Text

Response to Requests for Additional Information for the Review of the South Texas Project, Units 1 and 2, License Renewal Addiction - Set 26 (TAC ME4936 and ME4937)
	ML14224A151
Person / Time
Site:	South Texas
Issue date:	07/31/2014
From:	Gerry Powell; South Texas
To:	; Document Control Desk, Office of Nuclear Reactor Regulation
References
	NOC-AE-14003135, TAC ME4936, TAC ME4937
	Download: ML14224A151 (125)
	v • d • e

Nuclear Operating Company South Texas Pro/*t Electrc GenrtiS Station P.. Box 289 Mdsworff Taws 77483 ý A A A July 31, 2014 NOC-AE-14003135 10 CFR 54 File: G25 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 South Texas Project Units 1 and 2 Docket Nos. STN 50-498, STN 50-499 Response to Requests for Additional Information for the Review of the South Texas Project, Units 1 and 2, License Renewal ADDlication - Set 26 (TAC Nos. ME4936 and ME4937)

References:

1. Letter from G. T. Powell, STP, to NRC Document Control Desk, "License Renewal Application", dated October 25, 2010 (NOC-AE-1 0002607)

(ML103010257)

2. Letter from NRC to STP, "Requests for Additional Information for the Review of the South Texas Project, Units 1 and 2, License Renewal Application - Set 26", dated December 18, 2012, (TAC Nos. ME4936 and ME4937) (AE-NOC-14002493) (ML12333A227)

3. Letter from D.W. Rencurrel, STP, to NRC Document Control Desk, "Supplement 2 to Request for NRC Staff to Suspend Safety Review of South Texas Project License Renewal Application", dated January 10, 2013, (TAC Nos. ME4936 and ME4937) (NOC-AE-13002943) (ML13024A413)

4. Letter from G.T. Powell, STP, to NRC Document Control Desk, "Response to Requests for Additional Information for the Review of the South Texas Project, Units 1 and 2, License Renewal Application - Set 26 Date Extension", dated March 20, 2014, (TAC Nos. ME4936 and ME4937) (NOC-AE-14003090)

(ML14098A420)

By Reference 1, STP Nuclear Operating Company (STP) submitted a License Renewal Application (LRA) for South Texas Project Units 1 and 2. By Reference 2, the NRC staff requested additional information for their review of the STP LRA. STP temporarily suspended license renewal activities and committed in Reference 3 to provide a response to Reference 2 by February 28, 2014. Reference 4 requested an additional date extension until July 31, 2014, for the Reference 2 submittal. STP's response to Reference 2 requests is provided in to this letter. Changes to LRA pages described in Enclosure 1 are depicted as line-in/line-out pages provided in Enclosure 2.

STI: 33874692 A4q7

NOC-AE-14003135 Page 2 of 3 There are two revised regulatory commitments, one deleted commitment,'and one completed regulatory commitment added to Table A4-1 of the LRA and are provided in Enclosure 3 to this letter. There are no other regulatory commitments in this letter.

Should you have any questions regarding this letter, please contact either Arden Aldridge, STP License Renewal Project Lead, at (361) 972-8243 or Rafael Gonzales, STP License Renewal Project regulatory point-of-contact, at (361) 972-4779.

I declare under penalty of perjury that the foregoing is true and correct.

Executed on "7- 8/ -,20/1/

Date G. T. Powell Site Vice President RJG

Enclosures:

1. STP Response to Requests for Additional Information

2. STP LRA Changes with Line-in/Line-out Annotations

3. Regulatory Commitments

NOC-AE-14003135 Page 3 of 3 cc: (electronic copy)

(paper copy)

Regional Administrator, Region IV A. H. Gutterman, Esquire U. S. Nuclear Regulatory Commission Morgan, Lewis & Bockius, LLP 1600 East Lamar Boulevard Arlington, Texas 76011-4511 Balwant K. Singal John Ragan Senior Project Manager Chris O'Hara U.S. Nuclear Regulatory Commission Jim von Suskil One White Flint North (MS 8B1) NRG South Texas LP 11555 Rockville Pike Rockville, MD 20852 NRC Resident Inspector Kevin Polio U. S. Nuclear Regulatory Commission Cris Eugster P. 0. Box 289, Mail Code: MNI16 L.D. Blaylock Wadsworth, TX 77483 City Public Service C. M. Canady Peter Nemeth City of Austin Crain Caton & James, P.C.

Electric Utility Department 721 Barton Springs Road Austin, TX 78704 C. Mele John Wester Jim Collins City of Austin City of Austin Electric Utility Department 721 Barton Springs Road Robert Free Austin, TX 78704 Texas Department of State Health Services John W. Daily Richard A. Ratliff License Renewal Project Manager (Safety) Texas Department of State Health U.S. Nuclear Regulatory Commission Services One White Flint North (MS 011-Fl)

Washington, DC 20555-0001 Tam Tran Balwant K. Singal License Renewal Project Manager John W. Daily (Environmental) Tam Tran U. S. Nuclear Regulatory Commission U. S. Nuclear Regulatory Commission One White Flint North (MS 011 F01)

Washington, DC 20555-0001

Enclosure 1 NOC-AE-14003135 Enclosure 1 STP Response to Requests for Additional Information Attachment A: List of susceptible components, broken down by size Attachment B: Calculation AES-C-1 964-4, "Evaluation of 6-Inch Flange Test", APTECH Project AES 93061964-1Q (June 3, 1994).

Attachment C: Table reflecting leaking components that have occurred since July 28, 2011 Attachment D: CREE 12-29261-95, "STP evaluation methodology and associated analyses calculating the critical bending stresses for the four flaw cases" Attachment E: Commitment No. 46, in response to RAI B2.1.37-4 Issue 5, Summary of the results of the leak rate analysis

Enclosure 1 NOC-AE-14003135 Page 1 of 98 SOUTH TEXAS PROJECT. UNITS I AND 2 REQUEST FOR ADDITIONAL INFORMATION, SET 26 (TAC NOS. ME4936 AND ME4937)

RAI B2.1.37-5

Background:

The staff has completed its evaluation of the response to request for additional information (RAI) B2.1.37-4 related to the Selective Leaching of Aluminum Bronze plant-specific aging management program (AMP). As a result of this review, there are several open questions.

Issue:

a) The wording of the commitments (i.e., 39, 44, and 45), the updated final safety analysis report (UFSAR) Supplement, and the aging management program (AMP) is not clear in relation to testing and inspection of removed components (e.g.,

Commitment No. 45, states that fracture toughness testing will be conducted but it does not discuss pressure and bend testing; Commitment Nos. 39 and 45, overlap in their descriptions of examinations). The staff believes that the intent of the proposed testing and inspections is as follows:

Profile Exam (PE) -removed leaking components will be tested/inspected for chemical composition (including aluminum content), mechanical properties, microstructure, degree of dealloying and cracking in order to establish the progression of dealloying, its impact on structural integrity, and to confirm the acceptability of using the existing correlation of observed outside diameter (OD) crack angle to project internal degradation.

" Analysis Confirmatory Test (ACT) -removed leaking components will be pressure tested and bend tested to confirm the results of the analytical methodology used to demonstrate structural integrity. In addition, samples will be tested/inspected for chemical composition (including aluminum content), mechanical properties, microstructure, degree of dealloying, and cracking.

The staff recognizes that different terminology might be established for the above tests and inspections in order to best communicate the program requirements.

However, given the currently proposed language in the AMP, UFSAR Supplement, and Commitments, the staff does not believe that testing and inspection requirements will be correctly interpreted in the future.

Enclosure 1 NOC-AE-14003135 Page 2 of 98 Request:

a) Revise the AMP, UFSAR Supplement, and Commitments to clearly state the intent of each test and the parameters that will be inspected or tested.

STP Response:

STP Program procedure OPGP04-ZA-0148 rev.0, "Aluminum Bronze Dealloying Management Program" has been developed and includes the following flow chart documenting the Essential Cooling Water (ECW) Component Examinations and Testing:

ECW Component Examinations and Testing - Information Flow --+

Decision Point Data Collection Updates and Dataplot/Trending

Evaluations Penodic (Committed to six month) system walkl- Document ýtReus No negative Record for RMS storage down for visual Dellying Dcmn eut inspection results Yes Length parameter to be In-service visual and Yes I out side netudn used for crack co-non-destructive Component Id and relation (outside to examinations outside crack length crack length(s) or inside surfaces) Ref. 1, absence of crack page 12 and Fig. 4-1 Perform dye penetrant test or volumetric examinations and record flaw (crack) profile Document generic Repair implications and safety Inenlsurface Operability Licensing Implications 0 Replace "O Determination evaluation Component Remove Coomponent fr 0 test per schedule

'11

5. Non-destructive examinations Document general Internal sutrfa *Condition of internal Record for RMS storage examinations surfaces

Extent of internal surface dealloying Time versus test pressure Determine load Evaluate analytical 7and bearing capacity of model and if warranted

Nonl-destructive tests Time v/s test dealloyed component factor uniform axial and

Benldtest load7 per Ref.2 global bending stress (component level) Determine load (am and ob) that bound Proof test carrying capacity per test results (Ref 3, Eq. 6-(Pneumatic) Visibe Ref. 3 methodology 2). For limit load case Proof tests (Hydro Bea Pressure ant c Sand test Determine margin on adjust flow stress ol.

with and without operation and design crack) sochs Record for RMS storage Non-destructive 7Dyonayd t examination post ct rispics hydro tests T C ore

Plot & trend material strength as material ages

aample suitability for ts

Trend extent of Yield and Ultimate Destructive tests Strength dimensional Yield and ultimate Fracture toughness- average dealloying strength test Dealloyed material layered v/s Fracture toughness Bending load/stress component service Extent of dealloying life through wall

Document fracture thickness toughness Bend test (three point acceptance limits coupon level)

Plot bending loads versus dimensional dealloying depth Plot and trend

Material remainder aluminum Metallurgical versus extent of examinations contents and dimensional dealloying

Chemical analysis Micrographs Comparison of

Morphology (Micro-structure) micrographs for unusual loss of dealloying metals as component ages

Enclosure 1 NOC-AE-14003135 Page 3 of 98 Flow Chart

References:

1. APTECH Project AES 93061964-1 Q, Document AES-C-1 964-5, titled 'Evaluation of the Significance of Dealloying and Subsurface Cracks on Flaw Evaluation Method', dated 1/23/1995; STP Record no. ST-7R-HS-090006, PFN M05.02.02

2. APTECH Project AES 93061964-1Q, Document AES-C-1964-4, titled 'Evaluation of 6-Inch Flange Test', dated 6/3/1994; STP Record no. ST-7R-HS-090003, PFN M05.02.02

3. APTECH Project AES 93061964-1Q, Document AES-C-1964-1, titled 'Calculation of Critical Bending Stress for Dealloyed Aluminum-Bronze Castings in the ECW System', dated 1/21/1994; STP Record no. ST-7R-HS-090002, PFN M05.02.02 LRA Appendices Al.37 and B2.1.37, Commitments 39, and 44 in Table A4.1, and LRA Basis Document PSALBZ (B2.1.37) are revised to reflect the intent of each test as defined below:

Analysis Confirmatory Test (ACT) - Removed leaking components that are pressure tested and bend tested.

The ACT results (pressure and bending moment) support the analytical methodology. The Linear Elastic Fracture Mechanics (LEFM)/Limit Load curves that provide the critical bending stress are based on crack angle use in the correlation of outer diameter (OD) to internal degradation (flaw/crack) angle for predicting internal degradation (APTECH Calc. AES-C-1 964-5). The ACT confirms that the analytical methodology used to calculate the load carrying capacity and structural integrity of the leaking components is conservative.

Leaking components are removed and are non-destructively examined for the presence of any visual crack identifications (inside/outside surfaces). This Profile Examination (PE) is then followed by destructive examinations for: microstructure; degree of dealloying (percent dealloying through component cross section); percent of dealloying through-wall thickness; and chemical composition (including aluminum content). When sufficient material is available for the preparation of a test coupon, mechanical properties (ultimate strength, yield strength, and/or fracture toughness) are obtained. The PE results provide the physical, metallurgical and mechanical properties used to trend the progression of dealloying and to confirm the acceptability of using the existing correlation of observed OD crack angle as the means by which STP projects internal degradation. provides the line-in/line-out revision to LRA Appendices A1.37 and B2.1.37. provides the line-in/line-out revision to LRA Table A4-1 for LRA Commitments 39 and 44 and completed LRA Commitment 46.

Issue:

b) Subsequent to the public meeting conducted on August 27, 2012, the staff determined that an additional 14 PEs and 8 ACTs would be required to establish a reasonable basis that a susceptible component would be able to perform its intended function throughout the period of extended operation (PEO). The additional 14 PEs will result in a total of 22 PEs being conducted; including those conducted in 1994 (reference AES-C-1964-5, "Evaluation of the Significance of Dealloying and Subsurface Cracks on Flaw Evaluation Method"). The staff's position is that the ACTs should include a sufficiently wide range of component sizes and internal crack angles to validate the analytical methodology.

Enclosure 1 NOC-AE-14003135 Page 4 of 98 Specifically, a minimum of 3 component sizes, with 3 tests in each size, is recommended. The staff recognizes that a six-inch fitting was subjected to an ACT in 1994.

The number of tests described above is based on the test outcomes supporting current design documents, such as calculation output curves that provide the critical bending stress versus crack angle and the correlation of OD crack angle to internal degradation. If any of these tests do not support the pertinent design output documents, further testing will be required. This testing to establish reasonable assurance will have to be completed and submitted to the staff prior to issuance of the final SER.

The staff also believes that continuing confirmation testing will need to be conducted through the end of the PEO in order to either (a) demonstrate that the nature (e.g., plug-like versus layer-like) and rate of degradation continue as they have in the past and therefore can be managed by the program, or (b) demonstrate, through trending, the need to replace the susceptible components prior to signs of external leakage. In its consideration of this continuing testing, the staff noted the long period of time before the renewed license will expire, the importance of the essential cooling water system, and the fact that further degradation will continue to occur. The staff's position is that, for PEs, 100% of leaking components should be tested/inspected until the end of PEO. In regard to ACTs and following completion of the above-mentioned 9 ACTs, 20% of future leaking components should be tested until the end of PEO.

Request:

b) Amend the AMP, UFSAR Supplement, and Commitments to reflect the recommended number of continuing confirmation tests discussed above, or provide a statistical or engineering judgment basis for using an alternative number of tests.

STP Response:

As of February 2014, STP has performed the following additional tests:

STP has removed 18 in-service cast components that are likely candidates for dealloying. These components were selected because 1) the same component in another train had previously dealloyed; and 2) these components have higher potential to crack (stress considerations). STP did not identify any new leaking components or leaking valves, during this scope of work.

One leaking flange, previously identified at ECW cross connect piping (ACTs and PEs performed)

Twelve additional non-leaking components, selected based on a potential of finding dealloying (e.g., same component in a different train had dealloyed previously; located in stagnant flow region). The degree of dealloying on the 12 additional non-leaking components was determined to be insignificant based on 4 profile exams and visual exams of the inner and outer diameters.

Enclosure 1 NOC-AE-14003135 Page 5 of 98

" Performed 3 additional ACTs (total of 4 ACTs). These tests include: 2 - 4" valves, 1- 10" flange, and 1 - 6" flange (all tested in 1994).

Performed 7 additional PE tests in 2013 (total of 15 PEs including 8 previous tests from 1994).

Performed 15 additional tensile tests from recently removed components (total of 22 tensile tests including 7 previously conducted tests from 1994).

Performed 14 additional Crack Tip Opening Displacement (CTOD) tests on the recently removed components (total of 18 fracture toughness tests including 4 previously conducted CTODs from 1994).

The following graphs display material properties (ultimate strength, yield strength, and fracture toughness), as trended from the above listed PE tests and pertinent STP observations.

Ultimate Tensile Strength Data for AI-Brz Castings at Room Temperature 120 1 1 T 1 T 1 I I I I A Smal Bore Fittings (Bechtel 1988) (CA954) 110

8-inch Pump Shaft Casing Heat 24900 (CA954) ol8-inch Pump Shaft Casing Heat 25838 (CA954) 100 i + i + i4-inch Valve EWFV-6936 (CA954) 04-inch Valve EWFV-6937 (CA954) 90

10xl0x6 Tee Piece #3 (CA952)

O 10xl0x6 Tee Piece #4 (CA952) 9! 80 ,O

10x1Ox4 Tee (CA952)

A q

70 60 Eo 50 0(i0

_ A_ _ _ _ _ ... A. _ _

40 30 20 10 0

0 10 20 30 40 50 60 70 80 90 10' Percent Dealloying, %DA STP Observation:

The reduction in material strength is consistent with the earlier work and shows an asymptotic limit of 30 ksi, based on the regression analysis of the test data. This is the same limit value assumed in the 1994 integrity assessment for the fully-dealloyed condition.

Enclosure 1 NOC-AE-14003135 Page 6 of 98 0.2% Offset Yield Strength Data for AI-Brz at Room Temperature 70 I I II

&Small Bore Fitlings (Bechtel 1988) (CA954)

8-nch Pump Shaft Casing Heat 24900 (CA954) o 8-inch Pump Shaft Casing Heat 25838 (CA954) 60 04-inch Valve EWFV-0936 (CA954) nch Valve EWFV-6937 CA954)

IIlbx0x6 Tee Piece #3 (CA952) 50 CI OxI xAPiece #4 (CA952)

(a SIMOxx4 Tee (CA952)

C?" 40 0

.,.-. . ...

30 20 10 0

0 10 20 30 40 50 60 70 80 90 100 Percent Dealloying, %DA 0.5% EUL Yield Strength Data for AI-Brz at Room Temperature 80 I I I7i S8-inch Puwp Shaft Casing Heal 24900 (CA954) o 8-inch Pump Shaft Casing Heat 25838 (CA954) 70 114-inch Valve EWFV-6936 (CA954)

D4-Inch Valve EWFV-6937 (CA954)

u10 x6 Tee Piece #3 (CA952) 60 - 1Oxl0x6 Tee Piece #4 (CA952) l 0xl0x4 Tee (CA952) 50 C4 40 0_

C',

30 20 10 0

0 10 20 30 40 50 60 70 80 90 100 Percent Dealloying, %DA STP Observation:

The trend in yield strength (approximately 28 Ksi) has been established, and has been determined to be consistent with that of the ultimate strength.

Enclosure 1 NOC-AE-14003135 Page 7 of 98 K-CTOD (Pmax Data) vs Percent Dealloylng on Uncracked Section (Properties Adjusted for Specimen %DA) 120 1 1 1 i 9 Srmall-Bore Vaves (CA954) 110

84ndt Pipe Casing Heat 24900 (CA954) -

0 8-inch Pipe Casing Heat 25838 (CA954) 100 ___ A 4-inch EWFV6937 Inlet Flange (CA954) -

o 10x10x6 Tee Piece #4 (CA952)

A 1 10Ax6 Tee Piece #11 (CA952) -

90 0 MUx10x4 Tee (CA952)

Fit Z5 80 _ _....Regression 70 '.-- + _

60 FO 60 at 50 0

1- T*

40 20 4 + 4 +/- 1 4 *1- I I 4 4 4 4 4-0 10 20 30 40 50 60 70 80 90 100 Percent Dealloying, %DA STP Observation:

Fracture toughness of 65 ksi in 112 for undealloyed material, as assumed in the original integrity assessment, remains valid.

For each of above material properties (ultimate, yield, and fracture toughness), a regression analysis was performed that determined the empirical correlation between the property and dimensional degree of dealloying in the test specimen. The resulting correlations provide the following information:

1) Trending the mechanical properties for use in structural integrity calculations, and

2) The evaluation of the CTOD test data for establishing the trend in fracture toughness. The tested material properties can then be used to support operability evaluations based on average degree of dimensional dealloying.

Where the degree of dealloying is indeterminate, STP will use material properties equivalent to those that would be found if the component was, on average, 60% dealloyed. STP will continue adding test data, as it becomes available through destructive examinations, to update the material property charts and reassess the material properties against measured average degrees of dealloying.

Volumetric examinations and radiography of STP's leaking components has not identified a quantifiable boundary between dealloyed and undealloyed areas. This information is necessary to determine internal flaw sizes and characterize the dealloying flaws; therefore, determining the size (length) of a potential internal flaw requires a correlation between OD crack angle and

Enclosure 1 NOC-AE-1 4003135 Page 8 of 98 internal degradation. The determined internal flaw length is used to confirm structural integrity to reasonably ensure that the ECW system remains Operable. Note that the internal dealloying flaw lengths can only be verified by conducting destructive examinations of the components.

STP has proactively removed additional components using various risk ranking parameters and did not identify any dealloyed components suitable for ACTs and PEs. Based on experience, it is unlikely STP will find the number of susceptible components desired by the NRC until through-wall leakage is observed in the future. STP instead proposes an alternate that will establish a reasonable basis upon which there can be confidence in the ability of susceptible components to perform their intended functions throughout the period of extended operation (PEO):

" STP will continue to perform ACTs and PEs on all identified leaking components until the NRC recommended additional 8 ACTs and 14 PEs are completed.

" If no leaking components are identified, STP will remove two cast components of different sizes per unit during scheduled outages lasting more than 30 days. The component removal strategy will be to remove a minimum of 3 component sizes with 3 tests in each component size plus one randomly selected component throughout the testing phase of this process.

This will continue until the NRC recommended additional 8 ACTs and 14 PEs are completed or total of 20 additional components are removed from service for additional testing.

" STP will perform PEs on all leaking components until the end of PEO.

" In regard to ACTs, following completion of the above mentioned 9 ACTs and 21 PEs, 20%

of future leaking components will be tested until the end of PEO, unless results indicate a larger testing regiment is warranted.

" STP will continue updating material property regression graphs following the completion of the component PE where sufficient material was available to perform material properties testing.

The current collection of ACTs and PEs represents reasonable assurance that a susceptible component will perform its intended functions through the current license. This is based on:

1) Correlations used to determine internal crack sizes have remained valid for the recently removed components for which additional ACTs were performed.

2) Review of the recent ACTs, PEs, and additional material property evaluations support the original (1994) analysis and subsequent aging of the in-service material through 2013. The results of the ACTs (pressure and bending moment), to date, support the analytical methodology that determines components load carrying capacity is conservative and that the components have maintained their ASME code safety factors.

3) The analysis methodology conservatively treats through wall dealloyed flaws as potential cracks, even though not all dealloyed locations are cracked i.e. no surface separation has occurred.

The proposed duration of ACTs and PEs, from the end of the current license through the end of PEO, also represents a reasonable approach to manage the future aging effects. This is because testing provides for timely identification and a continuous evaluation of any emergent leaking components, thereby providing the means to ensure that any ongoing aging effects related to dealloying do not adversely affect metallurgical properties or challenge the validity of the associated correlations.

Enclosure 1 NOC-AE-14003135 Page 9 of 98 LRA Appendices A1.37 and B2.1.37; Commitments 39 and 44 in Table A4.1 and LRA Basis Document PSALBZ (82.1.37) are revised to reflect:

100% of leaking components shall have PEs performed until the end of PEO.

For ACTs, following completion of the above-mentioned 9 ACTs, 20% of all future leaking components shall be tested until the end of PEO. provides the line-in/line-out revision to LRA Appendices A1.37 and B2.1.37. provides the line-in/line-out revision to LRA Table A4-1 for LRA Commitments 39 and 44 and completed LRA Commitment 46.

Issue:

c) The RAI response did not address the minimum level of degradation (e.g., degree of dealloying) that a component must exhibit in order to be used as an ACT specimen.

The degree of dealloying in a tested component must be sufficient so that its material properties (e.g., fracture toughness, yield strength) are representative of an advanced degree of dealloying. Therefore, some removed leaking components may not be acceptable specimens for validating the analytical methodology. An example would be a specimen that has a very narrow angle of through-wall dealloying and minimal layer-type dealloying around the circumference.

Request:

c) State and justify the minimum level of degradation that a component must exhibit in order to be used as an appropriate test specimen for ACTs.

STP Response:

The purpose of the ACT is to confirm that the analytical methodology conservatively predicts the load carrying capacity of leaking components removed from service. Any component that experiences leakage is an appropriate test specimen for the ACT. STP is not excluding any conditions from consideration, thus ensuring test results are relevant to all conditions.

Issue:

d) The response to RAI B2.1.37-4, Issue 3, "describe how the percentage of dealloying is identified when testing specimens," does not account for areas where dealloying has penetrated through-wall, but not progressed to completion (i.e., significant depletion of aluminum). While the AMP, UFSAR Supplement, and Commitments state that samples will be tested for chemical composition including aluminum, it is not clear how this data will be used in conjunction with determining the degree of dealloying.

There are many references to 100-percent dealloyed tensile properties throughout the analyses credited by the program. It is not clear to the staff that the tensile properties were obtained from specimens that were 100-percent dealloyed from both a dimensional (i.e., percent through-wall) and chemical composition basis (i.e.,

aluminum depletion).

Enclosure 1 NOC-AE-14003135 Page 10 of 98 Table 2.5, "Tensile Test results on Dealloyed Samples of CA-954 Material from Fittings," of ST-HL-AE-2748, "Failure Analysis and Structural Integrity of Leaking Small Bore Aluminum Bronze Cast Valve Bodies and Fittings in the ECW System,"

provides a compilation of test sample tensile values and the percent dealloyed. A footnote to the percent dealloyed column of this chart states, "based on SCM of tensile fracture surface." The staff does not know what "SCM" stands for, and no other criterion for the percent dealloyed values is stated in the document.

The staff believes that if the degraded components that are tested are not 100-percent dealloyed from both a dimensional and chemical composition basis, the material properties obtained from those tests may not represent the lowest possible values.

Therefore, the program needs to state how partially dealloyed material property results will be integrated into trending data.

Request:

d) State or provide the following:

a description of "SCM testing," as referenced in Table 2.5 of ST-HL-AE-2748, and what criteria were used to establish the percent dealloyed from this testing.

a copy of any other testing results that correlate tensile properties to percent dealloying based on both a dimensional (i.e., percent through-wall) and chemical composition (i.e., aluminum depletion) basis, if available

" how the percentage of dealloying will be determined, from a dimensional and chemical composition basis, for testing that will be conducted in the future

how partially dealloyed material properties will be integrated into trending data STP Response:

The documentation of the material properties test reports is available for NRC review. The summary of the test results and responses to specific requests are provided in the bulleted responses below.

Enclosure 1 NOC-AE-14003135 Page 11 of 98 Request:

a description of "SCM testing," as referenced in Table 2.5 of ST-HL-AE-2748, and what criteria were used to establish the percent dealloyed from this testing.

STP Response:

The description of "SCM testing" is provided in a footnote to the percent dealloyed column (Table 2.5) of ST-HL-AE-2748. The footnote refers to 100 percent dealloyed tensile properties as being the tensile strength of a specimen for which sectional-area measurement (SCM) after break was observed to be 100 percent dealloyed from a dimensional aspect (i.e., percent through-wall). The description does not, in any manner, refer to chemical composition (i.e.,

aluminum depletion). The footnote implies, that out of all specimens tested, only two were found to have the entire cross sectional area dealloyed where the break occurred, while the other specimens had partial areas dealloyed. The percent dealloyed is the percentage of total area estimated as dealloyed area.

Request:

a copy of any other testing results that correlate tensile properties to percent dealloying based on both a dimensional (i.e., percent through-wall) and chemical composition (i.e., aluminum depletion) basis, if available STP Response:

STP is not aware of any documented tests that have correlated tensile strength to percent dealloying based on both a dimensional and chemical composition. Tensile tests are performed per ASTM E8-01, "Standard Test Methods for Tension Testing of Metallic Materials," American Society for Testing and Materials, Vol.3.01, (2001). The tensile strength is then correlated to dimensional degree of dealloying.

The Brookhaven National Laboratory has published a utility chemical analysis, documenting aluminum content in dealloyed materials. The chemical analysis was based on energy-dispersive spectroscopy (EDS), a semi-quantitative measurement that relied on spot sampling at the location of incident electron beam; therefore, the information was considered as qualitative, rather than quantitative. Due to spot sampling the depleted aluminum content may vary along the dealloying path because of potential variation of crystallization and corroding environment. For component integrity analysis it is more appropriate to use material strength properties of a composite section based on degree of dealloying across the cross section (dimensional dealloying) and not on chemical composition basis.

Enclosure 1 NOC-AE-14003135 Page 12 of 98 Request:

how the percentage of dealloying will be determined, from a dimensional and chemical composition basis, for testing that will be conducted in the future STP Response:

STP uses ASTM E1282-11 Standard Guide for Specifying the Chemical Compositions and Selecting Sampling Practices and Quantitative Analysis Methods for Metals, Ores, and Related Materials. STP records the following:

DimensionalTestinq

1. The dimensional degree of dealloying is estimated as follows. The three different levels of dealloying associated with typical tensile fracture surfaces are visible by their reddish-brown color (shown below). The undealloyed area appears as the bright gold-tan region.

The dealloying measurements were made by optical analysis of the fracture surfaces. The area of each region (dealloyed and undealloyed) was measured by digital analysis of the fracture surfaces (pixel counting). The percent dealloying (%DA) was calculated as the ratio of dealloyed area over the total area. These values are reported for each tensile specimen as percent dealloying (dimensional degree of dealloying). One hundred percent dealloying in the test specimen is when the full section at the fracture plane is dealloyed.

Enclosure 1 NOC-AE-14003135 Page 13 of 98 Fracture Surface Appearance for Various Amounts of Dealloying in 0.35-inch Diameter Tensile Bars a) Negligible Dealloying b) 15.9% Dealloying c) 53% Dealloying

2. After completing the pixel counting activity, material strength properties (ksi) will be recorded and plotted on the y-axis; % dealloying (dimensional degree of dealloying) through component cross section will be plotted on the x-axis. Typical plots are shown in STP response 'b' above.

Enclosure 1 NOC-AE-14003135 Page 14 of 98 Chemical Testing STP has tested some selected samples of fractured surfaces for aluminum content by percent2

(%) weight. These measurements are obtained by taking detailed surface area scans of 1 mm in size along the linear traverses across the fracture surfaces using the Scanning Electron Microscope (SEM) and EDS. These scans included both dealloyed and undealloyed regions to obtain the distribution of Al, Fe, and Cu content within these regions.

STP observed that the transition from dealloyed to undealloyed AI-Brz is sharp and distinct, and visible to the eye. It is evident from the figure below that the Al and Fe compositions along the fracture surface (Traverse 1) indicate a relatively uniform but reduced amount of both Al and Fe within the dealloyed region from the ID surface to the maximum depth of dealloying. Beyond that point, the compositions of Al and Fe exhibit a step increase in magnitude within the undealloyed AI-Brz material.

Similar surface scans on other samples have shown the same trend. Within the dealloyed region, the distribution of depleted AL and Fe content is relatively uniform across the dealloyed region returning to the bulk chemistry level a very short distance into the undealloyed region.

The uniform distribution behavior is observed through the thickness as well as cross-width of the samples. This indicates the fracture path is essentially fully dealloyed with respect to the loss in aluminum and iron of the transformed phases within the eutectoid. This supports STP's simple dimensional definition for the amount of dealloying for a given test specimen fracture section based on an area ratio bases.

STP observations indicate that not all aluminum will deplete as components age.

Surface Area Scan - Traverse 1 10xlWx6-inch Tee CTOD Sample #11 Specimen SENB-2 18L 1- Fe 16- -Al (CMTR)

- - Fe (CMTR) 14 -Dealloylng Depth 12 ._

___ ________

CF 10 ____

0 8 7 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Line Distance, sit

Enclosure 1 NOC-AE-14003135 Page 15 of 98 Request:

0 how partially dealloyed material properties will be integrated into trending data STP Response:

STP is trending two yield strengths (0.2% Offset and 0.5% Elongation Under Load), ultimate strength, and fracture toughness for various degrees of dealloying.

A regression analysis has been performed to determine an empirical correlation between tensile properties and the fracture toughness with the amount of dealloying. The regression analyses also smoothed out scattered data to a trending curve (correlation). The extended trending curve is used to characterize the mechanical property in those instances where results from a physical test are not available.

Issue:

e) While the revised AMP, Enhancements, UFSAR Supplement, and Commitments describe acceptance criteria for tensile, yield and fracture toughness properties, the RAI response does not describe specific follow-on actions that would be taken When abnormal test or inspection results are obtained, beyond stating that results would be trended, an engineering evaluation would be performed, or that the condition will be documented in the corrective action program. The acceptability of the Selective Leaching of Aluminum Bronze plant-specific AMP will be based upon (a) either empirical testing results or attainment of dealloyed material properties to be used in revised structural integrity analyses, and (b) the continuing demonstration of the ability to detect aging using external visual inspections prior to the degradation adversely impacting the ability of a susceptible component to perform its intended function. The staff notes the possibility that results of the tests and inspections could invalidate the analytical assumptions to such an extent that structural integrity could not be reasonably expected to be demonstrated for leaking components, or that an in-situ leaking fitting could be found that cannot be shown to meet structural integrity requirements. In the latter case, given that there are approximately 300 other susceptible components, it would be unreasonable to assume that only this component was not capable of meeting its intended function, and therefore the basis of the program (i.e., using external visual inspections to detect degradation prior to adversely impacting the ability of a susceptible component to perform its intended function) would be invalidated. The staff requires further details to understand what specific actions will be taken for the following outcomes:

During a PE or ACT, a crack or degree of dealloying is discovered outside of the current correlation as shown on page 12 of AES-C-1964-5. It is unclear to the staff whether a new correlation curve will be developed and whether existing leaking components will be reanalyzed with the new correlation. It is the staffs position that, given that the correlation of OD crack angle to projected internal degradation will have been demonstrated to be nonconservative, some additional fittings will need to be immediately examined, even though not leaking, to determine whether this was a one-off data point or whether there are many more susceptible fittings which have larger internal cracking or dealloying than would be projected from observing the through-wall indications on the OD.

Enclosure 1 NOC-AE-14003135 Page 16 of 98 An ACT test result yields a data point below the size-appropriate acceptance curve (e.g., Figure 4-2, "Evaluation of Flange Bend Test Results," in AES-C-1964-6). It is unclear to the staff whether the analytical methodology will be revised to reflect the lower data point. For example, if it is suspected that the lower data point occurred because an appropriately low fracture toughness value was not used, it is unclear whether the fracture toughness value in the calculation would be decreased until the curve is sufficiently shifted. Also, it is unclear whether existing leaking components will be reanalyzed with the revised methodology. It is the staff's position that any existing leaking component should be considered not capable of performing its intended function until the cause of the discrepancy is understood, a new analysis curve is developed, and any existing degraded components are evaluated against the new analysis curve.

" The in-situ evaluation of a newly-discovered leaking fitting (i.e., the fitting has not yet been removed from service) results in a determination that the degraded component is not operable. It is the staff's position that such a result invalidates the effectiveness of the program, since the program is based on the capability of external visual examinations to manage aging prior to loss of intended function.

Consequently, the staff believes that all susceptible fittings should be considered not capable of performing their intended functions until a revised technical basis is established or the components are repaired or replaced.

" PE or ACT results demonstrate a trend where, due to continuing dealloying, tensile strength, yield strength, or fracture toughness properties are projected to be below the acceptance criteria prior to the end of the PEO. It is the staff's position that the initial testing used to establish reasonable assurance and the continuing confirmatory testing can provide a timely projection of degraded mechanical properties, and all susceptible components should be repaired or replaced prior to the as-found properties or the as-trended properties fall below the acceptance criteria.

PE or ACT results demonstrate that layer-type dealloying is becoming predominant over plug-type, such that it is no longer possible to project internal degradation based on external observations. The staff recognizes that there is some level of layer dealloying occurring in most fittings, as illustrated in Figure 3-1, "Typical Dealloying/Cracking Cross Sections," of AES-C-1964-5. However, the through-wall dealloying of the samples inspected in 1994 demonstrated a plug-like nature and a correlation of OD crack angle to internal degradation was able to be reasonably established. It is the staff's position that continued use of the correlation requires that a maximum percent of cross-sectional layer-type dealloying be established and justified as an acceptance criterion.

PE or ACT results demonstrate that cracking has extended into the un-dealloyed region. AES-C-1964-5 sections 3.0, "Method of Approach," and 5.0, "Significance of Part-Through Cracks," assume that cracking does not extend into the un-dealloyed portion of a component.

Enclosure 1 NOC-AE-14003135 Page 17 of 98 Although under this scenario the specific component that had cracking extending into the un-dealloyed portion would have already been replaced, anyone or more of the hundreds of susceptible fittings could potentially have cracking of this nature. It is the staff's position that all susceptible components should be considered not capable of performing their intended functions until the cause of the extended cracking is understood, a new analysis curve is developed, and the existing degraded components are evaluated against the new analysis curve.

Request:

e) For the following test or inspection result outcome examples, state what specific actions would be taken and the basis for those actions. Amend the AMP, UFSAR Supplement, and Commitments to state the specific actions for these examples:

During a PE or ACTT a crack or degree of dealloying is discovered outside of the current correlation as shown on page 12 of AES-C-1964-5, "Evaluation of the Significance of Dealloying and Subsurface Cracks on Flaw Evaluation Method," In responding to this scenario, include a statement of how many additional fittings will be immediately examined, even though not leaking, to determine whether this is a one-off data point or whether there are many more susceptible fittings which have larger internal cracking or dealloying than would be projected from observing the through-wall indications on the OD. If no additional fittings will be immediately examined, state the basis for not conducting this expansion of inspection scope.

An ACT test result yields a data point below the size-appropriate acceptance curve (e.g., Figure 4-2, "Evaluation of Flange Bend Test Results," in AES-C-1964-5)

The evaluation of a newly-discovered leaking fitting results in a determination that the degraded component would not have been operable (i.e., the local critical bending stress is too high as compared to the observed external crack or dealloying angle).

PE or ACT results demonstrate a trend where, due to continuing dealloying, tensile strength, yield strength, or fracture toughness properties are projected to be below the acceptance criteria prior to the end of the PEO.

PE or ACT results demonstrate that layer-type dealloying predominates over plug-type, such that it is no longer possible to project internal degradation based on external observations. In addition:

State the step-by-step process an examiner will use, when conducting profile exams to determine the transition point between layer-type and plug-type dealloying and thereby derives the internal dealloying angle.

ii. State the acceptance criterion for the maximum percent of cross-sectional layer-type dealloying that will be allowed to occur within the use of the current methodology for determining the acceptability of a degraded component.

Enclosure 1 NOC-AE-14003135 Page 18 of 98

PE or ACT results demonstrate that cracking has extended into the un-dealloyed region.

STP Response:

The following actions outline the proposed approach for the overall strategic actions for test or inspection results:

STP will reevaluate operability determinations of all leaking components left in service, thereby assuring their structural integrity. These determinations will use the established material strengths limits.

STP will assess extent of condition for each case by:

1) immediate walkdown of all ECW systems in both units for identifying leaking components;

2) increased frequency of monitoring based on severity of condition;

3) implement periodic walkdowns;

4) expanded scope of ACT and PE, and

5) schedule repair and replacement activities, based upon the risk significance of the component (but will not defer action beyond the next refueling outage into which it may be scheduled). The expanded scope for each case is further described under specific actions considering severity of conditions identified.

The NRC staff is concerned that previous RAI responses did not adequately describe specific follow-on actions that would be taken when test or inspection results outside of the acceptance criteria are obtained. Due to the uncertainties associated with such hypothetical cases, STP provided limited responses describing the process that would be followed (i.e., results trended; an engineering evaluation performed; the condition documented in the corrective action program; and perform a deficiency-specific "Operational Decision-Making Issue" (ODMI)). An ODMI provides a method to document decisions considered in the disposition and handling of conditions identified by the station. Subsequently, the staff has requested that STP not only describe process steps that would be taken, but also to describe the specific actions that STP anticipates implementing. The process that is common to all actions is described below and is followed by potential deficiency-specific actions that pertain to the staff-described scenarios.

Process for Results Outside of Acceptance Criteria For all scenarios, STP will use its corrective action program. Every deficiency will require an immediate determination of operability, an assessment of the extent of condition, and the performance of an appropriate cause evaluation. Each activity will be conducted to assure that there is reasonable assurance that the station can continue to operate safety.

For all non-conforming ACTs and PEs conditions, STP will reevaluate the operability of all leaking components remaining in service; these re-evaluations will consider any new technical implications that are identified by the non-conforming test result. The overall structural integrity of ECW system and its ability to meet its intended design basis functions will be the primary criteria in these re-evaluations.

Enclosure 1 NOC-AE-1 4003135 Page 19 of 98 If structural integrity cannot be demonstrated, STP will either repair or replace affected components; in all instances, compliance with the STP Technical Specifications will be maintained.

Following are some of the typical steps that STP may implement as part of the ODM I.

- Document condition in Corrective Action Program. Where possible, include acceptance criteria and severity of condition (see specific details below for Staff described scenarios)

- Notify Control Room of identified condition(s)

- Perform an Immediate Operability Determination

- Enter Technical Specification, as required, if the ECW trains are determined to be inoperable

- Perform a Prompt Operability Determination, using assistance from the Engineering organization

- Implement immediate compensatory measures during any period of extended evaluation. Such measures could include:

o Operations would observe identified locations during each shift for potential leakages.

o System Engineers will immediately walk down all trains of the ECW system, in both units.

- Conduct an extent of condition evaluation and provide interim compensatory measures beyond those noted above, based upon the specific technical implications of the deficiency

- Develop a plan for long-term corrective actions that include changes to long-term ECW program and replacement of affected components.

STP would develop a deficiency-specific ODMI for these conditions, detailing specific steps, based on the severity and risk-significance of the conditions identified. Depending upon the severity (material conditions/ASME Safety Factors, potential impacts on plant safety, and risk significance), STP would remove additional components for further testing.

Request:

During a PE or ACT, a crack or degree of dealloying is discovered outside of the current correlation as shown on page 12 of AES-C-1964-5, "Evaluation of the Significance of Dealloying and Subsurface Cracks on Flaw Evaluation Method," In responding to this scenario, include a statement of how many additional fittings will be immediately examined, even though not leaking, to determine whether this is a one-off data point or whether there are many more susceptible fittings which have larger internal cracking or dealloying than would be projected from observing the through-wall indications on the (OD). If no additional fittings will be immediately examined, state the basis for not conducting this expansion of inspection scope.

Enclosure 1 NOC-AE-14003135 Page 20 of 98 STP Response:

STP uses a correlation to size internal flaws/cracks that are not able to be measured using volumetric examinations. STP measures the internal flaw length following removal of the component during PEs and compares it to the estimated ID crack length as originally estimated using the correlation. The average crack length is determined by averaging the measured outside and inside diameter lengths.

Acceptance Criteria:

1. Load Carrying Capacity: ACT results results show a higher load capacity than the predicted load carrying capacity.

2. Determination of ID Crack Length: The measured ID crack length is less than 110% of correlation estimated ID crack length.

If acceptance criterion are not met, the severity of the condition will be determined.

Severity of Condition:

The following ASME Section Xl Appendix H or C safety factors determine severity levels. The safety factors are recalculated using.the average crack length to determine severity.

Severity NormallUpset Emergency /Faulted Number of Level Condition Condition Additional Tests II SF < 1.5 SF < 1.2 2 ACTs on sister component from remaining trains 5 PEs I SF > 1.5 SF > 1.2 1 ACTs and and 3 PEs SF < 2.77 SF < 1.39 If the recalculated safety factors are within the ASME Code allowed limits, no additional actions are required other than precautionary actions intended to address the extent of condition as shown in the following Decision Flowcharts.

Enclosure 1 NOC-AE-14003135 Page 21 of 98 Exclusive OR 0 OR 0 AND Function

Enclosure 1 NOC-AE-14003135 Page 22 of 98 Follow Process Path 'A' /

Common Steps (PO) Specific Steps Initiate Conditi on Report Notify Control R Room

" Immediate/Pro mpt Operability Determinations (PE to Recommend)

Select 1 Additional Components

" Technical Speci from Sister Trains for 1 ACT and Warranted 3 PE

Implement Ren sedial Measures as Recommended y PBais ona P Perform Causal Analysis

-ECWS Walkdown by PE onalkdwn a wekl weekly Basis 4- - 1

Drive Closure to ODMI Tasks; 4( .....

- Daily wa

- Apparen tkdown of leaking components by PE Add additional Tasks As Warranted

- Extent o Condition by PE f Repair/Replacement ate Rondiir/Replace b t Evaluate additional Rcmedn uteTest Results cin

- Immedia Recomme endations by PE; Long term Recommending Further Actions recomme ndation to follow Causal Analysis

" Develop Detaileed ODMI to Follow (PE in consultat ion with Plant Personnel)

XOR Update ECW Move to Program Severity Level II

Enclosure 1 NOC-AE-14003135 Page 23 of 98 Notify Control Room For Notify Control Potential Entry Room Potential to Tech. Spec.

Entry to Tech.

Spec.

--

4,

ECWS Operability Indeterminate. PE to Evaluate Operability of All Leaking Components Left in Service

Notify Control Room if Component Determined Not Operable For Tech. Spec. Required Action

Continue with Enhanced Monitoring BY Both PO and PE

Continue Monitoring of Leak Rate for all Leaking Components

Continue Implementation of ODMI Including

- Perform Causal Analysis

- Extent Of Condition

- Additional ACT/PE Tests (All Sister Components (S Total) and Randomly Selected 3 Additional Components. Minimum of 5 ACT plus 12 PE to be performed)

Develop and Implement Long Term Corrective Actions

- Update ECW Program

-Update Co-relation

-Update Analytical Model

- Update Material Properties

- Systematic Replacement of Suspect Components

- Relief Request

- AMP/UFSAR Update

Enclosure 1 NOC-AE-14003135 Page 24 of 98 Request:

An ACT test result yields a data point below the size-appropriate acceptance curve (e.g., Figure 4-2, "Evaluation of Flange Bend Test Results," in AES-C-1964-5)

STP Response:

An ACT data point below the size-appropriate acceptance curve suggests either analytical methods over-predict the load carrying capacity or factors other than dealloying affect test results. STP will perform a causal analyses to determine why the ACT yielded a data point below the size-appropriate curve. STP will develop an ODMI with specific actions based on severity of identified conditions. Additional ACTs and PEs may be required to determine if reduced material strengths or the fracture -toughness appear to be the cause. The sister components and one randomly selected component from the affected train (total of 6 additional components) will be tested. Additionally, STP will reevaluate operability determinations of all leaking components still in service.

Acceptance Criteria:

S The ACT pressure > hydro test pressure (125% of Design Pressure ~ 150 psi) 0 Bending load > 125% of applied loads (unintensified Eq. 9D ASME code stresses)

Severity of Condition:

The below listed criteria determines the severity levels.

Severity Criteria Number of Components to be Level Tested II The ACT pressure < hydro test pressure 5 ACTs sister component from (125% of Design Pressure - 150 psi) remaining trains and 1 ACT randomly selected Bending load < 125% of applied loads component from affected train (unintensified Eq. 9D stresses 8 PEs The ACT pressure < hydro test pressure 3 ACTs (125% of Design Pressure - 150 psi) 5 PEs or Bending load < 125% of applied loads (unintensified Eq. 9D stresses Specific remedial measures are based on severity as recommended by the following Decision Flowcharts.

Enclosure 1 NOC-AE-14003135 Page 25 of 98 Reevaluate Operability Using Measured Average Crack Length To Confirm ASME Safety Factors

ýV

Enclosure 1 NOC-AE-14003135 Page 26 of 98 Follow Process Path 'A' A

Notify Control Room Recommend)

Implement Initiate Condition Report

.....

Immediate/Prompt Operability Determinations (PEto Technical Specification Entry Actions When Warranted i Implement Select3AdditionalComponents from Sister Trains for 3 ACTand fro Sise rTanfo3ACad 5Perorm Causal Analysis Implement Remedial Measures as Recommended PeDriveClosure to ODMI Tasks.

- ECWSWalkdown by PE on a weekly Basis

- - - Add additional Tasks Aspr of leaking components byPO CuebFEWrat

-Daily walkdown

-Apparent Cause by PEWrane

-Extent of Condition by PEWarne Evaluate additional Test Results Immediate Repair/Replacement Recommending Further Actions Recommendations by PE; Long term recommendation to follow Causal Analysis Develop Detailed ODMI to Follow (PE in consultation with Plant Personnel)

XOR Update EC

Enclosure 1 NOC-AE-14003135 Page 27 of 98 Notify Control Room For Notify Control Potential Entry Room Potential to Tech. Spec.

Entry to Tech.

Spec.

--I-

" ECWS Operability Indeterminate. PE to Evaluate Operability of All Leaking Components Left in Service

Notify Control Room if Component Determined Not Operable For Tech. Spec. Required Action

" Continue with Enhanced Monitoring BY Both PO and PE

" Continue Monitoring of Leak Rate for all Leaking Components

Continue Implementation of ODMI Including

- Perform Causal Analysis

- Extent Of Condition

- Additional ACT/PE Tests (All Sister Components (5 Total) and Randomly Selected 1 Additional Components. Minimum of 5 ACT plus 8 PE to be performed)

Develop and Implement Long Term Corrective Actions

- Update ECW Program

-Update Co-relation

-Update Analytical Model

- Update Material Properties

- Systematic Replacement of Suspect Components

- Relief Request

- AMP/UFSAR Update

Enclosure 1 NOC-AE-14003135 Page 28 of 98 Request:

The evaluation of a newly-discovered leaking fitting results in a determination that the degraded component would not have been operable (i.e., the local critical bending stress is too high as compared to the observed external crack or dealloying angle).

STP Response:

The structural integrity of the ECW system provides a safety-related design basis functions that is paramount for the safe continued operation of both STP units. If structural integrity cannot be demonstrated, STP will either repair or replace affected components.

Request:

PE or ACT results demonstrate a trend where, due to continuing dealloying, tensile strength, yield strength, or fracture toughness properties are projected to be below the acceptance criteria prior to the end of the PEO.

STP Response:

STP will monitor material properties of Aluminum Bronze coponents to ensure that they do not fall below the acceptance criteria prior to the end of the PEO, and will be trending these properties through the use of PEs. The PE data from all leaking dealloyed components will be added to the trend projection curves using a regression methodology. The magnitude of adverse trend is measurable and the updated properties will be used to estimate structural integrity of those affected components.

STP will monitor adverse trends and implement corrective measures (including replacement of affected components) before structural integrity of the ECW system is challenged. These measures include the following:

Engineering evaluation of the remaining components determined to be at risk,

" Enhanced monitoring and non-destructive /or destructive examinations program,

Perform additional ACTs and PEs performed (approximately 5 ACTs and 18 PEs),

Updated critical bending stress curves found in AES-C-1964-1,

" Systematic replacement of components determined to be at risk,

PSALBZ "ECW Aging Management Program" reviewed and updated to incorporate resulting information, and

Notification to the NRC of pertinent changes to ECW program.

CriteriaDefining Adverse Trend:

A decrease of 100% dealloyed material strengths and fracture toughness by 15% will be considered an adverse trend. The 15% is selected because the estimated variation of yield strength from mean (based on 0.2% yield strength test data) is approximately 4.1 ksi. which is equivalent to 15% of the lowest measured material strength.

Enclosure 1 NOC-AE-14003135 Page 29 of 98 Number of components to be tested:

3 ACTs and 12 PEs from randomly selected components will be performed. If these tests demonstrate an adverse trend, an additional 5 ACTs and 18 PEs will be performed.

Severity of Condition:

The deviation in the post-test material properties will determine severity levels.

Severity Acceptance Criteria Number of Probable Actions Level Components to be Tested 11 Continued deviation more 5 ACTs and - Enter Technical Specification.

than 15% from previously 18 PEs - Notify Control Room.

measured properties (from randomly - Seek temporary relief from the NRC for severity I tests) for 100% selected continued operation until root cause can dealloyed material component be determined from affected train More than 15% deviation 3 ACTs - Enter Technical Specification.

from previously measured 12 PEs - Notify Control Room.

properties for 100% - Seek temporary relief from the NRC for dealloyed material continued operation until root cause can be determined.

- Additionally tests are required to confirm potential entry to Severity Level II Specific remedial measures are based on severity as recommended by the following Decision Flowchart.

Enclosure 1 NOC-AE-14003135 Page 30 of 98 Reevaluate Operability Using Recently Tested Material Property To Confirm ASME Safety Factors V

Enclosure 1 NOC-AE-14003135 Page 31 of 98 Follow Process Path 'A' Common Steps " (P) """ Specific Steps Initiate Condition Report Notify Control Room Immediate/Prompt Operability Determinations (PEto i

Recommend)

Select 3 Additional Components Technical Specification Entry Actions When from Sister Trains for 3 ACTand 12 PE Warranted Implement Remedial Measures as Recommended 1Perform Causal Analysis

- ECWS Walkdown by PEon a weekly Basis - - - . Drive Closure to ODMITasks; components byPO Drive AddaddiioalnT Tasks Closureitionalaskd A ; ....

Daily walkdown

- -Apparent by leaking Cause of PE

-Extent of Condition by PEWarne immediate Repair/Replacement

Evaluate additional Test Results Recommendations by PE; Long term Recommending Further Actions recommendation to follow Causal Analysis Develop Detailed ODMI to Follow (PE in consultation with Plant Personnel)

Enclosure 1 NOC-AE-14003135 Page 32 of 98 Notify Control Room Potential Entry to Tech.

Spec.

I-T -

" ECWS Operability Indeterminate. PE to Evaluate Operability of All Leaking Components Left in Service

" Notify Control Room if Component Determined Not Operable For Tech. Spec. Required Action

Continue with Enhanced Monitoring BY Both PO and PE

" Continue Monitoring of Leak Rate for all Leaking Components

" Continue Implementation of ODMI Including

- Perform Causal Analysis

- Extent Of Condition

- Additional ACT/PE Tests (All Sister Components (5 Total) and Randomly Selected 3 Additional Components. Minimum of 5 ACTs plus 18 PE to be performed)

- Develop and Implement Long Term Corrective Actions

- Update ECW Program

-Update Co-relation

-Update Analytical Model

- Update Material Properties

- Systematic Replacement of Suspect Components

- Relief Request

- AMP/UFSAR Update 9

Enclosure 1 NOC-AE-14003135 Page 33 of 98 Request:

PE or ACT results demonstrate that layer-type dealloying predominates over plug-type, such that it is no longer possible to project internal degradation based on external observations. In addition:

L. State the step-by-step process an examiner will use, when conducting profile exams to determine the transition point between layer-type and plug-type dealloying and thereby derives the internal dealloying angle.

ii. State the acceptance criterion for the maximum percent of cross-sectional layer-type dealloying that will be allowed to occur within the use of the current methodology for determining the acceptability of a degraded component.

Request:

PE or ACT results demonstrate that layer-type dealloying predominates over plug-type, such that it is no longer possible to project internal degradation based on external observations.

STP Response:

The predominant type of dealloying observed is a combination of plug and layer dealloying occurring simultaneously. Exclusive layer type dealloying has not been observed because when a component casting cools, the casting does not cool at a uniform rate. Therefore, the phase structure throughout the component body is not identical.

An "Operational Decision-Making Issue" will be developed to further investigate and implement corrective measures for any component that demonstrates predominate layer-type dealloying.

The investigation may require additional destructive examinations. Remedial measures may include increased monitoring, or more frequent examinations to replacement effected components. The analytical methodology may also have to be reevaluated and updated as necessary.

Request:

State the step-by-step process an examiner will use, when conducting profile exams to determine the transition point between layer-type and plug-type dealloying and thereby derives the internal dealloying angle.

STP Response:

The following provides the step-by-step process used to conduct a profile exam:

The component is sectioned at the plane of externally observed dealloying.

The sectioned surface is etched with Silver Nitrate solution, which distinguishes the dealloyed areas.

The section is photographed for measuring subareas (manual or digital) of the dealloyed sectional surfaces.

Enclosure 1 NOC-AE-14003135 Page 34 of 98

The angle of the outside flaw along the OD is constructed from the measured length of the through-wall flaw.

The angle for the extent of the internal flaw is determined where non de-alloyed metal begins.

For situations where some amount of layer dealloying exists at the through wall penetration, then a transitional measurement for the internal flaw angle is determined at the point where the layer is approximately 50% of the wall thickness.

" The average flaw length is then determined by averaging the OD and internal flaw angles.

Request:

ii. State the acceptance criterion for the maximum percent of cross-sectional layer-type dealloying that will be allowed to occur within the use of the current methodology for determining the acceptability of a degraded component.

STP Response:

The acceptance criterion for a dealloyed component is a component that does not leak. Non-leaking components average 60% through-wall thickness dealloying before leaking occurs. The distribution of sampled aluminum bronze fittings for STP Unit 1 is plotted in figure 2.5 (Ref. STP Letter to the NRC ST-HL-AE-2748 dated November 1, 1988, Attachment 2, Page 38 of 58). All components that were dealloyed more than 60% through their cross sections developed leaks.

When the PE determines that average dealloyed wall thickness exceeds 60% and sufficient material is available for preparation of a test coupon, mechanical properties will be obtained.

The resulting test data will then determine impact on previously performed operability and potential impact on the ECW program.

Request:

PE or ACT results demonstrate that cracking has extended into the un-dealloyed region.

STP Response:

The scenario assumes part of a circumferential crack is extending into undealloyed base material. The likely conditions that could cause crack tip to extend into undealloyed base material are as follows:

" Physical crack existed through dealloyed material,

The crack growth occurred through dealloyed material because of conducive environment and/or applied loads, or

The crack now extends through undealloyed material mainly because of applied loading.

The crack may have penetrated through minimum required wall thickness resulting in excessive primary membrane stresses and a potential to tear through the wall thickness.

The layered geometry of dealloying is not uniform through the component cross section.

Dealloying without cracks has sufficient material strength to sustain applied loads.

It is reasonable to conclude that the crack pre-existed in the component.

Enclosure 1 NOC-AE-14003135 Page 35 of 98 It is also reasonable to assume that a crack extending through base material will be limited to a deeply penetrated segment of dealloyed area and not through entire dealloyed cross section of component. The local leakage resulting from such crack will be identified through the monitoring program.

STP performs ACTs and PEs through the PEO allowing timely identifications and implementations of corrective measures as follows:

" Engineering evaluation of the remaining components determined to be at risk,

" Enhanced monitoring, and destructive examination program,

Perform additional ACTs and PEs performed (Approximately 5 ACTs and 18 PEs),

Updated critical bending stress curves found in AES-C-1964-1,

Systematic replacement of components determined to be at risk.

PSALBZ "ECW Aging Management Program" reviewed and updated to incorporate resulting information, and

Notification to the NRC of pertinent changes to ECW program.

CriteriaDefining Adverse Trend:

One non-leaking component PE exhibiting all below listed characteristics:

Presence of layered dealloying throughout the circumference of component section.

Average thickness of layered dealloying exceeds 60% through wall thickness

" Presence of circumferential crack in the dealloyed layer. Average crack angle (2E) to be less than 70 degrees

Crack Depth penetrates undealloyed base material at least 20% of remainder undealloyed thickness at crack tip location Severity of Condition:

Crack penetration length will determine severity levels.

Severity Acceptance Criteria Number of Probable Action Level Components to be Tested 11 Length of ID crack 5 ACTs and - Enter Technical Specification exceeds 70 degrees (20) 18 PEs - STP may seek temporary relief from and has penetrated at randomly the NRC for continued operation until least 20% of base material selected root cause can be determined component from affected train Length of ID crack is NOT 3 ACTs - Enter Technical Specification exceeding 70 degrees 12 PEs - Notify Control Room (2W) and penetration in - Seek temporary relief from the NRC base material is less than for continued operation until root 20% of base material cause can be determined

- Additionally tests are required to confirm potential entry to Severity Level II Specific remedial measures are based on severity as recommended by the following Decision Flowcharts.

Enclosure 1 NOC-AE-14003135 Page 36 of 98

-A XOR Follow Process Path

'A' Update ECW Program Follow Prcs Paths 'B'

Enclosure 1 NOC-AE-14003135 Page 37 of 98 Follow Process Path 'A'

- . Initiate Condition Report Notify Control Room

_U

Immediate/Prompt Operability Determinations (PEto Recommend) Select 3 Additional Components

" Technical Specification Entry Actions When from Sister Trains for 3 ACTand fo Per T f Warranted 12 FE)

" Implement Remedial Measures as Recommended Perform CausalAnalysis

- ECWSWalkdown by PEon a weekly Basis - - - - e Drive Closure to ODMI Tasks; ......

-Daily walkdown of leaking components byPO Add additional Tasks As Apparent Cause by PE Warranted Extent of Condition by PE Evaluate additional Test Results

- Immediate Repair/Replacement Recommending Further Actions Recommendations by PE; Long term recommendation to follow Causal analysis

" Develop Detailed ODMI to Follow (PE in consultation with Plant Personnel)

XDR

Enclosure 1 NOC-AE-14003135 Page 38 of 98 Notify Control Room Potential Entry to Tech.

Spec.

--I-ECWS Operability Indeterminate. PE to Evaluate Operability of All Leaking Components Left in Service Notify Control Room if Component Determined Not Operable For Tech. Spec. Required Action Continue with Enhanced Monitoring BY Both PO and PE Continue Monitoring of Leak Rate for all Leaking Components Continue Implementation of ODMI Including

- Perform Causal Analysis

- Extent Of Condition

- Additional ACT/PE Tests (All Sister Components (5 Total) and Randomly Selected 3 Additional Components. Minimum of 5 ACTs plus 18 PE to be performed)

- Develop and Implement Long Term Corrective Actions

- Update ECW Program

-Update Co-relation

-Update Analytical Model

- Update Material Properties

- Systematic Replacement of Suspect Components

- Relief Request

- AMP/UFSAR Update

Enclosure 1 NOC-AE-14003135 Page 39 of 98 Issue:

f) The staff has questions regarding how field observations of leaking degraded components are used in conjunction with the analytical output of AES-C-1964-1, "Calculation of Critical Bending Stress for Dealloyed Aluminum-Bronze Castings in the ECW System," and the existing pipe stress analyses in order to analyze for structural integrity as it relates to the component performing its intended function. In particular, the staff has concerns related to:

In the correlation in AES-C-1964-5, the observed OD crack angle is used to derive an average through-wall dealloying angle. However, the critical bending stress curves in AES-C-1964-1 use a crack angle, not an average through-wall dealloying angle. The staff lacks sufficient information to be able to understand the link between the correlation and its use in the critical bending stress curves. Note that the response to RAI B2.1.37-4, Enclosure 1, page 3 of 9, incorrectly characterizes the correlation, "[t]he examination results were used to establish a correlation between length of a flaw on the outer diameter and the size of any internal crack and the extent of the dealloyed region of the component."

Also, it is not clear to the staff why an average angle would be used when Figures C-2200-1, "Flaw Characterization-Circumferential Flaws," and C-4310-1, "Circumferential Flaw Geometry," of ASME Code Section X1, and Figure 5-1, "Circumferential Flaw Geometry -Net Section Collapse Model," of AES-C-1964-1 use the inside dimensions of the flaw.

The staff plotted the OD and inside diameter (ID) crack and dealloying angle data from Section 4.1, "Metallurgical Data," of AES-C-1964-5 (i.e., dealloyed OD vs.

dealloyed ID and crack OD vs. crack ID). Two crack data points and three dealloying data points fell outside (nonconservative) of the correlation. If it is not appropriate to use an average through-wall dealloying angle, a new correlation using inside dimensions will need to be developed. The staff lacks sufficient information to understand whether such a new correlation could affect the structural integrity determination of recently degraded components, and by extension, degraded components discovered during the PEO.

" The wording of the response to part (e) of RAI B2.1.37-3 is not clear on what minimum structural factor will be used for the normallupset conditions and emergency and faulted conditions.

" It is not clear to the staff how external dimensions of the indication are sized. For example, when an indication consists of a crack within a larger dealloyed region, it is not clear which feature is measured. Also, it is not clear how a singular rounded (surface) indication, or multiple in-line rounded (surface) indications, are characterized.

Enclosure 1 NOC-AE-14003135 Page 40 of 98 It would appear that, based on the external dimensions of the flaw, an average flaw angle is developed based on the AES-C-1964-5 correlation and used as input into the critical bending stress analyses in AES-C-1964-1, regardless of whether the through-wall degradation is dealloying with no crack, a part-through crack with dealloying, or through-wall crack with dealloying. However, the staff seeks confirmation that this is correct. The responses to the scenario-based questions in the request should resolve this issue

Given the ambiguities between the calculations, it is not clear to the staff that the steps in a structural integrity determination of a degraded susceptible aluminum bronze component in the essential service water system can be consistently performed without a procedure. In addition to the ambiguities, based on plant-specific OE, consistent performance is also challenged since these evaluations are conducted infrequently.

Request:

State:

Why an average through-wall dealloying angle is the output of the correlation in AES-C1964-5 rather than the inside wall dimension.

" How the correlation from AES-C-1964-5 will be modified if use of the average dealloying angle is not appropriate. Additionally, reconsider the structural integrity evaluation for any degraded components discovered since 2011 and state whether the components would still be considered to meet structural integrity criteria (using this modified correlation) and therefore would still be capable of performing their intended function with the new correlation.

" Whether the structural factor for the normal/upset conditions will always be at least 2.77, and for emergency and faulted conditions at least 1.39. If not, state what the minimum structural factors would be and the basis for the values being less than those stated in ASME Code Section XI.

" For the four scenarios of OD observed degradation below:

L. Four small rounded indications of through-wall dealloying located in a circumferential axis at 10:00, 11:00, 1:00, and 2:00 on a 10-inch flange.

ii. One indication at 10:00, one-half inch long, with what appears to be rounded ends and no measurable width on a 4-inch flange.

iii. One "greenish" stain approximately 1/8 inch diameter at the 10:00 position on a 6-inch flange.

iv. One crack-like indication, one-half inch long, within a larger greenish stain with a circumferential length of one inch.

Enclosure 1 NOC-AE-14003135 Page 41 of 98 State:

" the size of the OD flaw

" the corresponding size of the internal flaw that would be used in the structural integrity determination

which figure would be used from AES-C-1964-1

the stress component input values that would be utilized from the highest stress location in the essential service water system with susceptible components for that size as obtained by the stress analyses on record and how they would be combined in the structural integrity determination

what structural factor will be used

the critical bending stress as derived from the figures in AES-C-1964-1 whether the component would be considered to be capable of meeting its intended function What site procedure provides step-by-step instructions for determining the structural integrity of a degraded susceptible aluminum bronze component in the essential service water system? If no such procedure is currently used, state the basis for why it is acceptable to have the staff completing the evaluation steps in the absence of written instructions.

Request:

Why an average through-wall dealloying angle is the output of the correlation in AES-C-1964-5 rather than the inside wall dimension.

STP Response:

The average through-wall dealloying angle is used to estimate flaw length. This approach is comparable to one described in NRC GL 90-05 where flaw length is estimated at the required minimum thickness (tmin).

ASME Section Xl Appendix H, Figure H-2200-1 'Flaw Characterization - Circumferential Flaws' depicts flaw length 'T at front tip of the crack 'a' through thickness 't'. Note staff reference ASME Section Xl, Appendix C figure C-2200-1, 'Flaw Characterization-Circumferential Flaw' is identical to Appendix H figure H-2200-1. ASME Section Xl, Appendix C, Figure C-4300-1,

'Circumferential Flaw Geometry' has no specific length shown. The length 'T'is defined as general flaw length dimension in a nomenclature of Appendix C.

Using the average through-wall angle provides an estimate of the through-wall flaw length used in the analysis described in AES-C-1964-5. The critical bending stress curves developed in the APTECH calculation AES-C-1964-1 provide a tabulated solution to limit load; additionally, fracture analysis equations are included for quick reference. The evaluating engineer is still responsible for determining appropriate crack angle (e/Tr), based on conditions observed in the field.

Enclosure 1 NOC-AE-14003135 Page 42 of 98 Request:

How the correlation from AES-C-1964-5 will be modified if use of the average dealloying angle is not appropriate. Additionally, reconsider the structural integrity evaluation for any degraded components discovered since 2011 and state whether the components would still be considered to meet structural integrity criteria (using this modified correlation) and therefore would still be capable of performing their intended function with the new correlation.

STP Response:

Use of average through-wall angle is appropriate because it has provided adequate estimates of flaw lengths to date. The correlation was based on test data gathered from previously sectioned components, and is representative of the average through-wall angle described previously.

STP identified OD and ID measured crack lengths from five additional components (1-24" and 4-30" Diameter Pipe size). The existing correlations shown in Figure 4.1 in APTECH calculation AES-C-1 964-5 bound these five components. Additional information obtained from future PEs will be compared to Figure 4.1 "Correlation between through wall cracks and through wall dealloying", found in AES-C-1964-5. When warranted, the correlation that bounds the PE data will be updated.

Request:

Whether the structural factor for the normal/upset conditions will always be at least 2.77, and for emergency and faulted conditions at least 1.39. If not, state what the minimum structural factors would be and the basis for the values being less than those stated in ASME Code Section Xl.

STP Response:

The ASME Code Section XI structural factors for the normal/upset conditions (2.77) as well as the emergency and faulted conditions (1.39) will be applied when determining operability for components with dealloyed conditions. Whenever ASME Section XI structural factors can not be met, a ODMI will be developed to address non-conforming condition using process similar to one described under issue 'e' above. ASME Section XI structural factors below 1.0 will require immediate repair or replacement of leaking component.

Request:

For the four scenarios of OD observed degradation below:

L Four small rounded indications of through-wall dealloying located in a circumferential axis at 10:00, 11:00, 1:00, and 2:00 on a 10-inch flange.

ii. One indication at 10:00, one-half inch long, with what appears to be rounded ends and no measurable width on a 4-inch flange.

Enclosure 1 NOC-AE-14003135 Page 43 of 98 iii. One "greenish" stain approximately 1/8 inch diameter at the 10:00 position on a 6-inch flange.

iv. One crack-like indication, one-half inch long, within a larger greenish stain with a circumferential length of one inch.

STP Response:

Attachment D presents the methodology and a sample calculation that demonstrates how APTECH calculation AES-C-1964-1 estimates critical bending stresses. The sample calculation is provided for Case i and includes all equations used. Following the same methodology, the results of all four cases requested above are summarized in APTECH calculation AES-C-1964-1 Table 1, "Evaluation Summary". The information requested is organized by columns for each case.

(Note: The scope of the current version of the APTECH calculation is limited to commonly observed dealloying cases and pipe sizes 3 inches and larger.)

STP uses the ASME Code recommended methodology that include different acceptable variations such as: when considering Case i, the four flaws could be analyzed in two different ways. First, the evaluation could treat them as four independent flaws; alternatively, they could be combined into two flaws by combining the data at positions 10 and 11, and 1 and 2. The station then calculates the neutral axis and critical bending stresses using equations published in the following references.

References:

1. Failure Bending Moment for Pipe With an Arbitrary-Shaped Circumferential Flaw, authored by Yinsheng Li, Kunio Hasegawa, Akira Shibuya, and Nathaniel Cofie.

Published in a Journal of Pressure Vessel Technology dated August 2011, Volume 133.

2. Prediction of Collapse Stress for Pipes With Arbitrary Multiple Circumferential Surface Flaws, authored by Yinsheng Li, Kunio Hasegawa, Akira Shibuya, and Nathaniel Cofie. Published in a Journal of Pressure Vessel Technology dated December 2010, Volume 132.

3. Net Section Plastic Collapse Analysis of Two-Layered Materials and Applications to Weld Overlay Design, authored by Arthur F.

Deardorff,

Nathaniel Cofie, David G.

Dijamco, and Aparna Chintapali. Published ASME PVP 2006 Pressure Vessel and Piping Conference July 2006.

Issue:

g) The staff also seeks the following information to complete its evaluation of the proposed AMP:

" A list of the number of remaining susceptible components, broken down by size.

" A copy of AES-C-1964-4, "Evaluation of 6-Inch Flange Test," submitted on the docket.

" An update on leaking components that have occurred since July 28, 2011, the last entry in Table 1, "ECW De-Alloying Data," of the response to RAI B2.1.37-1.

Enclosure 1 NOC-AE-14003135 Page 44 of 98

" The results of the leak rate analysis stated in Commitment No. 46, in response to RAI B2.1.37-4 Issue 5.

" The "scope of program" and "parameters monitored or inspected" program elements of the Selective Leaching of Aluminum Bronze program state, "components greater than one inch will be replaced by the end of the subsequent refueling outage." The staff noted that UFSAR Section 9A, "Assessment of the Potential Effects of Through-Wall Cracks in ECWS Piping," states, in part, that relief requests are submitted when leaks are identified except for, "leaks in lines 1 inch or under which are exempt from ASME Code Section Xl replacement rules."

The staff cannot find a basis for allowing one inch and under lines to have repair or replacement times extend beyond the subsequent refueling outage.

" Request:

g) Provide the following:

" A list of the number of remaining susceptible components broken down by size.

This list is required for the staff to conduct an independent review of the analytical output information in relation to flaw size tolerance.

" A copy of AES-C-1964-4, "Evaluation of 6-Inch Flange Test." This calculation will be used by the staff as input to determine the acceptability of the proposed aging management program and, therefore, should be on the docket.

" An update to Table 1 of the response to RAI B2.1.37-1 to reflect leaking components that have occurred since July 28, 2011.

" The basis for why 1-inch and under lines are not replaced by the end of the subsequent outage. Also, state the basis for why 1-inch and under lines can be demonstrated to meet their intended function prior to replacement STP Response:

" A listing of the number of susceptible components, collated by size, is provided as Attachment A.

" A copy of AES-C-1964-4, "Evaluation of 6-Inch Flange Test," Is provided as Attachment B.

" An update to Table 1 of the response to RAI B2.1.37-1, reflecting leaking components that have occurred from July 28, 2011, through the end of 2013, is provided as Attachment C.

The results of the leak rate analyses referenced in Commitment No. 46, in response to RAI B2.1.37-4 Issue 5, are provided as Attachment E.

Enclosure 1 NOC-AE-14003135 Page 45 of 98 UFSAR Section 9A, "Assessment of the Potential Effects of Through-Wall Cracks in ECWS Piping," states, in part, that relief requests are submitted when leaks are identified except for, "leaks in lines 1 inch or under which are exempt from ASME Code Section Xl replacement rules." Change Notice CN-3073 revised the UFSAR, removing the relief request exemption for leaks in lines, 1" and below.

LRA Appendices A1.37 and B2.1.37, and LRA Basis Document PSALBZ (B2.1.37), are revised to document that STP will replace leaking components by the next refueling outage.

Enclosure 1 NOC-AE-1 4003135 Page 46 of 98 Attachment A List of the susceptible components, broken down by size.

Enclosure 1 NOC-AE-14003135 Page 48 of 98 Attachment B Calculation AES-C-1964-4, "Evaluation of 6-Inch Flange Test,"

APTECH Project AES 93061964-1Q (June 3, 1994).

Enclosure 1 NOC-AE-14003135 Page 49 of 98 CALCULATION COVER SHEET S T- 7Z- W* -o 7ooo "pirki w,,cr *> ,- "?

Document No.: AES-C-1964-4 Client: Houston Lighting and Power Company Title: Evaluation of 6-Inch Flange Test Project No.: AES 93061964-IQ APTECH Office: Sunnyvale Sheet No. 1 of 31 Purpose: The purpose of this calculation is to evaluate the pressure test and bend test data for a 6-inch aluminum-bronze cast flange.

Assumptionsc See Section 2.0 for major assumptions.

Results: The pressure test results indicate the flange was able to carry at least 4.4 times the design pressure in its degraded condition without failure. The bend test results indicate the bending stress to fail the flange was 23.3 ksi. This stress value exceeded the predicted critical bending stress calculated for the flange geometry. Therefore, the flaw evaluation method for calculated critical bending stress is conservative.

Prparcd Chocked VcfiIed Approved By: By: By: By:

Revision Revision Description No.: Date: Date: Date: Data:

0 -Yin-- ^ _Z 'At/ _-SJ_

OAEI7 MAPT-11-cur ENOMRLMO GERVIOM W_

REV. 908

Enclosure I NOC-AE-14003135 Page 50 of 98 ENGINEFRINQ 8M10VICE8 M4.

Made by: Date: Client:

Document No.: AES-C-1964-4 e iL&P Checked by: Date: Project No.:

Tide: Evaluation of 6-Inch Flange Test , Mki* AES 93061964-10 Revision No.: Sheet No.:

0 2 of 31 TABLE OF CONTENTS Section Title Pape

1.0 INTRODUCTION

3 2.0 ASSUMPTIONS 4 3.0

SUMMARY

OF TEST PROCEDURE 5 3.1 Test Geometry 5 3.2 Pressure Test Procedure 8 3.3 Bend Test Procedure 8 4.0 PRESSURE TEST RESULTS 10 5.0 BEND TEST RESULTS 13 6.0 COMPARISON OF CALCULATED AND MEASURED 18 CRITICAL BENDING STRESS 6.1 Summary of Post Test Measurements 18 6.2 Calculated Critical Bending Stress 20 7.0

SUMMARY

OF CONCLUSIONS 23

8.0 REFERENCES

24 APPENDIX A - Calculation of Critical Bending Stress for 25 6.Inch NPS Casting Under Pure Bending QAE17 REV. 9988

Enclosure 1 NOC-AE-14003135 Page 51 of 98 WA P'lrECW Document No.: AES.C.1964-4 Mae by- ""711#3 Dale. HL&P C

Client:

Chrckcd by, Date: Projec No.-

Title: Evaluation of 6-Inch Flange Test tO ftllvf 1I AES 93061964.1Q Revision No.: Sheet No.:

0 3 of 31

1.0 INTRODUCTION

A 6-inch flange was pressure tested (hydrotest) and tested in three-point bending by HL&P to establish the structural capacity of cast aluminum bronze (AI-Bionre) castings in a service-degraded condition. The flange was previously removed from service due to dealloying and leakage from a through-wall crack. The dealloying/crackingwas located at the weld region of the flange and ran circumferentially around the casting.

The pressure test was performed on a flange/pipe assembly. The flangepipe assembly was comprised of two flanges bolted together with two short pipt segments that were capped at each end. The internal surface was coated with a thin layer of Belzona to prevent the crack from leaking at low pressures. The flange/pipe assembly was internally pressurized (hydrotested) until the flange leaked. The flange/pipe assembly was then depressurized and loaded in three-point bending until failure. The purpose of this calculation is to evaluate the test results and to compare the final failure bending load to the predicted failure load from the fracture mechanics model developed for circumferentially flawed Al.Bronze castings (j).

The principal results of the test were recorded manually (2). Strain gage and pressure transducer data were recorded electronically and stored on disk (2). Fabrication of the test assembly, installation of strain gages and prcs3ure sensors, recording of signals, and testing wicm all piwfuormd by HL&P contract personnel.

QAE17 REV. 9S8,

Enclosure 1 NOC-AE-1 4003135 Page 52 of 98 NRNPTG CHu ENGINEERING SERVICE&, NO.

Mad b"y: Dale: Client:

Document No.: AES-C-1964-4 A*-IV&/P& HLIP Chocked by: Date: Project No.:

Title: Evaluation of 6-Inch Flange Test I Mft/ql AES 93061964-_Q Revision No.: Shoot No.:

0 4 of 31 2.0 ASSUMPTIONS The following assumptions are used in the evaluation of test results:

1. Beam theory was used to determine the bending moment and stress in the flange-pipe test assembly.

2. The different material properties between the steel and Al-Bronze segments of the flange-pipe assembly were ignored. These differences will have little or no effect on the stress determination at the plane of interest.

3. In the evaluation of the bend test results, the effect of the part-through crack was conservatively ignored.

QAE17 RIEV. 9Jsa

Enclosure 1 NOC-AE-14003135 Page 53 of 98 ENGINEERING SERVICES, INC.

Mab: Date: Client:

Document No.: AES-C-19644 /eL&/9 A3 JH y1L&P Checked by: Dale: Project No.:

Title: Evaluation of 6-Inch Flange Test t11 MW01 AES 93061964-IQ Revision No.: Sheet No.:

0 5 of 31 3.0

SUMMARY

OF TEST PROCEDURE 3.1 Test Geometry The flange/pipe test specimen is schematically shown in Figure 3-1. The test flange was welded to an Al-Bronze pipe segment. A mating flange/pipe assembly was fabricated from an Al-Bronze flange and steel pipe and bolted to the Al-Bronze flange-pipe assembly. Both pipe ends were capped to create a sealed assembly for pressure testing. The overall length of the test assembly was approximately 55 inches. Fabrication of flange-pipe assembly and test fixture hardware was performed by HL&P.

As a backup to the load measuring devices, strain gages were applied to the test pipe. All instrumentation was installed and monitored by on-site personnel. Four axial gages (two at 0( and two at 181?) were applied approximately 2 inches axially from the outboard weld edge. These four gages were wired in the bridge to measure bending strain. The 1800 gage was at a circumferential location of approximately the center of the circumferential crack. Later measurements on the failed flange (4) indicated the axial position of the bending gages to be 3A5 inches from the crack plane cross section. A three element (axial, 450, hoop) rosette gage was also applied approximately 4 inches from weld edge at 181r position. Later measurements on the failed flange indicated the rosette to be 5.25 inches from the fracture plane.

The nominal dimensions for 6-inch NPS Schedule 40 pipe are given below:

D = 6,625 inches t = 0.280 inch

& = 6.625/2 = 3.3125 inches R, = R,- t = 3.3125 - 0.280 = 3.0325 inches R = (R. + R0j2 = 3.1725 inches RKt = 3.1725/0.28 = 11.33 QAE17 REV. 9J88

Enclosure 1 NOC-AE-14003135 Page 54 of 98 IAPTSECH.

ENGI&CMING ISERVICES, FaC Made by: Date lient:

Document No.: ABS-C-1964-4 ,z-/a.491i HN E P Checked by: Date: Project No.:

Tide: Evaluation of 6-Inch Flange Test .Ž-Om %SMI"1 ii AES 93061964-IQ Revision No.:- Shcet No.:

0 6 of 31 64 AA -3400us/8 ken. 4 ",t Ptr CL zH eoaae

S.

-or 01 J

Figure 3 Flange/Pipe Assembly.

QAEI7 REV.. 9186

Enclosure 1 NOC-AE-14003135 Page 55 of 98 ENGINEEIRLIG S8tVICES, MN.

Mad by: Date- Client:

Document No.: AES-C-1964-4 7V aClP Chocked by: Date: Project No.:

Title: Evaluation of 6-Inch Flange Test i 10 M"11 AES 93061964-1Q Revision No.: Sheet No.:

_______________________ 0 7 of 31 0*

7Zs7-te"7s Aq)

Figure 3 Schematic Illustration of Bend Test Fixture.

QAEI7 REV. 919t

Enclosure 1 NOC-AE-14003135 Page 56 of 98 EGIEI4PTECHr W)GItNEERMq 6nVIOES. INC.

Document No.: AES-C-1964-4 Title: Evaluation of 6-Inch Flange Test r;*

iH7iw7 7 Madebv

_.4 Checed y:

.. J Date.'

Dte; 5 il' 41 Client:

CIent Project N4o.:

ABS 93061964-10 Revision No.: Sheet No.:

0 8 of 31 The pipe perimeters along the OD and ID surfaces are:

Pop - nD n(6.625) - 20.813 Inches piD a 2xR1 - 2n(3.0325) - 19.054 inches 3.2 Pressure Test Procedure The pipe assembly was filled with water and then pressurized manually by a hand pump. The pump was an AMETJK twin seal pressure pump Model T-1, Serial No. 92541 with a maximum pressure capacity of 15,000 psi (a). In addition to the pressure transducer, pressure was measured by a dial pressure gage which was monitored by the pump operator. The pressure transducer output was recorded. The pressure was increased in approximately 50 psig increments and held for approximately 15 seconds at each pressure plateau.

The test was terminated at 530 psig internal pressure when leakage occurred due to failure of the coating seal and pressure could not be maintained by the pump. Strain and pressure gage values were recorded during the test with a sample rate of five readings per second.

3.3 Bend Test Procedure After the pressure test was completed, the pipe assembly was drained of water and placed in a three-point bend fixure attached to a mechanical tension testing machine. A schematic of the test fixture is shown in Figure 3.2. The fixture was constructed from wide flange steel beam and A516 Grade 70 steel plate. The end brackets and center clevis were designed to allow free rotation of pipe ends. The maximum load capacity of the machine is 120,000 lbs. The pipe assembly was mounted in the machine with the crack located on the bottom side (maximum tension side). Measurements were made from the central load point to each end of the pipe where the end plates make contact with the pipe (pinned-ends). After positioning the end plates, C-clamps were fixed to the beam to prevent sliding. The beam was also clamped to the machine cross-head to prevent slippage during the test. The load was controlled hydraulically by monitoring the dial gage. The load was increased in approximately 5000 lb load increments until failure of the flange. The load on the dial QAE*7 RSV. 90~

Enclosure 1 NOC-AE-14003135 Page 57 of 98 IRI PTeiCHr ENCr.ERING COWICK W Made by: DAI Client:

Document No.: AES-C-1964-4 &4-.*+/-.2+/-Ltf jL&

Checked by: Date: Project No.:

Title: Evaluation of 6-Inch Flange Test I I WI AES 93061964-10 Revision No.: Sheet No.:

0 9 of 31 gage was recorded manually at various times during the test. The maximum load was indicated by the follower Indicator on the dial. Strain gage values were recorded during the test with a sample rate of five readings per second.

QAE17 REV. 9M88

Enclosure 1 NOC-AE-14003135 Page 58 of 98 ENlIWEERING 8EVZCESo I3.

Made. Date. Client:

Document No.: AES-C-1964-4 2 .,_Iis,/9-_

Chocked by: Date: Project No.:

Titl: Evaluation of 6-Inch Flange Test AV L Mii!1. AES 93061964-1Q Revision No.: Shoot No.:

0 10 of 31 4.0 PRESSURE TEST RESULTS The pressure test assembly and instrumentation are shown in Figure 4-1. The pressure test data as recorded by the pressure transducer are plotted in Figure 4.2 (1). The recorded data covers a period of time of approximately eight minutes. Also shown in Figure 4-2 is the recorded hoop strain. In general, very good agreement in the trend between hoop strain and internal pressure is observed. At approximately 390 psi, small leakage was observed emanating from the crack (2) indicating rupture of the Internal coating. Pressure was then increased until a maximum pressure of 530 psig was reached. Pressures higher than 530 psig could not be maintained because pressure loss due to leakage exceeded manual pump pressure rate. Therefore, the pressure integrity of the degraded flange is >530 psig. For a system design pressure of 120 psig and a maximum operating pressure of 80 psig (a), the following margins on pressure are calculated:

Margin on design Z 530/120 a 44 times Margin on operation > 530/80 - 6. times QAE17 REV. 91"

Enclosure 1 NOC-AE-14003135 Page 59 of 98 ENGIN~EERING SERVICES. HG Made by: Data: Chient:

Documnent No.: AES-C.1964-4 HL&P checked Date: Project No.:

Title: Evaluation of 6-Inch Flange Test .. LL 15(WI r '% AES 93061964-1Q Revision No.: Sheet No.:

_ 11 of 31 0

Figure 4 Pressure Test Setup.

QAEI7 REV. 9188

Enclosure 1 NOC-AE-14003135 Page 60 of 98 8

ENGCIEMMGOMM U$. HO.

Mad ate:Client:

Document No.: AES-C-1964-4 jqJfrŽ 9 HL&P Checked by: Date: Project No.:

Title: Evaluation of 6-Inch Flange Test U I mi'tqj AES 93061964-1Q Revision No.- Sheet No.:

0 12 of 31 aw 50 4300 W200 0

0 aO 200 300 400 5W0 TIME, (s)

Figure 4 Flange Pressure Test Data.

QAEI7 RV.FV 01M

Enclosure 1 NOC-AE-14003135 Page 61 of 98 EMAPTN ENGINEMSERVG IHS

ICE%, IM.

Ma by Date," clent:

Document No.: AES.C.1964-4 J.55*. HL&P Cbecked by: Date: Project No.:

Title: Evaluation of 6-Inch Flange Test -A lC )15i ABS 93061964-IQ Revision No.: Sheet No.:

0 13 of 31 5.0 BEND TEST RESULTS The flange-pipe assembly was loaded in three-point bending as shown in Figure 5-1. The crack was placed on the tensile side of the assembly. The following critical lengths were measured prior to loading (2):

II = Distance from center load point to left pin support - 251/2 Inches 1,2 = Distance from center load point to right pin support = 241/2 Inches Lc = Distance from right pin support to cracked plane = 21% inches The total length between pin supports (L) is L1 + L2 = 251/2 + 241/2 = 50 inches.

The test was photographed and video recorded by HL&P. The bend test assembly and loading frame are shown in Figure 5-2. This photograph shows the flange/pipe under load during the performance of the test.

The bend test load versus time is shown in Figure 5-3. The loading rate was approximately 1000 lbs/min.

Also shown in Figure 5-3 is the bending strain recorded by the gages. In general, the trend of bending strain is in agreement with the indicated load. It is apparent that permanent plastic straining had occurred during the test by the observation of negative strain near zero test load.

Several audible 'pops" were heard during the loading. The "popse that were noted during the test are shown in Figure 5-3. The maximum load achieved during the test was 18,200 lbs. The load dropped off in a stable manner after maximum load was reached. At a load of 2000 lbs, the crack had extended to about 3/4 of circumference. Final flange separation did not occur until after the test was stopped and the pipe assembly was being removed from the fixture.

0AE17 REV. 9/M8

Enclosure 1 NOC-AE-14003135 Page 62 of 98 ENGINMME4 GUM=a WO.

Document No.: AES-C-1964-4 Title: Evaluation of 6-Inch Flange Test P

L1 = 251/2 inches

= 241/2 inches L2 = 21% inches

= 1, + L, = 50 inches Figure 5 Pipe Assembly Loading.

QAE17 REV. 9)8M

Enclosure 1 NOC-AE-14003135 Page 63 of 98 ENWI4ERIN. SE"vS*. M Made by: DOw: lt:

Document No- AES-C-1964-4 ActL ___P Checked by: Date: Project No.:

Tide: Evaluation of 6-Inch Flange Test ..... A Lbe Mt0"t'(q AES 93061964-lQ Revision No.: Sheet No.:

0 15 of 31 Figure 5 Flange/Pipe Assembly During Testing.

'JAW' RSV. 9/18

Enclosure 1 NOC-AE-14003135 Page 64 of 98 IS14APTICHr GINEIRING SGOVl*M. IN.

Documnent No.: AES-C-.64-4 IHUP Made= by:

Chocked by:

Date-Date:

Client:

Project No.:

Tide: Evaluation of 6-Inch Flange Test *[ tm flrC AES 93061964-1Q

'Revision No.: Sheet No.:

0 16 of 31 20 1

,BDATA LEGEND PW== 4sk 16 14 j 4

2 STPAN 0

-2 o 200 400 600 800 1000 1200 TIME, (s)

Figure 5 Flange Bend Test Data, QAE17 RE!V. 9M8

Enclosure 1 NOC-AE-14003135 Page 65 of 98 ENGINEERING SERVICE. M ChlacWby:. Dale: *MOMb.

Docamest No.: AES-C- 196"4 L'iv5/ HL&P 11Ue; Evaluation of 6-Inch Flange Test . 15 Mf~ql AM 9061964-IQ 0 17 of 31 The maximum applied stress at the crack plane vbs calculated *hon the assernmby geometry and maximum load eIploying beam theory (k). The moment at the location of the crack is:

M - K., 4 / L)

M - 18,200(25.50) (21.625) / 50 - 200,720 in4bs The maidmum monun in the assembly acting directly under the load point is:

M -- PI Lj.I/L M - 18,200(25.50) (24.50) / 50 - 227,410 in4bs The noninal moment at the crack plane location is 201/227 or approximately 89% of the rnmadnuim nr in the assemby during testing QAE17

Enclosure 1 NOC-AE-14003135 Page 66 of 98 ENGINEERING SERVICES. INC.

Made: Dae:. Client:

Document No.: AES.C-1964.4 Act IAM H__

Checked by: Date: Project No.:

Tide: Evaluation of 6-Inch Flange Test X \ hq1J AES 93061964-1Q Revision No.: Sheet No.:

on0 18 of 31 6.0 COMPARISON OF CALCULATED AND MEASURED CRITICAL BENDING STRESS 6.1 Summary of Post Test Measurements The fracture surface of the failed flange section was examined by HL&P (4). The examination identified the extent of deailoying as well as the location and size of cracks. The results of this examination are illustrated in Figure 6-1. The section was dealloyed circumferentially to a depth from approximately 35% to 90% of the wall thickness. TWo existing cracks were observed: a through-wall crack at 180( position and a part-through crack at approximately 330'. With regard to the bend test, the part-through crack did not significantly affect the structural bending capacity of the flange since it was located in the compresive region of the section.

From the angular position of the through-wall crack (20 where 0 Is defined as the half crack angle), the following ID and OD surface lengths are computed:

top - (200D 1 360°) POD - ((210 - 155) 1 360] 20.813 4Do, - 3.18 inches 20o, - 55' 4C - (2eD / 360r) P. - [(225 - 145) / 360] 19.054

- 4.23 inches 201D - 80P QAEI7 RRV. 9/88

Enclosure I NOC-AE-14003135 Page 67 of 98 ENGINEERING SERVICES. INC.

by: D1ate-~ Ciliet:

Document No.: AES-C-1964-4 L#,Lf2 HL&P Checked by. Date: Project No.:

Title: Evaluation of 6-Inch Flange Test \ 15 trM qj AES 93061964-IQ Revision No.: Sheet No.:

0 19 of 31

-iN- DWally1011 A Ctack Figure 6 Cross Sectional View of Fracture Surface Showing Dealloyed Regions and Cracking.

QAE17 REV. 9/88

Enclosure 1 NOC-AE-14003135 Page 68 of 98 ENGINEERING SERVI *4 0.

Made Date: Client:

Document No.: AES-C-1964-4. 4J /*j!L HL&P Checked by:. Date: Project No.:

Title: Evaluation of 6-Inch Flange Test ... Z I&MR114 AES 93061964-1Q Revision No.: Sheol No.:

0 20 of 31 The average crack length is:

, (3.18 4 4.23) / 2 - 3.71 inches 28,., - (55 +80)12 - 67.5P 6.2 Calculated Critical Bending Stress The critical bending stress for Al-Bronze castings in the ECW system was previously determined for the purpose of evaluating the safety margins of degraded castings (1). The calculated critical stress is compared to the stress achieved in the flange bend test in order to ver4 the theoretical failure models. Since the bend test was performed with no internal pressure, the calculations contained in Ref. I were revised to redefine the axial pressure stress to zero. This revised calculation is given in Appendix A of this calculation.

The calculated critical bending stress for failure of the flange under pure bending is shown in Figure 6-2. The critical bending stress for both limit load and fracture models are illustrated. This critical bending stress is the elastically calculated stress based on the "uncracked" section properties of the flange-pipe that would fail the casting with a given through-wall crack length, L In order to compare these model results with the results of the bend test, the maximum moment from the test must be converted to an elastically equivalent bending stress for the uncracked section.

The elastic stress computed at the crack plane (assuming crack is not present) is calculated from:

M/Z Z - Section modulus 4 (Re -1,1) 1 R.

QAE17 REV. 9/88

Enclosure 1 NOC-AE-14003135 Page 69 of 98 NRINAPTGECH..

ENCIINE:ERING SEPVWIME. MN.

Made by. Date: Client:

Document No.: AES.C-1964-4 Checked by:

77Ad, 1& 3 Date:

HL&P Project No.:

Title: Evaluation of 6-Inch Flange Test 18 Mf '11 -AES ABSA 93061964-1Q Revision No.: Shlot No.:

0 21 of 31 CRITICAL BENDING STRESS FOR THROUGH-WALL CRACK CAST FLANGE BEND TEST 80 70 60 40 30 0.0 0.0 0.1 02 03 0.4 0.5 Crack Angle, Oft Figure 6.2 - Calculated Versus Measured Bend Test Results.

QA1SI7 REV. 9)88

Enclosure 1 NOC-AE-14003135 Page 70 of 98 ENGINEERING 8EuVIOE. INo.

Mad .: Date: Client:

Docunent No.: AES-C-1964-4 JU M1L/,t HL&P Checked by: Date: Project No.;

Title: Evaluation of 6-Inch Flange Test 4- Jj* IS Mr AES 93061964-1Q Revision No.: Sheet No.:

0 22 of 31

- '(3.31254 - 3.03254) / 3.3125 - 8.496 ins Using the previously calculated moment at the plane of failure:

- 200,720 / 8.496 - 23,630 psi Therefore, the maximum "elastiC' bending stress acting at the crack location is 23,630 psi.

This stress value is plotted in Figure 6-2 for the ID and OD surface flaw lengths (i.e., 20 = 80* and 55%

respectively). The test failure point fell within the range of the model predictions. It would be expected that the actual behavior of the flange lay somewhere between the limit load and fracture model results given the large amount of dealloying present (Figure 6-1). From the failure cross-section shown in Figure 6-1, the average dealloying depth away from the cracks is between 50 to 70%. Even with this amount of dealloying, the fracture stress was calculated to be (164 + 22.6)/2 = 19.5 ksi from Page 30 for an average crack angle of 68W.Therefore, the fracture model margin in predicting this test is 23.63/19.5 or 1.21. The fracture model is conservative even with 50 to 70% part-through dealloying. This result is possible because the fracture conditions of the section wil] be controlled by the tougher (undealloyed) material.

Despite the excessive dealloying and somewhat irregular crack shape, the fracture model gave a conservative estimate of the flange failure stress even when the OD surface length of the through-wall crack was used.

For this calculation, the test prediction is 23.63/22.6 = 1.05. Therefore, the model is conservative even with subsurface cracks and dealloying to the extent shown in Figure 6-1.

QAE17 REV. gig&

Enclosure 1 NOC-AE-14003135 Page 71 of 98 nGNPTECtQ 84QMM"tI*8MWK=., I Madei1by Date: Cliet:

Document No- AES-C-19o44 l IS/f4 HL&P Cecked b Date: Project No.

Title: Evaluation of 6-Inch Flange Test .xLmAES 93o61964.lQ Revision No.: Sheet No.:

0 23 of 31 7.0

SUMMARY

AND CONCLUSIONS The following summary and conclusions are drawn from the flange test results and analysis:

1. The pressure integrity of the dealloyed/cracked flange exceeded 6.6 times maximum operating pressure and 4.4 times design pressure of the ECW system.

2. The maximum load resisted by the flange-pipe assembly was 18,200 lbs. Ibis load was equivalent to a nominal bending stress of 23,630 psi in the pipe.

3. The calculated critical bending stress based on the fracture model was 16.4 to 22.6 ksl depending on whether ID or OD surface flaw length is used to define through.wall crack angle.

4. Based on the above findings, the dealloyed/cracked flange exhibited significant structural integrity.

The flaw evaluation method for computing critical bending stress is conservative.

QAE17 REV. 9M88

Enclosure 1 NOC-AE-14003135 Page 72 of 98 E*NGINEIERM* SOEWKINCE.NO Document No.: AES-C-1964.4 At I Client Checke by: Dae:' Project No*:'

Title: Evaluation of 6-Inch Flange Test

[Revision S\(-&

0 No.:

t5 MM 41 AES 93061964-1Q Sheet No.:

24 of 31

8.0 REFERENCES

1. Document No. AES-C-1964-1, "Calculation of Critical Bending Stress for Dealloyed Castings in the ECW System," APTECH Project AES 93061964-IQ (November 1993) (ICD 1-2).

2. Document No. AES-S-1964-1, "Flange Test Notes and Summary," APTECH ProjectAES 93061964-1Q (November 18, 1993)(ICD 1-4).

3. "Flange Test Raw Data and Summary Information,' HLI.P (November 18, 1993) (ECD E-26).

4. Houston Lighting and Power Company Lab Report MT-4907 by W.FJ. Deeg, "Mappingof Dealloying in Aluminum Bronze Pipe to Flange Weld Bend Test" (December 10, 1993) (ECD E-25).

5. Bechtel Calculation RC5401, "DGB ECW Return Lines, Trains A, B & C" (July 20, 1992) (ECD-5).

6. Roark, RJ., Formulas for Stress and Strain. 4th Edition, McGraw Hill (1965), Prob. 12 Pg. 106.

QAEI7/

RtEV. 9/si

Enclosure 1 NOC-AE-14003135 Page 73 of 98 RNPTIECHr EN0114EERING $ERVIOES, RC, M y Dat. Clie~nt:

Document No.: AES-C-1964-4 IH,/L HT&P Checked by: Dale: Project No.:

Title: Evaluation of 6-Inch Flange Test 1 M" q4 ABS 93061964-IQ Revision No.: Sheet No.:

0 25 of 31 Appendix A CALCULATION OF CRITICAL BENDING STRESS FOR 6-INCH NPS CASTING UNDER PURE BENDING Al INTRODUCTION The critical bending stress for combined pressure and bending loadings was previously determined for all casting sizes in the ECW system (1). This appendix calculates the critical bending stress for zero pressure (pure bending) for the 6-inch NPS case. The results of this calculation are used for comparison with experimentally measured bending loads from the 6.inch flange test conducted by HL&P.

A2 LIMIT LOAD ANALYSIS The limit load model and evaluation are discussed in Ref. 1. The flaw model geometry is shown in Figure A-I. The governing equations for critical bending stress P, for pure bending case Is given by:

-P-1 [2 sing -sin 0] (A-Ia) 0 - 3 1-(0/h)) (A-lb) where,

=Fl Fow stress = 45 ksi (1) 0 = Half through-wall crack angle 3 = Angular position to neutral axis QAEI7 REV. 9/88

Enclosure 1 NOC-AE-14003135 Page 74 of 98 ENGINEERING SSVICES. INC.

Document No.: ABS-C-1964-4 'D!1 1 HLIP Title: Evaluation of 6-Inch Flange Test Check edby: Da ABS 93061964-10 Revision No.: Sheet No.:

0 26 of 31 t

Neutral axis Figure A-I - Circumferential Flaw Geometry.

QAE17 RBV. 9/88

Enclosure 1 NOC-AE-14003135 Page 75 of 98 Emt I WTCHr ENOMNERING SERMCK* INC;.

Made by: ate* Client:

Document No- AES-C-1964.4 94__. HL ___ .

Checked by: Date: Project No.:

Title: Evaluation of 6-Inch Flange Test -. t-16. Z MA q AS 93061964-1Q Revision No.: Sheet No.:

0 27 of 31 Equation A-I was solved for a range of crack angles. The results for the critical bending stress for limit load are shown in Table A-I. For the test flange, the OD crack angle is 5V:

- - 0.153 P,' - 42.4 ksi For an ID crack angle of 80' as measure for the test flange:

0 a 8(r a 0.222 ii 360' 1*- - 354 ksi Therefore, the limit load model predicts a failure stress of 35A to 42.4 ksl for the flange bend test. This stress represents a globally applied 'elastic4 stress based on gross section properties.

A3 FRACTURE ANALYSIS The same basic flaw model shown in Figure 6-1 was used in the fracture assessment. The fracture condition is given by:

K, - K'.

REV97 REV. 9/88

Enclosure 1 NOC-AE-14003135 Page 76 of 98 ENIMPTICH ENGIEEMN 6EMVICE% MN Docunmnt No.: AES-C-1964-4 I HL&P a210 Checked by: Date: Project No.:

Title: Evaluation of 6-Inch Flange Test _V 18 m 41 AES 93061964-1Q Revision No.: Sheet No.:

0 28 of 31 Table A-I

SUMMARY

OF LIMIT LOAD RESULTS FOR PURE BENDINO (6-INCH NOMINAL PIPE SIZE)

Inut Parmnetme:

D. - 6.625 in R - Mean radius - 3.2725 in PN - Mean perimeler w 2hR - 29(3.1725) w 19.933 in I - 0.280 In RA - 11.93 Crack Length (in) a a L22*

o.ooi 0.0199 0.0031 1.5692 1.5724 57.206 0.00$

0.O0S aO.997 0.0157 1.5629 15787 56.*44 0.010 0.0314 1.5551 1.5865 56.389 0.015 0.2990 0.0471 1.5472 15944 55.930 0.020 03987 0.0628 1.5394 1.6022 55.469 0.025 04983 0.0785 1.5315 1.6101 55.004 0.030 0.5980 0.0942 1.5237 1.6179 54.536 0.040 0.7973 0.1257 1,5080 1,6336 53.592 0.050 0.9967 0.1571 1.4923 1.6493 52.638 0.060 1.1960 0.1885 1.4765 1.6650 51.673 0.070 1.3953 0.2199 1.4608 1.6808 50.700 0,080 1.5947 0.2513 14451 1.6965 49.720 0.090 1.7940 0.2827 14294 1.7122 48.732 0.100 1.9933 0.3142 14137 1.7279 47.738 0.110 2-1927 0.3456 1.3980 1.7436 46.738 0.120 2.3920 0.3770 13823 1.7593 45.735 0.130 2,5913 0.4084 03666 1.7750 44.728 0.140 17907 0.4398 13509 1.7907 43.718 0.350 2.990D 0.4712 1,3352 ism" 42.707 0.153 3.0454 0GA80 1.3308 t.8l1g 42.426 0.200 3.9867 0.6283 1.2566 1.8850 37.653 0-222 4.4296 0.6981 1.2217 1.9199 35.426 0.250 4.9834 0.7854 1.1791 19635 32.677 0.300 59800 0.9425 1.0996 2.0420 27.874 0.350 6.9767 1.0996 1.0210 2.1206 23.327 0.400 7.9734 1.2566 0.9425 21991 19,107 0.450 8,9700 1.4137 0.8639 2.2777 15.273 0.500 9.9667 1.5708 0.7854 2.3562 11.866 0.550 10.9634 1.1279 O.7069 2.4347 8.915 0.600 11.9600 1.8850 0a6293 2.5133 6.432 0.700 13.9534 2.1991 0L4712 2.6704 2.835 0.800 15.9467 2.5133 0L3142 2.8274 0.867 QAE17 REV. 9/88

Enclosure 1 NOC-AE-14003135 Page 77 of 98 ENGOIPERWOG 8EW]Ci, INC.

Made by: Date, Client:

Document No.- AES-C-19644 ... A M_ _P Checked by: Date: Noject No.:

Titk: Evaluation of 6-Inch Flange Test R..MLon 15 mAAI AS 93061964NoQ Revision No.- Sb02t No.:f..

0 29 of 31 and from Ref. I for pure bending, the critical bending stress for fracture, V, is:

(A-2)

F, (n, 2)W' where, K4t+ = Fracture toughness = 65 ksi in"(l)

I f Crack length at mean radius position Fý = Surface correction factor for global bending The correction factor Fb is taken from Re. 1:

Fb - 1 +*A (o0t)" +

B (e/M)L' +. (8/n)" (A-3) where, A, = -3.26543 + 1.52784 (R/t) - 0.072698 (R/t)2 + 0.0016011 (R/t)'

Bb = 11.36322 - 3.91412 (R/t) + 0.18619 (Rft)2 - 0.004099 (R/t)9 Cb = -3.18609 + 3.84763 (R/t) - 0.18304 (R/t)' + 0.00403 (R/t)s Equation A-2 was solved for a range of crack angles. The results for the critical bending stress for fracture are shown in Table A-2. For the test flange, the OD crack angle is 550:

1 - 55- 0.153 o 22.6 ksi For an ID crack angle of 80" as measured for the test flange:

QAE17 REV. 9/88

Enclosure 1 NOC-AE-14003135 Page 78 of 98 EHGN4EERING SMO4ES. INM.

Made : Date: Client:

Document No.: A*S-C-1964-44 j j,,/ HI..&P Checked by: Date: Project No.:

Title: Evaluation of 6-Inch Flange Test t aE, rI 't ABS 93061964-10 Revision No.: Sheet No.:

0 30 of 31 8 8 0.222

- 16.4 ksi Therefore, the fracture model predicts a failure stress of 16A to 22.6 ksi for the flange bend test. This stress represents a globally applied "elastic" stress based on gross section properties.

QAEI7 REV. 9M

Enclosure 1 NOC-AE-14003135 Page 79 of 98 nIPTVCH.

SENGINEERING 6E*IE INO.

Ma DDate- Client.

Document No- ABS-C-1964-4 _ _ 1_ 42_9_# Hu&P Checked by: Date: lPoject No.:

Tidle: Evaluation of 6-Inch Flange Test, iIS Vhit1 ,AES 93061964-10 Revision No.: Sheet No,:

0 31 of 31 Table A-2 SUWARY OF FRACrURE RESULTS FOR PURE BENDING (6.INCH NOMINAL PIPE SIZE)

D. - 6.625 in t - 0.280 in R - 3.125 In RAt - 11.33 P1 - 19.933 in A, - 7.0417 E - o15.0449

, - 22,7727 Crak Length (in)

Cr~d( Anglre OWh~ .... - _ll (am f F4 Mg~. &-b 6"OW 0.001 0.0199 0.0031 1.000 367.25 0.005 0.0997 0.0157 1.002 163.87 0.010 0.1993 0.0314 1.007 115.37 0.015 0.2990 0.0471 1.013 93.67 0.020 0.3987 0.0628 1.019 80.60 0.025 0.4983 0,0785 1.026 71.58 0.030 0.5980 0.0942 1.034 64.84 0.040 0.7973 .. 0.1257 1,052 55.22 0.050 0.9967 0,1571 1.071 48.51 0.060 1.1960 0.1885 1.091 43.45 0.070 1.3953 0.2199 1.113 39.45 0.080 1.5947 0.2513 1.135 36.17 0.090 1.7940 0.2827 1.159 33.42 0.100 1.9933 0.3142 1.182 31.07 0.110 11927 0.3456 1.207 29.03 0.120 ,3920 0.3770 1.231 27.23 0.130 2.5913 0.4084 1.256 25.64 0.140 17907 0.4398 1.282 24.22 0.150 2.9900 0.4712 1.308 22.94 0.153 3.0454 0.4800 1.315 22.60 0.200 3.9867 0.6233 1.442 18.01 0.222 4.4296 0.6981 1.505 16.37 0.250 4.9834 0,7854 1.588 14.63 0.300 5.9800 0.9425 1.752 12.10 0.350 6.9767 1.0996 1.945 10.09 0.400 7.9734 1.2566 1181 8.42 0.450 8.9700 1,4137 2.474 7.00 0.500 9.9667 1.5708 2.843 5.78 0.550 10.9w34 1.7279 3.307 4.74 0.600 11.9600 1.8850 3.888 3.86 0.700 13.9534 2.1991 5.491 2.53 0.800 15.9467 2.5133 7.855 1.65 OAR17 REV. 9MS

Enclosure 1 NOC-AE-14003135 Page 80 of 98 Attachment C Table reflecting leaking components that have occurred since July 28, 2011

Enclosure 1 NOC-AE-14003135 Page 81 of 98 TABLE I - ECW DATA Undated from July 28. 2011 - 2013 No Date Component Metallurgical Exam Location Information without References Type Information Metallurgical Exam Comments 55 7-28-11 U2 Cast 1-EW-FV6936 Residue buildup at several CR 11-12309 Valve Body ECW 2B Return discrete spots on the valve Header body at the Return Header Blowdown Valve machined inlet portion near the flange.

56 1-9-12 U2 4" Cast C2EWFV6937 Residue buildup indicative of CR 12-1044 valve body Return Header through-wall dealloyinq at Blowdown Valve Valve Body 57 6-12-12 U2 10" Cast 3R282TEW0274 Residue buildup indicative of CR 12-22876 flanae Chiller ECW through-wall dealloyinq on Cross-Tie valve the cross-tie side flange flange 58 3-4-14 U1 1"-1/2" 3R281TEW0283 Discoloration spots at 9 CR 14-4206 Root Valve CCW Pump o'clock and 2 o'clock on shop Socket Supplemental weld Adapter Cooler 11A FI/FT high side root valve

Enclosure 1 NOC-AE-14003135 Page 82 of 98 Attachment D CREE 12-29261-95, "STP evaluation methodology and associated analyses calculating the critical bending stresses for the four flaw cases" (FOR INFORMATION ONLY. THE CASES ANALYZED ARE HYPOTHETICAL IN NATURE AND DO NOT REPRESENT ACTUAL PLANT CONDITIONS.)

The attached CREE provides a typical analytical methodology used by STP to evaluate the four hypothethecal non-conforming conditions. It is not intended to be the bounding analytical methodology for evaluating all future potential non-conforming conditions.

Enclosure 1 NOC-AE-14003135 Page 83 of 98 O0GP04-ZA-0002, Condition Report Engineering Evaluation (CREE) Page 1 of 12 Rev. 19 Form 1 Engineering Evaluation CR Action #: 12-29261-95 CR Level: CNAQ-E DTL #1008468 except as noted below CREE Type: r GENERAL Evaluation (See Addendum 2)

MATERIAL DEFICIENCY --- > (Classify) DEGRADED NONCONFORMING _ NEITHER (See Addendum 1) [DTL #10084891 [DTL #10084881 Aging ECO E RIS 2005-20 Issue 17 GL 86-10 Evaluation.[ FME (See Addendum 7) (See Addendum 8) (See Addendum 9) (See Addendum 10)

Problem Statement:

STP Nuclear Operating Company (STPNOC) submitted a License Renewal Application (LRA) for the South Texas Project Units 1 and 2 via STPNOC letter dated October 25, 2010, from G.T. Powell to NRC Document Control Desk, "License Renewal Application" (NOC-AE-10002607). Within NRC Letter dated December 18, 2012, "Requests for Additional Information for the Review of the South Texas Project, Units 1 and 2, License Renewal Application - Set 26 (ST-AE-NOC-14002493) the NRC staff requested additional information for review of the STP LRA. Specifically, part "f' requests that STP identify how field observations of leaking degraded components are used in conjunction with the analytical output of AES-C-1964-I, "Calculation of Critical Bending Stress for Dealloyed Aluminum-Bronze Castings in the ECW System," and the existing pipe stress analyses in order to analyze for structural integrity as it relates to the component performing its intended function. The staff described four flaw cases in the ECW System requiring STP methodology and estimations of the critical bending stresses that STP will use in evaluating operability. The purpose of the .CREE is to document the STPNOC evaluation methodology and associated analyses required to calculate the critical bending stresses used for the four flaw cases provided by the NRC.

==

Conclusion:==

See Table 1: Evaluation Summary (Pages 6 and 7) for the analyses results and responses in relation to the NRC staff described four flaw cases in the ECW System.

Additional Actions Required? V No r Yes If Yes, list CR Action #s N/A Tod ~Maey 0/,,/2qq wit ..f eiTechnical "iew Required if SCAQ/CAQY,

,

Preparer (Print/Sign) Date Technical Reviewer (Print in) Date SW ~~ aah/A(Richard Kerse IL Supervisor (Prlnt/Sign) f Date Manager Approval Required if SCAQ/CAQ-S Other Reviewers (Print/Sign) Date Manager (Print/Sign/Title) Date This form When complete, SHALL be retained.

Enclosure 1 NOC-AE-14003135 Page 84 of 98 OPGP04-ZA-0002, CREE # 12-29261-95 Page 2 of 12 Rev. 19 Form 3 CREE Continuation Sheet

Background

STP Nuclear Operating Company (STPNOC) submitted a License Renewal Application (LRA) for the South Texas Project Units I and 2 via STPNOC letter dated October 25, 2010, from G.T. Powell to NRC Document Control Desk, "License Renewal Application" (NOC-AE-10002607). Within NRC Letter dated December 18,2012, "Requests for Additional Information for the Review of the South Texas Project, Units I and 2, License Renewal Application - Set 26 (ST-AE-NOC-14002493) the NRC staff requested additional information for review of the STP LRA. Specifically, part "f' requests that STP identify how field observations of leaking degraded components are used in conjunction with the analytical output of AES-C-1964-l," Calculation of Critical Bending Stress for Dealloyed Aluminum-Bronze Castings in the ECW System," and the existing pipe stress analyses in order to analyze for structural integrity as it relates to the component performing its intended function. The staff described four flaw cases in the ECW System requiring STP methodology and estimations of the critical bending stresses that STP will use in evaluating operability. The four flaw cases/scenarios are described as follows:

i. Four small rounded indications of through-wall dealloying located in a circumferential axis at 10:00, 11:00, 1:00, and 2:00 on a 10-inch flange.

ii. One indication at 10:00, one-half inch long, with what appears to be rounded ends and no measurable width on a 4-inch flange.

iii. One "greenish" stain approximately 1/8 inch diameter at the 10:00 position on a 6-inch flange.

iv. One crack-like indication, one-half inch long, within a larger greenish stain with a circumferential length of one inch.

The NRC staff requested that STP state the following for each of the aforementioned cases:

. The size of the OD (Outside Diameter) flaw.

0 The corresponding size of the internal flaw that would be used in the structural integrity determination.

0 Which figure would be used from AES-C-1964-1.

0 The stress component input values that would be utilized from the highest stress location in the Essential Cooling Water System (ECWS) with susceptible components for that size as obtained by the stress analyses on record and how they would be combined in the structural integrity evaluation.

a What structural factor would be used 0 The critical bending stress as derived from the figures in AES-C-1964-1 and whether the component would be considered to be capable of meeting its intended function.

Evaluation The four cases described above are evaluated in the following section. A spreadsheet has been developed to calculate the critical bending stresses for both the limit load and fracture mechanisms (LEFM). Case i will be solved step by step to show the methodology within the spreadsheett-The-remaining cases are solved using the spreadsheet and are contained within Attachment 1.

Case "i)" described above requires evaluation of four small rounded indications of through-wall dealloying located in a circumferential axis at 10:00, 11:00, 1:00, and 2:00 on a 10-inch flange. Assuming each of the indications is approximately 1/8" long, the angular distance between the 10:00 and 11:00 flaw would be less than 30 degrees; this would also be true for the indications at the 1:00 and 2:00 positions. For the indications between 11:00 and 1:00, the angular distance would be greater than 30 degrees. Given this, the flaw will be assumed as one large flaw with a length equivalent to the farthest extent of each flaw.

This form when complete, SHALL be retained.

Enclosure 1 NOC-AE-14003135 Page 85 of 98 I OPrP4-ZA-0002, Rev. 19

12-29261-95 iCREE Page 3 of 12 Form 3 CREE Continuation Sheet The outside diameter length of the flaw is given by the following:

Outside Diameter Length (LOD) = Outside Radius (Ro) x Angular Distance (20)

LeO - (RO) (20) = (10.75/2)(120-)(ni/180-) = 11.257" Outside Diameter Flaw Length Therefore, LOD is assumed to be approximately 11.75" to 12" for conservatism. The flange is modeled using piping properties.

Inputs:

NPS = 10" Nominal Component Size t = 0.365" Piping Wall Thickness (Ref. 6)

D. = 10.75" Nominal Outside Piping Diameter (Ref. 6)

S, = 25 ksi Yield Stress (Ref. 3)

S 0 = 65 ksi Ultimate Stress (Ref.3)

K~c = 65 ksi*in.. Fracture Toughness (Ref.. 3)

Analysis:

Ro = Da/2 = 10.75/2 = 5.375 in. Outside Radius Rm = (D, - t)/2 = (10.75-0.365)/2 = 5.1925 in. Mean Radius of = (Sy + SJ)/2 = (25+65)/2 = 45 ksi. Flow Stress

0. = Leo/Do = 12"/10.75" = 1.1163 radians Outside Diameter Flaw Half-Angle 20e = 2(0j)(180'/7c) = (2)().1163)(180/IM) = 127.91620 Outside Diameter Flaw Angle Average and inside crack lengths are determined per Aptech provided relationships listed below (Ref. 4):

20d = 5( 2 0j) 00<20.< 8*

20 4 0 d= ' 8° 5 200< 280 20A.= 20,+12° 20 > 280 2 0 20d = 0+12c = 127.91620+ 120= 139.91620 Flaw Angle at Mean Radius d= (20d)(rd180')(1/2) = (139.9162°)(idi 80*)(1/2) = 1.2210 radians Flaw Half-Angle at Mean Radius L = Od(D. - t) = (1.2210)(10.75-0.365) = 12.6801 in. Flaw Length at Mean Radius a = U/2 = (12.6801)/(2) = 6.3400 in. Flaw Half-Length at Mean Radius O/-n = 1.2210/ c = 0.3887 Unitless Crack Angle This form when complete, SHALL be retained.

Enclosure 1 NOC-AE-14003135 Page 86 of 98 F

OPGPr4-ZA-Rev. 19 I 12-29261-95 CREE Cotia# Page 4 of 12 1 Form 3 CREE Continuation Sheet Limit Load Analysis P = 120 psig Design Pressure for ECW System (Ref. 6) oa= (P*Do)/(4*t) (120*10.75)/(4*0.365) =883.562 psi = 0.8836 ksi Axial Membrane Stress (Ref. 3)

(1- (;)-!-)

a3= (z/2)(1-0.3887-(0.8836/45) = 0.9295 radians Angular Position of Neutral Axis(')

2 of P'b= (2a/sn)(2sm(P)-sin(OD)) = ((2*45)/(n))*(2sin(0.9295)-sin(1.2210) = 18.9977 ksi Critical Bending Stress (LLPC)

Fracture Analysis The linear elastic fracture mechanics analysis performed for a through wall circumferential crack where K1 applied stress intensity factor is maintained below K1 c (fracture toughness ofthe base material). The fracture toughness used within Aptech Calculation AES-C-1964-1 is 65 ksijkin. The fracture mechanics equations listed below are taken from APTECH calculation AES-C-1964-1 (Ref. 3).

The free surface correction factors are functions that depend on crack angle, Oht, and casting geometry, RM_/t. For the range of Rmdt between 10 and 15, a simplified "curve fit" expression was developed from the work ofFolias and Erdogan for short length cracks, and work from Sanders for long cracks is used.(2)

For uniaxial tension:

R*,*/t = (5.1925)/(0.365) = 14.22601 A,. = -2.02917+1.67763(R/t)-0.07987(R/t) 2+0.00176(R/t)5

= -2.02917+1.67763( 14.22603)-0.07987(14.22603)'+0.00176(14.22603)3= 10.7399 B,,= 7.09987-4.42394(R/t)+0.21036(R/t)2 -0.00463(R/t)3

= 7.09987-4.42394(14.22603)+0.21036(14.22603)2_0.00463(14.22603)3= -26.5926 C. = 7.79661+5.16676(R/t)-0.24577(R/t)2 +0.00541(R/t)3

= 7.79661+5.16676(14.22603)-0.24577(14.22603)2+0.00541(14.22603) = 47.1359 15 2 35 F. = I+A.(O/n) ' +B .(Oh/) "+C.(O/C) "

= 1+10.7399 (0.3887)l'-+-26.5926 (0.3887)25 +47.1359 (0.3887)3.5 = 2.8232 For Global Bending:

2 3 Ab = -3.26543+1.52784(R/t)-0.072698(R/t) +0.001601 l(R/t)

= -3.26543+1,52784(14.22603)-0.072698(14.22603)2+0.0016011(14.22603)s = 8.3667 Notes:

1. p is only valid for a/t = 1.0 (i.e. assumption is a through-wall crack) and (0+0) <5t.

2. The free surface correction factors used in this analysis are consistent with those contained in Ref. 3 Table 6-5.

This form when complete, SHALL be retained.

Enclosure 1 NOC-AE-14003135 Page 87 of 98 I

I OPGPr4-ZA-0002, Rev. 19 CREE # 12-29261-95 Page 5 ofJ12]

Form 3 CREE Continuation Sheet Bb= 11.36322-3.91412(R/t)+0.18619(R/t) 2- 0.004099(R/t)3

= 11.36322-3.91412(14.22603)+0.18619(14.22603)2- 0.004099(14.22603)3 =-18.4393 Cb = -3.18609+3.84763(Rit)-0.18304(R/t)2+0.00403(R/t) 3

= -3.18609+3.84763(14.22603)-0.18304(14.22603)2+0.00403(14.22603)3 = 26.1094 Fb = l+Ab(O/t)+'+Bb(8/fl)2'+Cb(e/lt)3.

= 1+8.3667 (0.3887)"'+(-18.4393 (0.3887)2")+26.1094 (0.3887)3.1 = 2.2464 2

Ob = (KIC)/(Fb(na)" ) - O0(Fm/Fb)

= ( 6 5)/(2 .2 4 64 (70 6,3 4 )"') - (0.8836)(2.8232/2.2464) = 5.3730 ksi Therefore, Fracture controls and the critical bending stress is 5.3730 ksi.

Conclusion A summary of the critical bending stress analysis results and responses for the NRC questions given is given in Table 1: Evaluation Summary on the following pages.

Additional Required Actions None.

References

- These reference numbers provided only correlate with the body of this CREE and do not apply to Table 1: Evaluation Summary.

1. STPNOC letter dated October 25, 2010, from G. T. Powell to NRC Document Control Desk, "License Renewal Application" (NOC-AE- 10002607) (ML103010257)

2. NRC letter dated December 18, 2012, "Requests for Additional Information for the Review of the South Texas Project, Units I and 2, License Renewal Application- Set 26 (TAC Nos. ME4936 and MB4937)"

(ST-AE-NOC-14002493) (ML12333A227)

3. Document No. AES-C-1964-1, "Calculation of Critical Bending Stress for Dealloyed Aluminum Bronze Castings in the ECW System", APTECH Project AES 93061964-IQ, Revision 0, December 1993. STP STI: 1436366.

4. Document No. AES-C-1964-5, "Evaluation of the Significance of Dealloying and Subsurface Cracks on Flaw Evaluation Method", APTECH Project AES 93061964-lQ, Revision 0, December 1994. STP STI: 30040905.

5. Notused.'

6. 5L019PS0004, Specification for Criteria for Piping Design and Installation, Revision 24.

This form when complete, SHALL be retained.

Enclosure 1 NOC-AE-14003135 Page 88 of 98 CRIEEl12-29M]1

-955 Table 1: Evaluation Summon

enfopewdt mg .. ve .e from . th- would et be utlilzed.:

hthe teteeee l.totion The critial bo*dineg eteet am "

The atue ef the of the : Inke ttemte Cooeling

= ; ee . detlved frem the fltm I ASS- "

Scemareo N.b ODlah)*(Outeide intrnal that wouldflaw be Whic igh fill- would be ted . ft-nm with saseqptflde "o What fir-ate394-om Wha etreeterat C.-1964-1 end weterth whther heI Numbee Dintaetg ft.. hued erutma dn the from AIRS-1964-I eonmte obtained by for that ie tr*aalN faor cl would be ued aompoeonewould be conaidered ca pable of mwettp it, Intended Neart~urn-Od. I

t-ttar.1rclt.

tegrtty on reerd and he,, they would teeetle.

-. lution be comblned in thestrtrl evoloftae, Wttl n I . The eiee of Intvel flawe.mdetreetined -ig 1.Deme tNo.

t AES-C-1964-1, Option 1! theoorrenltion eqeeti- provded i. the Ce3alethm.o. of Critical Bneding Street Ceitel bending ttree ea-i.g APTECH Celculetion AES-C- 19"4-5, R-. 0, for Dcallnyed Almlet Beme lrge flaw from 10:00 to 2:00 peg. 12 f31. CeetinS. i. the ECW Sy-tee." Ite. 0.

poMiteo will be nppr.ietcly 5.3 2. The flew Imogt is oeuedd to the -eereet deimnl Doemete 1993. STP STI: 1436366.

kei (-Ieln ed -e1-. U. 5.37 kti) per IrWA-3200(a). 2. Cols., Nethelel endethee.'Tilero (tEJ*id - Centrois Bendieg Stroma; lUe1leg fee Pipemwith a. Arbiaery-GJ*W*I. : rtii*atl boedietg -wmfor I.LPC Sutltn: Gnus 1: Figuer 7-6 from APTECH Sheped Cie uf-reeetiel Flew".

was calcnlated te be epprounaietely 3. ýfe., Nthanienl and othere.

One lonit flaw 12.68" oalculeoen AES-C-IT964-1 18.99 ksi) bed o. Fige 7-6 Predietioc ef Collepe Sutro fee of 12" I oenybe .e-d provided reantod within Rofeeeere1. STP Pipee with Arbitrary Multiple Ieee. flaw fro. 10:00 to 2:00 -e--erne the ceewponet will be Ciumferial Surfae Flaw.".

m - -ed capable of mootieg it. Lneuded 4.Ne used.

STP dece not tee the high-et desige fOctie. de. to the frt that 5. Docunent No. APS-C-l 964-5, sres lecetlen in the EM no applied oompeeet "Evluation of the Sigrtfien- or Sy-e ttt uen- theeempent lree-MeIoading. were proeided. D-e1ein g and Subertahe Cracko eperifi sree.. net veilehle. For NeoeApet Flaw Evel.Ution Method". APTECH The cop.o.t. epe-ifi esaeuee Smrl Conditions the Project AES 93061960-1Q. Roeleire 0,

.e inueoted bmr the applicable etttetttel fae- that December 1994. STP PT[: 30040905.

pipe etree calcul.ttioe at the nede woeld he seedis 2.77 I. The anegeul peition of the nrtral e e 0) ore peiet(e) coerpending to that ed for bending the ret retion it celzlted by neabo Ordiee 2: 922ie-2:

TQ1n Ue eeeletiee teeheiques 2: eetie/ol~eote where load tombieodth mepeerfored i pee leregery/Fa.lted Seieer Ceeditions the Qglten.2:

U.e toeehique contained wlthin eentthtog the indieidel impect ((X/t0)a ef-nh flaw (LLPC only).

Frer 1/8" to Peeeflaws of eoeened in Reth -rs 2 and the applicabl. ASME Sectioe IIl etretere faetor thrt Retrfc e. 2 and 3. APTECH 2. The time of iiternl flaw. m det.eeoid mro

" flewe pee peiely 3. The APTECO Ogew equiet= . Per steucturml woeld beed is 1.39 flinem apply only for eitgle flaw the oltaeione povided in the loeletion ntetgrity eeelysie, peier ealuatone and -ot be teed for AI ILCH Celculetion AS-C.196S4-5, Rae. 0, ASME Section 1.25" Ione tch contined w Refroe

=ithin per Appendie Cr XI, Panlmp1h apply only for single fl.w me.h:e : and beedingetrem Appendix St. thi optLio. STP did not calculate paee 12 .f731, IWA-3400 (b) Ievltie- rnd eeoet he eeperotod and evaluated per the critical beedeg -ero for thie 3. The flaw length is eended to the neerout deciml need for thieoption. the e.~t.ietn tenof ASKIE npLion. pee IWA-3200(.).

AppMdi H or C.

I. The. ngnl" psiti of'thee neuli (13)for bending ebout the net tootle. in elintnd by Two fle. mming the individt imepact (E(W/t)0) feach appcximetely Otion 3: tie. tetoiqe eoteiend within flaw (LLPC oely).

3.0'! long ach One,n 3: U. Rehniqee U.letlee ltefee 2 and 3. APTECH 2. The tive of i.ntel fgw. -edetroinoed esing (Combine Twe Ierge .e..o d i. Refee e 2 and fig-e apply only for ciegle flaw the

leot tion eqeeiee prmvided in the flawoat 10:00 flaw. 3. The AVTFPCHOigro ev0luetio- andcanoet be need for APTECH Celelefon AES]--1964-5, R-e. 0, end 1100 Opptoeitely eenioedwithin Referene I this option. STP did -t ahleelatc pnge 12of31.

4.1" leng e. h epply only for tingle flaw the critical bercin g terees for tide 3. The flew in.gth it weeded te the ne-ret decimeal alo 1:00 end eveletItn*1 d enot he option. pe- IMA-3200a1).

2:W postion) ae-d for this option.

This form when cmplelet. SHALL be roteined.

Enclosure 1 NOC-AE-14003135 Page 89 of 98

.- The val~huesthaoidb rfe Th.rsize of ofth o dls from thehighest stress cO.Fieia 'Me esitirsl headting Waes.as The size of inter Of the the lataotho Coalog Water " drived from the iflipart In AES-Seokesai (OuidO thottwosidftob Which figure would be used Systemawith suooeptible What setrutural C-1964-1 nd whether the N br Diameter) used th from AES-C-1964-S composutis for that size as factor would be used component would be eonsidersed .Notea/Comeets References flaw structural obtained by the Wtrea aofssieo capable of ciethegs its Intended fategrity on record and how they would function" be combined is the structural evaluation I Itegrtiy evaluatton I SCitiulbendiogstromswiltbe t. The slzes of internl flaws er determined using I. Do mntNo. AES-C-1964-1, approximately 35.6 ksi (calculated the correlation equations provided in the "Cetoulation of Critical Bending For Normal/tpdet vaele i1 35.62 hU.)(LEFM - APTECH Calcuiltion AES-C-1964-5, Rev. 0, Stress for Deolloyod Aluminum Service Conditions the Controls Bending Stress; critical page 12 of 31. Broeze Castings in the BCW System."

structural factor tUmt heading somas for LLPC wao 2. The flaw length is uroodedto tie nearest decimal Draft Rv. 0, Drcember 1993.

Component specific stress from would be used is 2.77 calculated to he approximately 46.4 per IWA-3200(a). 2. Not zd.

i. 0.5" 1.4881"the applicable pipe se aed for ksi) based on Figure 7-3 contained Docrent No. AES-C-1964-1, calculation AcS-C-1964-1 clculatizo A TES-CH1Br calculation at the node oorreponding points) to that Emgency/Faulted Service Conditioon the incomponent cerere willi. STP be essumes tie capable of "Calculation Stress of Critical for Deolloyod Bonding Aluminum scctioo'clement. structuore factor that meeting its intended design Brmone Co*tings in the ECW System."

would be uaed is 1.39 function due to the fact that no Rev. 0, December 1993. STP STi:

per Appendix C or applied component 1436366.

Appendix H. strcsscac oodings wern provided. 4. Document No. AES-C-1964-5, "Evaluation oftie Significalce of Doelloying end Subsrotme Cmcs on Critical bending nso will be I. The aimc of internal flowo are determined using Flow Evoluation Method", APTECH For Normul/J~p.t appro.10orately 42.6 kai (calculato the correlation equations provided in ihe Project ABS 93061964-1Q, Revision 0, Service Conditions the value is 42.69 kho)(LEFM - AlTECH Calcolatiot AES-C- 1964-5. Rev. 0, December 1994. STP STI: 30040905.

stroctnaou thotor that Controls Bending Streas; critical page 12 o.31.

Comapoorot spenific o~s fro m would ho u i0277 at bending sess for LLPC was 2. The flaw length is rounded to the nearet decimal tire epplicable pipe otresr calculated to be approximatoly 51.5 per IWA-3200(a).

0.25" Figure tih. pipe and for ksi) based on Figure 7C4conained caluaige7on A ES-C1964- aculaion at the anod. point(o) BEegroc ylulted hn booed Fig

1. ure

- he corresponding to that Service Conditions the mReference I. STP capabes the soctionclementL etructrol factor that comeponent will he cpablo of would be used is 1.39 meetong its intohded design per Appendix C or foronin duo to the fon that no xH. applied component Appodi stres/lodings were provided.

I. STP assumes flaw is on a 6" flange.

Critica] bending stress will be 2. The aizm of internal flows are determined using For *oreatlUpont approximotely 28.0 hai (calculated the orrelation APTEFCH equations Calculation provided in the AES-C-1964-5, Rev. 0, pae 12 of 1 5.

Service Conditions the value is 28.07 khi) (UEFM -

ooControls Bending Stressa critical page 12 of3l.

structural factor that 3. The flaw length is roueded to the Ioarnot decimal Componet specific tome from would be used is 2.77 bending strs for LLPC was per IWA-3200(a).

the applicoble pipe setres and for colvtatoed to be auppmnimatoly46.4 iv. P 2.2148" Figura 74 from APTECH laoegeocy/Faltod hsi) based on Figure 7-4 containd calculation AES-C-1964-l c onaeap od e point EcgCo td in Rference 1. STP aessrro the rocrrepooding tothat ServiceCooditions tho section/elemaet. stofctural factor that component will ho capable of would be urod is 1.39 mreting its intended design per Appendix C or function due to the fact that ao Appeadi iH.. applied component sarses/alloodings were provided.

This form when comiplete, SHALL be retained.

Enclosure 1 NOC-AE-14003135 Page 90 of 98 : Critical Bending Stress Analyses This form when complete, SHALL be retained.

Enclosure 1 NOC-AE-14003135 Page 91 of 98 CREE 12-29261-95 Page 9 of 12 CALCMULA1;ON OF CRITICAL BENDING STRESS FOR DEALLOYED ALUMINUM BRON7JI, CASTINGS ComEonent Geometr Casting Number Nominal Component Size NPS = 1 in.

Weld Number WallThickness Single/Multiple Flaws Nominal Outside Diameter Do =10.75 in Crack Detected Outside Radius Ro = 5.375. in.

Average Dealloying <601/o or Indeterminate Mean Radius RM- = 5.1925 in.

Piping Stress Calculation Pipe Stress Node FanDOa Material Pronerties Outside Diameter Flaw Length Leo= 12 in. Yield Stress Sy 25 ksi S. 6 65 ksi Outside Diameter Flaw Half-Angle 0c= 1.1163 radians Ultimate Stress LOD =

Outside Diameter Flaw Angle 20c 127.9162 degrees Flow Stress Kfcý 4 kss Flaw Angle at Mean Radius 139.9162 degrees Fracture Toughness Gac= 0 65 kI]m.

Flaw Half-Angle at Mean Radius 1.2210 radians Flaw Length at Mean Radius 12.6801 in. Pressure Stress Flaw Half-Length at Mean Radius a* 6.3400 in.

OD/7 Unitless Flaw Angle at Mean Radius 0.3887 Membrane Stress U iUtLod Analysix Comments Angular Position of the Neutral Axis 0- 0.9295radass Case i:

Critical Bending Stress cmc. =118.997 ksl Four small rounded indications of through walldealloying located in a circumferential axis at 10:.00, 11:00, 1:00, and 2:00 Fracture Ansavsis on a 10-inch flange. This evaluation assumes one large flaw with a length equivalent to the farthest extent of each flaw.

Ams= 10.7399 Bm= -26.5926 Cm=a 47.1359 Free surface correction factor for uniform stress Fm= 2.8232 Ai = 8.3667 BB= -18.4393 Q3 = 26.1094 Free surface correction factor for bending stress Pa 2.2464 Critical Bending Stress 5.3730 Ub. = ksi Summar Limit Load Critical Bending Stress ObCLL=1897 Fracture Critical Bending Stress Dominant Failure Mode LiJFR= FR Controlling Critical Bending Stress 5.3730~

This form when complete, SHALL be retained.

Enclosure 1 NOC-AE-14003135 Page 92 of 98 CREE 12-29261-95 Page 10 of 12 CALCULATION OF: CRITICAL BENDING STRESS FOR DE4LOVED ALUMINUM BRON..* CASTINGS F1gw Location hformation Comoonent Geometry Casting Number Nominal Component Size NPS= 4 in Weld Number Wall Thickness [i= .237in Single/Multiple Flaws Nominal Outside Diameter Do = 4. In Crack Detected Outside Radius Ro .2 n Average Dcalloying <60/o or Indeterminate Mean Radius Rm- .31 n Piping Stress Calculation Pipe Stress Node

]Uawliata Material Pronertdes Outside Diameter Flaw Length Lou 0.5 in. Yield Stress Sy = ksl Outside Diameter Flaw Half-Angle 0.1111 radians Ultimate Stress Su = 65.. ksi Sc=

Outside Diameter Flaw Angle 20c= 12.7324 degrees Flow Stress of= 45. ksi 40.0000 degrees Fracture Toughness Kic 65 ks'in.

Flaw Angle at Mean Radius Flaw Half-Angle at Moan Radius 0.3491 radians Flaw Length at Mean Radius 1.4881 in, Pressure Stress Flaw Half-Length at Mean Radius 0,7440 in, Soa Unities s Flaw Angle at Mean Radius 0.1111 Membrane Stress O= 0.5696 ks Limit Load Analysis Comments Angular Position ofthe Neutral Axis 0=1 1,3764 Iradians Case ii:

Critical Bending Stress cFbc=l 46.4182 ksi One indication at 10:00, one-half inch long, with what appears to be rounded ends and no measurable width on a 4-Fracture Anais inch flange.

AM= 7.8788 Bm= -19.0405 Cm= 38.3209 Free surface correction factor for uniform stress FM= 1.2310 AB= 5.7599 B3 = -11.7608 Ca= 19.5445 Free surface correction factor for bending stress Fa= 1.1739 Critical Bending Stress Obo= 35.6205 ksi Summary Limit Load Critical Bending Stress O'osLL=4618 Fracture Critical Bending Stress crboF= 35620 Dominant Failure Mode UWFR=LFR Controlling Critical Bending Stress 35.20 This form when complete, SHALL be retained.

Enclosure 1 NOC-AE-14003135 Page 93 of 98 CREE 12-29261-95 Page II of 12 CALCULATION OF CRITICAL BENDING STRESS FOR DEALLOVED ALUMINUM BRONZE CASTINGS FlawLAocatfon Information Comnonent Geometry Casting Number Nominal Component Size NPS = ain.

t= 0.8 in.

Weld Number WallThickness Single/Multiple Flaws Nominal Outside Diameter Do = 6.6a5_ in.

Crack Detected Outside Radius Ro =3 in.

60 Average Dealloying < %/oor Indeterminate Mean Radius RmLn- 3.1725 in.

Piping Stress Calculation Pipe Stress Node Material Proverties Outside Diameter Flaw Length LOD = 0.25 in. Yield Stress Sy = 25 ksi Outside Diameter Flaw Half-Angle Oc = 0.0377 radians Ultimate Stress degrees S.c=1 65 Ikgi~t Outside Diameter Flaw Angle 20c = 4.3242 Flow Stress Flaw Anglo at Mean Radius 20D = 21.6210 degres Fracture Toughness Kic M65jks'i~In Flaw Half-Angle at Mean Radius OD 0.1887 radians Flaw Length at Mean Radius 1.1972 aI. Pressure Stess Flaw Half-Length at Mean Radius Lnn= in.

Unitless Flaw Angle at Mean Radius 0.0601 Membrane Stress (m 0,7098 ke Umit Load Analysls Angular Position ofthe Neutral Ais F1= -7 radians Case iii:

Critical Bending Stress oba,=F-51. ks5 One "greenish" stain approximately 1/8" diameter at 10:00 position on a 6-inch flange.

Fracture Anavwis AM= 9.2855 BM= -22.7542 CM= 42.6558 Free surface correction factor for uniform stress FM = 1.1188 An= 7.0417 Ba = -15.0449 Ca= 22.7727 Free surface correction factor far bending stress FB = 1.0916 Critical Bending Stress Ube = 42.6966 ksi Limit Load Critical Bending Stress ObrLL=F-51.1 Fracture Critical Bending Stress OXF -141696 Dominant Failure Mode LUFR~l FRI Controlling Critical Bending Stress CniL.ý This form when complete, SHALL be retained.

Enclosure 1 NOC-AE-14003135 Page 94 of 98 CREE 12-29261-95 Page 12 of 12 CALCULATION OF CRITICAL BENDING STRESS FOR DEIL)UYED ALUMINUMBRONZE CASTINGS Flaw Location Information Component Geometry Casting Number Nominal Component Sire NPS = 6 in.

S t- 0.8 n.

Weld Number Wall Thickness Single/Multiple Flaws Nominal Outside Diameter Do = 6.625. in.

Crack Detected Ro = 3.12 n..

Outside Radius Average Dealloying <60%/ or Indeterminate Mean Radius RMm = 3.17 in.

Piping Stress Calculation Pipe Stress Node Flaw~Dn Material Proerties Outside Diameter Flaw Length LOD = 1 in. Yield Stress Sy = ks S&= 6... ksi Outside Diameter Flaw Half-Angle ec= 0.1509 radians Ultimate Stress of= kei Outside Diameter Flaw Angle 20c = 17.2968 degrees Flow Stress Flaw Angle at Mean Radius 20D - 40.0000 degrees Fracture Toughness Kic =1 65 1kli/in.

Flaw Half-Angle at Mean Radius *0.3491 radians On =

Flaw Length at Mean Radius L= 2.2148 in. Pressure Stress a =

Flaw Half-Length at Mean Radius 1.1074 in.

Unitless Flaw Angle at Mean Radius 0.1111 Membrane Stress Onl 6.7098 lksi LimtLoad Analysis Comments Angular Position of the Neutral Aids P= .31 rdin Case ivM Critical Bending Stress One crack-like indication, one-half inch long, within a larger greenish stain with a circumferential length of one inch.

Fracture Anavs AM=

9.2855 BM= -22.7542 Ct= 42Z6558 Free surface correction factor for uniform stress FM= 1.2698 AB= 7.0417 Ba= -15.0449 Ca= 22.7727 Free surface correction factor for bending stress Fa = 1.2093 Critical Bending Stress Obo = 28.0717 kit Summary Limit Load Critical Bending Stress Gbo.LL 633 Fracture Critical Bending Stress Dominant Failure Mode LL/RJFR J Controlling Critical Bending Stress 28.71 This form when complete, SHALL be retained.

Enclosure 1 NOC-AE-14003135 Page 95 of 98 Attachment E Commitment No. 46, in response to RAI B2.1.37-4 Issue 5 Summary of the results of the leak rate analysis Excerpts taken from:

(STP Calculation 14-EW-003, "Flood and Leak Rate Analysis for a Circumferential Crack in Above Ground ECW Piping")

Enclosure 1 NOC-AE-14003135 Page 96 of 98 STP has administrative leakage limits of 8 GPM, 0.3375 GPM, and 2.3 GPM for the Mechnical Auxiliary Building (MAB), Standby Diesel Generator Buiding (SBDG), and the Essential Cooling Water Intake Structure (ECWIS) respectively. Therefore, the maximum total leakage at any time is controlled at approximately 10.5 GPM assuming each of the supplied buildings has at least one actively leaking component.

Flow I" requirements for tne suppiiea safety relatea equipment. unit 1 I rain A li ypical)

Safety-Related TAG/TPNS 1' Design ECW piping Flow Safety Comments Equipment Specified Flow Capacity factor Flow To Equipment (Flow Requirement Inlet GPM Capacity -

GPM (Ref. 4, (Ref. 3) Flow 5, and 6)(3, Requirement)

Standby Diesel 3Q151MDG0134 560 GPM 572 GPM 12GPM Total ECW flow Generator 6"EW1 125WT3 requirement Inter-coolers @ 6.35 Ft per 1350 GPM @

(Ref. 4) Second (FPS) 70' TDH 10"EWi 106WT Standby Diesel 3Q151MSA0134 628 GPM for 628 GPM 0 GPM,4 , 3 Generator Jacket Water 6"EW1 127WT3 CAPABLE Auxiliary Cooler @6.97 FPS SUPPLYING Equipment 0 GPM(4) 1498GPM Skid Coolers 298 GPM for 298 GPM (Ref. 4) Lube Oil 4"EW1129WT3 Cooler @ 7.51 FPS Essential 3V111VCH004 1100GPM 1100 GPM @ 0 GPM14' Tube Side HX HVAC Chillers 7.05 FPS (300 Ton)

Component 3R201NHX101A 15000 GPM 15000 GPM 0 GPM141 Tube Side of HX Cooling Water 30"EW1 102WT Heat 3 Exchanger @ 7.04 FPS Component 3V101VAH001 36 GPM121 75 GPM 39 GPM per Tube Side HX Cooling Water 3"EW1 113WT3 Design Pump 40 to 50 @7.17 FPS Supplementary GPM per 25 GPM Coolers procedure per procedure OPOP02-EW- OPOP02-EW-0001 0001

01) All IJAi I VN numbers are reTerencea rrom Piping and Instrumentation Diagram (I-&lU)

Drawing 5R289F05038, Sht. 1, Rev. 15.

(2) Specification for Safety Class Air Handling Units 3V259VS0005 for the HL&P STPEGS, Page 19, Item C7 for CCW Pumps. Note that normal operating procedure (OPOP02-EW-0001, Rev. 67, page 37 of 67), requires operation to set initial flow 40 to 50 GPM (3) Design Flows are referenced from respective DBD and/or from respective equipment specification documents.

(4) The network flow analysis suggests potential leakages could impact Standby Diesel Generator Auxiliary equipment (Jacket water and lube oil cooler) in the SBDG building, and the Essential HVAC Chiller (300T) and CCWHX in the MAB because estimated flow requirements equals flow capacity (Flow Capacity - Flow requirement = 0 GPM).

Enclosure 1 NOC-AE-14003135 Page 97 of 98 The table above indicates that zero gallon flow safety margin exists for the Standby Diesel Generator Auxiliary equipment (Jacket water and lube oil cooler), Essential HVAC Chiller (300T) and CCWHX.

Additional review of Hydraulic Network Analysis (Ref. MC-5812, Rev. 2) was performed to assure that safety-related equipment with zero margins will not be deprived of cooling flow when ECW leakage is allowed. The Hydraulic Network Analysis was performed for:

1. Normal (two train in operation)

2. Loss of Offsite Power (LOOP)

3. Safety Injection (all three trains in operation).

The mode of operation assuming a single failure in one of the trains during a LOOP was also analyzed. This case, however, assumed cross-tie operation during which 1330 GPM flow was supplied to the cross train. The cross-tie feeding lowered actual ECW flow from a normal design flow of 15,000 GPM to 14,285 GPM. The Log Mean Temperature Difference between the ECW (tube side of CCWHX) and CCW (shell side) using design temperature conditions will remain within design bound as long as the ECW inlet temperature remained less than 980 F. Thus, even at reduced ECW cooling flow, the design CCW heat load can be removed effectively. STP no longer uses cross tie operation; therefore, there is some additional flow capacity margin not credited in this analysis. The analysis review concludes there is flow margin to account for leakage in the ECW system.

The cooling water supply to safety-related equipment has adequate flow margins assuring their design bases functions with allowed loss of essential cooling water. For the remainder of the safety-related equipment, the flow capacity exceeds the design specified flow requirements by more than the 10.5 GPM maximum anticipated combined losses due to leakages.

STP has also estimated crack lengths that are likely to leak cooling water below the administrative limit. For selected upstream components, crack lengths are estimated to limit leakage rate below administrative leakage limits. In order to minimize impact on the downstream safety-related equipment, STP will be monitoring leakage rate as well as length of the crack allowed while a leaking component is in service. The table below summarizes analysis (PICEP) results.

Enclosure 1 NOC-AE-14003135 Page 98 of 98 1

Summary of Acceptable Leak Rates and Critical Crack Sizes( )

Building ID Administrative Flooding Leak Rates Crack Size Pipe Size Limits(2" Limits through (inches) Limiting Evaluated Crack to Leakage Rate Diameter GPM below in Inches (Dealloyed Administrative Material) Limit (Dealloyed material)

Mechanical 8 GPM over 7 8 GPM over 15 8 GPM over 7 7.9 Inch 30 Auxiliary days days days 6.4 Inch 14 Building 7.24 inch 10 8.1 Inch 8 7.72 Inch 6 6.0 Inch 3 Stand-By- 0.3375 GPM 0.1575 GPM 0.3375 GPM 3.1239 Inch 8 Diesel over 7 days over 30 days over 7 days Generator Building ECW Intake 2.3 GPM 545 GPM over 2.3 GPM over 3.018 Inch 24 Structure over 7 days 1.44 hours5.092593e-4 days <br />0.0122 hours <br />7.275132e-5 weeks <br />1.6742e-5 months <br /> 7 days I

1) These crack sizes are not intended to demonstrate structural integrity of the component and shall not be used for that purpose. It is to be used for estimating safety factor available for the observed leakage rate to potential leak rate through the crack size. (For example, 6" long crack is required to attain leak rate of 8 gpm for a 3 inch pipe. The critical crack size at which pipe may collapse is also approximately 6", therefore, to secure a safety factor of 2 one must not allow physical crack longer than 3 inches.)

2) Thirty days is assumed to restore make-up capability to the EC Pond after Design Basis Accident, while 7 days is assumed as sufficient time required establishing temporary pump facility to drain leakages out of MAB, ECWIS, and DGB buildings. Administrative limits are determined to maintain safety factors greater than 2 to flood limit.

==

Conclusion:==

The allowed loss of essential cooling water supply to the safety related equipment has adequate flow margins assuring the design bases functions are met. Also the leakage rate and crack lengths will be monitored further assuring structural integrity of the ECWS components.

Enclosure 2 NOC-AE-14003135 Enclosure 2 STP LRA Changes with Line-in/Line-out Annotations List of Revised LRA Sections RAI Affected LRA Section B2.1.37-4 A1.37 B2.1.37-4 B2.1.37

Enclosure 2 NOC-AE-14003135 Page 1 of 16 AI.37 SELECTIVE LEACHING OF ALUMINUM BRONZE The Selective Leaching of Aluminum Bronze program manages loss of material due to selective leaching of aluminum bronze (copper alloy with greater than eight percent aluminum) components exposed to raw water within the scope of license renewal.

The Selective Leaching of Aluminum Bronze program is an existing program that is implemented by STP procedure. The procedure directs that every six months (not to exceed nine months), an inspection of all aluminum bronze components be completed.

STP has buried piping with less than eight percent aluminum content, and that is not susceptible to dealloying. However, there are welds in which the filler metal is a copper alloy with greater than eight percent aluminum material. Therefore, the procedure directs that a yard walkdown be performed above the buried piping with aluminum bronze welds, from the intake structure to the unit and from the unit to the discharge structure to look for changes in ground conditions that would indicate leakage. If a leak from below-grade weld is discovered by surface water monitoring or during a buried ECW piping inspection, a section of each leaking weld will be removed for destructive examination.

Aluminum bronze (copper alloy with greater than 8 percent aluminum) components which are found to have indications of through-wall dealloying are evaluated, and scheduled for replacement by the corrective action program. Components with indications of through-wall dealloying, a..eoiatod with piping greator than one inch in diametor, will be replaced by the end of the Ree)d 8ig-outage.

Volumetric examinations of aluminum bronze material components that demonstrate external leakage will be performed where the configuration supports this type of examination to conclude with reasonable assurance that cracks are not approaching a critical size.

Profile Examinations (PEs) will be performed on 100% of leaking components. The PEs consists of non-destructive examination of the leaking component for the presence of any visual crack identifications (Inside/outside diameter) and destructive examinations for microstructure, degree of dealloving. Percent of dealloying through wall thickness and chemical composition (including aluminum content). When sufficient material is available for preparation of a test coupon, mechanical properties (ultimate strength, yield strength, and/or fracture toughness) will be obtained.

Pressure tests and bending tests (i.e. Analysis Confirmatory Tests (ACTs)) will be performed on leaking components to obtain maximum pressure and bending moment. The ACTs confirm that the analytical methodology used to calculate the load carrying capacity and structural integrity of the leak components is conservative.

ACTs will be performed on 100% of the leaking components until 3 confirmatory ACTs from 3 different component sizes have been tested. Following the 9 confirmatory ACTs, 20% of all removed leaking aluminum bronze components will be tested until the end of the Period of Extended Operation.

Enclosure 2 NOC-AE-14003135 Page 2 of 16 If at least two leaking components are not identified two years prior to the end of each 10-year testinq interval, a risk-ranked approach based on those components most susceptible to degradation will be used to identify candidate components for removal, and PE and ACT testing will be performed so at least two components are tested during the 10-year interval.

D~trijctk'r~ r~-imin~tion nf r~ich Ir~-ikinn comnnnrrnl romovod fromn service will be porfOrmned to determnine the dogree of dealleying until 10 p~rcent oftosusceptiblo comnponents in the ECWV system are examined. The degreo of dealloying and cracking will be trended by comparing

A Metallugical testingof leaking aluminum bonzn* material components in the ECW syStem r*emomd from ill be pe*Ifored to update the sthmmmainertvnlesto*o load carrying capacfity and to determnine the degree of dealleying by destructive examination.

Metallurgic~al testing of the removed leaking coemponent will be perfoFrmed until at leaSt three di*ff*ent size components of two samples each are tested, and at least nine total samples are tested. The metallurOGal testing will dfractue toughness testing of test samples that include a cr.ackin the dealydmtra where sufficient sample siz supor bed_ tersting.

Additionally, the samples will b-e te-ste-d for c~homical comporsition icungaluminum content, m*echanical properties (such as yield and ultimate tensile strengths) and mF:icr.trcture.

Ultimate tensile strength will be trend-e-d and- comwpared to the acceptance criterion. The degree of dealleying and cracking will be trended by comparn eMmnainreutswt previus eamination results.

Beginning 10 years prior to the period of extended operation; for eac-h 10- year interval, periodic metallurgiGal testing-of aluminum bronze material Gcmp9nents will be peFrformedteUpdate the structural integrity analyses, confiFrm lead*fcrryiRg capacity, .and deter*mine exent degree oe dealloying. For each 10 year interval beginning 10 years prior to the period of e~dendd operatien, 20peFGrcenof leaking above ground components removed fromI service, but at least one, will be tested every five years. Tonsile test samples fromn a removed component will be tested to Onclude both leaking and noen leaking portions ef the component. if at least w leaking com~ponents are not identified two years prior to the end of each 10 year testing interval, a risk ranked approach based- on those components most susceptible to degradation will be used to fiden~tify candidate components for removal and testing so at least two components are tested during the 10 year nevl The sam ples will be tested for chemical composition; including alumninum content, mnechanical properties (such as yield and ultimate tensile Strengtnsj and mIcreFstruerure. Thno samples will bo destructively eXamninedt determin.e the degree of dealleying and thepresten,,,,e o.f c-ra-cks. Ultimate strength, yield stren-gth, and/or fracture tou-ghness UItimate tensile s*tength will be trended and compared to the acceptance criterion. The degree of dealloying and cracking will be trended by comparing examination results with previous examination results.

An engineering evaluation will be performed at the end of each PE and ACT teeti-e to confirm the analytical methodology used to calculate the load carrying capacity and structural integrity of the leak components is conservative. deteFrmine ifthe sample size r ires adjustment based on the re6sut Of the testso.

The acceptance criterion for ultimate tensi*e strength and yield strength values of dealloyed aluminum bronze material is greater than or equal to 30 ksi.

Enclosure 2 NOC-AE-14003135 Page 3 of 16 The acceptance criterion for the fracture toughness is greater than or equal to 65 ksi in112 for non-dealloyed aluminum bronze castings and at welded joints in the heat affected zones. The acceptan~e critorion for yield strength iSequal to or greater th-an one half of the ultfimnate St~eR§4h.

If a criterion is not met, the condition will be documented in the corrective action program to perform a structural integrity analysis to confirm that the load carrying capacity of the tested material remains adequate to support the intended function of the ECW system through the period of extended operation.

Enclosure 2 NOC-AE-14003135 Page 4 of 16 B2.1.37 Selective Leaching of Aluminum Bronze Program Description The Selective Leaching of Aluminum Bronze program manages loss of material due to selective leaching for aluminum bronze (copper alloy with greater than eight percent aluminum) components exposed to raw water within the scope of license renewal. This plant-specific program will use requirements of the Selective Leaching of Materials program (B2.1.17) specifically relating to aluminum bronze components. The selective leaching of aluminum bronze is applied in addition to the Open-Cycle Cooling Water program (B2.1.9).

The Selective Leaching of Aluminum Bronze program is an existing program that is implemented by plant procedure. This procedure directs that every six months (not to exceed nine months), an inspection of aluminum bronze (copper alloy with greater than eight percent aluminum) components be completed.

STP has buried copper piping with less than eight percent aluminum content that is not susceptible to dealloying. However, there are welds in which the filler metal is copper alloy with greater than eight percent aluminum material. Therefore, the procedure directs that a yard walkdown be performed above the buried piping with aluminum bronze welds, from the intake structure to the unit and from the unit to the discharge structure to look for changes in ground conditions that indicate leakage.

Aluminum bronze (copper alloy with greater than 8 percent aluminum) components which are found to have indications of through-wall dealloying are evaluated, and scheduled for replacement by the corrective action program. Components with indications of through-wall dealloying, greater than one inch, will be replaced by the end of the next Fef-ueling-outage.

Periodic destructive and non-destructive examinations of aluminum bronze material components will be performed to update the analytical methodology used to demonstrate structural integrity aialyeee confirm load carrying capacity, and determine etent degree of dealloying.

Aging Management Program Elements The results of an evaluation of each element against the 10 elements described in Appendix A of NUREG-1 800, StandardReview Plan for Review of License Renewal Applications for Nuclear Power Plants are provided below.

Scope of Program (Element 1)

The Selective Leaching of Aluminum Bronze program manages loss of material due to selective leaching for aluminum bronze (copper alloy with greater than eight percent aluminum) pumps, piping welds and valve bodies exposed to raw water within the scope of license renewal. These aluminum bronze (copper alloy with greater than eight percent aluminum) components with raw water internal environments are susceptible to loss of material due to selective leaching (dealloying).

STP has analyzed the effects of dealloying and found that the degradation is slow so that rapid or catastrophic failure is not a consideration.

Enclosure 2 NOC-AE-14003135 Page 5 of 16 A structural integrity analysis performed when dealloying was first identified confirmed that 100 percent dealloyed aluminum bronze material retains sufficient load carrying capacity. This structural integrity analysis determined that the leakage can be detected before the flaw reaches a limiting size that would affect the intended functions of the essential cooling water and essential cooling water screen wash system.

Volumetri. examinations of aluminum bronze material components that demonstrtate etern.al leakage willlr*.*,i*.o be performned

.wmmm where the configuration suppef this typo of exua.mnin-ation Go

v ~vmmvm,,m-----------------------------vL---vL . .u~ -,vm~m~vL D RturI.'t ... i,.,e.stil.. 6...* . L...G.t.K, a., .not ppFr,, .ina "GFITIcui 2e.,.

Destructive examination of each lcakin~i compoenet removed froM see~ice will be Performned 1÷,, * -- Zl__ pf'*lAI OffeFtoRminenS egree o:t GealIIYIng Uffili W percenI AT Mne s;uscrpjIjIoe comAponents !n Me v system are exam.;ied. The degree of deall.ying and cr.acking Will be t"e-ded by comparing examfination results with previous examination results.

Metallurgical testing of leaking aluminum bronze mnaterial components in the ECGW smystem removed fro be performed to update the str-6-uctual inegrity analyses, to confFirm Ae~cowll lead carrYing capacity and to deteFrmine the degree of dealleying by destructiVe examinRation.

Metallugicaal testing of the removed leaking coemponent will be performsed until at least three different size components of two samples each are tested, and at least n;ine totMal samnples, are tested. The mnetallurgical testing will include fracture toughness testing of test samples that include a crack in the deallvyed material where sufficient sam;nple size supps bend testing.

Additionally, the samples will be tested for chemical comnpoSition including aluminum1F content, mnechanical pFope~ter, (such as, yield and ultimate tensile strengths) and ~icroctructure-.

Ultim~ate tensile stren~gth Will be tren~ded and co9mpared to the acceptance criterion. Degree Of dealloying anid c~raking Will be trended by compain exmnation results With previou examination results.

As pa~t of the testing descnribhed- above s aples fromn three aluminum bron~ze comAponents removed fro- erise.in 20-12 will bhe tested for chemicaal comAposition incGluding aluFmium con~tent, mnechanical P~prepties (such as yield an~d ultimate tensile Strengths) and micreFstructureA. The -Alumnu bWW Frone samples, exposed to ECGW systemA raw water envromet will come fromn a pump shaft line casing pipe and firomi twov small cast valve bodies. The pump shaft line casing pipe was remoeved fromA cervie in 2012 and the two small cast valve bodies will be remoeved from eo._ -_cin 2012. The components to be sampled halve been exposed to EGCW cycteR maw wator environment since the ECWGV systemA entered Seirec.

Priority Will be given to selecting 100% dealleyrd component samples. STP w*illcmplete this, teSting prior to the end of 2012.

Beginning 10 years prior to the period of extended operation for each 10 year inter.'al, periodic.

mnetallugical testing will be perforeFd- to confirmF that the lead carrying capaci4ty of aged dealleyed aluminum bronze mnaterial inthe ECWA systemf remains adequate to suppo~te intended function of the sytmdrn'he period of extended qpopration. For each 10 year interval beginning 10 years prier to the period of extended operation, 20 percent of leakn above ground components remoeved fromA cerise, but at least one, will be te-sted- evewy iv years. Tensile test samples fromn a removed comRponent Will be tested to incl.ude both leaking and non leaking portions of the component.

Enclosure 2 NOC-AE-14003135 Page 6 of 16 if at loact two leaking components are not identified two yearS prior to the end of each 10 year testing interal, arick ranked approAch based on thso components most susceptible to dogradation will be used to identify c_AndVdato compoRnRet for romrmval and testing so at least Meo components aro tested during the 10 year interyal. The componont will be Goctioned to size the inside su.face flaws, if present, and... mapping of the dealleyed sufa, e areas for doterm~ining the e~dent degrfee of the dealleying. The samples will be tested foFrchemica composition including alu miR Mnum- cntent, mecshanical PFpeopoier. (such as yield and ultimate tensile strengths) and m~icrostrcuroU~. Ultimate ten~sile strength will be trended and coempared to the acceptance criterion. The degree of dealloying and c~racking will be trended by compringexamnation results withprioseantoneul.

An engineering evaluation will be performl d atlltVhpe en,d of eacih test to dete1rmvinei the samIple sizreuirs ad~justment based on the results of the tests. The sturutural integrity analyses will be udate as equired to validate adequate load carr,'ing capacity.

Plant procedure dierects that over; six months (net to exceed nine moneths) an inspection of all susc~eptible alumilnuim. bronze (coepper alloy with greater than eight pe~rcent aluminum) above ground components be completed to identify anY components that sh;ow evyfide~nce of doalloying. Aluminum bernze (copper alloy with greater than 8 percen~t alumfinumR) components whicsh are fu-nd- to h-ave indications of through wall deallcying are evaluated, and scheduled for replasemnent by the corrective action program. ComAponents greater t-han onRe finch will be replaced by the enRd of the subsequent refueling outage.

STP has buried copper alloy piping with less than eight percent aluminum that is not susceptible to dealloying. However, there are welds in which the filler metal is copper alloy with greater than eight percent aluminum material. Therefore, the procedure directs that a yard walkdown be performed above the buried piping aluminum bronze welds, from the intake structure to the unit and from the unit to the discharge structure to look for changes in ground conditions that indicate leakage. If leaking below-grade welds are discovered by surface water monitoring or during a buried ECW piping inspection, a section of each leaking weld will be removed for destructive examination.

Preventive Actions (Element 2)

The Selective Leaching of Aluminum Bronze program does not prevent degradation due to aging effects but provides for inspections to detect aging degradation prior to the loss of intended functions, replacement of degraded components, and testing to confirm lead carrying capacity of aged dealloyed aluminum bronze material .

The Open-Cycle Cooling Water program (132.1 .9) uses an oxidizing biocide treatment (sodium hypochlorite and sodium bromide) to reduce the potential for microbiologically influenced corrosion.

Parameters Monitored or Inspected (Element 3)

The Selective Leaching of Aluminum Bronze program includes visual inspections every six months (not to exceed nine months) for dealloying in all susceptible aluminum bronze (copper alloy with greater than eight percent aluminum) components.

Enclosure 2 NOC-AE-14003135 Page 7 of 16 Upon discovery of visual evidence of througqh-wall dealloving. components are evaluated against the analytical methodology used to calculate the load carrying capacity and structural integrity of the leak components to verify the continued use of the component until replaced.

DUring these inspeptiens,if evidence of through wall deallying is diSc-*ered, the -omponent-arc evaluated- and scnheduled for replacaement by the correctfive action program. Components, greater than one incah, will be roplaccd by the end of the Re~d rofucling outage.

Every 6 months, a walkdown is performed above the buried essential cooling water piping containing copper alloy welds with aluminum content greater than 8 percent. During the walkdown of the buried essential cooling water piping, the ground is observed for conditions that would indicate leakage due to selective leaching. Whenever aluminum bronze materials are exposed during inspection of the buried essential cooling water piping, the components are examined for indications of selective leaching. If leaking below-grade welds are discovered by surface water monitoring or during a buried ECW piping inspection, a section of each leaking weld will be removed for destructive examination.

Volumetric examinations of leaking aluminum bronze material components that demonstrate external leakage will be performed where the configuration supports this type of examination to conclude with reasonable assurance that cracks are not approaching a critical size.

Profile Examinations (PEs) will be performed on 100% of leaking components through the end of Period of Extended Operation. The PE consists of non-destructive examination of the leaking component for the presence of any visual crack identifications (inside/outside surfaces) and distractive examinations for microstructure, degree of dealloying., percent of dealloying through wall thickness and chemical composition (including aluminum content). When sufficient material is available for preparation of a test coupon, mechanical properties (e..q ultimate strength, yield strength, and/or fracture toughness) will be obtained. The PE results provide the physical, metallurgical and mechanical properties used to trend the progression of dealloving and to confirm the acceptability of using the existing correlation of observed OD crack angle as the means by which STP proiects internal degradation.

Pressure and bending moment tests (i.e. analysis Confirmatory Tests(ACTs)) will be performed on leaking components to obtain pressure and bending moment. The ACTs will be used to confirm the analytical methodology used to calculate the load carryinq capacity and structural integrity of the leaking components is conservative. .The ACT confirms that the analytical methodology used to calculate the load carrying capacity and structural integrity of the leaking components is conservative.

ACTs will be performed on 100% of the leaking components until 3 confirmatory ACTs from 3 different component sizes have been tested. Following the 9 confirmatory ACTs, 20% of all removed leaking aluminum bronze components will have ACTs performed until the end of the Period of Extended Operation If at least two leaking components are not identified two years prior to the end of each 10 year testing interval, a risk-ranked approach based on those components most susceptible to de-gradation will be used to identify candidate components for removal, and PE and ACT testinq will be performed so at least two components are tested during the 10-year interval.

Enclosure 2 NOC-AE-14003135 Page 8 of 16 Detection of Aging Effects (Element 4)

The Selective Leaching of Aluminum Bronze program includes visual inspection of aluminum bronze (copper alloy with greater than eight percent aluminum) components to determine if selective leaching of these components is occurring.

EvYer; six months6 (not to oXcoed nine months), an inspection of SUGceptiblo above groun aluminum beroze (copper alloy with greater than eight percent aluminum) componentei com~pleted to identify any compn~en8ts that show evidence of doalloying. EvYer; 6 moneths, a vall*dIvn is povlormed above the buried essential cooling water piping containing copper alloy welds with an AluminumR content greater than 8 percent. DuFrin the walkdowR, the coil is obascred to iden~tify condfition~s that mnay be an indication of leakage due to selective leaching9.

V'.henever aluminum bGroze m~atterials are exposed during inspection of the buried essential cooling water and ECWV sc-reen wash system piping, the componentS Jare exam~inedfo inRdications of selective leaching. if leaking below grade welds are discoereed. by su~face water mon9itoring Or during a buried ECWV pipin ispetion, a secation of each leaking we~ld w'ill be 4 4

.. .~ n A fn Alnr i -+; , .n nI. ii n,.

i Aluminum berone (copper alley with greater than 8 percent aluminum) comnponents which arc f- A #nin nhiait k( VkmAaAAI fn +k ki ii rAa a H, fi 1, +. rA Ait ekn- A It A f C1ri W GI'WW r-I V 17MCP CP FULIM VVCX V CM,,77 replamement by the corrective actien *prgrmmm. G vmpmnemtS, greater than one inch, will be replaced by the end of the next refuelfing outage.

Volumetric examinations, when configuration allows, of aluminum bronze material components that demonstrate external leakage will be used pe"..,edwhere4 te configuration. s.....

this type of ex.am.ination to conclude with reasonable assurance that cracks are not approaching a critical size.

The PE results provide the physical, metallurgical, and mechanical properties used to trend the progression of dealloving and to confirm the acceptability of using the existing correlation of observed outside diameter (OD) crack angle to project internal degradation.

The ACTs are used to confirm the' analytical methodology used to calculate the load carrying capacity and structural integrity of the leak components is conservative.

Destructive exmnto feach leakin copnnt removed fromA sewrsie will be pe~feFmed to aetermnine the aegree OT aealleying uni or the SUscopmibc comIponents in the Fiuvv auprcet system are examined. The degree of dealleying *craking and Will be tRonded by coIng examination results with previous examination results.

Metallur;gial testig of leaking aluminuml.;Fn bronze material compnemnts in the E=CA system remvved froem sermice will iiedbe pevfG to update the struc tural integrity analyses, to cnifirm load caFmYing capacity and to determmine the degree of dealloyimg by des*trutiVe e*xam*ination.

MetallUrmgical testing of the reFmoved leaking compnllent Will be peFvmmmmm-d until at IlaVst three difmfervt size components of tvw samples each are tested, and at least nine total samples, are tested. ThemvmetalFluri*a' testing will include fFa*ture toughnesms testing Of test sample that include a crack in the deallmyed material where sufficiVent sample size supports bend testing.

Additionally, the samples will be tested for chemical com.position iRcluding aluminum content, m~echanical properties, (such as, yield and ultimate tensile strengths) and mnicrostructure-.

Ultimate tensile strength will be tPrnded and compared to the acceptance criterion.

Enclosure 2 NOC-AE-14003135 Page 9 of 16 Dogroc of dealleying and cr.acking will be trended bycomprn emnftionp rocul-tr, With As pan*of the testing decriFbed above, i a imples fromA three AlumR*inu*

m bnze compenente remevd from Vvin 2012 wil1 be týeted for G, r.chemica tcmpiti including A aluminum content, Mochanical PFpeopoies (euczh as yield and ultimate tonsile stren~gths) and m'iGcrOetructuro. The aluminum bronze samples exporsed to EGW 6yctemA raW water enionet will coem~e fromn a pump 6haft line casing pipe and fromA two sm-all c-ast v-alve bodice. The pump shaft line casing pipe Wac Frnemved- fromn Ser~icc in 2012 and the two em~ail c:at valve bodies will be removed f*ro . , ... o in 2012. The eam,* comrponent have been, exposed to ECW system raw water enViAronmet since the ECW system entered

,eerice.

Poity will be given to 6electing 100% dVallvyed co*mpo*nvent samples. STP will complete this testing prior to the en~d of 2012.

Beginning 10 years6 prior to the period-of exten-ded operation forF eacanh 10 year intorwai, periodic.

mnetallugic~al testing will be performePd- to-conAfirmR that the load carr,'ing capacity of aged deallyed aluminum bronze material in the EWVV system romaine adequate to SUppolt the intended function of the system during the perFid of e)dended operation. For V-Ach I1 year

,,teval beginning 10 years prior to the peried of evended operation, 20 percent of leak i-above groun~d components removed fromA 6ervhe, but at least one, will be tested oe;five yeaFr. Tensile test samples from a removed compo*nent will be tested to include both leaking an~d non leakin~g pGrtiO9R of thea com~ponent. Ifat leasit two; leaking components* areno identified Meo years prior to the end of eacsh 10 year testing interwal, a risk ranked approac based on these components moest susceptible to degradatfion will be ursed to identify csandidate compon~en~ts for remoeval and testing so at least two components are tested during the 10 year Snterval. The component will bhe sec-tioned to soize the inside surfacae flaws, if present, andior to mnap the dealco surfac areas for determinfinig the extent degree of the dealloying.Th samples will beP testePd- for chemical comRposition including alum~in;um content, m~echania ffpropoies, (such as yield and ultimate tensile strengths) and mnic~rotruc~tur. Ultimate tensile stFeIgth will be trended and compared to the acceptance criterion;. The degree Of dIallcying and c~raking will be trended by cOmprn examination results With previou exmiation Feeults.

An engineering evaluation will be performed at the end of each PE and ACTs testing interval to confirm the analytical methodology used to calculate the load carrying capacity and structural integrity of the leak components is conservative, test to determlfine if the sample size reuie adjustment based o; the results of the tests.

The analytical methodology used to demonstrate structural integrity will be updated as required to confirm that ti-lvaidame-the adequate load carrying capacity of the aluminum bronze material is adequate oI sup1ort the inte ndedVfunction of the ECW system throuIgh the period of extended operation.

Monitoring and Trending (Element 5)

The degree of dealloying and cracking will be trended by comparing examination results with previous examination results.

Enclosure 2 NOC-AE-14003135 Page 10 of 16 Ultimate strength, yield strength, and/or fracture toughness will be trended. The-+ltumate te*;Gie *t*regth rFeut1 rFrom the m 1etalurgi*sal aluminu1 bronze materiAl tpesing will be monitored and trended. Trending provides monitoring of the degree of dealloying, the degree of cracking, and-the ultimate tensile-strength, yield strength and fracture toughness for aging aluminum bronze material through the period of extended operation.

Upon completion of each test, the data trended will be evaluated against the acceptance criteria, for ultimate tensile str*egth.

Acceptance Criteria (Element 6)

Dealloying of al-Ruminu bronze csomponents ic a well known phenomenon at S-TP. A4long termA mpr...mont plan was, developed in May 1992. As -ares-ult of those analyses, alumi.n bronze (copper alloys with greater than eight percen9t almnu)cmponents are visually Sinspected ee; sI months (not to emncemed nine months). Upon discoevery of visual evidencse of through wall dealloying, components are evaluated, aid scheduled folr replaement by, he crrective action programn. Components, greater than one inch, will be replaced by the end ot the nAe, refueling .ue outage. tothe sloAw nature of dallying, this replacrvement antor.

proVides reasonable assurance that the systems and compoenets within the scope of this programn will continue to pe~fFRm their intended functions consistent with the current lien~sing basis for the period of extended operation.

The ASME Code Section Xl structural factors for the normal/uDset conditions (2.77) as well as the emergency and faulted conditions (1.39) will be applied for acceptance of dealloyed conditions.

The acceptance criterion for ultimate tens ultimate strength and yield strength values of dealloyed aluminum bronze material is greater than or equal to 30 ksi.

The acceptance criterion for the fracture toughness is greater than or equal to 65 ksi in1' 2 for non-dealloyed aluminum bronze castings and at welded joints in the heat affected zones.

The accreptan-e- c-riterionR for yield strength is equal to or greater than one-half of the uldtimate stFength.

If an acceptance criterion is not met, the condition will be documented in the corrective action program and te-pe-4teIm a structural integrity analysis will be performed to confirm that the load carrying capacity of the tested material remains adequate to support the intended function of the ECW System through the period of extended operation.

Corrective Actions (Element 7)

Upon discovery of visual evidence of through-wall dealloying, components are evaluated against the analytical methodology used to calculate the load carrying capacity and structural integrity of the leak components, and components are scheduled for replacement by the next outage, and scheduled for replacement by the next outage.

When the ACT does not confirm the structural integrity analyses, STP follows its corrective action program as defined in the 10 CFR Part 50 Appendix B, to address emergent conditions to assure continued safe operation of the units.

Enclosure 2 NOC-AE-14003135 Page 11 of 16 A Operational Decision-Making Issue (ODMI) detailing specific steps based on identified conditions will be developed. These steps include notifying the control room of the condition, initiating a condition report and performing field walkdowns to determine compensatory action.

STP site QA procedures, review and approval process, and administrative controls are implemented in accordance with the requirements of 10 CFR 50 Appendix B and are acceptable in addressing corrective actions. The QA program includes elements of corrective action, and is applicable to the safety-related and nonsafety-related systems, structures and components that are subject to aging management review.

ConfirmationProcess (Element 8)

STP site QA procedures, review and approval process, and administrative controls are implemented in accordance with the requirements of 10 CFR 50 Appendix B and are acceptable in addressing confirmation processes and administrative controls. The QA program includes elements of corrective action, and is applicable to the safety-related and nonsafety-related systems, structures and components that are subject to aging management review.

Administrative Controls (Element 9)

See Element 8.

OperatingExperience (Element 10)

A review of the STP plant-specific operating experience indicates that macrofouling general corrosion erosion-corrosion, and through-wall dealloying have been observed in a ECW system components. STP has concluded that the through-wall dealloying degradation is slow in aluminum bronze cast components therefore rapid or catastrophic failure is not likely to occur. STP has determined that the leakage can be detected before the flaw reaches a limiting size that would affect the intended functions of the essential cooling water and essential cooling water screen wash system. A long range improvement plan and engineering evaluation were developed to deal with the dealloying of aluminum bronze components when dealloying has been identified. Based on these analyses, the approach has been to evaluate components, and schedule replacement by the corrective action program. Co,,mponnt with indicatienseof through wall dealleying, aserocated with piping greater than onc finch in diameter, will be.. placod by the end of the nedt refueling outage. A monitoring and inspection program provides confidence in the ability to detect the leakage.

Enhancements Prior to the period of extended operation, the following enhancements will be implemented in the following program elements:

Scopo of P4ogram (Eement 1)

Pro~edures Wwilbe nRhManced to:

Enclosure 2 NOC-AE-14003135 Page 12 of 16 Perform. volumotric examinations o*f "luinu bronze material comp.nents that demonstrate e~deFnal leakage whero the configuration supports this type of eXamination to concrlude wfith reasonable assuraneo that crac-ks- a;re not approaching -A critical si6ze-.

Pe*orm detructiVe e.xAm.A.toR of each le.king c.mponent removed from .... e t*o determine th oge f dealleying until 10 percent of the 6usceptiblo components inth ECWV systemA are oXamined. The degrop of dealleying and cracking will be trendod-by compaing eamination results with previous examination results.

Prior to the period of extended operation, mnetallurgical testing of leaking aluminum bron;Zo mnaterial components in the EGW systemA removed from RpcorPic will be perfoFrmed4to update the etructural integrity analyses, to confim lead carigcpct and to determine the degree of deal.ying by destructive examinatio.Mea.. lteting of the rem leaking component will be performned until at least three differenRt si~ze componentsm of twoe samplers each are tested, and at least nine total eamples are tested. The m~etallurgica testing will include fracture toughness testing of test samplec that include a crack inth dealloyed material where sufficient sample size supports bend testing. Additionally, the samples will be tested for chem~ical com~position; including aluFminumA content, m~echanical properties, (such ac yield and ultimate tensile strengths,) and m~icrostructuro. UlJtimat tensile strength will be trend-ed- and comnpared to the accveptance criterion. The degree of dealloying and cracking will be trendod by comparin exmiation results with previou emaminRation Fresults-.

As part of the testing descr.ibed above, test sox sam~ples from threez aluminnumA bFroze components, re-moved- from spr~ce in; 2012 for chemicnnal co-m-position including alU~quminu content, mnechanical propertice (such as yield and-ultmat tnile tegths,) and FiroGFMUStrutue. The aluminums bronze test samples exposed to ECWGV system raw water enviFronment are to come fromA a pump shaft line casing pipe and fromn two Small cast valve bodies. The pump shaft line casing pipws emved from corviee in 2012 and the two small cast valve bodies W~i bermvdfo11roi 02 Priority shall begiven to selectin~g 100% dealleyed comAponent samples.

Beginning 10 years prior to the perio-d o-f exten-ded operation; for each 10 year ner'l periodicsally test sample ofaoegrund ECWV system components removed fromA service for chemical copoito inldn g aluminum cBontent, m~echanic*al propertfies (such as yield and ultimate tensile strengths) and mirsrcu e.Fr eac-h 1.0 year interyal beginning 10 years6 prior to the period of extended operation, 20 percent of leaking coemponents, ramoved frmsri, but at leasit one, will be tested every' five years. Tensile test samples fro a dcomponent shall be tested to include both leaking and noný

?em leaking portions of the comAponent. if at least two leaking components are noet identfe tWo years prior to the end of eacsh 10 year testing interdal, a risk ranked approach will be used based-on tho-se co-mponents mest suscoptible to degradation to identify candidate somponents for removal and testing so at least two com~pon~ents are tested during the 10 year interval. The component wil! bhe scindto size the isid surface flaws., if present, andior mapping of the dealloyed 6urfacoa are-as for determ~ining the degree of the dealleying. The samnples will be tested foFrchemical composition including alumfinum content, mnechanical properties (such as yield and ultimate tensile strengths) and mniGroStructure.

Enclosure 2 NOC-AE-14003135 Page 13 of 16 Ultimate tensile strength will be teRndod and coempared to the acceptance criterion. The degree of deallmying and cra.cking wfill be trmeled by r,,cmring ex*amintion results with viu examination resulta.

Performn an egnrig evaluation at the end OF e-ac-h test te determ~ine if the sample size raquires adljustment based en the results of the tests.

PerfermA a structural integrity analysis to confirmA that the lead carr,'ing capacity of th tested mnaterial remains adequate to support the intended functfion of the ECWV syste through the period of extended operation.

ParametersMonitored and Inspected (Element 3)

Procedures will be enhanced to:

Indicate that whenever aluminum bronze materials are exposed during inspection of the buried essential cooling water piping, the components are examined for indications of selective leaching. If leaking below-grade welds are discovered by surface water monitoring or during a buried ECW piping inspection, a section of each leaking weld will be removed for destructive examination.

Perform volumetric examinations of leaking aluminum bronze material components that demonstrate external leakage where the configuration supports this type of examination to conclude with reasonable assurance that cracks are not approaching a critical size.

Perform Profile Examinations (PE) on 100% of leaking components. The PE consists of non-destructively examination of the leaking component for the presence of any visual crack identifications (Inside/outside diameter) and distractive examinations for microstructure, degree of dealloving, percent of dealloying through wall thickness and chemical composition (including aluminum content). When sufficient material is available for preparation of a test coupon, mechanical properties (ultimate strength, yield strength, and/or fracture toughness) will be obtained.

Perform pressure and bending tests (Analysis Confirmatory Tests) on leaking components to obtain maximum pressure and bending moment.

Require ACTs be performed on 100% of the leaking components until 3 confirmatory ACTs from 3 different component sizes have been tested. Following the 9 confirmatory ACTs then 20% of all removed leaking aluminum bronze components will have ACTs performed until the end of the Period of Extended Operation.

Require at least two components be tested (PEs and ACTs) during the each 10-year interval. If at least two leaking components are not identified two years prior to the end of each 10 year testing interval, a risk-ranked approach based on those components most susceptible to degradation will be used to identify candidate components for removal testing.

Enclosure 2 NOC-AE-14003135 Page 14 of 16 Detection of Aging Effects (Element 4)

Procedures will be enhanced to:

Indicate that whenever aluminum bronze materials are exposed during inspection of the buried essential cooling water piping, the components are examined for indications of selective leaching. If leaking below-grade welds are discovered by surface water monitoring or during a buried ECW piping inspection, a section of each leaking weld will be removed for destructive examination.

Perform volumetric examinations of leaking aluminum bronze mateiiaI-components that demonstrate e.ternal leakage where the configuration supports this type of examination to conclude with reasonable assurance that cracks are not approaching a critical size.

rerrorm uoesrutwiv examination (94; -AA- 1 ]K-aK om !nen remoEVeO fromserwicc -IV determnine the dcgroo of dealleying until 10 percen-t- of the cSusceptible components in h 9GW system are examined. The degree of dealleying and cracking Will be trended-by cmaig examination results with previous ex~aminRation results.

Meta*l*urgial testing of leaking alumninuMm. bhronz.ie material Gomp*onent in the E.W-=rA' System removed fromA 6er~ice il be per Ifored to update the Strucua integrit analyses, to confirmA camole size lead cUD caFF/inge benvt tting capacity . and toAdiinalth vte deteFrmine the degreeaolcwl of do.alleying b by odeStructiv cei e examination. Metallurgfical testing Of the Frnemved leaking comnponen~t will be perfored until at least three different size components of two samples each are tested, and at least nine total samples are tet-,ed. The metallUrgical testing will include fracture tough*ne testing of test samploc that incGlude a crack in the dealleyod mnaterial where sufficient

...... .. s... iz . . . ... b. e.. n . .. .. . . .A d . . ei.. e .. a .i .. . 6,e

. .. .. . .... b. e. .. .. . ... ... ..... .

com*po+ition includi'ng aluminum content, m"ec'hanical properties (such as yield and ultimate tensile strengths) and micros~twruture. Ultimate tensile ctrength will be trended and compared to the acceptanceecriterion. The degree of dealloying and cracking will be ternded b, oprn examination results with previou6 examination results.

As part of the testing described above, test sox sampleS from three aluminumA bFroz-e components evmm*imi c 4v removead blvu uvvv.iccfrommvvPeA'ce vemomvmlnt :2012 irm m~cr*vfor chemnical m invl~ composition roiy including ni alumiu egvnt content, vmehanical prperties (such as yield and ultimate tensilestmRengths) and

,.cr-- tu-u---e. The aluminum bronze test samples exposed to E-CW systemA raw water envionmet are to come#frm a pump shaft lin asnpipe and fromn two sm~all cast valve bodies. The pump shaft line casing pipws emved fromn serMie in 2012 and the two selecting 100% dealloyed component samples-Beginning 10 years prior to the perioKd of extended operation foreach 10 year interFal

--.. 'A rouriooic~uiv* tet~t ~imoie~ i UT JDOVU urouno z~.vv evctom comoonents romovoo irom ~er:ico for chemica c l o ncu alumninum coVntent, mAe*han**al prperties (such as yield Sltima s engths)

,nter,.al and m*,icstruGtue. For each 10 year beginning10 years prert the period of extended operation, 20 percent of leaking components remoed fom sr~i-,Wbt a;t least one, will be tested oveny five years. Tensile test samples fro aeoed coemponent shall be tested to include both leaking and non leaking portions of the component.

Enclosure 2 NOC-AE-14003135 Page 15 of 16 if at least tw:o leaking components are not identified two yoars prior to tho end of oach 10 ye'ar testing interyaI, a rick ranked approach will bhe ussed- bhaed- on~ thosse components moest susceptible to degradation to identify candidato coemponents, for Femeyal and tcsting eo at least two components are tested during the 10 year neF l The component will be sectioned to- siu-ze the inside surf-ace flaws, if present, anR.dlor mapping of the doalloyed surfacae areas for deteFrmining the degree of the dealleyfing. The samples will be tocted for chemical comFposition including aluminum content, mnechanical properties (such ae yield and ultimate tensile 6trengths) and micrestructUre. Ultimate tensile Strength will be teRnded and compared to the acceptanco criterioen. The degree of dcalloyfing and crFacking will be trendod by coemparfing examnination results With pre iou exam.ination resulte.

Perform an engineering evaluation at the end of each PE and ACTs testing interval to confirm the analytical methodology used to calculate the load carrying capacity and structural integrity of the leak coml~onents is conservative, test to dete~rmine if thes soample requr adjustment based on the results of the tests;.

sire Uodate the analytical methodolo-gy used to demonstrate Pe~fGFm-a structural integrity analysis as required confirming te reiifiFFA that the load carrying capacity of the aluminum bronze material remains adequate to support the intended function of the ECW system through the period of extended operation.

Monitoring and Trending (Element 5)

Procedures will be enhanced to:

Trend the degree of dealloying and cracking by comparing examination results with previous examination results.

Trend ultimate tensile strength. yield strength, and/er fracture toughness results from the mnetallurglical aluminum bronRze mnaterial PE testing.

Upen completion of each test, evaluate the data trended against the acceptance criteria fcr ultimate tensile strength.

Acceptance Criteria (Element 6)

Procedures will be enhanced to:

S~ecify the ASMVE Cede Section Xl structural factors for the normal/upset conditions (2.77) as well as the emergency and faulted conditions (1.39).

Specify the acceptance criteria e6Li4GF;--for ultimate tesilei estrength and yield strength values of dealloyed aluminum bronze material is greater than or equal to 30 ksi.

Specify the acceptance criterion for fracture toughness is 65 ksi in112 for non-dealloyed aluminum bronze castings and at welded joints in the heat affected zones.

Spec~ify the accGeptance criterion for yield strength is equal to or greater than one half ot the ultimate strength.

Enclosure 2 NOC-AE-14003135 Page 16 of 16 Initiate a corrective action document when the acceptance the criterion is not met.

CorrectiveActions (Element 7)

Procedures will be enhanced to:

Specify that upon discovery of visual evidence of through-wall dealloving., components are scheduled for replacement by the next outage.

Specify that when the ACT does not confirm the structural integrity analyses, STP will follow its corrective action program as defined in the 10 CFR 50 Appendix B, to address emergent conditions to assure continued safe operation of the units. Specify that a ODMI detailing specific steps based on identified conditions will be developed. These steps include notifying the control room of the condition, initiating a condition report, and performing field walkdowns to determine compensatory action.

Conclusion The continued implementation of the Selective Leaching of Aluminum Bronze program provides reasonable assurance that aging effects will be managed such that the systems and components within the scope of this program will continue to perform their intended functions consistent with the current licensing basis for the period of extended operation.

Enclosure 3 NOC-AE-14003135 Enclosure 3 Regulatory Commitments

Enclosure 3 NOC-AE-14003135 Page 1 of 5 A4 LICENSE RENEWAL COMMITMENTS Table A4-1 identifies proposed actions committed to by STP for STP Units 1 and 2 in its License Renewal Application. These and other actions are proposed regulatory commitments. This list will be revised, as necessary, in subsequent amendments to reflect changes resulting from NRC questions and STP responses. STP will utilize the STP commitment tracking system to track regulatory commitments. The Condition Report (CR) number in the Implementation Schedule column of the table is for STP tracking purposes and is not part of the amended LRA.

Table A4-1 License Renewal Commitments Item # Commitment LRA Implementation Section Schedule 39 Enhance the Selective Leaching of Aluminum Bronze procedure to: B2.1.37 Complete no later

examine aluminum bronze materials exposed during inspection of the buried essential than six months prior cooling water piping for evidence of selective leaching, to the period of

perform periodic mnetallurgical tcsting of brone Wlmnm material components to Update extended operation.

the structur..al integrity analyses, confirm, load car./ing capacity, and determnine de gee of Inspections to be deall'ying as follows; complete no later oAboe . ground

.. W System components... re-mo.ved.....

. , f.......

o will be testcd as

..... than six months prior follow:': to the PEO or the end Fo.

- each 10 year inte:..al beginning 10 yearFs prio to the perid* of eXn*de*d of the last refueling operation, 20 percGent of leaking com~ponents- re-moepd-fromn scricc, but at least outage prior to the one, will be tested eve.. five years. PEO, whichever

. T-eAnie test samples from. a removed*omponent will be tested to includ: both occurs later.

lea-;king and non leaking portions of the comAponent.

. If at least two leaking componenAts are no-t idePntifie-d bNO years prior to the end of CR 11-28986 eacsh 109 year testing inteR'al, a risk ranked approach based nn thosea components Most susceptible to degadation will b-e u*sFe..d- to identity sandidate GomPonents for re.m-oval an~d t~esting so at least two components; are tested- during the 10 year

. The samples will be tested for c-hemic-al coemposition including aluminum content, mnechanical properties (such as yield an~d ultimate tensile strengths) and mricr est-r --c-t --re.

. TrFend ultimate tensile strength and comnpare to the acceptance criterion6.

.- Determine degree of dealleying and presenceP of c-rac~ks by destructive

_______ ~~examination. Trend the degree of dealloying and cracking by compariwng________________

Enclosure 3 NOC-AE-14003135 Page 2 of 5 Table A4-1 License Renewal Commitments Commitment LRA Implementation Section Schedule eXamination results with previu e resulIts.

WmAtio dr Penrifm ae engineering evaluation at the end of eah test to determine if the fample d stt equi e sm a tmnt bsd on the resul of the tests.

. The accseptanco criterion for ultimate tensilo strength value of aluminum bronze material isgreaterF than o-r equal to 30 ksi. The acceptan~e c-riter-ion forF yield strength isequal to or greater than. one half of the ultimate strength.

. Initiate a correctie Ractio document when the acceptanre criterion is not Met.

and, if a leak from below-grade welds isdiscovered by surface water monitoring or during a buried ECW piping inspection, a section of each leaking weld will be removed for destructive examination. ________________

Enhance the Selective Leachino of Aluminum Bronze orocedure to u~ndate the strictuiral B2.1.37 July 31, 2014 integrity analyses, confirm load carrying capacity, and determine degree of dealloying as (revised per follows: NOC-AE-14003090)

Perform volumetric examinations of leaking aluminum bronze components where the configuration supports this type of examination to conclude with reasonable assurance CR 12-22150 that cracks are not aooroachina a critical size.

Perform Profile Examinations (PE) on 100% of leaking components. The PE consists of non-destructive examination of the leaking component for the presence of any visual crack identifications (Inside/outside surfaces) and distractive examinations for microstructure, degree of dealloying, percent of dealloying through wall thickness and chemical composition (including aluminum content). When sufficient material is available for preparation of a test coupon, mechanical properties (ultimate strength, yield strenqth, and/or fracture toughness) will be obtained.

Perform pressure and bending tests (Analysis Confirmatory Tests (ACTs) on leaking components to obtain pressure and bending moment.

Require ACTs be performed on 100% of the leaking components until 3 confirmatory ACTs from 3 different component sizes have been tested. Following the 9 confirmatory ACTs then 20% of all removed leaking aluminum bronze components will have ACTs performed until the end of the Period of Extended Oneration Require at least two components be tested (PEs and ACTs) during the each 10-year interval.

Enclosure 3 NOC-AE-14003135 Page 3 of 5 Table A4-1 License Renewal Commitments Item # Commitment LRA Implementation Section Schedule If at least two leaking components are not identified two years prior to the end of each 10 year testing interval, a risk-ranked approach based on those components most susceptible to degradation will be used to identify candidate components for removal testing.

" Perform an engineering evaluation at the end of each PEs and ACTs testing interval to confirm the analytical methodology used to calculate the load carrying capacity and structural integrity of the leak components is conservative.

Update the analytical methodology used to demonstrate structural integrity used to demonstrate structural integrity as required confirming that the load carrying capacity of the aluminum bronze material remains adequate to support the intended function of the ECW system through the period of extended operation.

Trend the degree of dealloying and cracking by comparing examination results with previous examination results. Trend ultimate strength, yield strength, and/or fracture toughness results from the PE testing.

Upon completion of each test, incorporate new test data updating existing trend to evaluate impact on the acceptance criteria.

" Specify the ASME Code Section Xl structural factors for the normal/upset conditions (2.77) as well as the emergency and faulted conditions (1.39).

Specify the acceptance criteria criterion for ultimate tensile strength and yield strength values of dealloved aluminum bronze material is greater than or equal to 30 ksi.

Specify the acceptance criterion for fracture toughness is 65 ksi in 1/2 for non-dealloyed aluminum bronze castings and at welded ioints in the heat affected zones.

Initiate a corrective action document when the acceptance the criterion is not met.

Specify that upon discovery of visual evidence of through-wall dealloving. components are scheduled for replacement by the next outage.

" Specify that when the ACTs does not confirm the structural integrity analyses, o The corrective action program as defined in 10 CFR Part 50 Appendix B will be followed to address emergent conditions to assure continued safe operation of the units.

____________ J

Enclosure 3 NOC-AE-14003135 Page 4 of 5 Table A4-1 License Renewal Commitments Item # Commitment LRA Implementation Section Schedule o That a Operational Decision-Making Issue (ODMI) detailing specific steps based on identified conditions will be developed. These steps include notifying the control room of the condition, initiating a condition report and Performing field walkdowns to determine compensatory action.

Structural integrity analyses will be updated and testing will be conducted to confirm that mnethodologies and assumptions based on past informnation remnain valid.

" Six samples, fromn three aluminum bron~ze comnponents recently Fr~emved from serPoine

" The sam.ples will be tested- for, ch*m*ical compositioRn including aluminuAm c.ntent, mccrhanicral prope~ties (such as fracture toughness, yield And ultimFate tensile strengths)

" The acceptanae criterion fo-r u-ltima-te tPenSile strength value of aluminumF bFroneP mnaterfial is greater than or equal to 30 ksi. The acceptance crFiterion for fracture toughness is 65 ks f "in'fr " aluminum

'iRl442 hroQn.ze crsa-tinrgs a*nd at welded jo"ints in the heat affected zones. The acceptanGe criterion for yield strength is equal to or greater than one half of the ultlimiate sotrength.

STrenRd ultimate tensile strength and compare to the accepta-ne criterion.

" -DetermFinedegree of dealloyfing and peresnce of cr.acks by destructive examination.

Trend the degree of deall[ying an;d cracking by coma*ring evaminon rlesults with

,

previous exaination results-.

The structuiral integriy analyses will be updated, as required.

" The results, of the testing and any required changes to the structural integrity analyses will be completed and senit to the NRC staff4Gforeview. __________

45 Enhance the Selective Leaching of Alumninu'm. Bronz;e procedures to::) B2 74 j.Iy 3-1,204 4

" Volumetrically exami~ne alumnfiFunu bronze imatperial componpents in the ECWV system that (Fevised-pef demonstrate external leakage where the configuration suppets,this type of examnination, NOC AE 14003000)

" Desrdrucntaively examnine each aluminum bronze mnaterial comnponent in the ECWV system that demonstrates eXtern~al leakage for the presenae or absen~e of interal crFacks an~d for the All items incorporated degree of dealleyfing. Profiling Will continue until 10 percent of susceptible comnponents are into Item # 44 by exmineRPd- to validate the input parame~ters to the structural integrity analyses.NC-E1035 eTrFend the degree of dealloying and cracking by coprigexmnkation results with

____prvos examin~atfion resul-1ts. II CR 12-26987

Enclosure 3 NOC-AE-14003135 Page 5 of 5 Table A4-1 License Renewal Commitments Item # Commitment LRA Implementation Section Schedule

Metallurgically test aluminum bronze m~aterial com~ponents inthe ECWV systemn that demonstrate external leakage until the following population of components istested:

a At least threerp different sizeo; mpone.nts, of toe s'amples each are tested, and At lePasot nine total samples are tested.

Peorm....f*racre toug -r hness

- testing i testof samples that include-a Rack i the dealloyed matferil .'whee s.ffiient sample size suppotw c bend testing.

dtUltimate tensile strength and comdpare to the acseptance citheron.

T4rener "Test samples forF chem~ical compositiNOn including almiumcotent, m~echania pwl pebies (such as yield and ultimaut tensile strengths) oand migcra structpe.

t Determine the degee of dealloying by destructive examination.

AT rend the degree of dealloying and cracking by comparigtexamiRation results with previos examination results.

4 Th acceptance c-rfite~rion for ultimate tensile strength value of alu.mOinum bronze mnaterial i girenatr than or equal to 30 ksi. The accoptance critelrio-n fo-r fract-ure toughness is,6-5 ks~i in for al-uminumbronze c~astings and at welded joints inR t-heP lh.eat-affected zones. The acceptance criterion for yield strength is equal to Or greater than one-Qhalfof the ultimate strength7

Perform anegneigevaluation at the end of eacoh tesot to- d-eterm~ine if the soample size requires adjustment based on the results of the tests.

aUpdate the structuWr-al integrit' analyses, as required to validate adequate loadcanig 46 Leak rates that could occur upstream of any individual component supplied by the ECW system N/A July 31. 2014 will be determined to validate the maximum size flaw for which piping can still perform its by this Letter intended function. NOC-AE-14003135

A summary of the results of these leak rates will be provided to the NRC for review. CR 12-27257

v t e Letter Sequence Response to RAI
TAC:ME4936, (Approved, Closed) TAC:ME4937, (Approved, Closed)
Initiation Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request, Request Acceptance... Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement, Supplement Administration Meeting, Meeting, Meeting Questions 8 February 2012 22 May 2012 14 April 2011 14 April 2011 14 April 2011 24 May 2011 6 July 2011 12 July 2011 28 July 2011 15 August 2011 15 August 2011 15 August 2011 18 August 2011 21 September 2011 22 September 2011 22 September 2011 4 October 2011 11 October 2011 11 October 2011 18 October 2011 3 November 2011 6 December 2011 5 December 2011 14 December 2011 6 December 2011 4 January 2012 16 February 2012 9 February 2012 30 January 2012 28 February 2012 21 March 2012 19 April 2012 12 April 2012 25 June 2012 14 June 2012 26 July 2012 12 September 2012 3 October 2012 19 November 2012 18 December 2012 6 March 2014 16 July 2014 13 April 2015 27 May 2015 28 May 2015 11 June 2015 5 October 2015 30 November 2015 30 November 2015 22 April 2016 14 June 2016 18 January 2017 ... further results Answers 25 October 2011 31 May 2012 31 May 2012 31 May 2012 6 September 2016 5 May 2011 12 May 2011 23 June 2011 9 August 2011 23 August 2011 18 August 2011 15 September 2011 15 September 2011 10 October 2011 21 November 2011 21 November 2011 4 November 2011 21 November 2011 17 November 2011 6 December 2011 15 December 2011 15 December 2011 5 January 2012 18 January 2012 6 February 2012 16 February 2012 27 February 2012 12 March 2012 5 March 2012 28 March 2012 28 March 2012 29 March 2012 17 April 2012 26 April 2012 3 May 2012 31 May 2012 14 May 2012 31 May 2012 31 May 2012 7 June 2012 14 June 2012 5 July 2012 27 June 2012 17 July 2012 4 October 2012 21 August 2012 6 December 2012 27 February 2014 18 February 2014 20 March 2014 ... further results Results Approval, Approval Other: ML110620203, ML11140A163, ML11224A265, ML11230A003, ML11318A121, ML11318A122, ML11318A123, ML11318A124, ML11318A125, ML11318A126, ML11318A127, ML11318A128, ML11318A129, ML11318A130, ML11318A131, ML11318A132, ML11318A133, ML11318A135, ML11318A136, ML11318A138, ML11318A139, ML11318A140, ML11318A141, ML11318A142, ML11318A143, ML11318A144, ML11318A145, ML11318A146, ML11318A147, ML11318A148, ML11318A149, ML11318A150, ML11318A151, ML11318A152, ML11318A153, ML11318A154, ML11318A155, ML11318A156, ML11318A157, ML11318A158, ML11318A159, ML11318A160, ML11318A161, ML11318A162, ML11318A163, ML11318A164, ML11318A165, ML11318A166, ML11318A167, ML11318A168... further results
MONTHYEAR2011-06-16 [Table View]

NOC-AE-14003135, Response to Requests for Additional Information for the Review of the South Texas Project, Units 1 and 2, License Renewal Addiction - Set 26 (TAC ME4936 and ME4937)

Text

References:

Enclosures:

Background:

References:

References:

Deardorff,

1.0 INTRODUCTION

SUMMARY

SUMMARY

8.0 REFERENCES

1.0 INTRODUCTION

SUMMARY

SUMMARY

8.0 REFERENCES

SUMMARY

Background

Navigation menu

NOC-AE-14003135, Response to Requests for Additional Information for the Review of the South Texas Project, Units 1 and 2, License Renewal Addiction - Set 26 (TAC ME4936 and ME4937)

Text

References:

Enclosures:

Background:

References:

References:

Deardorff,

1.0 INTRODUCTION

SUMMARY

SUMMARY

8.0 REFERENCES

1.0 INTRODUCTION

SUMMARY

SUMMARY

8.0 REFERENCES

SUMMARY

Background

Navigation menu

Search