GNRO-2013/00053, Follow-up Actions from Teleconference Held on Thursday, August 1, 2013, Related to Pre-Decisional Enforcement Conference Between NRC and Grand Gulf Held on Tuesday July 16, 2013

Follow-up Actions from Teleconference Held on Thursday, August 1, 2013, Related to Pre-Decisional Enforcement Conference Between NRC and Grand Gulf Held on Tuesday July 16, 2013

ML13221A272
Person / Time
Site:	Grand Gulf
Issue date:	08/08/2013
From:	Kevin Mulligan Entergy Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
EA-13-058, GNRO-2013/00053, IR-13-201
Download: ML13221A272 (23)

Text

~Entergy

"~-'-'~--"~'-"--'--"--'-~-"----

Entergy Operations, Inc.

P.O. Box 756 Port Gibson, Mississippi 39150 Tel: 601-437*7500 Kevin J. Mulligan Site VICe President Grand Gulf Nuclear Station GNRO-2013/00053 August 8th , 2013 U.S. Nuclear Regulatory Commission Attention: Ms. Jennifer Uhle Deputy Director, NRR One White Flint Mail Stop 13H 16M 11555 Rockville Pike Rockville, Maryland 20852

SUBJECT:

Follow-up Actions from Teleconference held on Thursday, August 1, 2013, related to Pre-Decisional Enforcement Conference between NRC and Grand Gulf held on Tuesday July 16, 2013 Grand Gulf Nuclear Station, Unit 1 Docket No. 50-416 License No. NPF-29

REFERENCE:

NRC Inspection Report # 05000416/2013201

Dear Ms. Uhle:

The attached documents are being submitted for the purpose of providing additional information related to RAls B.1.22-1 a, B.1.22-1 b, B.1.22-2, and B.1.41-3c of the Grand Gulf Nuclear Station License Renewal Application. This information was requested to be submitted during a teleconference held on August 1, 2013, between Grand Gulf Nuclear Station and the Office of Nuclear Reactor Regulation (NRR).

There is one new regulatory commitment identified in Attachment 6 of this submittal. If you have any questions or need additional information, please contact Christopher R Robinson at 601-437-7326 or Thomas Thornton at 601-437-6176.

Sincerely.

Fot{ THE SITE. \jlLE.. $:.£~I.c""T KJM/saw Attachments: (1) Response to NRC actions/requests from July 16th

• 2013 (2) Excerpts from EN-DC-315 rev. 10 (3) Discussion on Grand Gulf FAC program and FAC location #662 (4) Pictures/Drawing of LPCS Min Flow Line (5) Summary of Root Cause Evaluation (6) NRC Commitment Identification Table

GN RO-20 13/00053 Page 2 of 2 cc: NRC Senior Resident Inspector Grand Gulf Nuclear Station Port Gibson, MS 39150 U.S. Nuclear Regulatory Commission ATIN: Document Control Desk Washington, DC 20555-0001 This response is formatted such that the NRC question/request is listed, and then the Grand Gulf response is provided after in italics.

1. Provide final answers to the three example situations cited in the NOV:

a. Related to RAJ B.1.41-3c: Does (procedure) GN-MS-46 include all potential pipe wall thinning mechanisms? If not, then what other process is used to monitor and trend these mechanisms?

Grand Gulf Response:

No, GGNS-MS-46 provides guidance for monitoring wall thinning also known as loss of material, caused by erosiOn/corrosion, defined as: The degradation and consequent waf! thinning of piping components by a dissolution process and/or mechanicaVchemicai phenomenon which are affected by variables such as temperature, solids content, fluid velocity, water chemistry, component material, and component geometry in MIC susceptible systems.

Procedure GGNS-MS-46 is applicable for monitoring wall thinning in raw water systems and other components as necessary. Since raw water systems are susceptible to microbiologically influenced corroSion, Grand Gulf a/so uses procedures EN-DC-340 and SEP-MIC-GGN-001 to monitor raw water systems for microbiologically-influenced corrosion.

The Flow Accelerated Corrosion Program at Grand Gulf monitors susceptible components for wall-thinning caused by flow accelerated corrosion. In addition, specific components which are not susceptible to FAC have been administratively monitored through the site's FAC program, based on operating experience, to monitor for other wall thinning mechanisms, to include cavitation, flashing, liquid drop impingement, solid particle erosion, and erosion. These non FAC inspections are considered to be augmented inspection activities and leverage the FAC program's administrative controls for conducting these periodic inspections. The implementing procedure is EN-De-31S, with sub-tier procedures SEP-FAC-GGN-001, CEP-FAC-001, and GGNS-MS-41 providing details primarily regarding mechanics of perfonning inspections.

b. Related to RAls B. 1.22-1 a and 1b. Entergy to supply response resolving the inconsistencies among the responses regarding EOI management of stainless steel components and wall thinning mechanisms.

At the PEG conference, Entergy stated that its FAG Program (which is embodied in GGNS procedure EN-DG-315 and the associated implementing procedures) is used to monitor for FAG as well as several other non-FAG wall-thinning mechanisms. It was also discussed that one particular carbon steel component that was in the FAG Program was replaced with a stainless steel component; and that subsequent to that replacement, the stainless steel component was dropped from being monitored by the FAG Program. The staff is concerned that components in this program which are susceptible to being monitored for non-FAC issues could be dropped from the program altogether yet still be susceptible to non-FAC mechanisms; therefore, EOI's FAC program would not adequately manage aging effects for those components. Similarly, if a FAC-susceptible component is replaced by one not susceptible to FAC but is still susceptible to non-FAC mechanisms, it could again be dropped from EOl's program and thus not be adequately managed.

Grand Gulf Response:

The Flow Accelerated Corrosion Program at Grand Gulf was created to monitor wall thinning due to flow accelerated corrosion. Based on operating experience, specific locations have been added to the site program to monitor for wall thinning due to other mechanisms, such as cavitation, flashing, liquid drop impingement, solid particle erosion, and erosion. The implementing procedure is EN-DC-315, with sub-tier procedures SEP-FAC-GGN-001, CEP-FAC-001, and GGNS-MS-41 providing details for performing these inspections.

The particular carbon steel component being referenced (FAC location 662 - a section of LPCS minimum flow line) was evaluated as not susceptible to FAC in accordance with EPRI NSAC criteria due to single phase flow less than 200F. This component was added to the FAC program, to leverage the program's administrative controls, as a result of an extent of condition review following discovery of a pinhole leak in the RHR system minimum flow line in 2001. The RHR minimum flow line pinhole leak was attributed to erosion as a result of high flow velocities and high usage of the minimum flow line. Early documentation used erosion and FAC interchangeably. The FAC Program provides established controls for measuring and trending wall thinning. During 2002, FAC location 662 wall thickness was near the minimum acceptable value.

As a result, the component was replaced in 2004. As documented in design change ER-GG-2003-0348-000, stainless steel piping was selected for the replacement due to its higher resistance to erosion that was being experienced in the piping. Continued monitoring of this location was suspended due to the enhanced material properties of stainless steel and the fact that locations within the same line are continuing to be monitored within the FAC program.

Components not susceptible to FAC are administratively controlled by the FAC program in order to leverage the established controls for measuring and trending wall thinning. As a matter of practice, al/ wall thinning mechanisms and operating experience are considered prior to removing the administrative controls.

Regarding the use of stainless steel, Grand Gulf has more than 25 examples of components that have been replaced with stainless steel, yet still remain in the FAC program. It should be noted that if a component is removed from the administrative controls of the FAG program, its historical data will remain in the FAG program.

During a review of our existing programs for the purposes of this conference, we identified an opportunity to strengthen our program requirements to incorporate the use of additional criteria. Specifically, we will add a requirement to perform confirmatory inspections for wall-thinning when replacing components with alternate materials. This is similar to guidance suggested in LR-/SG-2012-01, but we are not committing to the ISG.

c. Related to RAJ 8.1.22-2: Resolve apparent inconsistencies in the responses, in particular actions on significancel extent of condition. This equates to #3. Verify what was actually done regarding your extent of condition determination in the case of the wall-thinning example, such as how the expansion of sample size was determined, safety significance, and a description of your aging management programs regarding pipe wall thinning. Describe what would have been the result if the NRC had not identified and challenged this issue.

Grand Gulf response:

In the case of the three examples cited in RAI 81.22-2a (FAC locations 314,353, and 795), where condition reports were not written for significant wall thinning, these components were found to be above minimum acceptable wall thickness and were projected to remain above minimum wall thickness until the next scheduled inspection or replacement opportunity. As a result, and in accordance with EN-DC-315 and the guidance of NSAC 202L, sample expansion was not warranted based on the measured wall thickness of these three components.

Two of these components were replaced in RF17 and one was replaced in RF18.

In evaluating the safety significance of this issue, we considered what would have happened if the NRC had not identified and challenged the issue of sample expansion due to significant wall thinning. We concluded that the actions which should have been taken are the same as the actions a/ready taken. Despite not writing condition reports for the three components in question, the components were evaluated to be above minimum acceptable wall thickness, and were projected to remain above minimum wall thickness until the next scheduled inspection or replacement opportunity. As a result, and in accordance with EN DC-315 and the guidance of NSAC 202L, sample expansion was not warranted based on the measured wall thickness of these three components.

Procedure GGNS-MS-46 is applicable for monitoring erosion in raw water systems susceptible to microbiologically-influenced corrosion. Grand Gulf uses implementing procedure EN-DC-340, with SUb-tier procedure SEP-MIC-GGN-001 to monitor raw water systems for microbiologically influenced corrosion.

The Flow Accelerated Corrosion Program at Grand Gulf monitors for the following wall thinning mechanisms: flow accelerated corrosion, cavitation, flashing, liquid drop impingement, solid particle erosion, and erosion. The implementing procedure is EN-DC-315, with sub-tier procedures SEP-FAC-GGN 001, CEP-FAC-001, and GGNS-MS-41 providing the mechanics for performing these inspections.

The procedural requirements of EN-DC-315 contain the technical basis for continued usage of in-service piping. The criteria are definitive and clear for pipe wall measurements and projected wear. Specifically, a pipe's projected thickness at the next inspection opportunity must be above a minimum acceptable wall thickness in order for the pipe to remain in service. The requirement to initiate a condition report to document "Significant wall thinning" does not affect the evaluation of the component for acceptability for continued service.

Any component with "significant wall thinning" must still satisfy the requirements for continued service. In the case of FAC locations 314, 353, and 795, these components were rep/aced in RF17 and 18, due to the fact they were approaching minimum acceptable wall thickness. The replacement of these components is based on meeting the minimum acceptable ASME design code specifications, and not dependent upon initiation of a condition report which documents "significant wall thinning. "

In evaluating the safety significance of this issue, we considered what would have happened if the NRC had not identified and challenged the issue of sample expansion due to significant wall thinning. We concluded that the actions which should have been taken are the same as the actions already taken. Despite not writing condition reports for the three components in question, the components were evaluated to be above minimum acceptable walJ thickness, and were projected to remain above minimum wall thickness until the next scheduled inspection or replacement opportunity. As a result, and in accordance with EN DC-315 and the guidance of NSAC 202L, sample expansion was not warranted based on the measured wall thickness of these three components.

2. Provide a more complete summary of the completed root cause determination mentioned in your PEC slides of July 16, 2013 (e.g., causes, extent of condition, extent of cause(s>> along with the EOI tracking number/document 10 number and completion date of that evaluation. The staff believes an appropriate summary would be sufficient since this determination could be a large document.

Grand Gulf response:

This item is included as attachment 5.

3. Provide EOl's perspective on the safety Significance of the cited apparent violation and why.

Grand Gulf response:

The cited apparent violation has three examples. We would like to provide our perspective on each example.

Forexample 1: The complete description and application ofGGNS-MS-46 was not adequately explained to the NRC in our response to RAI B. 1.43. We failed to adequately convey that the procedure implements inspection activities that are credited by the Service Water Integrity Program. Grand Gulf regrets this lack of clarity and causing delays in the regulatory process. If this condition had been left undiscovered by the NRC and not corrected, Grand Gulf would still continue to use GGNS-MS-46 to perform raw water system inspections. The results of those inspections would support various aging management programs described in the Grand Gulf LRA, such as the Service Water Integrity and Fire Water System programs. This example, if left uncorrected, would have no potential impact to the effectiveness ofprograms required for aging management review.

For example 2: In its response to RAI B.1.22-1, Grand Gulf did not disclose the fact that the site's flow accelerated corrosion program monitors components for wall thinning mechanisms other than flow-accelerated corrosion. Additionally, we erroneously stated that LPCSIHPCS components were experiencing traditional FAC. Consequently, we failed to fully describe appropriate aging management activities in our license renewal documentation. Grand Gulf deeply regrets this error. If this error had been left undiscovered by the NRC and uncorrected by Grand Gulf, it would have resulted in the LRA not completely documenting aging management activities that were necessary based on plant operating experience.

However, Grand Gulf would still continue to monitor the affected components for wall thinning. In fact, the discovery of this condition was a direct result of the fact that inspection results for the HPCS and LPCS components were listed in the documentation of the FAC Program outage inspections.

The components in question were determined not to be susceptible to FAC, but were monitored for wall thinning mechanisms. EN-DC-315 procedure has clear and definitive requirements to justify continued usage of the component based on wall thickness projections; not based on the wall thinning mechanism. The components in question were subjected to these requirements, and were replaced when warranted by wall thickness projections. EN-DC-315 procedure remains in use. This example, if left uncorrected, would have no potential impact to the effectiveness of programs required for aging management review.

For example 3: In its response to RAI B. 1.22-2, Grand Gulf failed to recognize that condition reports should have been written to identify three examples of "significant wall thinning" as a result of ambiguous guidance in EN-DC-315. As a result, we stated inaccurately that no significant wall thinning had been detected and that condition reports were not required to be written. If this error had been left undiscovered by the NRC, or uncorrected by Grand Gulf, Grand Gulf would still evaluate and justify the continued use of the component in accordance with EN-DC-315. EN-DC-315 procedure has clear and definitive requirements to justify continued usage of the component based on wall thickness; not based on the wall thinning mechanism. The three components in question (FAC locations 314, 353, and 795) were subjected to these requirements, correctly evaluated, and subsequently replaced. Additionally, these components were not found, or projected to be, below minimum acceptable wall thickness prior to the next refueling outage, and therefore, did not meet sample expansion criteria. This example, if left uncorrected, would have no potential impact to the effectiveness of programs required for aging management review.

In addition to the above, the staff understands the following information will be provided as promised by EOI during the PEC. EOI should also provide dates when this information will be provided:

1. Ears assessment of the extent of condition in regards to other responses that were not complete or accurate (related to license renewal). (Related to the Planned Corrective Actions slide of July 16, 2013)

Grand Gulf response:

Of the 62 RAI and response examples picked for audit purposes, only one was found to contain an additional example of conflicting information being submitted in the response to RAIB.1.41.-3b. This is another example of our miscommunication regarding GGNS-MS-46 procedure. We incorrectly stated that we do not credit GGNS-MS-46 for managing loss of material due to erosion. We believe the error is resolved as a result of the discussion held today.

2. These items to be provided under the RAI process as part of response to a new RAJ from the staff, if not already adequately addressed by EOI in the information supplied above:

a. Does the FAC Program contain a provision for non-FAC wall thinning issues to be included in this program? If not, then how do you capture and include these types of issues?

Grand Gulf Response:

Susceptible components are monitored for wall-thinning caused by flow accelerated corrosion. In addition, specific components which are not susceptible to FAG have been administratively mon;tored through the site's FAG program, based on operating experience, to monitor for other wall thinning mechanisms, to include erosion, cavitation, flashing, liquid drop impingement, and solid particre erosion. These non-FAG components and their inspections performed under the FAG program are considered augmented inspection activities. These augmented inspection activity leverage the program's administrative controls for periodic inspections. The implementing procedure is EN-DG-315, with sub-tier procedures SEP-FAC-GGN-001, GEP-FAG-001, and GGNS-MS-41 providing details primarily regarding mechanics of performing inspections.

We will add a requirement to perform confirmatory inspections for wall-thinning when replacing components with alternate materials. This is similar to guidance suggested in LR-ISG-2012-01, but we are not committing to the ISG.

By doing so, we will perform the recommended confirmatory inspection on components removed from the FAG program.

b. Describe the stainless steel replacement example. Why was stainless steel selected?

Grand Gulf Response:

The particular carbon steel component being referenced (FAC location 662 - a section of LPCS minimum flow line) was not originally included in the FAC program, as this component is not susceptible to FAC in accordance with the EPRI NSAC202L guidance. The component was added to the FAG program based on GGNS operating experience following discovery of a pinhole leak in the RHR system minimum flow line in 2001. The FAC Program provided established controls for measuring and trending wall thinning. During 2002, the component wall thickness was near the minimum acceptable value. As a result, the component was replaced in 2004. As documented in design change ER-GG 2003-0348-000, stainless steel piping was selected for the replacement due to Its higher resistance to erosion.

c. Why is it acceptable not to continue monitoring this situation under the FAC Program?

Grand Gulf Response:

As documented in design change ER-GG-2003-0348-000, stainless steel piping was selected for the replacement due to its higher resistance to the erosion that was being experienced in the piping. Continued monitoring of this location was suspended due to the enhanced material properties of stainless steel and the fact that locations within the same line remained in the FAC program.

We will add a requirement to perform confirmatory inspections for wall-thinning when rep/acing components with alternate materials. This is similar to guidance suggested in LR-fSG-2012-01, but we are not committing to the ISG.

By dOing so, we will perform the recommended confirmatory inspection on components removed from the FAC program.

3. With regard to the FAC Program (EN-DC-315), provide a description of the procedure change relative to corrections made to address the situation that resulted in CRs not being written for repair/replacement of component(s) identified as having "significant wall thinning."

Grand Gulf response:

In revisions 1 and 3 of EN-DC-315, (in place at the time of the inspection of the three examples which should have had condition reports written) the requirement to initiate a condition report was only listed in section 5. 11 titled "Components failing to meet initial screening criteria." Prior to this section, namely, sections 5.7 "Evaluation of UT inspection data" and 5. 10 "Disposition of inspection results" lists criteria to either justify continued usage of pipe or perform additional actions.

Due to the lack of a definition for the term "initial screening criteria, " the responsible engineer believed that section 5.11 didn't apply because the piping did not fail "initial screening criteria. " To correct this ambiguity, sections 5.7 "Evaluation of UT inspection data" and 5.10 "Disposition of inspect;on results" both now contain the requirement to initiate a condition report if significant wall thinning is detected. Additionally, in section 5.4, 87.5% of nominal wall thickness was established as the initial screening criteria.

ATTACHMENT 2 EN-DC-315. Rev. 10, Flow Accelerated Corrosion Program 1.0 PURPOSE

['I] The purpose of this procedure is to implement a common approach to establish programmatic control. updating, and documenting Flow-Accelerated Corrosion (FAC) programs for standardization at Entergy's nuclear plants.

[2] The objective of the FAC program is to predict, detect, monitor and minimize degradation in single and two-phase flow piping (safety and non-safety related systems) to prevent failures while enhancing plant safety and reliability.

[3) This procedure provides criteria and methodology for selecting components for inspection, performing inspections, evaluating inspection data and disposition of results, sample expansion requirements, piping repair Ireplacement criteria, program responsibilities and documentation requirements.

[4] This procedure may be used as a guide for evaluating systems and components that are not included in the FAC program.

[5J The frequency of the activities described in this document shall be on a refuel outage basis, unless otherwise noted. However, in some cases, online or mid cycle inspection and evaluation may be performed.

3.0 DEFINITIONS

[39J Sample Expansion - The addition of inspection locations based on significant or unexpected wall thinning during planned inspection(s} as detailed below:

[40] Significant Wall Thinning - Wall thinning to a thickness which is the largest of:

(a) Wall loss greater than 40% thickness (b) Continuing wear that has an additional 40% wall loss (c) One half ofthe remaining wall is lost [Y2 (tmeas + t accpt )]

(d) Wall loss in a low margin system that has a thickness 20 mil greater than design minimum thickness (taccPt + 0.020) inch 5.4 PREPARATION OF OUTAGE INSPECTION PLAN

[10] Obtain Minimum Acceptable Wall Thickness (taccpt)

(a) Obtain taccPt values for each component.

ATIACHMENT2 (b) The minimum acceptable wall thickness, taccpt, values should be obtained from EN-CS-S-008-MULTI as applicable OR from an approved site method (e.g. FAC Manager).

(c) Values for taccPt should be obtained from design engineering OR it may be delegated to another department OR qualified personnel. These values may be ascertained prior to OR during an outage.

(d) If taccpt has not been obtained from Design Engineering or designee THEN a conservative initial screening value of 87.5% may be applied in lieu of taccpt with the exception of Low Margin system.

5.10 DISPOSITION OF INSPECTION RESULTS

[1] The following are used to disposition component inspection results. Reference Attachment 9.3 for logic diagram.

NOTE I. Certain components may have very little margin remaining as a consequence of high stresses in the line even though tpred ~ 0.875 tnom AND therefore may require evaluation, for example Feedwater, Condensate, RHR, etc.

[2J IF tpred is ~ 0.875 tnom, (AND is not in a low margin system) the component is acceptable as is AND may be returned to service.

[3] IF tpred is < 0.875 tnom. and greater than 40% wall loss is detected, evaluate for sample expansion (Reference section 5.13) AND also perform a Wear (W), Wear Rate (WR) Remaining Service Life (RSL) and Next Scheduled Inspection (NSI) evaluation.

[4] IF tpred is ~ 0.3 t nom

• for lSI Class 1 piping repair OR replacement is required in accordance with the requirements of ASME Section XI Repair and Replacement Program OR perform a detail structural evaluation to determine if the component is acceptable to be returned to service.

[5] IF tpred is ~ 0.2 tnom, for lSI Class 2, Class 3 piping repair OR replacement is required in accordance with the requirements of ASME Section XI Repair and Replacement Program OR perform a detail structural evaluation to determine if the component is acceptable to be returned to service.

[6] Non-safety related repair OR replacement shall be evaluated as warranted in accordance with applicable site programs and procedures.

ATTACHMENT 2

[7] IF tpred is 2!: taccPt and the remaining service life of the component is greater than or equal to the number of hours in the next operating cycle the component is acceptable for continued operation; however monitoring is required in accordance with program requirements.

[8] IF tpred is < taccPt , a structural evaluation is required in accordance with site approved procedures OR engineering standards. Also a sample expansion evaluation is required. Repair or replacement in accordance with the requirements of ASME Section XI Repair and Replacement Program OR other site approved process may also be required.

[9] IF Significant Wall Thinning is detected an evaluation shall be performed for sample expansion (Ref. Section 5.13)

[10] IF t meas is < 0.875 toom. evaluate for sample expansion (Reference section 5.13)

AND also perform a Wear (W), Wear Rate (WR) Remaining Service Life (RSL)

AND Next Scheduled Inspection (NSI) evaluation, to disposition the component as acceptable for continued service.

{11]  !.f...tmeas is > 0.875 toom AND the component is not in a low margin system only a RSL AND the NSI evaluation is required

[12] IF t meas is < taccpt. generate a condition report. A structural evaluation is also required in accordance with applicable site procedures OR engineering standards.

[13] IF Significant Wall Thinning is detected generate a condition report.

5.13 SAMPLE EXPANSION An evaluation for Sample Expansion is required for the following:

(a) When a component is inspected AND is found to have wall loss greater than 40% thickness (b) When a component is found to have an additional wall loss of 40% after the initial inspection.

(c) When a component loses one half the remaining margin thickness (% (tmeas

+ taccpt) during re-inspection AND is above the design minimum thickness.

(d) When inspection of components that are in a low margin system that are marginal above the design minimum thickness (taccPt +20 mil)

ATIACHMENT2

[1] IF a component is discovered that has a current OR projected wall thickness less than the minimum acceptable wall thickness (taccPt), THEN additional inspections of identical OR similar piping components in a parallel OR alternate train shall be performed to bound the extent of thinning except as provided below.

[2] WHEN inspections of components detects significant wall thinning AND it is determined that sample expansion is required, the sample size for that line should be increased to include the following:

(a) Components within two diameters downstream of the component displaying significant wear OR within two diameters upstream IF the component is an expander OR expanding elbow.

(b) A minimum of the next two most susceptible components from the relative wear ranking in the same train as the piping component displaying significant wall thinning.

(c) Corresponding components in each other train of a multi-train line with a configuration similar to that of the piping component displaying significant wall thinning.

[3J IF the expanded inspection scope detects additional degradation, the sample expansion should continue until no additional components with significant wear are detected.

[4] Sample expansion is NOT required IF the thinning was expected OR IF the thinning is unique to that component (e.g., degradation downstream of a leaking valve).

[5] Inspections of components from the current OR past outages may satisfy the sample expansion criteria, therefore, some of the sample expansion requirements can be met without performing additional inspections.

[6J Sample expansion is NOT required for components that are being re-inspected IF normal OR expected wear is detected OR wear unique to that component, except where noted above. All other wear patterns encountered shall be evaluated by the FAC Engineer to determine IF sample expansion is required.

ATIACHMENT2 ATTACHMENT 9.3, WALL THINNING EVALUATION PROCESS MAP Logic Diagram - Evaluation of Pipe Wall Thinning Start 1/',,

/~""-,,- //'proo " ~ Repair or

~ >'"dth' 0 875 tran" " . , ~nom for Class 1 piping 6t Replacement

~. /'C k s~,~~,2't..",.,torClaSS2.ClaSS3 Required, reqUire n ess ",,- and non-safety Additional Inspection

", ~ related piping Required I " "

i y I

'1 Sample Expansion I y'~

Determine need for expanded inspection scope II and for future inspections of oompooen.

//

<: tl:l'ed ::> "'GCpt Structural evaluation required per ENN*CS-S-008 or

. ENS-PS-S-001

~

Acceptable for Acceptable for Continued Continued Repair or Replace

[ Acceptable As Is Operation. Future Operation. Inspect Component per Inspection or Repair! Replace Plant Procedures L_ _ Required Next Outage

ATTACHMENT 3 EN-DC-315 includes program elements developed from guidelines in EPRI NSAC-202L, "Recommendations for an Effective Flow Accelerated Corrosion Program". Entergy procedure EN-DC-315 was developed to implement a common approach to establish programmatic control, updating, and documenting Flow Accelerated Corrosion (FAC) programs at Entergy's nuclear plants. The program includes perfoonance indicators, self-assessments and benchmarking as methods for monitoring program and plant performance. The objective of the FAC program is to predict, detect, monitor and minimize degradation in single and two-phase flow piping (safety and non-safety related systems) to prevent failures while enhancing plant safety and reliability. As such, the program recognizes and includes components that may be subject to wall thinning due to other mechanisms such as cavitation, flashing, liquid drop impingement and solid particle erosion.

The GGNS FAC program includes a System Susceptibility Evaluation (SSE) which addressed all large and small bore piping, categorizing lines by modeled, non-modeled large bore piping and small bore piping susceptible to FAC. There are 474 components included in an EPRI CHECWORKS predictive model. Through consideration of non typical operation of systems and operating experience from the plant and industry, additional components are included in the program. These include both susceptible non-modeled and other components identified with potential wall thinning issues. The GGNS program database includes 1031 total identified componentswith inspection history. The long teon strategy is to reduce susceptibility through the use of improved materials for replaced components or proactive replacement of piping with corrosion resistant material, improved water chemistry, and incorporation of local design changes.

With this strategy, there are 176 components that are no longer inspected based on changes implemented.

Components associated with safety related Emergency Core Cooling Systems (ECCS) were added to the program based on operating experience and consideration of system operation including shutdown cooling configurations during outages. In 2001, a pin-hole leak was discovered in a 4" elbow on the A Residual Heat Removal (RHR) system minimum flow line. As a result of this condition, an expanded scope of components was identified for inspection that included similar lines on RHR B, RHR C, High Pressure Core Spray (HPCS) and Low Pressure Core Spray (LPCS). Based on these inspections, replacements, and upgrade actions taken, additional components were added as expanded scope. These activities are described in the table below;

ATIACHMENT3 ECCS System piping scope - number of components included in scope and year of scope expansion System I 2001 I 2002 I

I 2004 2010 I

RHRA 9J1) 2 I 1 i RHRB .4(2) 2 (3) I RHRC 4 (4) ~@L~_+- 3 {6} 2 HPCS 3 (7) -

LPCS 2 (8) 1 (9} I 2 (10)

(1) Includes repaired location which had leak, component was replaced with like carbon steel material in 2002 and has had 3 additional inspections to monitor, 2 other components required re~inspections and remain acceptable.

(2) 3 components including two elbows and straight pipe were replaced in 2004 with stainless steel material (3) Both components required re-inspection and remain acceptable (4) 2 components required re-inspection and remain acceptable (5) 2 components required re~inspection and remain acceptable (6) 3 components required re-inspection and remain acceptable (7) 1 component was replaced in 2008 with stainless steel material and 1 component required re~inspection and remains acceptable (8) Includes component location 662 which was replaced in 2004 with stainless steel material (9) 1 component required re-inspection and remains acceptable (10) 1 component required re~inspection and remains acceptable The attached drawings depict component location 662 on the LPCS minimum flow line and the location of other components monitored in the system. Note that component locations 667 and 750 are in the 4" minimum flow line upstream of location 662 and continue to be inspected. The elbow at location 667 was added as a result of expanding scope from a 2002 inspection of location 662. The piping at location 750 was expanded scope in 2004 based on visual inspection during replacement of piping at location 662.

Additionally, Grand Gulf has committed to the following action:

"Components subject to wall~thinning mechanisms other than FAC, which are replaced with alternate materials (e.g. replacing a carbon steel pipe with stainless steel), shall continue to be periodically monitored at a frequency commensurate with their post replacement wear rates and post-replacement cumulative run hours."

ATTACHMENT 3 Further details on justification for use of stainless-steel in FAC location #662 Due to a pinhole leak in the first 90 degree elbow (FAC Item number 662) downstream of motor operated valve 01E21F011-A on line 4"-HBB-13, the 4" carbon steel LPCS Minimum Flow and Test Return line downstream of motor operated valve 01 E21 F011-A to butt welded branch fitting connected at 14"-HBB-9 was replaced in RF13 with ASME SA-312, Gr. TP-304L stainless steel material on line 4"-HCB-71 per ER-GG-2003-0348 000-00.

Per NSAC-202L-R3 (Recommendations for an Effective Flow-Accelerated Corrosion Program), section 4.2.2 (Exclusion of Systems from Evaluation), some systems or portions of systems can be excluded from further evaluation due to their relatively low level of susceptibility. Lines made of stainless-steel piping or low-alloy steel piping with nominal chromium content equal to or greater than 1X % (high content of FAC-resistant alloy) can be excluded from inspection program.

The flow characteristic of 4"-HCB-71 LPCS Minimum Flow and Test Return line is single-phase since the design, maximum, and normal temperatures of the piping are 200,185, and 95 degrees, respectively. Per MS02, Rev. 51, the design, maximum, and normal pressures of the piping are 250, 230, and 200 psig, respectively. Since this line is not subject to other damage mechanisms such as cavitation and liquid impingement erosion, future inspections were excluded from the Grand Gulf inspection program in accordance with NSAC-202L guidelines.

Welding an 11'-89/16" of stainless steeI4"-HCB-71 piping between two sections of carbon steel piping sections will not introduce a galvanic corrosion problem at the bi metallic weld joints. This is due to the relatively small quantity of 4"-HCB-71 stainless steel material upstream of very large body of 14"-HBB-9 carbon steel piping. It should be noted that the carbon steel butt welded branch fitting connected at 14"-HBB-9 is much thicker than the upstream 4" stainless steel piping. Also, the Low Pressure Core Spray Minimum Flow and Test Return piping is not subject to continuous flow at all times during normal plant operation.

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Summary of the Root Cause Evaluation GGNS License Renewal Apparent Violation of 10CFR54.13 "Completeness and Accuracy of Information 11 Corrective Action Program Tracking Number: CR-GGN-2013-04074 Approved on: July 24,2013 Problem Statement During the time period of May 2012 to October 2012, Grand Gulf site personnel and License Renewal Office failed to provide complete and accurate information in responses to Requests for Additional Information (RAls) related to implementation of aging management activities for Grand Gulf's (GGNS)

License Renewal Application (LRA). This resulted in a notice of apparent violation of 10CFR54.13 subject to escalated enforcement.

Root Cause Insufficient engagement and oversight by site personnel in the development and approval of responses to Requests for Additionallnforrnation resulted in incomplete and inaccurate information being submitted to the U.S. Nuclear Regulatory Commission (NRC) as part of the License Renewal Process.

The organization of the license renewal project team for Grand Gulf differed from all previous Entergy license renewal applications in that it did not contain a dedicated team from the site responsible for developing and certifying responses to RAls. An executive-level decision was made to deviate from our normal practice to ensure that Grand Gulf staff could devote their efforts to ensuring the success of an unprecedented Extended Power Uprate (EPU) outage, while relying on the corporate license renewal staff to develop and provide responses to LRA RAls. The vulnerability of this decision was exposed when complex technical issues involving Grand Gulf specific procedures and historical actions arose.

Team certification or peer reviews are suggested by EN-U-106 NRC Correspondence" (Revision 9, U

August 23, 2011) section 5.4 for technical or complex matters. These were not adequately obtained due to the unique organizational structure of the Grand Gulf license renewal project. This weakness came to fruition when incomplete and inaccurate information was provided on the docket to the NRC.

Contributing Causes

1. 1) Weaknesses exist in the governing document(s) that provide guidance for responding to complex technical License Renewal Application RAts.

When technically complex issues arose involving Grand Gulf specific procedures and programs, the lack of clear guidance or definition of what a "technically complex* issue is resulted in responses being submitted to the NRC that were from a perspective focusing on License Renewal Program requirements (e.g. NUREG-1801) and not descriptive of the site-level programs/procedures actually being questioned by the NRC.

1. 2) EN-DC-315 "Flow Accelerated Corrosion Program" (Revision 1, April 2, 2008) contained ambiguous guidance that was open to interpretation.

In one section of the Entergy fleet procedure EN-DC-315, "significant wall thinning" was not identified as an initial screening criterion requiring initiation of a condition report, therefore condition reports were not written in some cases. EN-DC-315 did not state the requirement to document "significant wall thinning" in all sections of the procedure governing inspection results and evaluation of inspection data.

Consequently, the manner in which the Grand Gulf site applied this criterion to its engineering practices may have differed from other sites' interpretations of when a condition report is required to be written.

Extent of Condition The condition being extended from the Root Cause Analysis report was the failure to provide complete and accurate information associated with the GGNS license renewal project RAls. For the purposes of the extent of condition evaluation, the RAI Level was characterized as an initial RAI or a follow-up to a previous RAJ. A Level 1 RAI is the initial RAt based on the LRA or Audit unresolved issues. A Level 2 RAI is a follow-up to a Level 1 RAI and so on.

In order to review the extent of condition all Level 3 (9) and 4 (3) RAls responses were reexamined to determine if incorrect or inaccurate information was submitted to the NRC. Additionally, a representative sample of Level 1 (44) and Level 2 (6) RAls were selected. The Level 1 and 2 RAls were selected randomly. This sample was based on similar guidance provided in EN-QV-109, "Audit Process." (Revision 24, June 27, 2013) For the purposes of performing an adequate and timely Root Cause Evaluation (RCE), a determination was made to review a total of 62 RAI responses related to the GGNS LRA.

Of the sixty two RAI responses that were reviewed, one additional example of miscommunication regarding the full details of the GGNS-MS-46 procedure was identified.

Extent of Cause The root cause of this condition is isolated to the responses to RAls associated with the GGNS license renewal project. A review of other license renewal projects performed in the Entergy fleet indicated that dedicated site teams were established to support answering technical questions relating to RAls.

Based on the change analysis performed in support of the evaluation, it appeared that the lack of a site team dedicated to the license renewal project at GGNS was unique. Not having a license renewal team onsite directly resulted in a lack of site engagement with the project, and it ultimately led to receiving the avoidable notice of violation.

Additionally, the untimely overlap of Grand Gulf's EPU and Grand Gulf's LRA was a unique factor that directly attributed to the root cause. Had the two major projects not been performed concurrently, there would have been no reason to deviate from the normal practice of having a dedicated site team assigned to the license renewal project. Therefore, the Root Cause Evaluation concluded that the extent of cause is limited to only the GGNS License Renewal Application.

Safety Significance The condition documented in this RCE deals with poor practices in the development of correspondence by the Grand Gulf site and corporate License Renewal Group. The conditions have no significant implication for public health and safety or common defense and security as described in Title 10 Code of Federal Regulations Part 54, and do not pose any increase in risk to nuclear, radiological, or industrial safety. The violation examples, if left uncorrected, would have no potential impact to the effectiveness of programs required for aging management review.

Corrective Actions Corrective Action to Prevent Recurrence Entergy will revise EN-U-106 to drive engagement of multiple departments and/or sites in developing responses to RAls when more than one response is referring to the same issue, the issue is

• technically complex, or when organizations external to a site (such as vendors, headquarters, license renewal, etc) are providing a response that involves site-specific programs or procedures.

• NOTE: (This will include a clear definition. with examples, of "technically complex.")

Completed Actions Entergy revised procedure EN-FAP-LR-011 "License Renewal Application Maintenance" (Revision 4, December 29,2012) and included the addition of a RAI response checklist as attachment 7.4 and requirements to use the checklist after preparing an RAI response. (Ref. CR-GGN-2012-8208)

Entergy revised EN-DC-315 (ReviSion 9, July 15, 2013) to clarify the process for determining "Significant Wall Thinning" that warrants an entry into the corrective action program.

(Ref. CR-GGN-2013-2489 CA-3)

Interim Action Grand Gulf Licensing and Engineering departments are now reviewing and certifying, respectively, the responses to RAls for the remainder of the Grand Gulf LRA.

Long Term Action Entergy License Renewal Director will share the lessons learned and operating experience from this event with the Nuclear Energy Institute License Renewal Task Force.

Entergy Licensing Programs Manager will share the lessons learned and operating experience from this event with the Entergy fleet.

Attachment 6 Sheet 1 of 1 Regulatory Commitment This table identifies actions discussed in this letter for which Entergy commits to perform. Any other actions discussed in this submittal are described for the NRC's information and are not commitments.

TYPE (Check one) SCHEDULED ONE-TIME CONTINUING COMPLETION DATE I COMMITMENT ACTION COMPLIANCE <If Required)

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Components subject to wall-thinning mechanisms other than FAC, which are N/A X N/A replaced with alternate materials (e.g.

replacing a carbon steel pipe with stainless steel), shall continue to be periodically monitored at a frequency commensurate with their post-replacement wear rates and post-I re~lacement cumulative run hours.

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