ML18039A786
| ML18039A786 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 05/21/1999 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML18039A783 | List: |
| References | |
| NUDOCS 9905250307 | |
| Download: ML18039A786 (14) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION C
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SAFETY EVALUATIONBYTHE OFFICE OF NUCLEAR REACTOR REGULATION OF THE SECOND 10-YEAR INTERVALINSERVICE INSPECTION PROGRAM PLAN ANDASSOCIATED RELIEF RE UESTS FOR TENNESSEE VALLEYAUTHORITY BROWNS FERRY NUCLEAR PLANT UNIT3 DOCKET NUMBER: 50-296
1.0 INTRODUCTION
Inservice inspection of the American Society of Mechanical Engineers (ASME) Code Class 1,',
and 3 components shall be performed in accordance with Section Xl of the ASME Boiler and Pressure Vessel (B8PV) Code and applicable addenda, as required by 10 CFR 50.55a(g),
except where specific written relief has been granted by the Commission pursuant to 10 CFR 50.55a(g)(6)(i).
10 CFR 50.55a(a)(3) states that alternatives to the requirements of paragraph (g) may be used, when authorized by the U. S. Nuclear Regulatory Commission (NRC), if (i) the proposed alternatives 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 ASME 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 Code of record for Browns Ferry Nuclear Plant, Unit 3, is the 1989 Edition.
2.0 EVALUATION By letters dated January 10, 1997, and June 12, 1998, Tennessee Valley Authority (TVA) submitted its Second 10-Year Interval Inservice Inspection Program Plan and associated requests for relief for Browns Ferry Nuclear Plant, Unit 3. TVAprovided additional information by its letter dated October 29, 1998. The Idaho National Engineering and Environmental Laboratory (INEEL), has evaluated the information provided by TVAin support of its Second 10-Year Interval Inservice Inspection Program Plan and associated requests for relief for Browns Ferry Nuclear Plant, Unit 3. Based on the results of the review, the staff adopts the
'ontractoi's conclusions and recommendations presented in the Technical Evaluation Report (TER) attached.
The information provided by TVAin support of its alternatives to the Code requirements has been evaluated and the basis for disposition is documented below.
e905a50307-9~05m PDR ADQCK 05000296 P
PDR Enclosure 1
J The staff determined that based on its review of TVA's documents provided, no deviations from regulatory requirements or commitments'were identified in TVA's Second 10-Year inspection Interval,lnservice Inspection Program Plan, Revision 0 for Browns Ferry Nuclear Plant, Unit 3.
2.1 Re uest for,Relief 3-ISI-1: ASME Code,Section XI; IWB-2420(b), requires successive Inspections when flaw or relevant conditions are evaluated and qualified for continued service.
Request for Relief 3-ISI-1 was evaluated previously and denied (NRC letter and,Safety Evaluation dated July 8, 1997).
2.2 Re uest for Relief 3-ISI-4: ASME,Section XI, Examination Categories B-K-1 and C-C, Items B10.10 and C3;20, Integrally Welded Attachments.
Request for Relief 3-ISI-4 was withdrawn (TVAletter dated October 29, 1998).
2.3 Re uest for Relief 3-ISI-5: Approval to Implement Alternatives Contained in Code Case N-547, Alternative Requirements for Pressure Retaining Bolting of Control Rod Drive (CRD)
Housings.
Request for Relief 3-ISI-5 was withdrawn (TVAletter dated October 29, 1998).
2.4 Re uest for Relief 3-SPT-1: Alternative Pressure Test for Welded Repairs or Replacements in Class 1, 2, and 3 Systems.
Request for Relief 3-SPT-1 has'been evaluated and is authorized (NRC letter and Safety Evaluation dated March 10, 1997).
2.5 Re uest for Relief 3-SPT-2:
10-Year Hydrostatic Test Requirements for Code Class 1, 2, and 3 Systems.
Request for Relief 3-SPT-2 was withdrawn (TVAletter dated October 29, 1998).
2.6 Re uestfor Relief 3-ISI-2: IWF-5300, Inservice Examination andTestRequirementsfor Snubbers.
Request for Relief 3-ISI-2 has been evaluated and is authorized,(NRC letter and Safety Evaluation dated May 3, 1999).
2.7 Re uest for Relief 3-ISI-3: Use of Code Case N-524", Alfemafive Examination Requirements forLongitudinal Weldsin Class 1 and 2 Piping ASME Code,Section XI, Table IWB-2500-1, Examination Category B-J, Item B9.12 requires 100% surface and volumetric examinations of longitudinal piping welds in Class 1 piping 4-inch nominal pipe size and larger to be performed in conjunction with examination of the circumferential welds selected for examination, as defined in Figure IWB-2500-8. The length of longitudinal weld required to be examined is at least one pipe diameter, but not more than 12 inches, from the circumferential weld intersection point..
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Examination Categories C-F-1 and C-F-2, Items C5.12, C5.22, C5.52, and C5.62 require 100%
surface and/or volumetric examinations of longitudinal piping welds in Class 2 piping to be performed in conjunction with examination of the circumferential welds selected for examination, as defined,in'Figure IWC-2500-7, for at least 2.5t of each longitudinal weld at the circumferential weld intersection.
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.
Pursuant to 10 CFR 50.55a(a)(3)(i), TVAproposed an alternative to the volumetric and/or surface examination for the length of longitudinal piping welds required to be ex'amined in accordance with Tables IWB-2500 and IWC-2500. TVAstated:
"As an alternative to the requirements of the 1989 Edition (no addenda) of ASME Section XI, Browns Ferry Nuclear Plant willadopt the provisions of ASME Code Case N-524 for the examination of Class 1 and 2.longitudinal piping welds."
The ASME Code,Section XI requires the examination of one pipe diameter, but not more than 12 inches, of Class 1 longitudinal piping welds. For Class 2 piping welds, the length of longitudinal weld required to be examined is 2.5 times the pipe thickness.
These lengths are measured from the iritersection with the circumferential weld. TVA's proposed alternative is to examine only the portions of longitudinal weld within the examination area of the intersecting circumferential weld in accordance with Code Case N-524, Alternative Examination Requirements forLongitudinal Welds in Class 1 and Class 2 Piping.
Longitudinal welds are produced during the manufacture of the piping, not in the field as is the case for circumferential welds. Consequently, longitudinal welds are fabricated'under strict manufacturing standards, which provide assurance of structural integrity. These welds have also been subjected to the preservice and initial inservice examinations, which provide additional assurance of structural integrity.
No significant loading conditions or material degradation mechanisms have been identified to date that specifically relate to longitudinal seam welds in Class 1 and 2 nuclear plant piping.
The most critical region of the longitudinal weld is the portion that intersects the circumferential weld. Ifdegradation associated with a longitudinal weld were to occur, it is expected that it would be located at the intersection with a circumferential weld. Since this region will be examined during the examination of the circumferential weld, TVA's alternative provides an acceptable level of quality and safety.
The staff concluded that the use of Code Case N-524 provides an acceptable level of quality and safety. Therefore, TVA's proposed alternative, to use Code Case N-524, is authorized pursuant to 10 CFR 50.'55a(a)(3)(i).
The use of this Code Case should be authorized for the second 10-year interval at Browns Ferry, Unit 3, or until the Code Case is approved for general use by reference in Regulatory Guide 1.147. Afterthat time, TVAmust followthe conditions, if any, specified in the regulatory guide.
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1 2.8 Re vest for Relief 3-ISI-6: Use of Code Case N-532, Alfemafive Requiremenfs to.Repair and Replacemenf Documentation Requirements and,lnsenrice Summary Report Preparation and Submission as Required by IWA-4000 and IWA-6000 The ASME;Code,Section XI, Paragraph IWA-6220 requires that TVAprepare reports using, NIS-1, Owner's Report..for Inseeice inspections, and NIS-2, Owner's Report forRepair or.Replacemerits; IWA-6230 requires that these reports be filed with the enforcement and regulatory authorities having jurisdiction'at the plant site within 90 days of the completion of the inservice inspection conducted during, each refueling outage.
Pursuant to 10 CFR 50.55a(a)(3)(i), TVAproposes to implement Code Case N-532. TVA stated:
"For BFN Unit 3 TVAwillinvoke the requirements of ASME Code Case N-532,
, 'Alternative Requirements To Repair. and, Replacement Documentation Requirements
.and Inservice S'.>mrna'nj Report Preparation and Submission as Required by IWA-4000 and IWA-6000;Section XI, Division 1 as an alternative to the ASME Section XI requirements listed above."
The use of Form NIS-1, Owner's Report For Inservice Inspections, and Form NIS-2, Owner's Report forRepairs or Replacements, and submital of an inservice inspection summary report.
Alternatives contained in Code Case N-532 allow TVAto submit these records in an abstract format on Form'IS-2A, Repair/Replacement Certification Record, and Foim OAR-1, Owner's ActivityReport, following,the completion of an inspection period.
The requirements associated with documentation of inservice examinations and repairs/replacemen'ts and the subsequent submittial of Forms NIS-1 and NIS-2 within 90 days following a refueling 'outage are administrative only. It is noted that repair and replacement documentatio'n reviews and'approvals by the Authorized Nuclear Inspector continue to be required by this Code Case and that TVAis required'to establish a Repair/Replacement Plan in accordance with IWA-6340 of the 1992 Edition of,Section XI.
4 TVAhas implemented Inspection Program B of the Code.
Under this program, examination schedules are satisfied on a,"per, period",basis.
Considering the milestones associated with Inspection Program B, submittial of the. results of examinations and an abstract of repairs/replacements on a periodic basis is a reasonable alternative.
In addition, the staff
-determined that the forms contained in Code Case N-532, which provide a summary of the status of repairs/replacements and a more detailed status of examinations by period and interval, are an improvement oyer report forms currently required by the Code.
For example, OAR-1 includes the status of examinations. credited for the period and percent credited to date for the interval, by Examination Category.
This type of information provides the. regulatory authorities a more comprehensive report on the status of the inservice inspection program.
e The staff concjuded that the Code recording and reporting criteria are only administrative requirements, the staff. determined, that use of the alternatives to Code requirements contained in Code Case.N-532.provides an acceptable level of quality and safety for Browns Ferry, Unit
- 3. Therefore; TVA's proposed alternative is authorized pursuant to 10.CFR 50.55a(a)(3)(i).
The use of alternatives contained in Code Case N-532 is authorized for the current interval. or,
until the Code Case is published in a future revision of Regulatory Guide 1.147. At that time, if TVAintends to continue to implement the alternatives of this Code Case, TVAis to followall provisions in Code Case N-532 with limitations issued in Regulatory Guide,1.147, ifany.
2.9 Re uest for Relief 3-SPT-3:
Use of Code Case N-546, Alternative Requirements for Qualification of VT-2 Visual Examination Personnel.
Request for Relief 3-SPT-3 was evaluated and authorized (NRC letter and Safety Evaluation dated September 28, 1998).
Use of Code Case N-546 remains authorized.
2.10 Re uest for Relief 3-SPT-4: ASME Code,,Section Xl,, IWA-5250(a)(2), Corrective Action Resulting'from Leakage at Bolted Connections.
Request for Relief 3-SPT-4 was evaluated and is authorized (NRC letter and Safety Evaluation dated September 28, 1998).
2.11 Re uest for Relief 3-SPT-5: ASME Code,Section XI, Table IWC-2500-1, Examination Category C-H, Items C7.10, C7.30, C7.50, and C7.70, Pressure-Retaining Components.
Request for Relief 3-SPT-5 was withdrawn (TVA letter. dated October 29, 1998)
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3.0 CONCLUSION
The staff concluded that no deviations from regulatory;requirements or commitments were identified in TVA's Second 10-Year inspection Interval,lnservice Inspection Program Plan, Revision 0 for Browns Ferry Nuclear Plant, Unit 3.
For TVA's proposed alternatives contained in Relief, Request Nos. 3-ISI-3, and 3-ISI-6, the staff concluded, that the alternatives provide an acceptable level of quality and safety.
Therefore, TVA's proposed;alternatives are authorized pursuant to 10 CFR 50;55a(a)(3)(i).
.Relief Request No. 3-ISI-1 was evaluated and denied in NRC SE dated July 8, 1997.
Relief Request No. 3-SPT;1 was evaluated and the proposed alternative authorized by NRC letter dated March 10, 1997. Relief Request Nos. 3-SPT-3 and 3-SPT-4 were evaluated and the proposed alternatives were authorized by NRC letter dated September 28, 1998.
Relief Request-3-ISI-2.has been evaluated and was authorized by NRC letter dated May 3, 1999.
By letter dated October 29, 1998, TVAwithdrew Relief Request Nos. 3-ISI-4, 3-ISI-5, 3-SPT-2, and 3-SPT-5 and deleted. them from the ISI Program Plan.
'rincipal contributor. T. K; McLellan Date:
'May 21, 1999
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Browns Ferry Nuclear Plant, Unit 3 Second 10-Year ISI Interval TABLE 1 SUNIMARYOF RELIEF REQUESTS
. Page 6 of gb:"w':.~',+.k.'gc..>>
~", Request~~
- ,,:Numbers kk.M~;gni. cx 3 3-ISI-1 3-ISI-2 tz".Compo n'crit'-'g Reactor Pressure Vessel Class 1, 2 and 3
gy~ ~A,)g 3~%@
atego B-A i';'No'";,5 B1.10, B1.30
>p.'-.":.Volume,'o'.,'Area',to'be.Ex'arnined5j-Flaw or relevant conditions in RPV weids Snubbers
,Required'Method-=
IWB-24200))
requires successive examinations during the next three periods I,'4~.:@~Alternative'~p<jj='-":
Examine areas containing the subject indications once during the third period of the second interval.
p ReliefRequeit,Status.-~-
Denied in SER dated July 8, 1997 Authorized (a3i) 3-ISI-3 Class 1 and 2 B-J, C-F-1, C-F-2 89.12, C5.12, C5.22, C5.52, C5.62 Longitudinal Pipe Welds Surface and Volumetric, as applicable Code Case N-524 Authorized (a3i) 3-ISI-4 Class 1
B-K-1, C-C B10.10 Integrally Welded Attachments C3.20 Surface or Volumetric Perform the examination of B-K-1 support integrally welded attachments on accessible portion without removing support members.
Withdr'awn 3-ISI-5 3-ISI-6 Class 1
Class 1, 2 and 3
B-G-2 NIA B7.80 CRD Bolting N/A NIS-1 and NIS-2 Summary Reports VT-1 Visual NIS-1 and NIS-2 forms Code Case N-547 Code Case N-532 Withdraw'n Authorized (a3i) 3-SPT-1 Class 1, 2 and 3
NIA N/A Repair and Replacement Visual Code Case N416-1 Authorized in SER dated March 10, 1997 3-SPT-2 Oass 1, 2 and 3
NIA NIA System Hydrostatic Testing Visual Code Case N498-1 Withdrawn 3-SPT-3 Class 1, 2 and 3
N/A N/A Visual Examiners VT-3 Visual Code Case N-546 Authorized in SER dated September 28, 1998
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Browns Ferry Nuclear Plant, Unit 3 Second 10-Year ISI Interval TABLE 1
SUMMARY
OF RELIEF REQUESTS Page 7 of igp+5(ws>@ w <<.r
@Relief~~
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~Requestqj 3-SPTA
~<<,'~System,of@~a
';..'.Component,'.-'lass 1, 2 and 3
i;Category.r NIA NIA
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.",'.Vo ume.'..or,'Area'to,be:,Ex'amtnedw",'.
Leakage Corrective Action VT-2 Visual Code Case N-566 r
g Relief.;Req'uest",Statu'e'j.
Authorized in SER dated September 28, 1998 3-SPT-5 Class 2 Piping C-H C7.10, C7.30, C7.50, C7.70 Pressure Retaining Components VT-2 Visual during System Pressure Tests Code Case N-522 Withdrawn
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