ML031080407
| ML031080407 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 03/27/2003 |
| From: | Martin R NRC/NRR/DLPM/LPD2 |
| To: | |
| Martin R, NRR/DLPM, 415-1493 | |
| References | |
| Download: ML031080407 (32) | |
Text
-U-Sample Administrative Technical Specifications
- Steam Generators with Alloy 600 TT Tubing 5.5.9 Steam Generator (SG) Program
- a. A Steam Generator Program shall be established and implemented to ensure that steam generator tube integrity is maintained n and aeyatonto describe SC condition monitoring, performance criteria, repair methods, repair criteria, and inspection intervals. The Steam generator Program shall address the following topies. Steam generator tube integrity is maintained by meeting the following tube integrity performance criteria:
- 1. Structural Integrity Performance Criteria: All steam generator tubes shall retain structural integrity over the full range of normal operating conditionsluding startup, operation in the power range, hot standby and cdoldown andal[1--
anticipated transients included in the design specificati6oi)>This includes retaining a safety factor of 3.0 against burst under thed%6rmal steal' A power primary to secondary pressure differential anfa' safety fa6t'r of against burst applied to the design basis accident witWthe lard&et primary secondary pressure differential. Apart from different lods, additi loadings associated with design basis accidents (e.g.',endirg moments, differential thermal loads), or combination of accident ih accoance with the design and licensing basis, shall be evaluated to detdrmineWtherthese loads may contribute to burst. In combination with the essociaie1presre differential, contributing loads that do affect b all be as esdjelastic analysis with a safety factor of 1.0 agains .1bfirs cnterion isper staff review. The staff may issue RAI.] ,
- 2. Accident Leakage Integrity Perform Criteria: The pnmro-secondary -e accident induced leakage rate fodl{6 limitir~gdesign basis accident, other than a steam generator tube rupture, eMee the leakage rate assumed in the accident analysis in terfsl of total ieaRagct fa 1Crs, andu eai agr uor an individual SC. Leakage ingot to exc*6edj150Ygallons per day (total fror'Iill iubs fo(Iiny individuaIs'li generatad6 gallons per day (totU6 frohi all dd~)ih all stea"m~g-h~n'eratcors. >
- 3. Operational !ega~e l aPnformance Criteria: This criterion is specified in LCO 3.4.13, R perationattlak age."
- b. Condition monit o means an evaluation of the "as found" condition of the tubing with respect to the s taintegrity and accident leakage performance criteria.
The "as fo~fhd" condition ref the condition of the tubing during a steam generator tube inspection outage, as determined from inservice inspection results or by other meanst ,Prior to the plugging~f tubes. Condition monitoring assessments shall be condcte~d during each outage during which the steam generators tubes are inspected, pluggd repaired tovcbfirm that the structural integrity and accident leakage perf rcrit e ing met.
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- c. Pe steam generator tubenspectio's -shall be performed. The scopeof ins bction
-w s zr t sUbej~-s tubies inispected).and ethodxofnspAction
- ,h all iihasto ensure _thereliable detectio ofany flaws-thatare present along the I~i~thoL~t ube'aeddibon.-;
b f hbt :o tubneholdo th tenay exceed the a lb stam gnrtr IL PYOfDPQ b to ensure that the steam generator tube integrity is maintained. In addition,
- 1. 100% of the tubes in each steam generator shall be inspected in the first refueling outage following installation.
- 2. Except as provided for In 5.5.9.c.3, inspect 100% of tubes at sequential intervals of 120, 90, and, thereafter, 60 EFPM. The first sequential interval shall be considered to begin at the first inservice inspection of the steamy generators. In addition, inspect 50% of the tubes by the refueling outage nearest the mid point of the interval and the remaining 50% byihekrefuelin outage near the end of the interval. No steam generatcr'can opera' forrmor than 48 EFPM or two fuel cycles without being inspected.> $
- 3. If a crack-like indication is found in any steam enerator t e, then Hex inspection for each steam generator for the degradtion-mec anism that ca'Isei the crack-like indication shall not exceed 24 EFPM oroefel cycle. (If a definitive information, such from examination of apuibedtube, indicates that the indication is not associated with crack(s),Atlien theindication nee(
not be treated as crack-like.)f(Note, this item is for presenitation'pu pses only since sufficiency of this criterion is under active review,
- 4. (Degradation activity threshold criteria neddedMfor roicrack-li k6eiindications?
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- d. Tube Repair Crit 6ould be piuqqedl (6r-epaired) m-P~thtI FNs-tdai-3 11h to contain flaws with a depth equal toug? Il1thickness shall be plugged Of repaired priofo
- e. Application of >this specification is permissible.
Reporting Requirements:
If the results of the steam generator inspection indicate greater than 1% of the inspected tubes in any steam generator exceed the steam generator tube repair criteria specified in Specification 5.Z.9, Steam Cenerator Program," a 5' report shall be submitted within 120 days after the initial entry into MODE 4 following completion of Fe HitedfterfWr inspection.
The report shall include:
- a. The scope of inspections performed on each SG.
- b. Nondestructive examination techniques used for each degradation mechanism.
- c. Location, orientation, and measured sizes (if available) of all indications. 7
- d. Number and location of tubes plugged or repaired during the inspection outaga in'clu ing thE reason for plugging/repair.
- e. Repair method utilized and the number of tubes repaired by eac;method
- f. The effective plugging percentage for all plugging and tube repairs each SG
- g. The results of condition monitoring, including the results of tubeyulls'nd in-situ testing.
- h. The planned operating interval until the next inspection
MEM Catawba SG Program LAR Duke / NRC Meeting March 27, 2003
__RI Agenda
. Introduction
- Response to NRC Comments
I Introduction
- Duke is committed to the industry's SG Program initiative and to developing the regulatory framework necessary to implement the necessary technical specifications
- The Catawba submittal represents the culmination of over ten years of work by the industry and NRC
- The Catawba LAR includes many significant improvements over the present technical specifications
- Industry is committed to continual improvement of our SG Program and guidelines
- We will continue to work with the staff to resolve technical issues Catawba SG Program LAR 3 Introduction
. Industry's efforts on the GLCP has led to the Catawba license amendment request and a TSTF submittal
- Industry's generic changes to the improved standard tech specs (TSTF-449) was submitted on March 14th
. Industry expects a parallel review of the two submittals Subsequent license amendment requests will be based on the TSTF Catawba SG Program LAR 4
E : 11IM Response to NRC Comments
- We are responding to comments initially discussed in a March 2 0 th phone call and forwarded by a letter to Duke dated March 24 th
- Industry representatives have been consulted in the development of our responses and the positions we will be presenting are representative of the industry at-large Catawba SG Program LAR S E
General Goal
- NRC requested that the words "inspection intervals shall be established and implemented to ensure tube integrity is maintained" be added at TS 5.5.9.e
. We will change the TS as requested Catawba SG Program LAR 6
4-i-
Frequency of Inspections
- NRC requested that the TS include the "frequency of 100% sample inspections and 50% sample inspections as a function of SG age" and tube material "(Alloy 600TT and 690TT only)"
We will accept the approach described in TS 5.5.9.c.1 (for Alloy 600TT) and 5.5.9.g.1 (Alloy 690TT) of Enclosure I to the NRC's September 9, 2002 letter to NEI (example on next slide)
Catawba SG Program LAR 7 Frequency of Inspections
- Draft example wording for 600TT tubes:
Except as provided for in 2., inspect 100% of tubes at sequential intervals of 120, 90, and, thereafter, 60 EFPM. The first sequential interval shall be considered to begin at the first in-service inspection of the steam generators. In addition, inspect 50% of the tubes by the refueling outage nearest the mid point of the interval and the remaining 50% by the refueling outage near the end of the interval.
Each steam generator shall be inspected every two refueling outages or 48 EFPM. whichever is less.
Cycle Limitations
. NRC requested that refueling cycles as well as EFPM be used to limit SG inspection intervals
. Our draft changes the words fuel cycles to refueling outages to maintain consistency with the Exam Guidelines
. We will accept the approach described in TS 5.5.9 of Enclosure 1 to the NRC's September 9, 2002 letter to NEI with the change noted on the previous slide Catawba SG Program LAR 9 Use_
Degradation Activity Threshold
. NRC requested that inspection intervals be limited to 24 EFPM or once per cycle if a tube's degradation activity threshold is exceeded
. We propose an approach consistent with that described in Rev 6 of the SG Examination Guidelines
- Using our definition of active damage mechanism and
Degradation Activity Threshold (Rev. 6 Appendix F.1) Active Damage Mechanism:
A combination of 10 or more new indications (e 20% through-wall) of thinning, pitting, wear (excluding loose part wear), or impingement and previous indications that display an average growth rate equal to or greater than 25% of the repair limit in one inspection-to-inspection interval in any one steam generator, One or more new or previously identified indications (> 20%
through-wall) which display a growth equal to or greater than the repair limit in one inspection-to-inspection interval, or Any crack indication (outside diameter intergranular attack/stress corrosion cracking or primary-side stress corrosion cracking).
Catawba SG ProgTam LAR 11 Degradation Activity Threshold
. Revision 6 allows the operational assessment to be used as the basis for establishing inspection intervals for damage mechanisms not associated with cracking Catawba SG Program OAR 12
MEI E - RVRNSM Degradation Activity Threshold
- We do not agree with the NRC's definition of degradation activity threshold for two reasons
. The use of degradation activity threshold does not allow for the operational assessment to adjust cycle limitations due to damage mechanisms not associated with cracking
. The definition of degradation activity threshold treats loose parts inappropriately Catawba SG Program LAR 13 Degradation Activity Threshold
. Operational Assessment
. Some degradation mechanisms are well understood and can be measured with sufficient accuracy to allow extended inspection intervals as long as they are supported by an operational assessment
- In these cases, use of the operational assessment should be allowed by the technical specifications Catawba SG Program LAR ]4
Degradation Activity Threshold
- Loose parts
- Loose parts can find their way into the SG at any time during operation. Due to the unpredictable nature of their occurrence, adjusting inspection intervals based on loose parts is not appropriate.
- Loose parts are a concern for other components within the primary system and detailed analysis for these components are not specified in the tech specs
- Loose parts evaluations are part of Rev 6 of the SG Examination Guidelines.
- Loose part wear evaluations are included in the operational assessment.
- Rev 6 includes requirements for secondary side visual inspections
- The current requirements in the integrity guidelines are being revised to increase the emphasis on the need to evaluate foreign object wear and its effects on inspection intervals Catawba SG Program LAR 15 Structural Performance Criterion
- Industry has worked with NRC Staffsince 1998 to develop a structural performance criterion. The latest industry criterion was incorporated in the Catawba submittal
- Technical Basis and Philosophy of Structural Performance Criterion
- RG 1.121 used as historical reference
- Not a design or licensing basis
- Consistent with ASME Section III Design Margins
- ASME Section Xl applies to in-serviceldegraded components
- Provide criteria/margins that are verifiable through Condition Monitoring
. InSitu Pressure Testing and Analysis
. Definition of Burst
- Terminology made consistent with Technical Specification/UFSAR
. Original NEI White Paper submitted to NRC June 1999
- Revision submitted to NRC November 2002 Catawba SG Program 1AR 16
I I MEEM MIMM Structural Performance Criterion Steam generatortubing shall retainstructural integrityover thefull rangeof normal operatingconditions (including startup, operation in thepowerrange, hot standby, and cooldowvn and all anticipatedtransientsincluded in the design specification) and design basis accidents. This includes retaining a safetyfactor of3.0 against burst undernormal steady statefullpower operationpnmary-to-secondarypressure diferentialand a safetyfactor of1.4 against burstforthe largestprimary-to-secondarypressure differentialassociated witi LevelD service. Additional conditions identifed in the design and licensing basis shall be evaluated to determine ifithe associatedloads contributesignificantly to burst. Contributing loads that do affect burst shall be assessed witht a safetyfactor of 1.0 and combined with the appropriateload due to the definedpressure differentiaL
- Bold print represents change from NEI 97-06 Rev 01 Basis for changes documented in NEI White Paper Catawba SG Program LAR 17 MMMUMMEM i 1011 MMMJM Structural Performance Criterion
- Previous - ". . .safetyfactor of 1.4 againstburst under limiting design basis accident"
- Change - "...safety factor of 1.4 against burstfor largest primary-to-secondarypressure differential associatedwith Level D service."
- Reason - Establishes level D events for the evaluation following RG 1.121 guidance. Corrects the ties to ASME Section III margins. Some design basis events are characterized as ASME Level C for which safety factor of 1.4 does not apply.
Ties safety factor to original design basis/specification.
- NRC Comment - concern that Catawba application of safety factors of 3.0 and 1.4 depart from design basis (ASME Section 111, GDC-2, RG 1.121)
Structural Performance Criterion
- Industry Response -
. No change in application of 3.0 safety factor.
- Change to 1.4 safety factor application is consistent with ASME Section III, despite the fact that ASME Section III is not specific to in-service steam generators.
- RG 1.121 not part of Catawba design basis - however the performance criterion wording is consistent with historically accepted applications of the RG.
. The performance criterion satisfies GDCs 1, 2, 4, 14, 30, 31, 32 with respect to tube integrity.
Catawba SG Program LAR 19 Structural Performance Criterion
- Previous - "Any additionalloading combinationshall be included as requiredby existing design and licensing basis."
- Change - "Additional conditions identified in the design and licensing basis shall be evaluated to determine ifthe associated loads contribute significantly to burst. Contributingloads that do affect burst shall be assessed with a safetyfactor of 1.0 and combined with appropriateload due to the definedpressure differential."
- Reason - First sentence represents clarification only not a change. Second sentence added to define safety factor for additional loadings consistent with ASME Section III for secondary loads and ASME Section XI flaw evaluation procedures Catawba SG Program LAR 20
Structural Performance Criterion
- NRC Comment - Safety factor of 1.4 should apply to combination of accident conditions (i.e., MSLB +SSE or LOCA+SSE).
. Response -
- The SSE loads are insignificant contributors to burst in most locations. SSE loads result in bending stresses, which, when included in a Code evaluation, result in an allowable margin of 1.0
- Some plants do not include SSE loads in their design basis
. The treatment of secondary loads is consistent with ASME Section III.
- The performance criterion must be verifiable in the field during SG inspections.
Catawba SG Program JAR 21 111111 111 IN Repair Methods
- NRC is concerned with our proposal to allow use of repair methods specifically included in the ASME Code
. We accept the NRC comment based on the statement that the NRC's approval of the ASME Code repair methods assumed that the methods were also dictated by the tech specs
. We request that this approach be considered in the NRC's endorsement of future Code changes Catawba SG Program 1AR 22
I M11mi M I =111MOMMIM MM Previously Identified Priority Guideline Issues
- NRC expressed the need to resolve SGMP Guideline issues regarding degradation assessments and the definition of burst
. NRC and industry have previously agreed that these are technical issues that will be resolved outside of the SG Program generic license change process
. Industry and NRC have agreed on a protocol for dealing with these issues and have developed a means of prioritizing them and tracking them to completion
. Industry agreed in our September meeting that we would enhance our guidance in these areas and the revision of the integrity assessment guidelines currently being prepared is dealing with these issues.
. Per our previous agreement, resolution of these items should not hold up the technical specification changes Catawba SG Program LAR 23 Emergent Issues x NRC has not identified the specific issues that fall within this area
. It is our understanding that all issues have been identified and are being resolved Catawba SG Program LAR 24
V II f Future Actions
. Catawba has requested a fee waiver for their submittal. One has been given to all the GLCP submittals to date.