ML20212B015
| ML20212B015 | |
| Person / Time | |
|---|---|
| Issue date: | 09/08/1999 |
| From: | Andersen J NRC (Affiliation Not Assigned) |
| To: | Bateman W NRC (Affiliation Not Assigned) |
| References | |
| NUDOCS 9909170231 | |
| Download: ML20212B015 (39) | |
Text
In f
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i UNITED STATES g.
j NUCLEAR REGULATORY COMMISSION o
2 WASHINGTON. D.C. 20666 4 001 September 8, 1999 MEMORANDUM TO: William H. Bateman, Chief Materials and Chemical Engineering Branch Division of Engineering THRU:
Edmund J. Sullivan, Chief NDE & Metallurgy Section G
Materials and Chemical Engineering Branch Division of Engineering i
FROM:
James W. Andersen, Project Manage
/
NDE & Metallurgy Gection Materials and Chemical Engineering Branc.
l Division of Engineering
SUBJECT:
SUMMARY
OF THE AUGUST 27,1999, SENIOR MANAGEMENT MEETING WITH NEl/EPRl/ INDUSTRY TO DISCUSS ISSUES INVOLVING IMPLEMENTATION OF NEl 97-06 On August 27,1999, the NRC staff met with representatives of Nuclear Energy Institute (NEI),
Electric Power Research Institute (EPRI), and industry to discuss issues regarding the implementation of the industry initiative entitled NEl 97-06 " Steam Generator Program Guidelines." Meeting attendees are identified in Attachment 1. The agenda and slides presented during the meeting are prehided as Attachment 2.
Jack Woodard (Southern Nuclear Company) and Jim Riley (NEI) led the discussion of the status of the key technical and regulatory framework issues (see slides in Attachment 2) which the staff and industry are working to resolve in support of a generic industry proposal to revise the steam generator (SG) regulatory framework. The NRC staff and industry representatives agreed, that in general, there has been substantial progress in resolving technice! snd regulatory framework issues. The majority of technicalissues are now conside ao resolved, I
and NRC staff noted that we are close in resolving the remaining open issues.
With regard to the open technical and regulatory framework issues, the following W3y poir.ts were made during the meeting:
<L
- 1. Structural Integrity Criteria. The industry presented its white paper " Deterministic
//.
Structural Performance Criterion, Pressure Loading Definition" and stated that the Ny\\'
following two criteria must be met to ensure structuralintegrity of the SG tubes (1) riormal steady state full power differential pressure timet a factor of safety of three (3aP) must be maintained, and (2) yield not exceeded for the full range of normal operating primary to secondary differential pressures. Industry management stated that utilities need to demonstrate that Criteria (1) bounda Criteria (2) or make adjustments to their SG Programs. Industry management stated that it would include a statement in CONTACT: J. Andersen, EMCB/DE f
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NEl 97-06 regarding these criteria. Specifically, the industry stated that NEl 97-06 would require licensees to ensure that loadings associated with all normal plant conditions, including start-up, operation in the power range, hot standby, cooldown, and all anticipated transients do not produce a primary membrane stress in excess of the yield stress, and is bounded by the 3AP definition.
The industry further stated (1) that it views the draft Regulatory Guide position (DG-1074) as a new regulatory position in this area and (2) that the new 10 CFR 50.72/50.73 rule needs to be consistent with the wording agreed upon. The staff and industry agreed to discuss this issue in more detail during a future conference call since the staff did not have time to review the white paper in detail.
- 2. Industry Commitment to NEl 97-06. Industry management stated that NEl 97-06 was developed as a guidance document and was not meant to be a regulatory document. In performance based space, the performance criteria in the the Technical Requirements Manual (TRM) referenced in the Technical Specifications (TS) should be sufficient, and that the steam generator program will be captured in the site 10 CFR Part 50, Appendix B procedures. The staff stated that having NEl 97-06 referenced in the Final Safety Analysis Report would provide the licensee and NRC with clear expectations which would be particularly important in inspection and enforcement space. In summing up this issue, the staff stated that for a performance based application no reference is needed, however, the staff needs to review NEl 97-06 to determine what information, if any, is not included in the draft TS and TRM which the staff feels may be necessary to include in the FSAR.
- 3. Repair and Alternate Repair Criteria (ARC) Approvals. Industry proposed that following initial NRC approval of performance criteria, ARCS, and repair methods, other licensees j
may atilize that approval for their own applications provided the licensee can
. demonstrate via 10 CFR 50.59 their plant specific application is bounded by the NRC's approval. Industry stated that the generic approval process is very time consuming and that their proposal would put the burden on the licensees to demonstrate their plant specific application is bounded. The staff stated that this issue is a long term discussion point and that it should not hold up the progress of finalizing NEl 97-06. The industry and staff also discussed several NRC approved repair methods and ARCS for which the industry would like generic approval. The staff agreed that it could review these (industry would prioritize) and stated that it would provide industry a review schedule.
- 4. TS and TRM Changes. Industry management discussed several minor TS and TRM changes they made with the latest draft of both documents. The staff stated that the changes were acceptable with the exception of the removal of the word " generically" from Section 5.5.9.3. 5.5.9.4, and 5.5.9.5 of the draft TS.
- 5. Round Robin Project. Industry management gave their perspective on the round robin project at the Argonne National Laboratory. The project sponsor is the NRC Office of Nuclear Regulatory Research and the industry stated that there was good cooperation among the key stakeholders and requested continued NRC management overview of the project.
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)
T 3
The meeting concluded with a discussion concerning the schedule for the submittal of the license change package and upcoming meetings and telephone calls. Industry management stated that the license change package would be submitted to the NRC three months after the agreement on all the issues. The next senior management meeting was tentatively scheduled for mid-October, with a technical meeting tentatively scheduled for September 29,1999. Both the staff and industry agreed on the need for telephone discussions prior to both of those meetings to resolve the last few issues.
Attachments: As stated l
l 1
t
(,.(
NEl/EPRl/ INDUSTRY STEAM GENERATOR ISSUES SENIOR MANAGEMENT MEETING AUGUST 27,1999
{
LIST OF ATTENDEES NAME ORG/ POSITION 1.
Jim Andersen NRC/NRR/DE/EMCB 2.
Jack Strosnider NRC/NRR/DE 3.
Michael Short Southern California Edison 4.
Jim Riley NEl 4
5.
Jack Woodard Southern Nuclear 6.
David Goetcheus TVA 7.
Rick Mullins Southern Nuclear 8.
Kevin Sweeney APS 9.
R.F. Keating Westinghouse i
- 10. Emmett Murphy NRC/NRR/DE/EMCB
- 11. Ted Sullivan NRC/NRR/DE/EMCB
- 12. BiH Bateman NRC/NRR/DE/EMCB
- 13. Deann Raleigh SERCH, Bechtel Power
- 14. Mike Schoppman FPL Washington Rep
- 15. Chris Dahlgren NUSIS/Scientech, Inc.
- 16. Darol Harrison Entergy
- 17. Bob Tjader NRR/ DRIP /RTSB
- 18. Steve Long NRR/DSSA/SPSB
- 19. Cheryl Beardslee NRR/DE/EMCB
- 20. Dan Mayes Duke Power
- 21. Mohamad Behravesh EPRI
- 22. Mati Merilo EPRI
- 23. John Jensen AEP
- 24. Dave Modeen NEl
- 25. Sherry Bernhoft FPC
- 26. Eileen McKenna NRR/ DRIP
- 27. Helen Cothron TVA
- 28. David Mauldin APS
- 29. Gary Beyers FPL
- 30. Jack Bailey TVA
- 31. Noel Dudley NRC/ACRS ATTACHMENT 1
e.
j 3
The meeting concluded with a discussion concerning the schedule for the submittal of the L
. license change package and upcoming meetings and telephone calls. Industry management stated that the license change package would be submitted to the NRC three months after the agreement on all the issues. The next senior management meeting was tentatively scheduled for mid-October, with a technical meeting tentatively scheduled for September 29,1999. Both the staff and industry agreed on the need for telephone discussions prior to both of those meetings to resobla the last few issues.
Attachments: As stated DISTRIBUTIONw/o att:
PDR SCollins RZimmerman 4
OGC BSheron EMCB RF ens Centerggi JStrosnider DOCUMENT NAME: G:\\EMCB\\ANDERSEN\\082799MTGSUM,WPD INDICATE IN BOX:"C"= COPY We ATTACHMENTENCLOSURE,"E"= OPY W/ATTENCL,"N"mNO COPY OPPICE EMCB:DE n EMCB:DE
,g NAME JAndersen EJSullivan f I
DATE 09 / O /99 J / 6 /99 OFFICIAL REC.ORD COPY t
l
- e
NRC / SGlWG Senior Manaaement Meetina on SIG Proaram License Chanae Package August 27,1999 12:00 to 2:00 PM White Flint 1,0-8B4 Introduction 15 min Active issue discussions 1.5 hr Technicalissues Structuralintegrity criterion NEl Regulatory Framework issues e
Committing to NEl 97-06 NEl Repair / ARC approval requirements NEl e
Tech Spec / TRM NEI Other issues Round Robin Project NEl Schedule 15 min
. License package schedule Next meeting l
ATTACHMENT 2
o
'!. 9 b
Steam Generator Program License Change Senior Management Meeting l
August 27,1999 Rockville, MD El Agenda e Introduction a TechnicalIssues
. Structuralintegrity criterion a RegulatoryIssues
. Committing to NEI 97-06
. Repair / ARC approval requirements
. Tech Specs / TRM
= OtherIssues
. Round Robin Project
. Schedule i
l
i introduction a Good progress to date a Good cooperation
. SG Program license change
. GL 95-05 meeting
. NDE Round Robin a Several issues rernain V'
Technical issues e StructuralIntegrity Criterion l
. Industry Position - Two (2) j Criteria j
e (1) Normal steady state full power differential pressure times a factor ofsafety of three
. (2) Yield not exceeded for full range ofreactor operation e Criterion (1) supports j
condition monitoring process i
e Utilities to demonstrate that (1) i bounds (2)or adjustments are j
required i
t 4
2
e r.
Technicalissues a Structuralintegrity Criterion
. Industry Position supported by
. Regulatory documentation
. Consistent application of regulatory documents for-25 years
. DG-1074 definition would result in:
. Unreasonable redermition of structural I
and plugging limits
. Significantly impact condition monitoring and operational assessment process
. New or different regulatory position
. New 50.72/50.73 rule needs to be consistent Y
Regulatory issues a Industry Commitment toNEl 97-06
. Tech Specs and TRMinclude key aspects and provide an acceptable level of reEulatory enforceability
. Not necessary in a performance based application
. Self assessments /INPO SG visits
. NEl 97-06 and referenced EPRI Guidelines are intended to be versatile documents that will evolve with technology and industry experience 3
\\
Regulatory issues l
= Repairand ARC Approvals j
. Generic approval process will be cumbersome and time consuming
. Review of W laser and ABB TIG sleeve SE's
. Issues are generally not site specific
. Mature processes
. substantial experience
. Similar results expected for most ARCS and remaining Repairs
. 50.59 process appears feasible El 3
Regulatory issues a Tech Spec changes
. SER generic approval of ARCS and repairs not required
. Report required ifgreater than 1% of the inspected tubes in the afectedsteam generator require repair 4
a 1,
Regulatory issues aTRM
. Concur with NRC comment on Condition C, failure to implement a repair
+... acceptable for continued operation based on meeting the Performance Criteria
. Accident induced leakage -
risk concern is I gpmper steam generator
. Stilllimited by design basis V' Other issues a Round Robin Project
. Important to Industry
. Good cooperation among l
ANL, NRC, and industry
. Continued management l
oversight by NRC and the l
industry to ensure success 5
I l
)
\\
Schedule a License Package schedule
. License change package to NRC three months after agreement on issues a Next Meetings
.Next technical meeting in late September 6
Definition of SAP 4
4 Industry White Paper Deterministic Structural Performance Criterion Pressure Loading Definition
- s..
Prepared by
~
~
NEl Steam Generator Task Force August 1999
)
Definition of SAP
\\
)
Determini tis Structural Pcrf;rm:nso Criterian I
t Pressure Loading Definition Executive Summary
. NEI has determined that the appropriate, historically supported loading definition for the deterministic structural integrity perfornunce criterion to be included in NEI 97-06 and the proposed regulatory framework should be:
For structural integrity assessments using a factor of safety of three, the loading condition shall be the pressure across the steam generator tube at normal steady statefull power Operation as depned in the design or equipment specipcation.
Based on comments received from NRC Staff regarding required safety margin, ASME Code requirements and current NRC Staff positions regarding licensing basis and risk
)
informed regulation, NEI has developed a position paper supporting an industry definition of the deterministic structural performance criterion. This paper illustrates a consistent industry approach for past application of the 3AP definition. In addition, the paper describes how the NEI 97-06 definition supports a performance based process by specifying criteria in a manner to provide reasonable assurance that the steam generator i
pressure boundary components are capable of providing necessary protection against spontaneous burst and burst as a condition of Chapter 15 accident events. Additimlly, the 3AP criterion is measurable through the condition monitoring process. The paper provides a review of ASME Code requirements and a historical overview. A discussion regarding the application of industry's definition is also provided.
Conversely, it is NEI's position that the description contained in DG-1074 is not consistent with past NRC positions, accepted industry practice and the intent of the
. ASME Code for original design and evaluation of inservice components. The definition specified in DG-1074 would result in an unreasonable redefining of structural and plugging limits and significantly impact the condition monitoring and operational assessment process. Industry concurs that historical regulatory precedence includes the need to assess the impact of the full range of reactor operation including startup, operation in the power range, hot standby and cooldown, and all anticipated transients that are included in the design specification. However, this evaluation should ensure that tubes with detected acceptable defects should not be stressed beyond the elastic rangc of the tube material. The need to ensure that loadings associated with all normal l
plant conditions, including start-up, operation in the power range, hot standby, cooldown and all anticipated transients do not produce a primary membrane stress in excess of the yield stress, and is bounded by the 3AP definition will be included in NEI 97-06 for clarity.
' Definition of SAP t
Deterministic Structural Performance Criterion Pressure Loading Definition l
Recommended Definition -
For structural integrity assessments using afactor of safety of three, the loading condition shall be the pressure across the steam generator tube at normal steady statefull power operation as depned in the design or equipment specipcation.
Discussion NEI has endeavored to determine the appropriate, historically supported loading definition for the deterministic structural integrity performance criterion. It is NEI's position that the description contained in DG-1074 is not consistent with past NRC positions, accepted industry practice and the intent of the ASME Code for original design and evaluation of inservice components. The definition specified in DG-1074 would result in an unreasonable redefining of structural and plugging limits and significantly impact the condition monitoring and operational assessme'nt process.
Based on comments received from NRC Staff regarding required safety margin, ASME Code requirements and current NRC Staff positions regarding licensing basis and risk informed regulation, NEI has developed a position paper supporting an industry definition of the deterministic structural performance criterion.
This paper will illustrate a consistent industry approach for past application of the 3AP definition. In addition, the paper describes how the NEI 97-06 definition supports a performance based process by specifying criteria in a manner to provide reasonable assurance that the steam generator pressure boundary components are capable of providing necessary protection against spontaneous burst and burst as a condition of Chapter 15 accident events. The paper provides a review of ASME Code requirements and a historical overview. A discussion regarding the application of industry's definition is also provided.
ASME Code Review A review of multiple industry documents, including NSSS design reports, sleeving
. topical reports, and regulatory submittals, indicates that all NSSS designers and multiple utilities have adapted the same ASME Section III Code equation, from paragraph NB 3324.1 to define minimum allowable tube wall thickness. The equation in NB-3324.1 is a tentative wall thickness for use in design. There are no requirements 1
l Definition cf SAP to account for inservice d:gridation. Th2 equttion as specified in the ASME Code is as t-follows:
I=
S. - 0.SP i
where t
= wall thickness l
P
= Design Pressure R
= inside radius S. = design stress intensity 4
In a typical design scenario, a tubing wall thickness is selected based on the results of this calculation. The proposed tubing size is then assessed against all other ASME required design analyses including but not limited to bending loads, combined primary plus secondary stresses, seismic loads and fatigue loads.
In establishing plugging limits, which per Regulatory Guide 1.121 should account for inservice degradation growth and NDE uncertainty, licensees and NSSS vendors were required to define minimum acceptable wall thickness.
A survey of industry documents indicated a consistent application of the definitions contained in NB-3324.1.
A typical interpretation of NB-3324.1 from Reference 1 is as follows:
AP R'.
l t ". =
(1)
P,,, - 0.5 AP where toi,, = minimum acceptable tube wall AP primary to secondary pressure differential R4 = tube radius P. = primary stress limit,i.e.,
P. normal s Su/3 P. upset s Sy P. faulted s lesser of 0.7Su or 2.4 S.
In' Reference 2, the similar interpretation was written as S AP R'.
l t ". =
(2)
Su - 0.5(P, + P,)
In assessing the minimum acceptable wall thickness based on normal operating conditions, all the submittals surveyed used normal steady statefull power AP as the basis L.
for primary-to-secondary pressure differential. It should be noted, that the early use of L
this equation was based on tube degradation which could be bounded by an l
j 2
L
w V
l Definition of SAP l
assumption of uniform wall thinning. However, the assumption of normal steady state l^
full poner operating pressure differential has been consistently used in the analysis, testing and verification of tubes with stress corrosion cracking for verifying a margin of three against burst.- It is also important to note that many of the documents surveyed in support of this paper received Staff review and approval.
Historical Regulatory Perspective L
NEI has reviewed historical information regarding NRC Staff positions on this issue.
From a review of the testimony of James Knight 3, Raymond Maccary4, Atomic Safety I
and Licensing Boards and Regulatory Guide 1.1216, it is clear that the primary requirements for margin of safety for steam generator tubes were:
(1) tubes with detected acceptable defects should not be stressed during the full range of normal reactor operation beyond the elastic range of the tube material, (2) the factor of safety against failure by burst at normal operating
. conditions should not be less than three.
Meeting requirement (1) assures that for the full range normal reactor operation (all ASME Level A and B conditions), the maximum membrane stress in the degraded tube will never exceed the yield stress for the tube material. Normal operation, as used here,
' includes start-up and operational and upset transients that are included in the design specification for the steam generator. For requirement (2), an explicit description of normal operating conditions that includes the full range of operational transients is not specified. However, Mr. Knight does point out that "... new steam generator tubes are typically manufactured with a wall thickness much greater that the wall thickness required by the design rules of ASME Code,Section III" (see previous discussion) and Mr.
Knight further indicates that approximately ' twice the thickness (nominal / minimum) is typical. If in fact minimum wall calculations were based on the full range of operational transients or RCS design pressure safety limits, it would not be unusual for the margin above minimum wall to be on the order of 10-20% and not the margins suggested by Mr. Knight. In fact, the examples given in References 3 and 4 use the normal operating differential pressure for the subject plant. Adopting the definition L
in DG 1074 would mquire plugging limits to be lowered well below many licensees current NRC endorsed 40% plugging criteria.
Statements in Regulatory Guide 1.121 provide additional insight for industry's consistent application of this criterion. Section 3.a.1 of the regulatory guide states that loadings associated with normal plant conditions, including start-up, operation in the power range, hot standby, cooldown and all anticipated transients should not produce a primary membrane stress in excess of the yield stress. Once again, this statement is explicit, whereas the statements in Section 2.a.2 and 2.a.4 of the RG simply state a margin of safety unoer normal operating conditions should not be less than three (3).
l 3
7 Definition of SAP In NUREG 14779, the NRC Staff position as stated in Section 3.2.2 under " Margins j
Against Tube Rupture" further stipulates that the limiting burst criterion of Regulatory Guide 1.121 is that, " burst pressure must be equal to at least 3 times the normal operating pressure differential across the tube." The NUREG reference value specified for a Westinghouse Model 51 steam generator is 1457 psi.
In a 1996 draft of the proposed draft regulatory guide " Steam Generator Tube Integrity" Section C.2.1.1. states that the deterministic structural performance criterion shall,
"... include a margin of not less than 3 against burst under normal operating conditions..." It is not until the March 1998 version of DG-10742, that the Staff extended the definition in C.2.1.1 to include, "...startup, operation in the power range, hot standby and cooldown, and all anticipated transients that are included in the design specification."
As such, NEI believes that the requirement specified in DG-1074 constitutes a regulatory position that is new or different from previously applicable Staff positions.
Application ofIndustry Definition NEI has reviewed multiple sources of information including sleeving topical reports, design and equipment specifications and licensee submittals in an effort to determine how loading conditions affecting. steam generator tubing and pressure boundary 4
components were assessed. This review considered application of the appropriate loading definitions, both during original design of components such as sleeves and plugs, and how the loading definitions have been applied during condition monitoring and operational assessments of steam generator structural integrity.
Original Design In establishing the safe limiting conditions for steam generator tubing, plugs and sleeves, the effects of loadings both at normal operation and postulated accident conditions are always evaluated. As such, all design requirements, specified in ASME Section III, Subsection NB, are applied to the initial design of RCS pressure boundary components. Consideration of primary membrane stress, bending loads, seismic, combined primary plus secondary stresses, and fatigue loads are addressed in the
. original design as required by the applicable Code paragraphs. Industry will continue to implement these requirements as appropriate for new steam generator designs and new repair methods proposed and submitted for NRC approval. However, as stated in Subsection NB-1110, "....[the ASME Section III rules) do not cover deteriorations that may occur in service as a result of corrosion, radiation effects, or instability of the material."
Instead, the performance of inservice steam generator components is assessed via condition monitoring and operational assessment as required by NEI 97-06 L
and not the ASME Code.
4
Definition of 3AP Condition Monitoring y
Regulatory Guide 1.160 and 10CFR50.65 state, in part, that licensees shall monitor the performance and condition of safety related components against established goals in a manner to provide reasonable assurance that such components are capable of fulfilling their intended functions. These goals are to be established commensurate with safety and, where practical, take into account industry-wide operating experience. In the case of steam generators, the performance criteria and definitions in NEI 97-06 provide the necessary protection against spontaneous burst, and burst as a condition of Chapter 15 f
accidents.
The information provided in this paper, has further demonstrated that the use of full power normal operating pressure differential is historically supported both by consistent industry application of the requirements and accepted regulatory positions.
The use of this definition provides for uniform application, and is measurable and comparable within the condition monitoring process. While the factor of safety applied during the condition monitoring process is comparable with safety factors in the ASME Code, it should be noted that there is no Code requirement (either in Section III or XI) to conduct proof testing of components to be removed from service. Industry has, instead, adopted the accepted historical definitions described above as a basis for surveillance, testing and monitoring of steam generator performance.
l For example, industry, through the development of the Steam Generator In Situ Pressure Test Guidelines 8, has established the a.ppropriate guidance for the verification of integrity performance through proof testing. In addition to a safety factor of three, the guidelines include adjustments to ensure representative testing.
Typical adjustments include temperature, test equipment instrument error and bladder corrections. The guidelines further state: "That all appropriate loads should be considered for the damage form.
For example, axial loads due to tube-to-shell temperature differences in OTSGs, or axial loading associated with locked tube supports in RSGs should be addressed to ensure test conditions are at least as severe as those expected during operating and accident events." These examples indicate that the use of industry's 3AP definition is conservative and appropriate to demonstrate structural integrity performance of degraded steam generator tubing.
Validation of Industry Definition While the use of industry's 3AP definition facilitates the condition monitoring process, NEI has serveyed the NSSS designs to demonstrate that the application of the definition L
is bounding of requirement (1) { or, Section 3.a.1 of Regulatory Guide 1.121) for the full range of reactor operation.
1 As part of this survey, it was recognized that there are some design basis transients which exceed the normal steady state full power primary to secondary differential 5
L-
. Definition cf SAP pressure for a limited tims. A review of the design basis transients for CE, BocW, and t
l'.
Westinghouse designed plants is summarized in Table 1. The table lists transients that
. may be experienced and exceed the normal full power differential pressure used in the 3AP definition.
Table 1 Typical Differential Pressures for NSSS Designs NSSS1 Normal steady state Maximum during Maximum during
' full pov.'era heatup/cooldown Trip s
Differentialpre.sure Differential pressure -
Differential pressure psi psi.
psi CE-A.
1270 1865 1480 l
CE-B.
1330 1950 1670 i
CE-C 1450 2150 1650 i
W-A 1491 1600 1515 i
W-B
-1491-
'1600 1515' W-C.
1250 1600 1400 W-D 1250 1600 1470 W-E 1286 1600 1411 B&W 1275 2050 1700 Notes:
(1)
The letter designations do not refer to a specific steam generator design (2)
Temperatures typically in range of 590-630 *F (3)
Temperatures less than 400 'F Generally, analpis of these transients shows that if a degraded tube can withstand three times the normal full power differential pressure at operating temperature, then the stress due to these transients is less than yield at the corresponding temperature.
For example, if the yield strength of tubes at the heatup/cooldown temperatures is greater than or equal to one-half of the ultimate tensile stress, and the differential pressure during heatup/cooldown is less than or equal to 1.5 times the normal I
6 i
1 b
i
Definition of SAP
\\
K1 operating pressure differential, then the performance criterion of 3NOAP is bounding as the no yielding criterion is satisfied.
In order to comply with the requirements outlined in NEI 97-06, this conclusion should be demonstrated for each plant using plant specific conditions and material properties.
1 Additional guidance is provided in the EPRI Steam Generator Integrity Assessment Guidelines,
u In summary, the industry 3AP definition has historical precedence, facilitates the condition monitoring process and is generally considered bounding. Application of the definition, coupled with the criteria and requirements of NEI 97-06 and supporting industry documents provide reasonable assurance of steam generator tube integrity.
More importantly, the structural and leakage criteria (including operational leakage) and assessment processes are measurable, achievable and provide appropriate defense-in-depth.
Conclusion i
The use of normal steady state full power operating pressure differential has time and time again been utilized as the basis for compliance with the three AP criterion. The Technical Specification plugging limits for the plants surveyed were based on full power differential pressure.
The surveyed design reports for minimum wall calculations for tubing and sleeves and Regulatory Guide 1.121 compliance calculations were based on normal full power differential pressure. Additionally, use of the values listed in the design or equipment specification ensures consistency of application.
As such, NEI believes the interpretation in DG 1074 constitutes a regulatory position that is either new or different from a previously applicable staff position, which represents a backfit per 10CFR 50.109. Additionally, based on the consistent application by industry in regulatory submittals and subsequent approvals by the NRC since 1975, compliance exception is not considered applicable, since this exception was intended to address situations "in which the licensee has failed to meet known and established standards of the Commission because of omission or mistake of fact." In conclusion, the current definition as provided by NEI in Reference 7 is supported for inclusion in NEI 97-06. The need to ensure that loadings associated with all normal plant conditions, including start-up, operation in the power range, hot standby, cooldown and all anticipated transients do not produce a primary membrane stress in excess of the yield stress, and is bounded by the 3AP definition will be included in NEI 97-06 for clarity.
7
p Definition of SAP l
References:
- 1. WCAP 13698 Revision 1, Laser Welded Sleeves for % inch Diameter Tube Feed-Ring Type and Westinghouse Preheater Steam Generators, Westinghouse Electric Corporation, May 1993.
2.' Letter LD-83-058, AB-CE to Mr. Darrell Eisenhut, Director, Division of Licensing USNRC, Rapid Depressurization and Decay Heat Removalfor System 80, dated June 9, 2
1%3.
- 3. Testimony of James Knight before the Atomic Safety and Licensing Board, January 1975.
- 4. Testimony of Raymond Maccary before the Atomic Safety and Licensing Appeal Board, January 1976.
l
- 5. Atomic Safety and Licensing Board, LBP-75-27, May 1,1975.
- 6. Draft Regulatory Guide 1.121, Basesfor Plugging Degraded PWR Steam Generator Tubes, August 1976.
- 7. NEI letter to NRC (S.J. Collins), Industry Steam Generator Program Initiative, dated j
December 17,1998.
- 8. EPRI TR-107620-R1 Final Report, Steam GeneratorIn Situ Pressure Testing i
Guidelines, Revision 1, June 1999.
i
- 9. NUREG 1477, Voltage Based Interim Plugging Criteria for Steam Generator
'Ibbes, June 1993.
- 10. Draft Regulatory Guide DG-1074. Steam Generator 7bbe Integrity, March 1998.
I1. EPRI TR-107621, Steam GeneratorIntegrity Assessment Guidelines, July 1999 (Draft).
~
8
m Commitment to NEI 97-06, Steam Generator Program Guidelines Issue:
l The NRC Staff desires a commitment to NEI 97-06 as part of a utility's steam generator I
license change package submittal as a means of defining the content of a steam generator program. The industry is does not believe it is necessary to make such a commitment to the NRC Staff.
History:
i NRC Staff and industry attempted to develop a steam generator rule; however, there
+
was inadequate justification for issuing the proposed rule.
The industry developed NEI 97-06 "to bring consistency in application ofindustry
+
guidelines related to managing steam generator programs."
+ Each PWR has committed to follow the guidance of NEI 97-06 in an NEI initiative.
Concerns:
+ The TRM/FSAR will contain the performance criteria referenced by the technical l
specifications. The performance criteria provide for tube integrity. The NRC Staff has adequate regulatory authority over programs which are intended to ensure the performance criteria are met. Requiring a commitment to NEI 97-06 is not performance based regulation, it is prescriptive regulation. In essence, the request is equivalent to requiring all PWRs to meet the perfomlance criteria and then directing the efforts that must be implemented to meet the performance criteria. The minimum level of programs desired by the industry for all PWRs to meet the performance criteria should not be a regulation. Prescriptive regulation, whether written by the NRC Staff or the industry, is unacceptable. Prescriptive guidance for a minimum level of performance developed by the industry is acceptable.
NEI 97-06 and referenced guidelines were developed to provide guidance to the
+
industry. They were not intended to be regulatory documents. However, they do provide guidance on the elements of a steam generator program. Revising the documents into regulatory guidance would require significant effort and the loss ofvaluable information.
+ Programs such as foreign material exclusion programs, industry self assessments, and chemistry guidance are intended to provide guidance to PWRs to assist in maintaining steam generator tube integrity. If the performance criteria continue to be met, the NRC Staff should not be interested in regulatory authority over these programs.
I
+ For example, a loose part results in a primary-to-secondary leak which requires a PWR to shutdown for a mid-cycle steam generator inspection. The NRC Staff's concern should be focused on whether the steam generator tubes meet the performance criteria. If the performance criteria continue to be met, corrective actions should be leP. to the utility. Based on the financial impact l
of an unplanned mid-cycle inspection, the utility has adequate incentive to implement a more reliable foreign material exclusion program. If the stearn
generator tubes did not meet the performance criteria, the NRC Staff would be quickly (8 or 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />) informed allowing for NRC Staffinvolvement in the proposed corrective actions.
+ NEI 97-06 contains a requirement for an operational assessment. The NRC Staff has indicated they have no cesire to review operational assessments for j
PWRs which continue to meet the performar.ce criteria. The NRC Staff j
should not have regulatory authority over the performance of operational assessments.
+ In the past, the NRC Staff has required a revision number /date for documents referenced in the technical specifications. The industry is unwilling to lock NEI 97-06 in the current version. Without the ability to revise NEI 97-05 and other gu:delines as necessary based on operating experience, these documents becorne a burden instead of a benefit.
Recommendation:
While all PWRs have committed through an NEl initiative to meet the guidance in NEI 97-06, the performance criteria included in the technical requirements manual (TRM)/FSAR provide an acceptable level of regulatory authority for the NRC Staff.
Consequently, a commitment to implement the guidance in NEI 97-06 in the technical specifications, technical requirements manual, or licensing package is not necessary.
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August 26,1999 Stresailined Approval of Performance Criteria, ARC's, and Repair Methods Issue:
NEI has p*oposed that following initial NRC approval of performance criteria, ARC's, and repair methods, other licensees may utilize that approval as their own provided the licensee can demonstrate via 10 CFR 50.59 their plant specific application is bounded Ly the NRC's approval.
The NRC has countered that only those activities that have received specific generic approval may be subjected to this treatment.
Beeltground:
Licensees are currently required.a submit a request to amend their technical specificationc before the NRC will consider authorizing a given ARC or repair method. This is because the stcam generator tuting is part of the reactor coolant pressure boundary.
NEI is interested in the application of a streamlined approach wi.ereby utilities may adopt existing criteria and methods approved by the NRC. Listed below are current repair methods, ARC's and the number of utilities interested in pursuing each:
- 1. Laser welded sleeves-4 utilities
- 2. TIG welded sleeves-3 utilities
- 3. Electrosleeve-13 utilities
- 4. A!!oy 800 sleeve-3 utilities
- 5. W' ARC-2 utilities i
- 6. F* ARC-2 utilities
- 7. GL 95-05 ARC for ODSCC - 2 utilities
- 8. OTSG reroll-3 utilities -
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i 1. PWSCC ARC at tube support plates - 2 utilities L
Discussion:
The NRC's position is based on their assessment most of the existing SER's prepared for these
' activities were developed on a plant specific basis and may not address issues relevant to other licensee facilities.
l NEI believes the gencic approval process will be cumbersome and actual benefits will be limited. A review was performi d of several safety evaluations to better assess the actual e
situation.
Repair Methods in Wide Use:
ABB TIG Welded Sleeves Two recent safety evaluations (sE'i> for the use of ABB TIG Weloed Sleeves were reviewed:
- 1. Dvember 1997-Prairie Island Initially requested - November 1996.
Supplemental Submit.tals - hurmt 15,1997, September 2,1997, and October 3,1997.
The SER notes that the buik of the technical and regulatory issues for this request are identical to those re'.*:wed in five previous safety evalua* ions for CE sleeves, thus this
- SE discusses only those issues warranting revision, amplification or inclusion based on recent experience.
Previously reviewed issues:
- 1. Structuralrequirements
- 2. Materialofconstruction
- 3. Welding
'4.
Nondestructive examination New issues raised:
Recent experience with installation end inspection of sleeves has highlighted several areas that were either not relevant to previous sleeving amendments or addressed in detail in the stafrevaluations in previous SE's. The issues discussed and a summary of the resolution method of the SE are discussed below:
- l. Preparation of tube surfaces prior to deci : - Ming Li; 2
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U Resolved by licensee's plans to conduct visual inspections of tube surface prior to welding. The SE places these inspections under the licensee's control as a function of field experience with the effectiveness of the cleaning process.
- 2. Adequacy ofinspection techniques used to accept sleeve welds The SE agreed with a licensee proposal to make visual inspection of completed welds optional.
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- 3. Inservice inspection requirements for sleeved tubes The SE agreed with a licensee proposal to inspect a 20% sample of sleeves at each refueling outage.
- 4. Omission of post weld heat treatment for sleeve welds The SE agreed with a licensee proposal to omit a their option PWHT of sleeve welds.
- 5. Sleeve plugging limits The SE did not approve a licensee proposal to use a higher than ASME Code allowed value for sleeve material ultimate tensile strength.
- 6. Changes in eddy current data acquisition rate from the original qualification The SE approved a licensee proposal to modify eddy current inspection parameters. The basis for approval was the prior NRC approval of the same parameters in a previous SE.
- 2. August 1998 - San Onofre Initially requested - September 1997.
Supplemental submittals - February 23,1998 l
Previous staff evaluations of ABB/CE sleeves addressed the technical adequacy for the i
sleeves in the four principal areas of pressure retaining component design:
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- 1. Structuralrequirements
- 2. Materialofconstruction
- 3. Welding
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- Experience with all types of SG tube sleeves has led to several areas of concem outside the scope of basic sleeve design and qualification discussed in previous SE's. These l
include:
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- 1. Weld preparation The SE agreed with licensee /ABB proposals to improve the cleaning process and with proposals for inspection of the previously plugged tubes prior to their being returned to service with sleeves.
- 2. Weld acceptance inspections The SE agreed with licensee proposals to enhance the sleeve weld acceotance criteria. These changes evolved from actual field experience.
- 3. InserviceInspection The SE agreed with a licensee proposal to inspect 20% ofinsta.ed sleeves at each r
refueling on the basis that it was consistent with EPRI guidelines.
- 4. Sleeve plugging limits The SE agreed to licensee proposals for plugging criteria more conservative than would be determined from staffregulatory guidance and the ASME Code.
- 6. Primary-to-secondary leakage limits The SE agreed to a licensee proposal to adopt a more conservative limit that was based on EPRI guidelines.
- 7. Change in reporting requirements The SE agreed to a licensee proposal to add to the administrative reporting requirements the details of sleeve inspections.
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Westinghouse Luer Welded Sleeves I
Four SE's were reviewed:
- 1.. October 1990- Farley l:
I Initially requested-August 1990 -
TMS SE is probably the initial staff review of the laser welded sleeve design by l:
Westinghouse. No prior SE's are noted. The staffs evaluation was based on the following general considerations:
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- 1. Sleeving is a repair technique that is an alternative to removing defective or degrading tubes from service by plugging.
- 2. Sleeves are designed to span a defective or degraded region of a tube and to maintain the primary-to-secondary pressure boundary under normal and accident conditions.
- 3. A successful sleeving system must provide a corrosion resistant sleeve material
)
with structural integrity and leak tightness of the sleeved tube.
- 4. The sleeving process must not have a detrimental effect on the serviceability of I
the existing tube.
In addition to the above general considerations, the staff s evaluation was based on the following specific considerations:
- 2. Fatigue and stress analysis results.
- 3. Mechanical testing to verify structural strengdi.
- 4. Leak rate testing of the sleeve to tube joints.
- 5. The sleeved tube can be monitore.i through periodic inspections with present eddy current techniques.
- 6. Plugging limit criteria.
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- 7. Material suitability.
- 8. Environmental considerations ard no significant hazards determination.
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In addition, the staff SE relied on a licensee commitment to utilize advanced state-of-the-art techniques as they are developed and verified after a 10 CFR 50.59 review.
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- 2. BeaverValley Initially requested-December 1992 Supplemental submittals - March 12,1993 and June 8,1993.
The staff had previously reviewed this sleeve design for Farley at the time of this SE.
New issues identified in this SE were:
Post Weld Heat Treatment The staff reviewed the use of PWHT to improve the corrosion resistance of the sleeve joint. 'Ihe licensee committed to the use of PWHT for all laser welded joints.
- 3. 1994 -Byron and Braidwood Initially requested-August 1993 Supplemental submittals - September 15,1993, September 16,1993, December 17,1993, January 19,1994, February 11,1994, and February 24,1994.
The SE covered both the Westinghouse laser welded and B&W kinetic processes. Only those portions applicable to the Westinghouse process are discussed in this white paper.
The staff reviewed the data pertaining to the Westinghouse Models D4 and D5 SG's and the specific design and installation parameters at Byron and Braidwood. New issues addressed in the SE are:
- 1. Corrosion Testing The SE addresses corrosion testing in substantially more detail than in the prior Farley SE. The staff SE required specific parameters for the PWHT process in the absence of sufficient test data on effects microstructure, chemistry, and joint crevices have on PWSCC. The staff believes that additional corrosion testing is needed to establish the design life for sleeved tubes in the presence of a crevice.
In view of these concerns, the staff required additional conditions on the inservice inspection of the sleeves. License conditions were added to conduct additional corrosion testing and the additional inservice inspection.
6
- 2. NDE The Jcensee committed to validate the adequacy of any system that is used for periodic inservice inspection and to upgrade testing methods, as better methods become available. The new methods can be applied as long as they can be demonstrated to provide the same or greater degme ofimpection accuracy as the methods currently reviewed and approved by the NRC.
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- 3. Leakage The staff concluded that current primary-to-secondary leakage limits were not sufficient to detect the early stages of sleeve degradation and requested a license amendment to reflect a primary-to-secondary leakage limit of 150 gpd/SG.
- 4. May 1995 - Maine Yankee Initial Request-April 1994 The staff had previously reviewed this sleeve design for Farley at the time of this SE.
New issues identified in this SE were:
)
- 1. % inch tubing The staff reviewed the licensee's conclusion that results of process qualification leak tests were applicable to the smaller diameter tubes at Maine Yankee. The staff did require additional qualification tests if any changes were necessary to the process.
- 2. Post Weld Heat Treatment The SE pointed out that the generic topical qualified as an option the seal weld joint without PWHT but that this option was not expected to be used at Maine Yankee.
- 3. Sleeve Service Life The SE explained the staff position that sleeving is unsuitable to ensure an unlimited service life for a repaired tube due to the sensitivity of Alloy 600 to stress corrosion cracking. The SE reviewed service life cerrosion testing of the sleeve weld joint observing that PWHT substantially added to thejoint life. As a result the SE requires use of PWHT, The licensee committed to participation in additional confirmatory testing to determine sleeve design life. The licensee will request a license amendment to limit leakage to 150 gpd.
7
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Similar to previous Westinghouse sleeve SE's, the licensee committed to use of enhanced and improved inspection techniques as they become available and industry acceptable.
1
- 6. Fill Factor The SE reviewed the use of smaller diameter probes above the sleeve and their impact on " fill factor". The SE approved licensee plans for addressing indications detected with the smaller probes.
- 7. Sleeving of Previously Plugged Tubes The SE approved licensee plans to inspect previously plugged tubes prior to placing the sleeve repair into service.
Analysis (Sleeves in Wide Use):
Examining the SE's including each added issue leads to several observations:
- 1. The SE's include additional issues developed by the staff or that arise from industry experience. In some instances the additional staff developed issues resulted in new requirements (example corrosion tests). In general the licensees were taking action to address issues resulting from industry experience.
- 2. For ABB TIG welded sleeves. SE's have now been issued on at least seven plants, three with ABB designed SG's (Model 2815 and 3410) and five with Westinghouse designs (Model 51 and D).
- 3. For W laser welded sleeves. SE's have now been issued on at least seven plants; two with ABB designed SG's and five with Westinghouse designs.
- 4. The SE's address issues within the scope of criteria in EPRI guidelines, the ASME Code, and Regulatory Guidance.
- 5. The SE's address deviations from previously approved approaches. Under NEI's
_ proposal such deviations would require staff approval prior to their "first use".
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- 6. Through NEI 97-06 and the proposed changes to the Technical Specifications, the trend is towards greater industry management of many of the issues raised in SE's (example NDE qualification).
Conclusions (Sleeves in Wide Use):
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The ABB sleeve design has received a significant level of review by the staff. As such, the design should be capable of generic approval. The staff has proposed the development of a
" generic SE". It is reasonable to conclude utilities have sufficient information available to them to pursue use of these sleeve designs under 50.59 and that a staff prepared generic SE is not l
needed.
l This repair method has received extensive review and substantial use within the industry. It utilizes proven techniques, materials and processes. Thus new issues with its use are most likely to arise from industry experience. For those situations, the staff has typically relied on the industry to develop appropriate responses. For cases where the staff wishes to provide input into that response or for issues that arise within the regulatory process, direct contact with NEI or generic approaches are available (IE Notices, Generic Letters, etc.).
First of Kind Approval:
May 1999-Callaway Electrosleeve Initially requested - April 1996, initial request superceded by revised request - October 1998 Supplemental submittals-January 11,1999, January 29,1999, February 25,1999, April 7,1999 and May 17,1999.
As a "first of kind" repair, the electrosleeve received a substantial review consisting of the following issues:
- 1. Code Case approval I
- 2. Process and installation procedures
- 3. Materialproperties
- 4. Corrosion evaluation I
- 5. Structuralevaluation
- 7. Flaw growth
- 8. Plugginglimits l
- 9. Leakage integrity
- 10. Quality Assurance 1
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In addition to the above issues the SE contained a discussion of future considerations. The SE concluded a limited two-cycle approach for the electrosleeve was acceptable. To obtain approval
')
without limitulon in the future, additional issues would require resolution by the staff. These are:
- 1. UT technique's ability to reliably depth size stress corrosion cracks
- 2. UT inspection technique, qualification data sets, a tube pull program and the effect of honing
- 3. Appropriate structural safety margins Finally, in the course of their review of this repair method, the NRC staffidentified issues with the performance of electrosleeves during postulated severe accident conditions. These severe accident conditions are beyond the current licensing basis of the "first of kind" plant, Callaway.
Analysis ("First of Kind"):
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l Under the NEI proposal, another licensee would examine the Callaway electrosleeve SE and attempt to reach a conclusion under 50.59 whether the design could be applied to their plant i
without prior NRC approval. To do so would require the licensee to accept all of the conditions (including the two-cycle limitation) presented by the SE. The remaining issues resolved within the SE should lend themselves to a review under 50.59.
l The SE cover letter observes that policy level issues associated with risk-informed regulation require further evaluation and guidance development. Further information on the performance of l'
electrosleeved tubes under severe accident conditions was not yet sufficiently developed to l
support the imposition oflimitations arising from a risk-informed perspective.
Conclusion ("First of Kind"):
With the exception of severe accidents, a licensee considering use of electrosleeves should be
- able to adequately proceed under 50.59. Use of electrosleeves would require agreeing to conditions placed on their use by the NRC staff, until those conditions have been dispositioned.
-The issue of severe accident conditions is complex. As additional information becomes available on the performance of electrosleeves under severe accident conditions, it is reasonable to assume the NRC staff will identify new issues to resolve. Further, individual plant differences are likely i
to lead to different conclusions regarding the likelihood of severe accident conditions.
Consequently, another licensee should engage the NRC staffin the severe accident issues of the electrosleeve before proceeding.
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Pr: pes d SG Tcch Spac Chnng:s Adrnin Section and Bases, Version 17 5.5.9 Steam Generator Procram 5.5.9.1 General Requirements A program shall be implemented through the licensee's procedures to ensure that the SG tube integrity performance criteria are maintained. The SG performance criteria are defined in licensee controlled documents (e.g., UFSAR, the Technical Requirements Manual].
5.5.9.2 Condition Monitoring Assessment Condition Monitoring Assessment means an evaluation of the "as found" condition of the tubing with respect to the performance criteria. The "as found" condition refers to the condition of the tubing during an SG inspection outage, as determined from the inservice inspection results or by other means, prior to the plugging or repair of tubes. Condition Monitoring Assessments shall be conducted during each outage (scheduled or unscheduled) during which the SG tubes are inservice inspected, plugged, or repaired to confirm that the performance criteria are being successfully maintained.
5.5.9.3 Performance Criteria The SG performance criteria are defined in licensee controlled documents (e.g.,
UFSAR, the Technical Requirements Manual]. Prior to use, the performance criteria must be reviewed and approved by the NRC. The licensee may revise its performance criteria to incorporate changes approved by NRC subject to the limitations and conditions set forth in the staffs approving document. The licensee's demonstration ofito satisfaction of these limitations and conditions must be documented in a written report available on-site for NRC inspection.
5.5.9.4 Tube Repair Criteria Tube repair criteria shall be described in and implemented by the steam generator program. Prior to use, the repair criteria must be reviewed and approved by the NRC. The licensee may use repair criteria approved by NRC subject to the limitations and conditions set forth in the staff's approving document. The licensee's demonstration ofits satisfaction of these limitations and conditions must be documented.in a written report available on site for NRC inspection.
5.5.9.5 Tube Repair Methods Steam generator tubes must be repaired using repair methods described in and implemented by the steam generator program. Prior to use, the repair methods (excluding tube plugs) must be reviewed and approved by the NRC. The licensee may As of 08/27/99,7:37 PM Page 1 of 2
.g Prepts d SG Tcch Sp;c Changr T
Admin Section and Bases, Version 17 use repair methods approved by NRC subject to the limitations and conditions set forth in the staffs approving document The licensee's demonstration ofits satisfaction of these limitations and conditions must be documented in a written report available on site for NRC inspection.
5.6.10 Steam Generator Tube Insnection Report If the results of the steam generator inservice inspection indicate greater than 1% of the inspected tubes in the affected steam generator require repair in accordance with the requirements of the [ Technical Requirements Manual], the i
licensee shall submit a special report within 120 days after the initial entry into Mode 4 following completion of the inservice inspection. The report shall summarize:
a) The scope ofinspections performed, b) Active degradation mechanisms found, c) NDE techniques utilized for each degradation mechanism, d) Location, orientation (oflinear type degradation indications) and measured sizes of degradation indications, e) Number of tubes plugged or repaired during the inspection outage for each active degradation mechanism, f) Repair method utilized and the number of tubes repaired by each repair
- method, g) Total number and percentage of tubes plugged and/or repaired to date, h) The effective plugging percentage in each steam generator; and i) The results of condition monitoring including the results of tube pulls and in-situ testing].
B LCO 3.4.13 RCS Onerational LEAKAGE l
APPLICABLE SAFETY ANALYSIS The Technical Specification requirement to limit primary to secondary leakage through any one steam generator to less than 150 gallons per day is significantly less than the initial condition of the safety analysis.
A limit of 150 gallons per day is based on operating experience as an j
indication of one or more propagating tube leak mechanisms. This q
1eakage rate provides additional assurance against tube rupture at normal and faulted conditions and provides additional assurance that flaws will not propagate to burst prior to detection by leakage monitoring methods and commencement of plant shutdown.
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i Propossd Technical Requiromants Manual Changes
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for Steam Generator Integrity, Version 18 Information listed here are the key elements to be included in the licensee controlled '
dccuments referenced in Technical Specification 5.5.9.1. Content, not format, is important.
TRM x.y Steam Generators NORMAL TNC x.y Each steam generator shall meet primary to secondary pressure CONDITION boundary integrity performance criteria as given below.
Performance Criteria (i) Structural criterion:
Steam generator tubing shall retain a margin of 3.0 against burst under normal steady state full power operation and a margin of 1.4 against burst under the limiting design basis accident concurrent with a safe shutdown earthquake.
(ii) Accident induced leakare criterion:
The primary to secondary accident induced leakage rate for the limiting design basis accident shall not exceed the leakage rate assumed in the accident analysis in terms of totalleakage rate for all steam generators and leakage rate for an individual steam generator. Leakage is not to exceed [1 gpm per steam generator, except for specific types of degradation at specific locations where the tubes are confined, as approved by the NRC and enumerated in conjunction with the list of approved repair criteria in the TRM].
(iii) Operational leakace criterion:
The RCS operational primary to secondary leakage through any one steam generator shall be limited to 150 gallons por day.
l Requirements related to the Operational Leakage criterion are delineated in Technical Specification 3.4.13 (RCS Opercutional LEAKAGE). The Operational Leakage criterion is applicable in MODE 1 through 4.
APPLICABILITY: MODES 1,2,3,4,5, and 6 l
l CONTINGENCY MEASURES:
j CONDITION REQUIRED ACTION COMPLETION TIME A. Meets performance Plug or repair the affected tubes Prior to entering criteria but exceeds in accordance with repair MODE 4 repair criteria in methods MODE 5 or 6 B. Does not meet Notify the NRC of the failure in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> As of 08/27/99,7:37 PM Page 1of3 L.
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Q Proposed Technical Rsquiramsnts Manual Changes
- g for Steam Generator Integrity, Version 18 Information listed here are the key elements to be included in the licensee controlled dccuments referenced in Technical Specification 5.5.9.1. Content, not format, is important.
CONDITION REQUIRED ACTION COMPLETION TIME performance criteria'(i) accordance with 10 CFR 50.2.
or (ii)in MODE 5 or 6 M
Plug or repair the affected tubes Prior to entering in accordance with repair MODE 4 methods M
Investigate to determine causal Prior to entering factors and perform corrective MODE 4 measures M
Submit a special report to the 60 days after entering NRC in accordance with 10 CFR MODE 4 50.4 including the performance criteria exceeded and a root cause evaluation of the failure.
M Submit a special report to the 120 days after entering NRC in accordance with 10 CFR MODE 4 50.4 describing corrective actions taken and the basis for the planned operating period.
C. Failure to implement a Notify the NRC of the failure in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> required repair accordance with 10 CFR 50.2.
discovered while in M
MODE 1, 2, 3, or 4 Determine steam generators In accordance with [the remain acceptable for continued licensee's corrective operation based on meeting the action program).
l performance criteria M
Submit a special report to the 60 days NRC in accordance with 10 CFR 50.4 providing a root cause evaluation of the failure, corrective actions taken, and the basis for the planned operating period.
{
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Proposed Technical Requiremsnts Manual Chengas i,
for Steam Generator Integrity, Version 18 Information listed here are the key elements to be included in the licensee controlled I
documents referenced in Technical Specification 5.5.9.1. Content, not format, is important.
VERIFICATION REQUIREMENTS VERIFICATION FREQUENCY SR x.y Verify steam generator tube In accordance with the steam generator l
integrity is in accordance with program l
the performance criteria TRM x.z Definitions The following definitions are applicable to Technical Requirement x.y only.
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Accident induced leakage rate means the primary to-secondary leakage rate occurring l
during postulated accidents other than a steam generator tube rupture. This includes the primary-to secondary leakage rate existing immediately prior to the accident plus additional l
primary to-secondary leakage induced during the accident.
i Burst is defined as the gross structural failure of the tube wall. The condition typically corresponds to an unstable opening displacement (e.g., opening area increased in response to constant pressure) accompanied by ductile (plastic) tearing of the tube material at the ends of the degradation.
Normal full power operation is defined as the conditions existing during MODE 1 operation at the maximum steady state reactor power as defined in the design or equipment speci6 cation.
Repair Criteria are those NDE measured parameters at or beyond which the tube must be repaired or removed from service by plugging. The repair criteria approved for use are:
40% nominal tube wall thickness e
[..........]
Repair Methods are those means used to reestablish the RCS pressure boundary integrity of SG tubes without retnoving the tube from service. Plugging a steam generator tube is not a i
repair. The repair methods approved for use are:
[ Laser welded sleeves]
[TIG welded sleeves]
[........]
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