ML062510302

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Email: (PA) Updated Section 4.3, Metal Fatigue for PNPS LRA
ML062510302
Person / Time
Site: Pilgrim
Issue date: 07/31/2006
From: James Medoff
NRC/NRR/ADRO/DLR
To: Patel E
- No Known Affiliation
References
%dam200612, TAC MD2296
Download: ML062510302 (17)
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Text

James Davis - FYI: Updated Section 4.3, Metal Fatigue for PNPS LRA Page1*

From: James Medoff To: INTERNET:erachp@comcast.net Date: 07/31/2006 11:10:37 AM

Subject:

FYI: Updated Section 4.3, Metal Fatigue for PNPS LRA Erach:

I am attaching the updated Draft Section 4.3 for your review. It includes Section 4.3.1 on Class 1 Fatigue, Section 4.3.2 on Non-class 1 Fatigue, and Section 4.3.3 on Environmental Fatigue. The writeup includes our assessments of the revisions to Commitments #31 and #35 on the LRA. The writeup for Section 4.3.3 needs to include your assessment of the updated Commitment #31. Although I incorporated your most recent input for Section 4.3.3, I have given you additional instructions on what to fill in with respect to assessing the applicant's revisions to Commitment #31, including instructions to assess the applicant's proposed changes to the commitment to account for the impacts of environmental effects on the critical PNPS Class 1 piping locations..

Try to get me back your comments and proposed revisions by close of business this Wednesday, August, 2 2006. Note the file only has two colors for printed text: black and red (i.e. redlined print). The redlined print will be amended at a later date, pending our review and acceptance of information that PNPS owes us and that needs to be docketed for the application.

Thanks, Jim Medoff CC: James Davis; Peter Wen

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FYI: Updated Section 4.3, Metal Fatigue for PNPS LRA Creation Date 07/31/2006 11:10:31 AM From: James Medoff Created By: JXM@nrc.gov Recipients comcast.net erachp (INTERNET:erachp @comcast.net) nrc.gov OWGWPO03.HQGWD01 JAD CC (James Davis) nrc.gov TWGWPO04.HQGWDO01 PXW CC (Peter Wen)

Post Office Route comcast.net INTERNET OWGWPOO3.HQGWDOO1 nrc.gov TWGWPO04.HQGWDO01 nrc.gov Files Size Date & Time MESSAGE 1673 07/31/2006 11:10:31 AM Draft Audit Report R27 Short Version 07-31-06.wpd 88016 07/31/2006 11:02:26 AM Options Expiration Date: None Priority: Standard ReplyRequested: No Return Notification: None Concealed

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-W.wpd JaeIai-rf ui eotR2 hr eso 07-31 James Davis - Draft Audit Report R27 Short Version 73-6wdP Page 11 4.3 Metal Fatigue A metal component subjected to cyclic loading at loads less than the static design load may fail due to fatigue. Metal fatigue of components may have been evaluated based on an assumed number of transients or cycles for the current operating term. The validity of such metal fatigue analysis is reviewed for the period of extended operation. The GALL Report identifies fatigue aging-related effects that require evaluation as possible time-limited aging analyses (TLAAs),

pursuant to 10 CFR 54.21 (c). The applicant provides its TLAA on Metal Fatigue in Section 4.3 of the LRA.

4.3.1 Fatigue Analyses for Class 1 Components 4.3.1.1 Summary of Technical Information In the Application LRA Section 4.3.1 provides the applicant's TLAA assessment for metal fatigue of Class 1 components in the reactor coolant pressure boundary (RCPB). The applicant identifies that metal fatigue analyses for PNPS RCPB components (i.e., Class 1 components) conform to the definition for a TLAA in 10 CFR 54.3. The applicant identifies that the Class 1 components include the reactor pressure vessel (RPV) and its appurtenances, the components internal to the RPV (RPV internals), and Class 1 piping. Henceforth, this TLAA will be referred to as the TLAA on Class 1 Metal Fatigue.

The applicant identifies that the original 40-year metal fatigue evaluations for the reactor coolant pressure boundary (RCPB) components that were designed to are based on the methods for calculating cumulative usage factor methods (CUFs) in Section III of the ASME Boiler and Pressure Vessel Code (Section III) if the components were designed in accordance with Section III. The applicant stated that these CUFs are calculated in accordance with the "Procedure for Analysis for Cyclical Loading" in Article NB-3000 of Section III.

The applicant provides the 40-year CUFs for the RPV and its appurtenances, the RPV internals, and the Class 1 piping commodity groups in Table 4.3-1 of the LRA. The applicant provides the design basis operational and transient categories that form the basis of the applicant's 40-year CUF value calculations in LRA Table 4.3-2. LRA Table 4.3-2 includes the design basis upper limits for these transient categories and the applicant's projections of the number of cycles that will occur for these transient through the expiration of the PEO..

LRA Commitment #31 In a letter dated Month Date, 2006 (MLXXXXXXX), the applicant has included Commitment

  1. 31 on the PNPS LRA. In this commitment, the applicant committed to perform updated 60-year CUF calculations for the piping in RRS piping Loops A and B. The commitment specifies that the updated CUF calculations will be performed in accordance with an NRC-endorsed Edition of the ASME Code or in accordance with an NRC-endorsed Code Case.

The commitment also includes a commitment to implement corrective actions if the applicant determines that any CUF value is greater than 1.0, including those for the environmentally impacted CUF values. The details for Commitment #31 are provided in Appendix A of the Final Safety Evaluation Report for the PNPS LRA.

James Davis - Draft Audit Report R27 Short Version 07-31 -06.wpd Page2if]

LRA Commitment #35 In a letter dated Month Date, 2006 (MLXXXXXXX), the applicant has included Commitment

  1. 35 on the PNPS LRA. In this commitment, the applicant committed to either: (1) perform updated 60-year CUF calculations for the RPV components, (2) manage the aging effect of
  • cracking -fatigue" using an NRC-approved inspection program, or (3) repair or replacement the affected components prior to entering the PEO and prior to exceeding a CUF of 1.0 for the affected RPV location. The details for Commitment #35 are provided in Appendix A of the Final Safety Evaluation Report for the PNPS LRA.

Impact of EnvironmentalConditions on CUF Calculations The applicant indicated that its evaluation of environmental factors on the CUF values for the Class 1 components is provided in LRA Section 4.3.3. The applicant provides the environmentally-impacted CUF values for Class 1 components in LRA Table 4.3-3. The project team evaluates the licensee's TLAA evaluations on environmentally-impacted fatigue analyses in Section 4.3.3 of this Audit Report.

4.3.1.2 Evaluation Regulatory Bases for Metal FatigueEvaluations 10 CFR 54.21 (c)(1) provides the three options (criteria) for accepting analyses that are identified as TLAAs:

(i) The analysis remains valid for the period of extended operation (PEO).

(ii) The analysis has been projected to the end of the PEO and remains acceptable.

(iii) The effects of aging on the intended function(s) will be managed during the PEO.

The GALL Report identifies fatigue aging-related effects that require evaluation as possible time-limited aging analyses (TLAAs), pursuant to 10 CFR 54.21(c). The staff provides its bases for evaluating TLAAs on Metal Fatigue in Section 4.3 of NUREG-1 800, Revision 1, "Standard Review Plant for License Renewal Application for Nuclear Power Plants" (SRP-LR).

Section III requires cumulative usage factor calculations (CUFs) as the basis for performing the metal fatigue analyses for those Class 1 components that were designed to Section II1.

Section III sets an acceptance criterion of 1.0 on CUF values and requires additional corrective action ifthese calculated values are projected to exceed this value at the expiration of the operating license. Section 4.3 of SRP-LR defines how the metal fatigue analyses for Section III components may be accepted in accordance with 10 CFR 54.21 (c)(1)(i), (ii), or (iii).

The ASME B31.1 design code (B31.1) requires a different type of fatigue analysis for those Class 1 components that were designed to B31.1 requirements. B311.1 requires calculation of a maximum allowable stress range for each B311.1 component that is subject to thermal cycling and a determination of the number of full thermal cycles that are projected to the expiration of the operating license. B31.1 then establishes what reduction factors must be applied to the maximum allowable stress ranges ifthe number of thermal cycles are projected to exceed 7000. Section 4.3 of SRP-LR defines how the metal fatigue analyses for 831.1 components

James Davis - Draft Audit eport R27 Short Version 07-31-06q.wpd Page 3 may be accepted in accordance with 10 CFR 54.21 (c)(1)(i), (ii), or (iii).

Scope of Review andAssessment The project team reviewed the following parts of the PNPS LRA relative to the applicant's TLAA on Class 1 Metal Fatigue: (1) LRA Section 4.3.1, (2) LRA Table 4.3-1, (3) LRA Table 4.3-2, (4)

Commitment #31, and (5) Commitment #35. The project team also reviewed those aging management review (AMR) line items in the LRA Tables 3.1.2-1, 3.1.2-2, and 3.1.2-3 in which "cracking -fatigue" (i.e., fatigue-induced cracking) was identified as an aging effect requiring management (AERM) and in which the TLAA on Class 1 Metal Fatigue was credited for management of the aging effect (henceforth referred to as the "Class 1 Fatigue AMRs").

The scope of the 40-year CUF values in LRA Table 4.3-1 for Class 1 components include those for the RPV, RPV nozzle appurtenances, RPV closure flange components, core shroud tie rods, and RRS piping Loops A and B. The project team also performed a review of PNPS License Renewal Document LRPD-06, PNPS 40-year design basis CUF calculations, and a General Electric Thermal Power Optimization Report for PNPS in order to assess whether the documents provided an acceptable basis for the 40-year CUF values that were listed for the Class 1 components in LRA Table 4.3-1.

The project team also reviewed the transient listed in LRA Table 4.3-2 to assess whether the total number of cycles projected to occur after 60 years of licensed operations has elapsed) will exceed the maximum number of cycles that are allowed for the transients by the PNPS design basis. The project team performed this review to determine whether the applicant should have included updated 60-year CUF calculations for those Class 1 components that were evaluated in accordance with 40-year CUF calculations, and ifnot, whether cycle counting alone, performed in accordance with the applicant's Fatigue Monitoring Program, would be sufficient to manage fatigue-induced cracking without implementation of the CUF updates recommended in GALL AMP X.M1, "Metal Fatigue of Reactor Coolant Pressure Boundary." The project team also compared the commodity groups in the Class 1 Fatigue AMRs to those commodity groups that were analyzed for metal fatigue in LRA Section 4.3.1 and in LRA Table 4.3-1.

The project team determined that LRA Table 4.3-2 and PNPS Document LRPD-06 both projected that the total number of cycles for over half of the operational transients analyzed in LRA Table 4.3-2 were projected to exceed the maximum number of cycles for these transients that are allowed by the current PNPS design basis. The project team also determined that the scope of the applicant's TLAA on Metal Fatigue of Class 1 Components did not appear to cover all of the commodity groups in the Class 1 Fatigue AMRs for which the TLAA had been credited for aging management of fatigue-induced cracking. The project team asked the applicant to respond to a series of questions in the following topical areas:

1. Requests for clarification on how the 40-year CUF values for those Class 1 components assessed in LRA Table 4.3-1 would remain valid for the PEO, particularly when the number of cycles for over half of the design basis transients were projected to exceed their design basis allowable limits at 60 years and when cycle counting alone was being relied on as the basis for accepting the TLAA in accordance with 10 CFR 54.21 (c)(1)(i).
2. Requests for clarification on why the 40-year CUF values for the Class 1 components listed in LRA Table 4.3-1 did not appear to reflect more recent 40-year CUF values provided in GE Thermal Power Optimatization Report for PNPS and why the some

J James Davis - Draft Audit Report R27 Short Version 07-3170ý-_VYRO Page 4 i s James Dav-** rf ui R pr 2 hr Version....07..31.........d..Page....

components in LRA Table 4.3-1 were exempted from Section III mandated CUF calculations.

3. A request for submittal a metal fatigue analysis discussion for those Class 1 piping components that were designed to the B31.1 requirements in manner that the applicant had provided for Non-Class 1 B31.1 components in LRA Section 4.3.2.
4. Requests for reconciliation of the commodity groups in the Class 1 Fatigue AMRs to those commodity groups that were analyzed in the TLAA on Metal Fatigue of Class 1 components.
5. A request for identification of all PNPS fracture mechanics or flaw evaluations that comply with the definition of a TLAA in 10 CFR 54.3.

The details of the project teams questions are provided in the Q&A Database, which was submitted onto Docket 50-293 in a letter dated Month Date, 2006 (MLXXXXXXXXXX).

The applicant responded to the project team's questions of the Class 1 Fatigue AMRs in a letter dated Month, Date, 2006. The applicant clarified that all of the RPV components were designed to Section III and stated that those RPV components which did not receive CUF calculations are bounded by the 40-year CUF calculations for the commodity groups in LRA Table 4.3-1. The applicant also stated that the following RPV components were exempted from receiving CUF calculations in accordance with Paragraph N-415.1, "Vessels Not Requiring Analysis for Cyclic Operation," of the 1965 Edition of Section II1: (1) RPV main steam nozzles, (2) RPV vent nozzles, and (3) RPV instrumentation nozzles. The applicant clarified that Paragraph N-415.1 exempts these components from CUF calculations because the stress ranges for the cyclical operating transients on these components are mild and are below the endurance limit for the materials of construction in the components. The applicant clarified that the CUFs for the remaining components in LRA Table 4.3-1 are therefore bounding for the RPV main steam, vent, and instrumentation nozzles. The staff concludes that this is acceptable because the applicant has exempted these nozzles from a CUF calculation in accordance with the exemption criteria of an applicable Section III paragraph. The applicant clarified that the stress ranges for the cyclical transients for recirculation outlet nozzle were above the stress threshold for exempting the components from a CUF calculation and therefore did not provide an acceptable basis for exempting the component in accordance with Section III paragraph N-415.1. The applicant therefore stated that the 40-year CUF value for the recirculation outlet nozzle should have been included in LRA Table 4.3-1 and stated that the LRA would be amended to correct this ommission. However, Question 504 with respect to this Issue is accepted but not closed because the staff is still awaiting the amendment of the LRA containing the revised Information.

In a letter dated Month Date, 2006, the applicant supplemented LRA 4.3 and provided Commitment #35 on the PNPS LRA. In this commitment, the applicant committed to either:

(1) perform updated 60-year CUF calculations for the RVP components (including RPV appurtenances and the core shroud tie rods), (2) manage the aging effect of "cracking -

fatigue" using an inspection-based program that ha been approved by the NRC, or (3) repair or replace the effected RPV location prior to entering the PEO and to exceeding a CUF value of 1.0. The activities within the scope of Commitment #35 will ensure that either the 60-year CUF values for the RPV components will be acceptable (i.e., less than a value of 1.0) during the PEO or that the components will be inspected, repaired, or replaced if the updated 60-year CUF values cannot ensure aging management of fatigue-induced cracking.

[Ja~mes Davis-Draft Audit Report R27_Short Version 07-31-06.wpd Pa.

  • 5" Commitment #35 also provides for NRC review of the activities that are within the scope of commitment. Based on this evaluation, the staff concludes that the applicant's TLAA on Metal Fatigue of the RPV components, when taken in conjunction with Commitment #35 is acceptable.

The project team also determined that the applicant had indicated that the RPV internal components were designed to the intent of Section III and had determined that the core shroud tie rods (i.e., core shroud stabilizer repair assemblies) were the only RPV internals that received 40-year CUF calculations. The project team asked the applicant to clarify the meaning of the phrase "designed to the intent of ASME Section III," as made in reference to the design of the RPV internals. The applicant responded to this question by letter dated July 5, 2006. The applicant clarified that, although the RPV internals were not specifically designed as ASME Section III components, the applicant did apply the Section III techniques for selecting the materials of construction, establishing the design wall thicknesses, and constructing the components. The applicant clarified though that it did not perform the Section III analyses and testing that would otherwise have been mandated if the RPV internals were Section III components. The applicant stated that it will amend the information in LRA Section 4.3.1.2 to delete the sentence "Although not mandatory, the design of the reactor vessel internals is in accordance with the intent of ASME Section III" from the LRA section. The project team concluded it would acceptable to remove the referred-to sentence from LRA Section 4.3.1.2 because the RPV internals are not Section III components. The applicant provided the amendment of LRA Section 4.3.1.2 in its response letter of July 19, 2006. Therefore, this issue is closed. The activities within the scope of Commitment #35 (as discussed in the previous paragraph) are applicable to the PNPS core shroud tie rods and provide an acceptable basis for

'concluding that the TLAA on Metal Fatigue, as applied to the core shroud tie rods, will provide an acceptable process for managing fatigue-induced cracking in the components.

In its response letter of Month Date, 2006, the applicant proposed to use the BWR Vessel Internals program to manage the aging effect of "cracking -fatigue" for those RPV internals that were not designed to Section II1. These RPV internals include the following commodity groups:

(1) control rod guide tubes, (2) core plate assemblies, (3) core spray lines, (4) fuel supports, (5) incore instrumentation and guide tubes, (6) jet pump assemblies, (7) core shroud, shroud support, and shroud repair assemblies, and (8) top guide assembly. The applicant's BWR Vessel Internals Program is a valid augmented inspection program to credit with the management of cracking because it incorporates both NRC-mandated inspections of the RPV internals that are required in accordance with 10 CFR 50.55a and Section XI of the ASME Code, as well as augmented inspection and evaluation activities that are performed in accordance with NRC-approved, recommended guidelines from the Boiling Water Reactor Vessel and Internals Project (BWRVIP). The staff confirmed that these components are within the scope of the applicable BWRVIP reports that form the basis for the applicant's BWR Vessel Internals Program. Based on this analysis, the project team concludes that it is acceptable to credit the BWR Vessel Internals Program with aging management of fatigue-induced cracking in these RPV internal commodity groups. The applicant provides its BWR Vessel Internals Program in LRA Section B.1.8. The project team assesses the ability of the BWR Vessel Internals Program to manage cracking for these RPV internal commodity groups in Section 3.X.X of this Audit Report.

The project team determined that the replacement piping for RRS Loops A and B was the only Class 1 piping that was designed to ASME Section III requirements and had received 40-year CUF calculations for the current operating period. In Commitment #31, the applicant

SJames Davis - Draft Audit Report R27 Short Version 07-31-06.Wd -. ge--_P committed to performing updated 60-year CUF values for RRS Loops A and B at least two years prior to entering the PEO. Commitment #31 will require the applicant to take corrective action, as defined in the commitment, ifany of the CUF values for the RRS piping are greater than 1.0. These activities will ensure that either the 60-year CUF values for the RRS piping components will be acceptable (i.e., less than a value of 1.0) during the PEO or that the components will be inspected, repaired, or replaced if the updated 60-year CUF values cannot ensure aging management of fatigue-induced cracking. Commitment #31 also provides for NRC review of the activities that are within the scope of commitment. Based on this evaluation, the staff concludes that the applicant's TLAA on Metal Fatigue of the RRS piping components, when taken in conjunction with Commitment #31 is acceptable.

The project team further evaluates the impact of the reactor water environment on the CUF values for the RRS piping loops in Section 4.3.3 of this audit report. The evaluation includes an assessment on how Commitment #31 will address the impact or the reactor coolant environment on the 60-year CUF values for the critical PNPS Class 1 components locations and how the activities of the commitment, when implemented, will ensure conformance with the recommended CUF analyses in NUREG-6260.

The applicant's response to the question on metal fatigue of the Class 1 piping components also confirmed that the components in the remaining Class 1 piping subsystems were all designed to B31.1 design code, with the exception of the following commodity groups:

(1) CRD detector, (2) CRD drives, (3) RRS pump casing and cover, and (4) main steam line flow restrictors. For those Class 1 piping components that were designed to B31.1, the design code's metal fatigue analysis requires of the maximum allowable stress range for the components to be reduced ifthe number of cycles for the full thermal transients is projected to exceed a threshold value of 7000 cycles. The applicant clarified that the total number of full thermal cycle transients projected through 60 years of operation was less than 7000 and that, based on this projection, the allowable stress range analyses for these components remain valid for the PEO in accordance with 10 CFR 54.21 (c)(1)(i) and do not need to be reduced.

The project team reviewed the thermal transients that were defined and summarized in LRA Table 4.3-2 and confirmed that the total number of full thermal transients projected at 60 years for PNPS will be less than 7000. Based on this confirmation, the project team concludes that the applicant has provided an acceptable basis for concluding that the maximum allowable stress range analysis for the B31.1 Class 1 piping components remains valid for the PEO in accordance with 10 CFR 54.21 (c)(1)(i). However, Question 504 with respect to this Issue Is accepted but not closed because the staff is still awaitingthe amendment of the LRA containingthe revised Information.

For management of "cracking -fatigue" in the CRD detector, the applicant stated that the component, although within scope, does not require an aging management review because the detector is periodically calibrated and checked for operability. The applicant therefore proposed amend the LRA by deleting the Fatigue AMR for the CRD detector from LRA Table 3.1.2-3.

The project team determined that this is an acceptable basis for removing the AMR on "cracking - fatigue" of the CRD detector from the LRA because the components is subject to periodic calibration and surveillance requirements. However, Question 504 with respect to this Issue is accepted but not closed because the staff Is still awaitingthe amendment of the LRA containingthe revised Information.

The applicant also clarified that "cracking -fatigue" is not an AERM for the CRD drives because

JamesDavis - Draft Audit Report R27 Short. Version 07-31-06.wpd .

the components operate a temperature less than 250°F and that this operating temperature is less than the applicant's thermal threshold of 270°F for inducing fatigue-induced cracking in the components. Reference XX supports the applicant'sbasis that a fatigue endurance limit (threshold)is reach In stainlesssteel materials for operating temperaturesthat are less than 2700F. Based on this assessment, the project team concludes that the applicant has provided an acceptable basis for concluding that "cracking -fatigue" is not an AERM for the CRD drives.

For the RRS pump casing and cover, the applicant credited the ISI program to manage "cracking -fatigue. The ISI examinations for reactor coolant pumps are mandated by 10 CFR 50.55a and ASME Section XI Examination Categories BL1 And BL2. The examination categories require volumetric examinations of the pump casing welds once every inspection internal and visual VT-3 examinations of the casings and covers once every inspection interval.

The volumetric examinations are capable of detecting an cracks in the welds. Since the ISI examinations for the pump casing include volumetric examinations of the casing welds, the ISI is an valid AMP to credit for management of fatigue-induced cracking in the components. The staff evaluates the ability of the ISI program to manage cracking in Section 3.X.X of this audit report.

The applicant credited the One-time inspection program to manage "cracking - fatigue" in the main steam line flow restrictors. The applicant stated that the main steam line flow restrictors are non pressure boundary components because they are welded internally to pipes that do serve as the pressure retaining components. Instead, the applicant informed the project team that the main steam line flow restrictors are designed to limit the rate of radioactive steam release during a design basis main steam line break downstream of the restrictors. Based on this discussion, the project team concurs that the main steam line flow restrictors do no serve a reactor coolant pressure boundary function for PNPS and that, based on the safety function to limit the rate of radioactive release during a postulated main steam line break, a one-time inspection using enhanced VT-1 visual examination (EVT-1) techniques is an appropriate inspection to determine whether fatigue-induced cracking is occurring in the flow restrictors.

The project team evaluates the ability of the one-time inspection program to manage cracking in Section 3.X.X of this audit report.

The project team also determined that the applicant had indicated that some fracture mechanics or flaw growth analyses could constitute TLAAs for the LRA but had failed to identify what these analyses were and to include an assessment of them against the acceptance criteria of 10 CFR 54.21 (c)(1). The project team asked the applicant to identify all fracture mechanics and flaw growth analyses that met the definition of a TLAA in 10 CFR 54.3 and, if any did exist, to amend LRA Section 4.0 to include them as TLAAs for the LRA and evaluate them for acceptance in accordance with 10 CFR 54.21 (c)(1). The project team also asked the applicant to provide enough technical information to justify whether or not these fracture analysis or flow growth analyses conformed to the definition of a TLAA in 10 CFR 54.3, and if so, to provide a basis for accepting these analyses in accordance with 10 CFR 54.21 (c)(1)(i),

(ii), or (iii). The project team is deferring closure of this question until the issuance of the safety evaluation report for the PNPS LRA because the response to the project team's question requires additional technical review by the NRC. The NRC's basis for determining whether or not these flaw growth analyses are TLAAs for the PNPS LRA will be issued in the Safety Evaluation Report with Open Items. This question therefore remains open for this audit report, pending the results of the review performed by the NRC Technical Engineering Staff.

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4.3.1.3 UFSAR Supplement The applicant provided the UFSAR Supplement summary description for the TLAA on Metal Fatigue of PNPS Class 1 components in LRA Section A.2.2.2.1. The project team determined that the UFSAR Supplement summary description did provide the applicant's basis for accepting the TLAA on Metal Fatigue of Class 1 components, as initially proposed in Section 4.3.1 of the LRA. However, the project team concluded the USFAR Supplement summary description, as initiallyproposed,may not adequatelysummarize the TLAA or provide an acceptable basis for accepting the TLAA under 10 CFR 54.21(c)(1), because the TLAA discussion did not appearto cover all of AMR commodity groups in LRA Table 3.1.2-1, -2, and

-3 for which the TLAA was credited with aging management of "cracking-fatigue." The project team determined that UFSAR Supplement summary descriptionA.2.2.2.1 might need amending if the pending informationfrom the applicant'sresolution of audit RAls 4.3.1-1 through 4.3. 1-X, would mandate that changes or supplements be made to the information provided in LRA Section 4.3.1 or to Commitment #31.

Therefore, the adequacy of the USFAR Supplement summary descriptionA.2.2.2.1 remains open at this time. Complete this section based on changes that will be made by Entergy to UFSAR Supplement A.2.2.2.1 and to Commitment #31.

4.3.1.4 Conclusion On the basis of its review, pending acceptable resolution of the project team's audit Questions on LRA Section 4.3 and pending acceptable amendments to LRA Section 4.3.1 and LRA Commitment #31, as discussed above, the project team concluded that the applicant has demonstrated, pursuant to 10 CFR 54.21 (c)(1)(i), that, for metal fatigue analyses for the Class 1 components, the analyses remain valid for the period of extended operation. The project team also concluded that the UFSAR supplement contains an appropriate summary description of the RV internals fatigue analyses TLAA evaluation for the period of extended operation, as required by 10 CFR 54.21(d).

4.3.1.5 References

1. PNPS Report No. LRPD-06, Revision 0, "Time Limited Aging Analyses - Mechanical Fatigue."
2. Altran Report No. 93177-TR-03, Revision 0, Volumes I, II, Ill, and IV, "Pilgrim Reactor Vessel Cyclic Load Analysis."
3. PNPS Calculation DC23A4096, Revision 3, "Loop A RRS Piping and Equipment Loads,"

July 25, 1994.

4. PNPS Calculation DC23A4097, Revision 2, "Loop B RRS Piping and Equipment Loads,"

February 26, 1988.

5. GE Report 25A5685, Revision 1, "Stress Report - Shroud Stabilizers Vessel,"

June 19, 1995.

6. GE Report GENE-771-79-1194, Revision 2, "Shroud Repair Hardware Stress Analysis,"

June 19, 1995.

James IDavisI - Draft Audit Repo .rIt R27 Short Version 07-311-06.výii6 Page 91]

Page9 James Davis- Draft Audit Report R27 Short Version 07-31 -06.wpd

6.Section III of the ASME Boiler and Pressure Vessel Code.
7. 1967 Edition of the ASME B31.1 Design Code.
8. NUREG-1 800, Revision 1, "Standard Review Plan for License Renewal Applications for Nuclear Power Plants," September 2005.

4.3.2 Fatigue of Non-Class 1 Components 4.3.2.1 Summary of Technical Information in the Application The applicant evaluated those safety systems that provide a safety function equivalent to those for ASME Code Class 2 and 3 systems. The applicant stated that these systems were designed to B31.1. The applicant stated that B31.1 requires the applicant to assess whether the projected number of thermal cycles for these systems through 60 years of licensed operations would require the applicant to reduce the maximum allowable stresses for the components in accordance with the B31.1 maximum allowable stress reduction criteria.

The applicant stated that the number of thermal cycles projected for these systems through 60 years of licensed operation will not exceed 7000 cycles. Based on this projection, the applicant determined that, in accordance with the B31.1 acceptance criteria, no reductions of the maximum allowable stresses for these systems is necessary for the period of extended operation. The applicant therefore concluded that the piping stress calculations for these systems remain valid for the period of extended operation and are acceptable in accordance with 10 CFR 54.21 (c)(1)(i).

4.3.2.2 Evaluation Regulatory Bases for Evaluating TLAAs on Metal Fatigueof Non-Class 1 Components The metal fatigue methods and criteria discussed in Section 4.3.1.2 for B31.1 methodologies are applicable to this assessment.

Scope of Review andAssessment The project team reviewed LRA Section 4.3.2, including LRA Table 4.3-2, "Project Cycles,"

relative to the TLAA on Metal Fatigue for Non-Class 1 components. The project team also reviewed the AMR line items in the LRA Tables 3.2.2-X, 3.3.2-X and 3.4.2-X (i.e.,. AMR line items in the Non-Class 1 AMR tables, which are the AMR tables for Emergency Safety Feature Systems, Auxiliary Systems, and Steam and Power Conversion Systems) in which "cracking -

fatigue" was identified as an AERM and in which the "TLAA - Metal Fatigue" was credited as the basis for management of the aging effect. The project team also reviewed PNPS Report No. LRPD-06, Revision 0, "Time Limited Aging Analyses - Mechanical Fatigue," relative to the applicant's metal fatigue methods for PNPS Non-Class 1 components.

The project team determined that LRA Table 4.3-2 indicates that the total number of thermal cycles projected for PNPS through 60 years of licensed operations is 1684 cycles. Based on this number, the project team concluded that the applicant has made a valid conclusion that the total number of thermal cycles at 60 years will not exceed 7000 and that the stress calculations

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for the Non-Class 1 piping commodity groups designed to B31.1 will remain valid for the PEO.

However, the project team determined that Section 4.3.2 did not clearly indicate which of these AMR commodity groups were designed to B31.1 and which commodity groups were not designed to B31.1 requirements. Thus, the project team was unable to conclude that the TLAA on Metal Fatigue was an appropriate means of aging management for those Non-Class 1 commodity groups that were designed to a design code other than B31.1. The project team asked the applicant to respond to the following requests:

(1) Identify which design codes were application to the non-piping commodity groups in the Non-Class 1 Fatigue AMRs.

(2) Clarify whether the design codes required a metal fatigue analysis and summarize what type of metal fatigue analysis calculation was required by the design code, if applicable.

(3) Discuss how the metal fatigue analysis was acceptable in accordance with 10 CFR 54.21 (c)(1)(i), (ii), or (iii), if applicable.

(4) Propose an acceptable AMP to manage the aging effect "cracking - fatigue" for the PEO ifthe design code did not a metal fatigue analysis for the particular Non-Class 1 commodity group.

The applicant provided its response to the project team's questions in the Question and Answer Database, which was docketed on Month Date, 2006. The applicant clarified that the following Non-Class 1 components were not designed in accordance with B31.1:

  • RHR pump casings, which were designed to Section III, Class C requirements
  • reactor building closed cooling water (RBCCW) heat exchanger tubes, which were designed to ASME Section ????, Division 1
  • All non-piping components in the AMR tables for the auxiliary systems (i.e.., in the LRA 3.3.2-14-X Tables).

The applicant clarified that the design codes for these components do not require metal fatigue analyses for the components and therefore proposed to credit the one-time inspection program to manage "cracking -fatiguem in these components in lieu of the TLAA on Metal Fatigue.

The applicant's One-Time Inspection Program is used, in part, to determine whether a specific aging effect of concern is occurring in components in which there has been no plant-specific operating experience with the aging effect. The applicant has not indicated any relevant operating experience with respect to the occurrence of fatigue-induced cracking in the RHR heat exchanger tubes and shells, RHR pump casings, or RBCCW heat exchanger tubes, or in the non-piping components for non-safety related systems within the scope of the 3.3.2-14 (a)(2) AMR Tables. GALL Program XI.M32, "One Time Inspection,* states that either an enhanced VT-1 (EVT-1) visual examination or volumetric examination techniques (i.e., either ultrasonic or radiographic techniques) are to be used to detect cracking in plant components.

The applicant's One-time Inspection Program (LRA AMP B.1.23) has been determined to be consistent with GALL AMP XI.M32 without exception. Therefore, staff concludes that it will be

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appropriate to credit a one-time inspection of these components using either an EVT-1 or volumetric examination technique to determine whether fatigue-induced cracking is an AERM for the PEO. The project team evaluates the ability of the one-time inspection program to manage cracking in Section 3.X.X of this audit report.

4.3.2.3 UFSAR Supplement The applicant provided the UFSAR Supplement summary description for the TLAA on Metal Fatigue of PNPS Class 1 components in LRA Section A.2.2.2.2. The summary description discusses how the number of full thermal transients is projected to remain below 7000 at the expiration of the PEO and, therefore, provides an acceptable description on the TLAA for Metal Fatigue for Non-Class 1 components in that it discusses how the maximum allowable stress range analysis for the components remains valid for the PEO in accordance with 10 CFR 54.21 (c)(1)(i). In the applicant's response to the project team's question on management of "cracking -fatigue" in Non-Class I components, the applicant clarified which components in the Non-Class 1 AMR tables were fabricated in accordance with B31.1 design requirements and which Non-Class 1 components were fabricated in accordance with design codes which did not require metal fatigue analyses. Therefore, based on the project team's review of UFSAR Supplement Summary Description A.2.2.2.2, the project team concludes that the summary description is acceptable because it provides an acceptable basis on how the Non-Class 1 B31.1 components remains valid for PEO in accordance with 10 CFR 54.21 (c)(1)(i) and because the applicant is no longer relying on the TLAA on Metal Fatigue to manage cracking in the Non-Class 1 components that were designed to non-B31.1 design codes.

4.3.2.4 Conclusion On the basis of its review, the project team concluded that the applicant has demonstrated, pursuant to 10 CFR 54.21 (c)(1)(i), that, for metal fatigue analyses for the Non-Class 1 components designed to B31.1 requirements, the analyses remain valid for the PEO.

The project team also concludes that the applicant has proposed a valid AMP to manage "cracking - fatigue" in those Non-Class 1 components in which "cracking -fatigue" is an applicable AERM and for which the design code of record is a design code other than B31.1.

The project team also concluded that the UFSAR supplement contains an appropriate summary description of the RV internals fatigue analyses TLAA evaluation for the period of extended operation, as required by 10 CFR 54.21 (d).

4.3.3 Effects of Reactor Water Environment on Fatigue Life In Generic Safety Issue (GSI)-1 90, "Fatigue Evaluation of Metal Components for 60-year Plant Life." the NRC assessed the generic impacts of the effects of reactor coolant environment on fatigue life of Class 1 components. In accordance with interim staff guidance document ISG-16, "Time-Limited Aging Analyses (TLAAs) Supporting Information for License Renewal Applications," the NRC has established its position that the environmental effects of the reactor coolant environments must be evaluated for their impacts on the 60-year metal fatigue CUF values for the high fatigue CUF locations listed in older vintage BWR plants.

4.3.3.1 Summary of Technical InformationIn the Application In LRA Section 4.3.3, the applicant summarized the evaluation of the effects of reactor coolant

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. .... ... . .......... d .... n ........ . ..... *ii .... iT Page 12 I environment on fatigue life of components and piping for the period of extended operation. The applicant evaluated the six locations identified in NUREG/CR-6260 (a total of nine components) using the guidance provided in NUREG-1801, chapter X.M1. These evaluations were performed using 40-year CUF values as identified in Table 4.3-1 of the LRA. The applicant stated that four of the nine components reviewed have environmentally adjusted CUF greater than 1.0. Table 4.3-3 provides the PNPS CUFs for NUREG/CR-6260 locations.

The LRA states that, prior to entering PEO, the applicant will implement one of the following actions for each location that may exceed a CUF of 1.0 when considering environmental effects:

(1) further refinement of the fatigue analyses to lower the predicted CUFs to less than 1.0; (2) management of fatigue at the affected locations by an inspection program that has been reviewed and approved by the NRC (details such as scope, qualification, method, and frequency will be submitted to the NRC prior to PEO);

(3) repair and replacement of the affected locations LRA Commitment #31 In a letter dated Month Date, 2006 (MLXXXXXXX), the applicant has included Commitment

  1. 31 on the PNPS LRA. In this commitment, the applicant committed to perform updated 60-year CUF calculations for the piping in RRS piping Loops A and B. The commitment specifies that the updated CUF calculations will be performed in accordance with an NRC-endorsed Edition of the ASME Code or in accordance with an NRC-endorsed Code Case.

The commitment also includes a commitment to implement corrective actions ifthe applicant determines that any CUF value is greater than 1.0, including those for the environmentally impacted CUF values. The details for Commitment #31 are provided in Appendix A of the Final Safety Evaluation Report for the PNPS LRA.

4.3.3.2 Evaluation Regulatory Bases In GSI-166, "Adequacy of the Fatigue Life of Metal Components," the NRC raised concerns regarding the conservatism of the fatigue curves used in the design of the reactor coolant system components. Although the issues raised in GSI-1 66 were resolved for the current 40-year design life of operating components, the staff identified that the same issues would have to be assessed for their impacts on possible licension extension for operating reactors.

The staff therefore issued GSI-1 90, NFatigue Evaluation of Metal Components for 60-year Plant Life," to address these issues with respect to license renewal. The NRC closed GSI-1 90 in December 1999, concluding that the calculations supporting resolution of this issue, which included consideration of environmental effects and the nature of age-related degradation, indicate the potential for an increase in the frequency of pipe leaks as plants continue to operate. However, the NRC also concluded that, consistent with existing requirements in 10 CFR 54.21, licensees should address the effects of reactor coolant environment on component fatigue life as AMPs are formulated in support of license renewal. The NRC's bases for performing these evaluations are given in NUREG/CR-6260, NUREG/CR 6583,

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. Report R2 Shor.. ersion 073-0.p "Effects of LWR Coolant Environments on Fatigue Design Curves of Carbon and Low-Alloy Steels," for carbon and alloy steels, NUREG/CR 5704, "Effects of LWR Coolant Environments on Fatigue on Fatigue Design Curves of Austenitic Stainless Steels."

Scope of Review andAssessment The applicant evaluated the component locations listed in NUREG/CR-6260 that are applicable to an older-vintage BWR plant for the effects of the reactor coolant environment on the fatigue life of the components. However, the applicant has not performed any 60-year CUF calculations. The 40-year numbers derived from Table 4.3-1 were multiplied by the Fn,values to arrive at the environmentally adjusted CUFs as shown in Table 4.3-3.

Table 4.3-3 indicated that there were no PNPS-specific CUF values available for RR outlet nozzle, core spray safe end, and feedwater piping, and the applicant used the generic values for these components from NUREG/CR-6260. The project team asked the applicant to clarify three issues related to the LRA Section 4.3.3 and LRA Table 4.3-3:

(1) notes for LRA Table 4.3-3 stated that generic values for these components were taken from NUREG/CR-6220. The project team asked the applicant whether this should have been NUREG/CR-6260. In its response, the applicant stated that this was a typo, it should be NUREG/CR-6260. The project team found the response acceptable.

(2) The project team Informed the applicant that NUREG-6260 CUF Is based on the specific plant used in the NUREG and Is dependent on that plant's piping configuration. That value could not be used by PNPS unless it justified that its piping configuration was same as the NUREG-6260 plant. The project team asked the applicant to justify the use of the NUREG/CR-6260 values. In its response, the applicant stated that the CUF values were Intended as typical values used to predict the magnitude of the effect of considering the reactor coolant environment on fatigue for PNPS. The applicant agreed to supplement the LRA to remove the CUFs from Table 4.3-3 that are taken from NUREG-6260. Furthermore, the applicant committed to perform additional environmentally adjusted fatigue analyses prior to PEO as stated below in (3).

(3) The project team asked the applicant to provide more details on its Implementation plan, specifically (a) how will further refinement of the fatigue analyses be performed? And (b) if an AMP Is used to manage fatigue, then Include a commitment to Issue for NRC approval 24 months prior to PEO. In its response, the applicant stated that further refinement of the ASME class I fatigue analyses for the RPV and nozzle locations will be performed considering the predicted number of transients at each location adjusted to the end of the extended license period using refined finite element evaluation as applicable. The refined analyses will account for environmental effects as applicable using FEN methodology described by the GALL Report or other Industry Codes and Standards as approved by the NRC. Furthermore, license renewal commitment 31 Includes a commitment to submit the AMP to the NRC 24 months prior to PEO if the aging management option is chosen. The applicant will Issue a supplement to the LRA to address this Issue. Erach Patelto amended this writeup based on the new changes to LRA Commitment #31.

James Davis - Draft AuditReport R27 Short Version 07-3 -06. ".d Page 14' The project team noted that this Issue is Interlinked with the issues Identified In subsection 4.3.1, Class I Fatigue. The CUFs for Class I components as Identified in Table 4.3-1 may need to be re-calculated for 60 years, before the refinement of the fatigue analyses can be performed for the environmental effects for locations identified in NUREGICR-6260. {OPEN ITEM - to be evaluated when supplement is Issued.) Erach Patel to amended this writeup based on the new changes to LRA Commitment #31.

4.3.3.3 UFSAR Supplement The applicant provided the UFSAR Supplement summary description for the TLAA on Environmental Effect on Fatigue of PNPS limiting locations as identified in NUREG/CR-6260 in LRA Section A.2.2.2.3. The project team determined that the UFSAR Supplement summary description does not adequately describe the impact of environmental impact of environmental fatigue on these locations. The applicant stated that the effects of environmental impact were evaluated for license renewal. However, these effects were only evaluated for 40 years, and not for the PEO.

The applicant needs to respond to Issues addressed in the subsection 4.3.3.2 project team evaluation and, If any commitment is made, then the commitment needs to be addressed in the UFSAR Supplement summary description. [OPEN ITEM) Erach Patelto amended this writeup based on the new changes to LRA Commitment #31. We will need an amendment of UFSAR Supplement A.2.2.3 to Include that an amended Version of Commitment #31 was placed on the application.

4.3.3.4 Conclusion On the basis of its review, pending acceptable resolution of audit Questions on LRA Section 4.3.3 'and pending acceptable amendments to LRA Section 4.3.3 and LRA Commitment #31, as discussed above, the project team concluded that the applicant has demonstrated, pursuant to 10 CFR 54.21 (c)(1)(i), that, for the environmental metal fatigue analyses for the Class 1 components, the analyses remain valid for the period of extended operation. The project team also concluded that the UFSAR supplement contains an appropriate summary description of the RV internals fatigue analyses TLAA evaluation for the period of extended operation, as required by 10 CFR 54.21 (d).

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