the discussion above, the staff concludes that relief is denied and that relief of this nature should be evaluated only for specific components using appropriate technical justification presented by the licensee.

Request for Relief RI-12: Section XI, Examination Category B-J, Item B9.12 and Examination Categories C-F-1 and C-F-2, items C5.12, C5.22 C5.42, C5.52, C5.62 and C5.82, Examination of Class 1 and 2 Longitudinal Piping Welds, requires surface and volumetric examinations of longitudinal piping welds in Class 1 piping that is 4-inch nominal pipe size and larger in conjunction with examination of the circumferential welds selected for examination, as defined in Figure IWB-2500-8. The length of longitudinal welds required to be examined is at least one pipe diameter, but not more than 12 inches, from the circumferential weld intersection point.

Examination Categories C-F-1 and C-F-2, Items C5.12, C5.22, C5.52, and C5.62, require volumetric and surface examinations of longitudinal piping welds in Class-2 piping in conjunction with examination of circumferential welds selected for examination, as defined in figure IWC-2500-7. At least 2.5t of longitudinal weld is required to be examined. For Items C5.42 and C5.82, a surface examination is required for longitudinal piping welds intersecting circumferential welds selected for examination, as defined in figure IWC-2500-7. At least 2.St of longitudinal weld is required to be examined.

The licensee has proposed as an alternative to perform the examinations in accordance with ASME Section XI Code Case N-524, Alternative Examination Requirements for longitudinal Pipe Welds in Class 1 and 2 Piping;Section XI Division J. Inaddition,thelicenseehaspro)osedtoexaminethepotentially critical portions of the longitudinal welds (tie portion that intersects the circumferential weld) in conjunction with examination of the circumferential welds.

When implementing the alternatives contained in Code Case N-524, longitudinal welds need not be examined beyond the examination zone of the associated circumferential weld. When the longitudinal weld can be identified, only that portion of the longitudinal weld intersecting the circumferential weld is required to be examined for flaws parallel and transverse to the weld. Where the longitudinal weld cannot be identified,100% of the circumferential weld shall be examined for flaws parallel and transverse to the weld to ensure that the longitudinal /circumferential weld intersection is examined. Code Case N-524, when implemented in its entirety, leads to examination of the most critical area of the longitudinal weld. Thus, the Code Case provides reasonable assurance of weld integrity and provides an acceptable level of quality and safety.

.g.

The staff concludes that the licensee's proposed alternative to use Code Case N-524 provides an acceptable level of quality and safety. Therefore, the licensee's alternative to use Code Case N-524 is authorized, )ursuant to 10 CFR 50.55a(a)(3)(1), for the current interval or until suc1 time as the Code Case is oublished 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 is to follow all Dravisions in Code Case N-524 with limitations issued in Regulatory Guide 1.14/, if any.

Request for Relief RI-13: This request is not in the scope of this review and has been evaluated in a separate report by the NRr Request for Relief RI-14 Revision 1: The licensee proposed an alternative to use Code Case N-509, " Alternative Rules for the Selection and Examination of Integrally Welded Attachments,Section XI, Division 1." In addition, CNS proposes to examine 10% of the integrally welded attachments in each Examination Category in each Code class in accordance with Code Case N-509 requirements. The Code requires that for Class 1, Examination Category B-K-1, volumetric or surface examination, as applicable, is required for all integrally-welded attachments exceeding 5/8 inch design thicknes. during the first and second intervals when implementing Program B. For Class 2, Examination Category C-C, surface examination is required for all integrally-welded attachments exceeding 3/4 inch design thickness. For Class 3, Examination Categories 0-A, D-B, and D-C, surface examination is required for all integrally-welded attachments corresponding to those component supports selected by IWF-2510(b).

The staff determined that the Code often specifies sampling to assure that service-related degradation is not occurring, and it is logical to extend the sampling process to welded integral attachments. With a sample of a minimum of 10% of all integral attachment welds in Code Class 1, 2, and 3 systems, *be staff concludes that degradation, if occurring, will be detected. Therefoi s, the staff concludes that the use of the alternatives contained in Code Case N-509, with a minimum 10% selection of all integrally-welded attachments in each Code class, provides an acceptable level of quality and safety. Pursuant to 10 CFR 50.55a(a)(3)(i), the licensee's proposed alternative is 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 intends to continue to implement this code case, the licensee should follow all provisions in Code Case N-509, with limitations issued in Regulatory Guide 1.147, if any.

Request for Relief RI-15: Section XI. Table IWB-2500-1 Examination Category B-0, item B14.10, CRD Housing Welds, Table IWB-2500-1, requires a surface examinetion to be performed on 10% of the peripheral CRD housing welds. The licensee requested relief from performing 100% surface examinations on 10% of the periphery CRD housing welds.

Based on the staff's review, it has determined that clearances between the support skirt and the CRDs restrict access for examination personnel, inside

the support skirt, making the Code-required surface examination impractical.

To perform the Code-required surface examination, the CRDs and reactor vessel support skirt would require design modification to allow access for examination. The staff has detemined that imposition of this requirement would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.

Surface examination of 50% of the eight peripheral CRD lower housing ticlds (eoutvalent to 100% of 4 CRDs required to be examined by Code) and the V'*-2 visual examinations of CRD housing welds in conjunction with Class I system leakage testing after.each refueling outage will detect a pattern of degradation, if present. Therefore, the staff determined that the licensee's proposed alternative provides reasonable assurance of operational readiness of the subject welds. Therefore,-the relief is granted pursuant to 10 CFR 50.55a(g endanger life or)(6)(i).

propertyThis relief or the is authorized common by security defense and law andand willisnot otherwise in the public interest, giving due consideration to the burden that could result if the requirement _were imposed.

Request for Relief RI-16: Examination Category B-G-1, item B6.10, Surface Examination of the Reactor Vessel Closure Head Nuts, requires a 100% surface examination of all reactor vessel closure head nuts. The licensee proposed as

-an alternative to-perform a VT-1 visual examination of the surface of all reactor closure head nuts, utilizing the acceptance criteria of IWB-3517, as delineatui in the 1989 Edition of ASME Section XI.

Typical relevant conditions that would require corrective action prior to putting closure head nuts back into service would include corrosion, deformed or sheared threads, deformation, and degradation mechanisms (i.e., boric acid

= attack). The applicable Code examination requirement for__ closure head nuts is-a surface examination. Surface examination procedures are qualified for the

= detection of linear flaws (cracks), and have acceptance criteria only for rejectable linear flaw lengths. When performing surface examinations in accordance with the 1989 Edition of.the Code, Item B6.10, the surface examination acceptance criteria is not provided. Without clearly defined-acceptance criteria, relevant conditions that_ require corrective _ measures may not be adequately addressed.

Article !WB-3000, Acceptance Standants. IWB-3517.1, Visual Examination, VT-1,

-describes relevant conditions that require corrective action prior to continued service of bolting and associated nuts. Included for corrective action in-IWB-3517.1 is=the requirement to compare crack-like flaws to the

- flaw standards ofelWB-3515 for acceptance. Surface examination acceptance criteria are typically limited to linear flaws i.e., cracking, aligned

-pitting, and corrosion). Because-tha VT-1 visua(l examination acceptance criteria include the requirement for evaluation of crack-like indications and >

other relevant conditions requiring corrective action,. such as deformed or I sheared threads, localized corrosion, deformation of part, and other 3 degradation mechanisms, it can be concluded that the VT-1 visual examination  !

provides a more comprehensive assessment of the condition of the closure head l

11-nut. Therefore, the staff determined that a VT-1 visual examination provides an acceptable level of quality and safety, in addition, it is noted that the 1989 Addenda of Saction XI changes the requirement for the subject reactor pressure vessel closure head nuts from surface to VT-1 visual examination and provides appropriate acceptance criteria.

Dased on its review, considering that the 1989 Addenda and later editions of the Code recuire only a VT-1 visual examination on reactor pressure vessel closure beac nuts, and the adequacy of the alternate examination, the staff concludes that the licensee's proposed alternative provides an acceptable level of quality knd safety. Therefore, the licensee's proposed alternative VT-1 visual examination is authorized pursuant to 10 CFR 50.55a(a)(3)(1).

Request for Relief RI-17: Class 1 and Class 2 Integrally Welded Shear Lugs on Piping, ASME Code,Section XI, Table IWB-2500-1, Examination Category B-K-1, Items B10.10, B20.20, B10.30, and 810.40 requires a volumetric or surface examination, as applicable, for integrally-welded attachments exceeding 5/8 l inch design thickness. IWC-2500-1, Examination Category C-C, item C3.70 l requires a surface examination of 100% of the length of all integral

attachment welds exceeding 3/4 inch design thickness as defined by Figure IWC-2500-5. The licensee has requested relief from )erforming the volumetric and surface examinations to the extent required by t1e Code for the following Class 1 and 2 integral attachment welds

FWB-BKl-8, FWC-BKl-8, MSA-BKl-6, PSA-BKl-19, RR-BKl-4A, RHB-BKl-16, RHA-CEl-2, RSA-CC-25, SDS-CEl-21.

The licensee has proposed, as an alternative, to examine integrally welded attachments in accordance with applicable Code requirements to the maximum extent practicable without removal of adjoining pipe clamps or restraints.

The applicable NDE data record will describe in detail the extent of the limitation and will be available for review. If indications are detected adjacent to the intervening piping clamp, the clamp will be removed for further evaluation.

The licensee is implementing Code Case N-509, which provides an alternative to the examination of 100% of Class 1, 2, and 3 integral attachmenti and reduces the number of integral attachment welds being examined. The statf concludes that the proposed alternative, in corbination with Code Ca e rl..09, is unacceptable. Because of the substantial reduction in intmM attacaent i weld examinations allowed by Code Case N-509, the staff concie ed all Wted integral attachment welds should be examined to the extent possible in order to provide an acceptable level of quality and safety. Therefore, the relief is denied since information has not been submitted to justify the authorization of an alternative pursuant to 10 CFR 50.55a(a)(3) or to grant relief per 50.55a(g)(6)(i).

Request for Relief RI-18: Section XI, Table IWC-2500-1. Examination Category C-C, Item C3.30, Integrally Welded Attachments to the Residual Heat Removal Pump Casings, requires a surface examination of 100% of the length of the pump integral attachment welds as definri by Figure IWC-2500-5. The licensee requested relief f om performing . < Code-required surface examination on the integral attachment welds of Residual Heat Removal Pumps lA, IB, IC, and ID.

12 Based on the staff's review, it is evident that the design of the base plate support and location of the welded attachments make the surface examination impractical. To perform the Code-required surface examinations, design-modification-to allow access for examination of the supports and welded attachments would be required. Imposition of this requirement would cause a considerable burden on the licensee without a compensating increase in reasonable assurance-of operational readiness of the subject welds.

The staff concluded that examination of other welded attachments and the VT-2 Code-required visual examination performed on the sub,k t? RHR pum) attachment welds:will detect significant degradation, if present, and that tie licensee's

, proposed alterr.ative provides reasonable assurance of operational readiness of the subject welds. Therefore, the staff concludes relief is granted pursuant to10CFR50.55a(g)(6)(1).

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-Request for Relief RI-19, Revision 1: This request is not in the scope of this ISI: review and has been evaluated separately by the staff.

Relief Request RI-20 Revision 1: Section XI, Table IWB-2500-1 Examination Category B-F, Item B5.130, Dissimilar Metal Butt Welds in Piping, requires i 100% surface examination of Weld RVD-BF-14. T h Code requires that the subject weld receive a 100% surface examination. The staff determined that.

due to the proximity of a rigid support, access to one side of the weld is restricted. As a result, the complete Code-required examination is r

impractical. To satisfy Code requirements, the rigid support must be removed by cutting or the line must be modified. Therefore, imposition of this requirement would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.

The licensee is examining the accessible portion of the subject weld, which results in 83% coverage. Based on the significant percent of coverage' obtainable, the staff concluded that, degradation, if occurring,-will be.

detected and the licensee's aroposed alternative provides reasonable assurance of structural integrity of tie subject welds. Therefore, the licensee's relief is granted pursuant to 10 CFR 50.55a(g)(6)(1).

Request for Relief, RI-21 Revision 1: Section XI, Table IWB-2500-1, Examination Category B-D, items B3.90 and 83.100, Reactor Vessel Nozzle-to-Vessel Welds, require 100% volumetric examination of reactor vessel nozzle-to-vessel welds as defined by Figure IWB-2500-7. The licensee requested relief from the Code-required volumetric examinations of the following nozzle-to-

-shell welds: .N1A&B, N2A-H, N2J&K, N3A-D, N4A&C N4B&D, N5A&B, N6A&B, N7, NBA&B, and the nozzle inner radius section for the N9 CRD nozzle.

Based on a review of the information provided. the staff determined that compliance with the. Code requirement _is impractical, because component configuration, insulation support. rings,. nozzle access hatches, and thermocouple pads and instrument lines limit scanning, precluding complete

_ volumetric examination of the nozzle-to-vessel welds and..the N9 CRD nozzle.

Providing a'ccess.to the examination areas would require design modifications. l

Therefore, imposition of this requirement would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.

The licensee is examining the accessible portions of the subject nozzle-to-shell welds and the CRD nozzle inner radius section to the extent practice 1, which results in coverages from 27% to 70%. Based on the percent of combined coverages obtainable for the subject nozzles, in conjunction with the VT-2 visual examination, it is reasonable to conclude that degradation, if occurring, will be detected. Therefore, the staff determined that the licensee's pro)osed alternative provides reasonable assurance of structural integrity of t w subject welds. The licensee's relief is granted pursuant to 10 CFR 50.55a(g)(6)(1).

Request for Relief RI-22: Section XI, Table IWD-2500-1, Examination Cttegory B-J. Item B9.31, Examination of Class 1 Pipe Branch Connection Welds, requires 100% surface and volumetric examination of branch pipe connection welds greater than 4 inches as defined in Figure IWB-2500-10. The licensee requested relief from 100% volumetric examination of Class 1 pipe branch

'onnection welds FWA-BJ-01 RAS-BJ-10, and RBS-BJ-6A.

The Code requires that the subject branch connection nlds receive 100%

volumetric and surface examinations. The licensee stated that 67% to 82%

volumetric coverage of the subject examination areas can be obtained. Based on the review of the information provided, the staff determined that the Code-required volumetric examination is impractical due to the configuration of the branch connections. To perform the complete volumetric examination, design modifications or replacement of the branch connections with those of a configuration that provides for complete coverage would be required.

imposition of this requirement would result in hardship or unusu&l difficulty without a compensating increase in the level of quality and safety.

The licensee proposes to perform the volumetric examinations to the extent practical, resulting in at least 67% volumetric coverage. Based on the coverage that can be obtained, in combination with the surface examination, significant degradation, if present, should be detected, Therefore, the staff concludes that the licensee's proposed alternative provides reasonable assurance of structural integrity of the subject welds. The relief is granted pursuant to 10 CFR 50.55a(g)(6)(i).

The licensee withdrew Request for Relief RI-23, Examination Category C-F-2, Item C5.51, Class 2 Piping Welds, by letter dated August 5,1996.

Request for Relief RI-24: Section XI, Table IWB-2412(a) and IWB-2420(a),

Successive Examination Requirements and the Sequence of Examination for Class 1 Bolting, require that the required examinations in each examination category shall be completed during each successive inspection interval in accordance with Table IWB-2412-1. lWB-2420(a) states that the sequence of component examinations established during the first inspection interval shall be repeated during each successive inspection interval, to the extent practical.

4 l

The licensee requested relief from the successive examination and sequence of examination requirements of the Code for the reactor pressure vessel bolting, nutt, washers, and threads in flange. The licensee has proposed in lieu of maintaining the Code required successive examination schedule, to re-examine the threads in the reactor vessel flange and the bushings during the first period; the closure head studs during the second period, and the closure washers Od nuts during the third period.

The Code requires that the successive examination and sequence of examination be maintained during subsequent intervals. In addition, the Code requires that a sample of examination areas be examined each period in accordance with Table IWB-2412-1. The licensee has noted that the Code scheduling criteria is based on Examination Category. The intent of the scheduling philosophy of items within an Examination Category is further defined in the 1991 Addenda of ASME Section XI. IWB-2112(a)(3) states; "If there are less than three items to be examined in an examination Category, the items may be examined in any two periods, or in any one period if there is only one item, in lieu of the percentage requirements of Table IWB-2412-1. Because there are greater than three bolts associated with the closure head, the staff concluded a schedule of examinations as required by Table IWB-2412-1 must be maintained.

Therefore, the relief is denied since information has not been submitted to justify the authorization of an alternative pursuant to 10 CFR 50.55a(a)(3) or l to grant relief per 50.55a(g)(6)(i).

Request for Relief PR-01: IWA-4700(a) and (b), Alternative Pressure Test Requirements for Code Class 1, Class 2, and Class 3 Systems Following Repair, Replacements, and Modifications, requires that, after repair by welding on the pressure-retaining boundary, a system hydrostatic test shall be performed in accordance with IWA-5000. IWA-5214, Repairs and Replacements, requires that a repaired or replaced component be pressure tested prior to resumption of service if required by IWA-4400 and IWA-4600. The test pressure and temperature for a system hydrostatic test subsequent to component repair or replacement shal) be the system test pressure and temperature specified in IWB-5222, IWC-5222, or IWD-5223, as appropriate for the system that contains the repaired or replaced component. The licensee has proposed 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, for Class 3 repair / replacement welds or welded areas, the licensee will supplement the pressure test with an additional surface examination on the root pass layer.

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 structural integrity of the components.

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 vitual examination to be performed at nominal u

operating pressure and temperature in conjunction with a system leakage test, in accordance with paragraph IWA-5000 of the 1992 Edition of Section XI, in lieu of the hydrostatic test. The 1989 Edition of Sections III and XI are the latest Code editions referenced in 10 CFR 50.55a. Comparison of the system pressure test requirements of the 1992 Edition of Section XI to those of the 1989 Edition of Section XI shows that:

1) The test frequencies and the pressure conditions associaisd with these tests have not changed;

2) The hold times have either remained unchanged or increased;

3) The terminology associated with the system pressure test requirements for all three (. ode classes has been clarified and streamlined; and

4) The NDE requirements for welded repairs remain the same.

Following welding, the Code requires volumetric examination (depending on wall thickness) of repairs or replacements in Code Classes 1 and 2 piping components, but only reyaires a surface examination of the final weld pass in Code Class 3 components. 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.

Considering the NDE performed on Code Class 1 and 2 systems and considering that hydrostatic pressure tests rarely result in pressure boundary leaks that would not occur during system leakage tests, the staff believes that increased assurance of the integrity of Class I and 2 welds is not commensurate with the burden of performing hydrostatic testing, further, it is also believed that the added assurance provided by a hydrostatic test of Class 3 welds is not commensurate with the burden of performing hydrostatic testing when a surface examination is performed on the root pass layer of butt and socket welds and a system pressure test is performed.

The staff concludes that compliance with the Code hydrostatic testing requirements for welded repairs or replacements of Code Class 1, 2, and 3 components would result in hardship without a compensating increase in the level of quality and safety. Therefore, the staff concludes that the proposed alternative is authorized, pursuant to 10 CFR 50.55a(a)(3)(ii), including the licensee's proposal to perform a surface examination on the root pass layer of Class 3 butt and socket welds.

Use of Code Case N-416-1, with the licensee's proposed augmented surface examination, is 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 intends to continue to implement this Code Case, the licensee should follow all the provisions in Code Case N-416-1, with

, limitations issued in Regulatory Guide 1.147, if any.

Request for Relief PR-02, Revision 2: Section XI, Table IWB-2500-1 Examination Category B-P, Item B15.10, Reactor Vessel Pressure-Retaining Boundary, requires a VT-2 visual examination during system pressure tests and system hydrostatic tests of the Class 1 reactor vessel prsssure-retaining boundary components each refueling outage. The licensee has proposed an alternative to the Code system pressure test. The licensee proposes to perform a VT-2 visual examination during the system leakage test at a pressure not less than that associated with 100% rated power and with systems in their normal line up to the extent practical, extending to the outermost valves in these systems.

The staff determined tnat Paragraph IWB-5221(a) requires that system leakage tests be performed at a test pressure not less than the nominal operating pressure associated with 100% rated reactor power. To obtain nominal

, operating pressure for CNS, the reactor must achieve 100% power. To perform a l' system leakage test at 100% power for nonisolable portions of a system is a l -major effort requiring many manhours from skilled maintenance and inspection personnel while causing excessive radiation exposure and personnel safety concerns. As an alternative to the system pressure test, the licensee proposes to perform a VT-2 visual examination during the system leakage test at a pressure not less than that associated with 100% rated power and with systems in their normal. line up to the extent practical, extending to the outermost valves in these systems. The staff determined that requiring the licensee to perform a system pressure test at 100% reactor power will result in a hardship without a compensating increase in quality and safety since the proposed alternative provides reasonable assurance of operational readiness of the subject components.

Therefore, the staff concludes that requiring a VT-2 visual examination at 100% reactor power would result in a hardship without a compensating increase in quality and safety. A VT-2 visual examination performed during the system leakage test at a pressure not less than that associated with 100% rated power provides reasonable assurance of the continued operational readiness of mechanical connections, extending to the Class 1 boundary. Therefore, the relief is authorized pursuant to 10 CFR 50.55a(a)(3)(ii).

. Request for Relief PR-03, Revision 1: Section XI, IWA-5250(a)(2), Corrective Action Resulting from Leakage at Bolted Connections, requires that the sources of leakage detected during the conduct of a system pressure test shall be located and evaluated by the Owner for corrective action. When the leakage is at a bolted connection, the bolting shall be removed, VT-3 visually examined for corrosion, and evaluated in accordance with IWA-3100. The licensee has proposed the following alternative to the ASME Section XI requirements for removal of bolting at leaking connections. for VT-3 visual examination:

If leakage occurs at a bolted connection during the performance of a system pressure test, an engineering evaluation shall be performed to determine if the associated bolting is susceptible to corrosion which could. result in further degradation and increased leakage. This evaluation shall address at a minimum:

1) type and' location of leakage

'21 historical leakage 3h bolting materials of the leaking component-41 visual evidence of corrosion

5) history of the bolt material degradation due to corrosion in siellar environments If the engineering evaluation indicates that the bolting material is not susceptible"to corrosion, then bolt removal fcr visual examination and further evaluation shall not be required. - However, termination of leakage -shall be addressed at the next available opportunity.-

If the evaluation detemines the need for a VT-3 visual examination of the bolting, one bolt closest to the source of leakage shall be-

l. removed, and in 1:eu of performing the Code required VT-3 visual L examination,-the bolting will be VT-1 visually examined per IWA-2211(a) and evaluated.in accordance IWB-3517.1. If the removed bolt has evidence of degradation,- all remaining bolting shall be removed and VT-1 examined and evaluated accordingly. All examinations and evaluations shall be traceable to the VT-2 documentation originally detecting the leakage and applicable records will be maintained per

-lWA-6000."

The 1989 Edition of the Code requires that, when leakage occurs at bolted

-connections, all bolting be removed for VT-3 visual examination. In lieu of

~t his requirement, the'l consee has proposed to evaluate the bolting to determine its susceptibility-to corrosion. If the bolting is susceptible to corrosion or the initial evaluation indicates the need for a more in-depth evaluation, the bolt closest _to the source of leakage will be removed, VT . -

examined. and evaluated in accordance with-IWA-3100(a).

The staff concludes that the licensee's proposed alternative is based on sound engineering judgement and that this alternative to the Code-required removal of bolting at a joint when leakage occurs provides an acceptable level of quality and _ safety. of the bolted connections and that the licensee's proposed

. alternative, to' evaluate the bolting-at a leaking connection, would detect degradation of bolting, if present. - Therefore, the relief is authorized pursuant to 10 CFR 50.554(a)(3)(i).

' Request for Relief PR-04: Section.XI, Table IWB-2500-1, Examination Category B-P, Items B15.50 and B15.51, Pressure Testing of the Reactor Pressure Vessel (RPV) Head Flange Seal l Leak Detection System, requires a VT-2 visual examination during: system hydrostatic tests. The licensee requested relief from the Code-required system pressure test of the RPV Head Flange Seal--Leak Detection System.- Line Number-1-MS-152-1.

The Code requires-that system pressure tests be conducted for those systems required to function during normal plant operation. The RPV Head Flange Leak Detection Line is pressurized only when the inner 0-ring fails. The design of u a

this line makes the Code-required system pressure test impractical. To perform the system pressure test in accordance with the requirements, the RPV Head Flange Leak Detection System and the RPV flange would have to be redesigned, fabricated, snd installed.

The licensee has comitted to perform a VT-2 visual examination on the RPV Head Flange Leak Detection Line when the reactor cavity is flooded. The proposed alternative will provide adequate assurance that gross inservice flaws in the subject line will be detected if any have developed.

The staff concluded that the system pressure test required by Section XI for the subject Class I line is impractical because of the possibility of damage to the RPV Head flange 0-ring seals. The VT-2 visual examination of the RPV Head Flange Leak Detection Line when the reactor cavity is flooded provides reasonable assurance that if gross inservice flaws have developed in the subject 11ne, they will be detected. Therefore, the staff c.oncludes that relief is granted pursuant to 10 CFR 50.55a(p)(6)(1).

Request for Relief PR-05.Section XI, Table IWC-2500-1, Examination Category C-H, Items C7.30 through C7.80, Class 2 Containment Penetration Piping and

, Valves, require that a system pressure test, inservice or functional (IWC-5221), and a system hydrostatic test (IWC-522?.) in conjunction with a VT-2 visual examination of pressure-retaining components, piping, and valves be performed.

The licensee has proposed as an alternative to implement Code Case N-522, Pressure Testing ,,f Containment Penetration Piping, in 11eu of the Code-

\

required pressure tests for portions of the subject iines that are Class 2 at the containment penetration.

System Penetration Number , __

Inst Air 22, 30E, 30F, 33E, 33F PCC, NI, & 2, 25, 26, 45C, SIE, 51F, 203A, 203B, 205, 220 SBNI RPV INST 40A, 40B, 40C, 40D, 47(A31)

Reactor- 29E, 209A, 209B, 209C, 209D, 213A, 2138, 215, 229A, 2298, Recirc. 229C, 2290, 229E, 229F, 229G, 229H, 229J, 229K, 229H Draias 18, 19. 43, 44 Demin Water 20 H202 36,'203A, 203B REC 23, 24 Service Air 21 TIP 35A, 35B, 35C, 35D, 35E l

i

' The staff determined that the licensee's proposal prov',2 a acceptable level of quality and safety. If the leak rate exceeds the Ap p ndix J acceptance criteria, additional measures will be applied to verify that the test failure is not due to a through-wall leak. These segments of lines are safety-related only because they function as part of the containment aressure boundary and F are relied on for containmer.t integrity. Therefore, tie staff determined that to test the penetration piping portion of the associated systems to the containment test criteria found in 10 CFR 50.55a, Appendix J provides a acceptable level of quality and safety.

Appendix J pressure tests verify the laak-tight integrity of the primary reactor containment and of systems and components that ronetrate containment by local leak rate and integrated leak rate tests. In addition, Appendix J test frequencies provide assurance that the containment pressure boundary is being maintained at an acceptable level while monitoring for deterioration of seals valves and piping.

The Class 2 containment isolation valves (CIVs) and connecting pipe segment must withstand the peak calculated containment internal pressure related to L the maximum design containn.ent pressure. The staff finds that the pressure-

! retaining ir,tegrity of the CIVs am' connecting piping and their associated safety functions may be verified wi h an Appendix J, Type C test if conducted l

at the peak calculated containment pressure. The seal between the connecting pipe segment and containment may be verified using an Appendix J, Type B test.

Therefore, when the connecting pipe segment is subjected to either a Type B or C test, its safety function is verified by the Appendix J test.Section XI, IWC-5210(b) requires that where air or gas is used as a testing medium, the test procedures shall include methods for detection and location of through-wall leakage in components of the system tested. Because an Appendix J.

Type C test most likely uses air as a testing medium, the licensee's test procedure should, meet the above requirement for the CIVs and pipe segments between the CIVs.

The staff concluded that an acceptable level of quality and safety will be provided by Appendix J tests when the licensee performs the Icak test at the peak calculated containment design pressure and implements a test procedure that provides for detection and location of through-wall leakages in the pipe segments that are being tested. Therefore, pursuant to 10 CFR 50.55a(a)(3)(i), the licensee's proposed alternative is auth0P12Ed.

The use of the Code Case in combination with the licensee's proposal should be authorized for the current interval or until such time as the Code Case is published in a future t evision of Regulatory Guide 1.147. At that time, if the licensee intends' to continue to implement this Code Case, the licensee is to follow all provisions in Code Case N-522 with limitations issued in Regulatory Guide 1.147, if any.

Request for Relief PR-06: Section XI, IWA-5244(b), Examination Category D-A, item D1.10, VT-2 Visual Examination of Redundant Systems for Buried a

.c 20-Components requires that for redundant-systems where the buried components are nonisolable, the VT-2 visual examination shall consist of a test:that -

determines-the change in flow between the ends of the buried pipe.

The licensee has proposed,_as an alternative, to test.this buried pipe in conjunction with quarterly testing of pumps. This test verifies flow by use of the existing monitoring systems for pressure and flow rate. Significant through-wall leakage would be detected in a similar manner to that expe:ted with the Code-required flow measurement test. The staff has determined that the licensee's proposed alternative provides an acceptable level of quality and safety.-

The licensee's proposed alternatise, to test the subject piping in conjunction with quarterly testing of pumps, will verify that the subject piping wili perform its design: function. The staff concludes that the licensee's proposed alternative provides an acceptable level of quality- and safety. Therefore, the licensee's proposed alternative is authorized pursuant to

.10 CFR 50.55a(a)(3)(i).

Request for Relief PR-07:- Section XI, Table IWB-2500-1, Examination Categories B-P, C-H, and D-A, 10-Year Hydrostatic Pressure Test. Requirements-for Class 1, 2, and-3 Systems, require a system hydrostatic pressure test at an elevated pressure and an accompanying VT-2 visual examination at least once each inspection interval.

l As an alternative to the Code requirements, the licensee has proposed an alternative _to performing the Codekrequired hydrostatic tests at elevated pressures for Class 1, 2, and 3 systems.

In lieu of the Code-required inydrostatic testing requirements, the licensee

-proposes to implement the alternatives to Code requirements contained in Code Case N-498-1, Alternative Rules for 10-Year System Hydrostatic Testing for Class 1, 2, and 3 Systems, dated May 11, 1994.

-The system hydrostatic test,'as stipulated in Section XI, is not a test of the structural integrity of the system but rather an enhanced leakage test.

Hydrostatic testing only subjects the piping components to a small-increase in c  ; pressure over the design pressure; therefore, piping dead weight, thermal expansion,. and seismic loads present far greater challenges to the structural

. integrity of a system. Consequently, the Section XI hydrostatic pressure test-is primarily regarded as a means to enhance leak detection during the '

examination of components under pressure rather than as a method to determine the structural integrity of the: components. In addition,-the industry experience indicates that leaks are not being discovered as a result of hydrostatic test pressures' causing a-preexisting flaw to propagate through the '

wall;L in most cases leaks are being found when the system is at normal

' operating pressure.

- Code Case N-498-1, Alternative Rules for 10-Year System Hydrostatic Testing for Class-1 and 2 Systems, was previously approved for general use on Class 1 o

1

. and 2 systems in Regulatory Guide 1.147, Rev. 9. For Class 3 systems, Code Case N-498-1 specifies requirements identical to those for Class 2 components (for Class 1 and 2 systems, the alternative requirements in N-498-1 are unchanged from N-498). In lieu of 10-year hydrostatic pressure testing at or near the end of the 10-year interval, Code Case N-498-1 requires a VT-2 visual I

examination at nominal operating pressure and temperature in conjunction with a system leakage test performed in accordance with paragraph IWA-5000 of the 1992 Edition of Section XI.

Class 3 systeas do not normally receive the amount and/or type of nondestructive examinations that Class 1 and 2 systems receive. While Class 1

-and 2 system failures are relatively uncommon, Class 3 leaks occur more frequently and are caused by different failure mechanisms. Based on of class 3 system f ailures requiring repair during the last 5 years,,a the review most common causes of failure are erosion-corrosion (EC), microbiologically-induced corrosion (MIC), and general corrosion.- In general, licensees have implemented programs for the prevention, detection, and evaluation of EC and MIC; therefore, Class 3 systems receive inspection commensurate-with their functions and expected ft.ilure mechanisms.

System hydrostai.ic testing entails considerable time, radiation dose, and money. The safety assurance provided by the enhanced leakage detection gained '

from a slight increase in system pressure during a hydrostatic test may be offset or negated by the necessity to gag or remove safety and/or relief '

valves (placing the system, and thus the plant, in an off-normal state), erect temporary supports in steam lines, and expend resources to set up testing with special equipment and gages. Therefore, system hydrostatic testing represents a considerable burden. Giving consideration to the minimal amount of increased assurance provided by the increased pressure associated with a hydrostatic test over that of a system leakage test, and the hardship associated with performing the Code-required hydrostatic test, the staff has determined that compliance with the Section XI hydrostatic testing requirements results in hardship and/or unusual difficulty without a compensating increase in the level of quality and safety.

The staff concludes that compliance with the Section XI hydrostatic testing requirements results in hardship and/or unusual difficulty with a t a compensating increase in the level of quality and safety. Perturming a system leakage test in accordance with Code Case N-498-1 will provide reasonable assurance of operational readiness. Therefore, the licensee's proposed alternative, to implement the pressure testing rules of Code Case N-498-1 for Code Class 1, 2, and 3 components, is authorized pursuant to 10 CFR 50.55a(a)(3)(ii). This alternative is 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 intends to continue to implement this code case, the licensee is to follow all provisions in Code

' Documented in Licensee Event Reports and the Nuclear Plant Deliability Data System databases.

.. 1

implement this code case, the : licensee is ') follow-all provisions in Code Case N-498-1,1with limitations issued in Regulatory Guide 1.147, if any.-

Request for Relief PR-08: Section XI, Table IWD-2500!!,1 Examination Category -

D-A, item D1.10, Hydrostatic Pressure Testing for the Main Steam Relief Valve Dischargt Lines, the Code requires an-inservice pressure test and/or a system nydrostatic. test to be performed. IWD-5222(f) states that for safety or relief valve piping that discharges into the containment pressure f.ukeression pool, a pneumatic test (at a pressure of 90% of the pipe submergence head of water) that demonstrates leakage integrity shall be performed in lieu of a system hydrostatic test. The licensee has proposed as.an alternative.to the Code requirements to perform a VT-2 visual examination of the Main Steam-Relief Valve discharge piping under normal plant operating conditions and from the hydr 9 static test requirements to perform a pneumatic test at 90% pipe submergence head once every inspection interval.

Based on the Information provided^by the licensee, the staff has determined that the licensee's proposed pressure test of the subject piping, in conjunction-with the reliet valve testing, provides an acceptable level of quality and safety. Tlierefore, the licensee's proposed alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(i).

. R9 quest for Relief PR-09: Section XI, IWA-5211(d).. Examination Category C-H, Item C7.40, Hydrostatic Test of HPCI and RCIC Discharge Piping, requires that pressure-retaining components within each system boundary be subjected to a system hydrostatic pressure test. The licensee has proposed an alternative to-the_ Class 2 hydrostatic pressure test- requirements for the HPCI 'and RCIC

' discharge piping between the injection check valve and the upstream isolation-valve.

'The licensee proposed as an alternative to the-Code requirements to test these Lportions.of the subject systems in conjunction with the Class 1 piping in-accordance with Code Case N-498.-- The staff determined that-the licensee's-proposed alternative to test the subject portion of piping in conjunction with the Class- 1 piping, will subject the Class 2 piping to pressures equal to the Class 1 piping, the staff has determined that the licensee's proposed alternative provides an acceptable level of quality and safety.

The_-staff concluded that the licensee's proposal to pressure test portions of

the Class 2 HPCI_and RCIC piping in conjunction with Class I pressure tests-provides an acceptal'e level of quality and safety. Therefore, the staff concludes-that the - 'censee's proposed alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(,).

CONCLUSIONS:

Based on the review'of the Cooper Nuclear Station, Thirti 10-Year Interval inservice inspection Program Plan, Revision 1, the licensee's responses-to the NRC's requests for additional information, and the recommendations for granting of relief by Section XI of the Code, the staff concludes that no

' deviations from regulatory requirements were identified.

For Requests for Relief RI-05, RI-15 RI-18 RI-20. Revision 1, RI-21, and RI-22, the staff concludes that the licensee has demonstrated that the related Section XI requirements of the ASME CODE are impractical, and that the proposed alternatives provide reasonable assurance of operational readiness of the subject components. Therefore, the staff concludes that the above requests for relief are granted pursuant to 10 CFR 50.55a(g)(6)(1). Granting relief is authorized by law and will not endanger life, property, or the common defense and security, and is otherwise in the public interest, giving due consideration to the burden upon the licensee that could result if the requirements were imposed on the facility.

The staff concludes that for Requests for Relief RI-02, Revision 1 RI-03, RI-07, RI-08, RI-10, RI-12, RI-14. RI-16, PR-01, PR-02, PR-03, Revision 1 PR-04, PR-05,, PR-06, PR-07, PR-08, and PR-09: 1) the licensee's proposed alternatives provide an acceptable level of quality and safety; or 2) Code compliance will result in hardship or unusual difficulty without a compensating increase'in quality and safety. Therefore, the staff concludes that the alternatives contained in the above reliefs are authorized pursuant l

to 10 CFR 50.55a(a)(3)(i) or 10 CFR 50.55a(a)(3)(ii).

For Request for Relief RI-06, Revision 1, RI-09, RI-11, RI-17, and RI-24, the staff concludes that the licensee did not provide sufficient justification to support the determination that the Code requirements are impractical, nor that to comply with Code requirement would result in hardship. Therefore, the staff concludes that the above requests for relief are denied.

Requests for Relief RI-13 and RI-19 were evaluated in separate reports by the staff. Both requests were granted by letters dated february 27 and

-June 7, 1996, respectively.

The licensee withdrew Requests for Relief RI-01 and RI-23.

Principal Contritiutor: T. McLellan Date: October 23, 1997 t

a