RBG-47846, Response to License Renewal Application NRC Request for Additional Information (RAI) Set 12

Response to License Renewal Application NRC Request for Additional Information (RAI) Set 12

ML18093A099
Person / Time
Site:	River Bend
Issue date:	04/03/2018
From:	Maguire W Entergy Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
RBG-47846
Download: ML18093A099 (16)

Text

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~ Entergy.

RBG-47846 April 3, 2018 Attn: Document Control Desk U.S. Nuclear Regulatory Commission 11555 Rockville Pike Rockville, MD 20852-2738 Entergy Operations, Inc.

River Bend Station 5485 U.S. Highway 61 N SI. Francisville. LA 70775 Tel 225-381-4374 William F. Maguire Site Vice President River Bend Station

SUBJECT:

Response to License Renewal Application NRC Request for Additional Information (RAI) Set 12 River Bend Station, Unit 1 Docket No. 50-458 License No. NPF-47

References:

1) Entergy Letter: License Renewal Application (RBG-47735 dated May 25, 2017)

2) NRC email: River Bend Station, Unit 1, Request for Additional Information, Set 12 - RBS License Renewal Application - dated March 6, 2018 (ADAMS Accession No ML18065A213)

Dear Sir or Madam:

In Reference 1, Entergy Operations, Inc (Entergy) submitted an application for renewal of the operating license for River Bend Station (RBS) for an additional 20 years beyond the current expiration date. In an email dated March 6, 2018, (Reference 2) the NRC staff made a Request for Additional Information (RAI) needed to complete the license renewal application review. provides the responses to the Set 12 RAls. Enclosure 2 describes two regulatory commitments.

If you require additional information, please contact Mr. Tim Schenk at (225)-381 -4177 or tschenk@entergy.com.

RBG-47846 Page 2 of 2 In accordance with 10 CFR 50.91 (b)(1), Entergy is notifying the State of Louisiana and the State of Texas by transmitting a copy of this letter to the designated State Official.

I declare under penalty of perjury that the foregoing is true and correct. Executed on April 3, 2018.

Sincere~/a Q,.,.....)DJ-FM/RMC/alc tJ' Enclosure 1: Responses to RAI Set 12 - River Bend Station : Commitments - River Bend Station cc:

(with Enclosure)

U. S. Nuclear Regulatory Commission Attn: Emmanuel Sayoc 11555 Rockville Pike Rockville, MD 20852 cc:

(w/o Enclosure)

U. S. Nuclear Regulatory Commission Attn: Lisa Regner 11555 Rockville Pike Rockville, MD 20852 U.S. Nuclear Regulatory Commission Region IV 1600 East Lamar Blvd.

Arlington, TX 76011-4511 NRC Resident Inspector PO Box 1050 St. Francisville, LA 70775 Central Records Clerk Public Utility Commission of Texas 1701 N. Congress Ave.

Austin, TX 78711-3326 Department of Environmental Quality Office of Environmental Compliance Radiological Emergency Planning and Response Section Ji Young Wiley P.O. Box 4312 Baton Rouge, LA 70821 -4312 RBF1-18-0051

RBG-47846 Responses to Request for Additional Information Set 12

RBG-47846 Page 2 of 12 Question REQUEST FOR ADDITIONAL INFORMATION LICENSE RENEWAL APPLICATION RIVER BEND STATION, UNIT 1 - SET 12 DOCKET NO.: 50-458 CAC NO.: MF9757 Office of Nuclear Reactor Regulation Division of Materials and License Renewal RAI 3.2.2.3.2-1 a (Generic Filtration Follow-up)

Background

The response to RAI 3.2.2.3.2-1, dated January 10, 2018, states that, unlike piping, strainers and filters (with the intended function of filtration) are designed to collect debris, whether from aging effects or other causes.

Consequently, provisions have been incorporated into the system design or operation to manage the debris collection, so the active function of providing system flow can continue to be accomplished. An overall summary of the response indicates that flow blockage would be detectable by: a) alarmed differential pressure, b) local indication of differential pressure, or c) abnormal operation indicated through performance monitoring of temperatures, pressures, or flows. In addition, the response indicates that some of these components are also periodically inspected and cleaned.

In its discussion regarding the IPA required by 10 CFR 54.21, the industry guidance endorsed by Regulatory Guide 1.188, "Standard Format and Content for Applications to Renew Nuclear Power Plant Operating Licenses," states that the information to be documented by the applicant should include an identification of the AERM and an identification of the specific program or activities [emphasis added by staff] that will manage the effects of aging for each component.

For the strainer in the main steam positive leakage control system, LRA Table 3.3.2-6 indicates that only the strainer is exposed to a treated water environment, which is consistent with the response's discussion regarding the compressor seal water cooler outlet strainer. However, PID-27-20C also shows a strainer (STR10BA), which takes a suction from the auxiliary building atmosphere through a 0.125-inch perforated screen, indicating an environment of indoor air.

Issue

1) Although considerations for debris collection may be incorporated into the system design or operation, the industry guidance endorsed in Regulatory Guide 1.188 states that the IPA should include an identification of the specific program or activities that are used to manage aging effects. For components with an intended function of filtration, it is not clear to the staff that in all cases the proposed operational controls (e.g., for abnormal operation), or maintenance tasks (e.g., periodic inspections or cleaning of strainers) are linked to a specific program.

For the suppression pool suction strainers, it is also not clear how fouling is trended to ensure that accumulation of debris will not prevent an intended function from being met prior to the next inspection.

In addition, given the normal movement of control rods, it is not clear to the staff that normal operation will be adequate to detect potential flow blockage in the hydraulic control unit (HCU) filters.

RBG-47846 Page 3 of 12

2) For the strainer STR 1 OBA in the main steam positive leakage control, it is not clear to the staff whether this.

component is within the scope of license renewal and whether LRA Table 3.3.2-6 includes a corresponding AMR item.

Request

1)

For each component in the table below provide additional information as follows:

Table No.

System Component Type Discussion from RAI Response 3.2.2-2 High Pressure Core Spray Suction Strainer Inspect and Clean 3.2.2-3 Residual Heat Removal Suction Strainer Inspect and Clean 3.2.2-4 Low Pressure Core Spray Suction Strainer Inspect and Clean 3.2.2-5 Reactor Core Isolation Suction Strainer Inspect and Clean Cooling 3.3.2-1 Control Rod Drive Filter Normal Operation will detect flow blockage.

Inspect and replace during rebuilds

a. For strainers where periodic inspections are performed, state: (a) the specific AMP to be used; (b) whether the maintenance tasks will be linked to the AMP; (c) how monitoring and trending will be conducted; and (d) the frequency of the inspections being credited.

b. For the HCUs, state the basis for why monitoring during normal operation will be adequate to detect potential flow blockage of the filters. If monitoring might not be adequate, state the basis for why the periodicity of rebuilds provides reasonable assurance that the intended function of the control rods will be met.

2)

For strainer STR1 OBA in the main steam positive leakage control system (PID-27-20C), provide additional information to clarify whether this component is within the scope of license renewal and, if so, state which aging management review item in LRA Table 3.3.2-6 is applicable.

Response

1) a. Periodic inspections are performed for the suction strainers in the high pressure core spray, residual heat removal, low pressure core spray, and reactor core isolation cooling systems. (a) These inspections will be performed as part of the Periodic Surveillance and Preventive Maintenance Program. (b) These inspection tasks will be linked to the Periodic Surveillance and Preventive Maintenance Program.

Changes to Appendix A and B that identify these tasks as part of the program are shown below. (c) The inspections of the suction strainers require all material/debris identified on the strainers to be cataloged and recorded to ensure the removed material/debris is identified and recorded. In addition, Engineering is required to inspect the removed material/debris. The task acceptance criteria limit the amount of debris. Not meeting the acceptance criteria requires initiation of a condition report to determine cause and corrective actions. (d) These inspections are performed once per refueling cycle. Changes to the LRA are provided below.

b. In accordance with Technical Specification requirements, control rods are exercised at least once per month. The control rod exercise test serves as a periodic check of the control rod system that would detect flow blockage in the HCU filters. Blockage would be indicated by abnormal operation of the control rod. In addition, the control rod travel speed is tested every refueling outage. This test would detect abnormal speeds indicative of blockage in the filters. These tests provide the information necessary to detect flow blockage in the HCU filters.

RBG-47846 Page 4 of 12

2)

As shown by the highlighting on PI 0-27 -20C, STR 1 OBA is subject to aging management review for license renewal as is STR1 OBB shown on PI0-27-200. Only the strainer housings were included in LRA Table 3.3.2-6. The strainers are stainless steel with 0.125 inch holes exposed to indoor air taking suction inside the auxiliary building. The potential for flow blockage is extremely low. In addition, these strainers are periodically inspected and cleaned as necessary, and flow blockage would be detected through normal monitoring of compressor performance. Changes to LRA Table 3.3.2-6 to include strainers in an indoor air environment are provided below.

The changes to LRA Sections A.1.34 and B.1.34 and Table 3.3.2-6 follow with additions underlined and deletions lined through.

A.1.34 Periodic Surveillance and Preventive Maintenance The Periodic Surveillance and Preventive Maintenance (PSPM) Program includes periodic inspections and tests to manage aging effects including cracking, loss of material, reduction of heat transfer, and change in material properties, in cases where no NUREG-1801 program was found appropriate to manage the particular aging effects for specific components. At a minimum, in each 10-year period during the period of extended operation, a representative sample of 20 percent of the population (defined as components having the same combination of material, environment, and aging effect) or a maximum of 25 components per population is inspected. Where practical, the inspections will focus on the bounding or leading components most susceptible to aging because of time in service and severity of operating conditions. Physical manipulation of elastomers is conducted in conjunction with visual inspections. Indications or relevant conditions of degradation detected are evaluated.

Credit for program activities has been taken in the aging management review for the following components.

Inspect the surface of the inflatable elastomer seal for the upper containment pool gates in the reactor building.

Inspect the surface of the inflatable elastomer seal for the spent fuel storage pool gates in the auxiliary building.

Visually inspect the surface of the high pressure core spray, residual heat removal, low pressure core spray, and reactor core isolation cooling suppression pool suction strainers for debris.

Addition to Section A.4, LICENSE RENEWAL COMMITMENT LIST 24 Periodic Surveillance Enhance the PSPM Prior to February 28, RBG-47735 and Preventive Program as described in 2025, or the end of the RBG-47846 Maintenance LRA Section A.1.34.

last refueling outage prior to August 29, 2025, whichever is later.

RBG-47846 Page 5 of 12 8.1.34 PERIODIC SURVEILLANCE AND PREVENTIVE MAINTENANCE Program Description There is no corresponding NUREG-1801 program.

The Periodic Surveillance and Preventive Maintenance (PSPM) Program includes periodic inspections and tests to manage aging effects, including cracking, loss of material, reduction of heat transfer, and change in material properties, in cases where no NUREG-1801 program was found appropriate to manage the particular aging effects for specific components. At a minimum, in each 10-year period during the period of extended operation, a representative sample of 20 percent of the population (defined as components having the same combination of material, environment, and aging effect) or a maximum of 25 components per population is inspected. Where practical, the inspections will focus on the bounding or leading components most susceptible to aging because of time in service and severity of operating conditions. Physical manipulation of elastomers is conducted in conjunction with visual inspections. Indications or relevant conditions of degradation detected are evaluated.

Credit for program activities has been taken in the aging management review for the following systems and structures.

Reactor building Inspect the surface of the inflatable elastomer seal for the upper containment pool gates.

Auxiliary building Inspect the surface of the inflatable elastomer seal for the spent fuel storage pool gates.

High I2ressure core Visually insl2ect the surface of the SUl2l2ression 12001 suction strainer sl2ray system for debris.

Residual heat removal Visually insl2ect the surface of the SUl2l2ression 12001 suction strainer system for debris.

Low I2ressure core Visually insl2ect the surface of the SUl2l2ression 12001 suction strainer sl2ray system for debris.

Reactor core isolation Visually insl2ect the surface of the SUl2l2ression 12001 suction strainer cooling for debris.

RBG-47846 Page 6 of 12 Table 3.3.2-6: Main Steam Positive Leakage Control System Component Intended Type Function Material Environment Piping Pressure Carbon steel Steam (int) boundary Piping Pressure Stainless steel Air - indoor boundary (ext)

Piping Pressure Stainless steel Condensation boundary (int)

Strainer Filtration Stainless steel Air - indoor (ext)

Strainer Filtration Stainless steel Treated water (ext)

Strainer housing Pressure Stainless steel Air - indoor boundary (ext)

Strainer housing Pressure Stainless steel Air - indoor boundary (int)

Aging Effect Requiring Management Loss of material None Loss of material None Loss of material None None Aging Management NUREG-1801 Table 1 Programs Item Item Notes Water Chemistry VII.E3.AP-106 3.3.1-21 C, 301,

Control - BWR 305 None VII.J.AP-123 3.3.1-120 A

Internal Surfaces VII. E5.AP-273 3.3.1-95 C

in Miscellaneous Piping and Ducting Components None VII.J.AP-123 3.3.1-120 8 Water Chemistry VILC2.A-52 3.3.1-49 C

Control - Closed Treated Water Systems None VILJ.AP-123 3.3.1-120 A

None VILJ.AP-123 3.3.1-120 A

RBG-47846 Page 7 of 12 Question RAI B.1.18-1: Fatigue Monitoring of Emergency and Faulted Transients

Background

The "parameters monitored or inspected" program element of GALL Report AMP X.M1, "Fatigue Monitoring,"

recommends that the program monitor and track all plant design transients that cause cyclic strains, which are significant contributors to the fatigue usage factor. The GALL Report AMP also states that the program ensures the fatigue usage remains within the allowable limit, thus minimizing fatigue cracking of metal components caused by cyclic strains in the material. LRA Section B.1.18 describes the applicant's Fatigue Monitoring Program.

During the audit, the staff noted that the following applicant procedure addresses the transients that are counted for fatigue management at the River Bend Station (RBS): EDP-MP-05, "Fatigue Management,"

Revision 2A. Specifically, Section 7.2, "Applicable Transient," of this procedure indicates that some adverse emergency or faulted transients may be counted as normal transients in the event the transients occur.

Issue It is not clear to the staff whether the applicant's monitoring of "some" emergency and faulted transients is consistent with the guidance in the GALL Report AMP that the program monitors all plant design transients that cause cyclic strains which are significant contributors to the fatigue usage factor.

Request Please clarify the use of the term "some" with respect to consistency between the LRA program and the guidance provided in the GALL report.

Response

RBS has not yet revised procedure EDP-MP-05, "Fatigue Management," Revision 301 (December 3, 2015), to reflect the changes necessary to track the appropriate transients against their cycle limits during the period of extended operation. This activity is identified in LRA Section 8.1.18, "Fatigue Monitoring," which includes Enhancement 1 to revise the program procedures to track the required transients. The revised procedure will include the results of RBS calculation 6247.547-604-014, "Adequacy of Cycles Being Tracked for Fatigue Monitoring," that was performed to identify all plant design transients that cause cyclic strains that are significant contributors to the fatigue usage factor.

Question RAI B.1.18-2: Fatigue Management and Monitoring for Containment Components

Background

The "parameters monitored or inspected" program element of GALL Report AMP X.M1, "Fatigue Monitoring,"

recommends that that the program monitor and track all plant design transients that cause cyclic strains, which are significant contributors to the fatigue usage factor. The GALL Report AMP also states that the program ensures the fatigue usage remaining within the allowable limit, thus minimizing fatigue cracking of metal components caused by anticipated cyclic strains in the material. LRA Section B.1.18 describes the applicant's Fatigue Monitoring Program.

LRA Section 4.6 addresses fatigue analyses for containment liner plate, metal containments and penetrations.

LRA Section 4.6 also indicates the following: (1) fatigue analyses for the floor liner plate complies with the

RBG-47846 Page80f12 requirements of ASME Boiler and Pressure Vessel (B&PV) Code,Section III, Division 2; (2) fatigue analyses for the steel containment cylinder and dome complies with the requirements of ASME B&PV Code Section III, Division 1, Subsection NE; (3) detailed fatigue calculations were generated for the containment penetrations at River bend Station (RBS); and (4) containment structural components (e.g., polar crane, equipment hatch and drywell combination door/hatch assembly) are evaluated for fatigue.

In addition, LRA Section 4.6 indicates that the applicant will manage the aging effects due to fatigue for the containment components using the Fatigue Monitoring Program in accordance with 10 CFR 54.21 (c)(1 )(iii).

Issue During the audit, the staff noted that the applicant's procedure, EDP-MP-05 (Revision 2A) addresses counted fatigue transients and fatigue management activities. However, this procedure does not clearly describe fatigue monitoring and management activities for the containment liner plate, metal containments, containment penetrations, and other containment structural components (such as polar cranes).

During the audit, the staff also noted that the following Engineering Report provides recent updates to fatigue analysis and usage results for various pressure boundary piping components at RBS: RBS-EP-17 -00006, Revision 0, "Fatigue Update for River Bend Nuclear Station Using FatiguePro Software." This report does not address fatigue analysis updates for the containment liner plate, cylinder, dome, penetrations and other structural components (such as polar cranes).

Request Provide a description of the fatigue monitoring program for the containment liner plate, cylinder and dome, penetrations, and other structural components (such as polar cranes) or, alternatively, provide the documents that describe the fatigue monitoring program for these structural components.

Response

The responses to RAI 4.6-1 and RAI 4.6-2 describe the fatigue analyses for the containment liner plate, cylinder and dome, penetrations, and other structural components (such as polar crane). As identified in the response to RAI 4.6-2, transients that must be tracked to allow fatigue assessment of these structural components are safety relief valve (SRV) actuations and earthquakes.

RBS calculation 6247.547-604-014, "Adequacy of Cycles Being Tracked for Fatigue Monitoring," identifies that SRV actuations and earthquakes must be tracked for fatigue assessment of piping penetrations.

LRA Section B.1.18, "Fatigue Monitoring," includes Enhancement 1 to revise program procedures to track the necessary transients. Upon implementation of this enhancement, program procedures will specify tracking of the appropriate cycles including the SRV actuations and earthquakes that must be monitored for fatigue assessment of containment structural components.

Question RAI B.1.18-3: Corrective Action Program Element

Background

The "corrective action" program element of GALL Report AMP X.M1, "Fatigue Monitoring," states that the program provides for corrective actions to prevent the usage factor from exceeding the design code limit during the period of extended operation. The program element in the GALL Report also states that acceptable corrective actions include repair of the component, replacement of the component, and a more rigorous analysis of the component to demonstrate that the design code limit will not be exceeded during the period of extended operation.

RBG-47846 Page 9 of 12 The following reference describes the program elements and basis of the applicant's Fatigue Monitoring Program in comparison with those of GALL Report AMP X.M1: Section 4.7., "Fatigue Monitoring" of RBS-EP-15-00006, Revision 0, "RBS License Renewal Project: Aging Management Program Evaluation Report Class 1 Mechanical."

Issue During the audit, the staff noted that the "corrective action" program element of the Fatigue Monitoring Program in the program basis document (RBS-EP-15-00006, Revision 0) does not address specific corrective actions such as repair of the component, replacement of the component, and a more rigorous analysis of the component. The program basis document only refers to the corrective action program. The lack of these corrective actions from the "corrective action" program element appears inconsistent with the guidance in GALL Report AMP X.M1.

Request Provide justification for why the program basis document does not address corrective actions such as component repair/replacement activities and more rigorous analyses. Alternatively, confirm whether the program includes relevant corrective actions in the "corrective action" program element.

Response

As indicated in LRA Section B.1.18, the RBS Fatigue Monitoring Program will be consistent with the program described in NUREG-1801,Section X.M1, Fatigue Monitoring, without exceptions. Therefore, the RBS program will be consistent with the corrective action program element described in NUREG-1801,Section X.M1. For clarification, the Fatigue Monitoring Program description (Section 7B) of RBS-EP-15-00006, "Aging Management Program Evaluation Report Class 1 Mechanical," will be revised to state acceptable corrective actions include repair of the component, replacement of the component, and a more rigorous analysis of the component to demonstrate that the design code limit will not be exceeded during the period of extended operation.

RBG-47846 Page 10 of 12 Addition to Section A.4, LICENSE RENEWAL COMMITMENT LIST No.

Program or Activity Commitment 11 a Fatigue Monitoring Revise the Fatigue Monitoring Program descriQtion (Section 7B) of RBS-EP-1S-00006, "Aging Management Program Evaluation Rel20rt Class 1 Mechanical," to state acceQtable corrective actions include reQair of the comQonent, reQlacement of the comQonent, and a more rigorous analy:sis of the coml2onent to demonstrate that the design code limit will not be exceeded during the l2eriod of extended oQeration.

Implementation Source Schedule (Letter Number)

Prior to February: 28, RBG-47846 2025.

RBG-47846 Page 11 of 12 Question RAI B.1.18-4: Operating Experience

Background

River Bend Station (RBS) Condition Report, CR-RBS-2016-00656 (1 /2212016) indicates the following information related to fatigue cycle monitoring: The FatiguePro software uses the COLLECT program to retrieve cycle and fatigue related data from the ERIS computer. During the retrieval of the cycle 18 data, it was noticed that the COLLECT program unexpectedly stopped automatically recording data from November 2012 to September 2013. The Collect computer has been restored to service. Data on the Collect computer was not recoverable.

Issue Data collection for fatigue cycles and related information is an important attribute for fatigue monitoring and management. The LRA does not provide information regarding this operating experience and resolution of the data collection issue.

Request Describe how the applicant resolved the fatigue data collection issue that is addressed in CR-RBS-2016-00656 and discuss how loss of this data was addressed as part of the Fatigue Monitoring Program.

Response

Additional computer data was extracted from the plant computer and a manual review of events was completed to supplement the missing data from the COLLECT computer station. The RBS collection of data for cycle counting no longer relies on an individual COLLECT computer station. Data can now be retrieved from the plant computer data storage.

Question RAI B.1.18-5

Background

The applicant's enhancement to the "preventive actions" program element of the Fatigue Monitoring Program states that an environmentally assisted fatigue analysis using NUREG CR-6909 will not use average temperature for complex transients. NUREG CR-6909 Report provides equations that can be used to calculate environmental fatigue correction factors.

Issue Given the applicant's statements concerning temperatures used in its fatigue analysis, it is not clear to the staff whether the applicant's analyses follow the guidance contained in NUREG CR-6909.

Request Please clarify whether the approach proposed is in accordance with NUREG CR-6909 and, if not, provide a description of how the approach used differs from the approved guidance and a basis for those differences. As part of the response, clarify what temperature is used to determine the environmental fatigue correction factor for complex thermal transients with multiple increasing and decreasing temperature excursions.

RBG-47846 Page 12 of 12

Response

The approach used for RBS is in accordance with NUREG/CR-6909.

As shown on page A5 of NUREG/CR-6909, an average temperature may be used to calculate Fen for the case of a constant strain rate and a linear temperature response. NUREG/CR-6909 Fen equations for carbon steel (Equation A.2), low-alloy steel (Equation A3), and stainless steel (Equation A9) have a minimum threshold temperature of 150°C below which the Fen value is minimized. The minimum threshold temperature of 150°C is to be used in the average when the minimum temperature of a transient pair is less than 150°C. The NUREG/CR-6909 equation for Ni-Cr-Fe (Equation A14) does not have a minimum threshold temperature; therefore, no minimum temperature for averaging is used.

The average temperature will not be used to calculate Fen for complex transients (transients not having a constant strain rate and linear temperature response). When a more detailed Fen calculation is required for a complex transient, the NUREG/CR-6909 Section 4.2.14 modified rate approach is used. The modified rate approach can be used to calculate Fen under conditions where temperature and strain rate are changing.

RBG-47846 Commitments Set 12

RBG-47846 Page 1 of 1 This table identifies actions discussed in this letter that Entergy commits to perform. Any other actions discussed in this submittal are described for the NRC's information and are not commitments.

Changes to LRA Section AA follow with additions underlined Addition to Commitment List (Appendix A.4)

Implementation Source No.

Program or Activity Commitment Schedule (Letter Number) 11 a Fatigue Monitoring Revise the Fatigue Monitoring Program descri(2tion Prior to Februar~ 28, RBG-47846 (Section 7B) of RBS-EP-15-00006, "Aging Management 2025.

Program Evaluation Re(2ort Class 1 Mechanical," to state acce(2table corrective actions include re(2air of the com(2onent, re(2lacement of the com(2onent, and a more rigorous anal~sis of the com(2onent to demonstrate that the design code limit will not be exceeded during the (2eriod of extended o(2eration.

24 Periodic Surveillance Enhance the PSPM Program as described in LRA Prior to February 28, RBG-47735 and Preventive Section A.1.34.

2025, or the end of the RBG-47846 Maintenance last refueling outage prior to August 29, 2025, whichever is later.

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