W3F1-2016-0077, Responses to Request for Additional Information Set 7 Regarding the License Renewal Application

Responses to Request for Additional Information Set 7 Regarding the License Renewal Application

ML16350A450
Person / Time
Site:	Waterford
Issue date:	12/15/2016
From:	Chisum M Entergy Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
W3F1-2016-0077
Download: ML16350A450 (8)

Text

Entergy Operations, Inc.

17265 River Road Killona, LA 70057-3093 Tel 504-739-6660 Fax 504-739-6698 mchisum@entergy.com Michael R. Chisum Site Vice President Waterford 3 W3F1-2016-0077 December 15, 2016 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001

SUBJECT:

Responses to Request for Additional Information Set 7 Regarding the License Renewal Application for Waterford Steam Electric Station, Unit 3 (Waterford 3)

Docket No. 50-382 License No. NPF-38

REFERENCES:

1. Entergy letter W3F1-2016-0012 License Renewal Application, Waterford Steam Electric Station, Unit 3 dated March 23, 2016.

[ADAMS Accession No. ML16088A332]

2. NRC letter to Entergy Requests for Additional Information for the Review of the Waterford Steam Electric Station, Unit 3, License Renewal Application - Set 7 dated November 15, 2016. [ADAMS Accession No. ML16320A002]

Dear Sir or Madam:

By letter dated March 23, 2016, Entergy Operations, Inc. (Entergy) submitted a license renewal application (Reference 1).

In letter dated November 15, 2016 (Reference 2), the NRC staff made a Request for Additional Information (RAI) Set 7, needed to complete its review. Enclosure 1 provides the responses to the Set 7 RAIs.

There are no new regulatory commitments contained in this submittal. If you require additional information, please contact the Regulatory Assurance Manager, John Jarrell, at 504-739-6685.

I declare under penalty of perjury that the foregoing is true and correct. Executed on December 15, 2016.

Sincerely, MRC/LEM

Enclosures:

1. Set 7 RAI Responses - Waterford 3 License Renewal Application

W3F1-2016-0077 Page 2 of 2 cc: Kriss Kennedy RidsRgn4MailCenter@nrc.gov Regional Administrator U. S. Nuclear Regulatory Commission Region IV 1600 E. Lamar Blvd.

Arlington, TX 76011-4511 NRC Senior Resident Inspector Frances.Ramirez@nrc.gov Waterford Steam Electric Station Unit 3 Chris.Speer@nrc.gov P.O. Box 822 Killona, LA 70066-0751 U. S. Nuclear Regulatory Commission Phyllis.Clark@nrc.gov Attn: Phyllis Clark Division of License Renewal Washington, DC 20555-0001 U. S. Nuclear Regulatory Commission April.Pulvirenti@nrc.gov Attn: Dr. April Pulvirenti Washington, DC 20555-0001 Louisiana Department of Environmental Ji.Wiley@LA.gov Quality Office of Environmental Compliance Surveillance Division P.O. Box 4312 Baton Rouge, LA 70821-4312

Enclosure 1 to W3F1-2016-0077 Set 7 RAI Responses Waterford 3 License Renewal Application to W3F1-2016-0077 Page 1 of 5 WATERFORD STEAM ELECTRIC STATION, UNIT 3 LICENSE RENEWAL APPLICATION REQUESTS FOR ADDITIONAL INFORMATION - SET 7 (CAC NO. MF7492)

RAI B.1.1-3

Background:

The detection of aging effects program element of Generic Aging Lessons Learned (GALL)

Report Aging Management Program (AMP) XI.M18 recommends periodic visual inspections (at least once per refueling cycle) of closure bolting for signs of leakage to ensure the detection of loss of material and loss of preload. Loss of preload or loss of material may result in leakage from the mating surfaces or joint connections of pressure boundary components. Periodic inspection of pressure boundary components for signs of leakage ensures that the effects of aging on closure bolting are detected and corrected before component leakage becomes excessive.

Issue:

The License Renewal Application (LRA) credits the Bolting Integrity Program to manage closure bolting of systems (e.g., nitrogen system, gaseous waste management system, auxiliary steam system, etc.,) that contain clear gaseous fluids. The staff notes that it is difficult to visually detect leakage of clear gaseous fluids and the GALL Report AMP XI.M18 does not provide specific guidance for the detection of leakage of clear gaseous fluids from a bolted connection.

Therefore, it is not clear how signs of leakage of clear gaseous fluids are detected for closure bolts included in the Bolting Integrity Program to ensure the detection of loss of material and loss of preload before there is a loss of intended function.

Requests:

State how signs of leakage of clear gaseous fluids will be detected from bolted closures included in the Bolting Integrity Program in order to ensure the detection of loss of material and loss of preload before there is a loss of intended function.

Waterford 3 Response EPRI 1010639, Appendix F, describes loss of preload as a design-driven effect and not an aging effect requiring management. Pre-load is the tension force developed in a fastener when it is tightened against a joint. Decrease in the pre-load in a bolt may be attributed to, but not limited to, one or more of the following effects: embedment, cyclic load embedment, gasket creep, thermal effects (e.g., yield stress effect, modulus of elasticity effect, and stress relaxation), and self-loosening. Proper joint preparation and make-up in accordance with industry standards is expected to preclude loss of preload. The review of WF3 OE did not identify instances in which non-Class 1 mechanical component failure was attributable to loss of pressure boundary bolting preload.

Nevertheless, the Bolting Integrity Program includes provisions to manage loss of preload primarily in the form of preventive measures, which include material selection (e.g., use of materials with an actual yield strength of less than 150 kilo-pounds per square inch [ksi]),

lubricant selection (e.g., restricting the use of molybdenum disulfide), applying the appropriate to W3F1-2016-0077 Page 2 of 5 preload (torque), and checking for uniformity of gasket compression, where appropriate, to preclude loss of preload, loss of material, and cracking. If these preventive measures were ineffective, leakage would be expected in fluid-filled systems, from which leakage is readily apparent. Corrective actions addressing preventive measures would then apply to bolted closures in general including those serving in systems containing gaseous environments.

Effectively, bolted closures on fluid-containing systems would represent a sample of the overall bolted closure population, including bolted closures in gas-filled systems.

In addition to preventive measures to preclude leakage, the program provides for identification of leakage from bolted closures included in the Bolting Integrity Program during periodic inspections conducted during system walkdowns. Other plant personnel may also identify leakage during routine maintenance and operational activities. During these inspections and other activities, personnel can identify leakage from bolted closures through visual and audible indications. Visual indications can include residue on nearby components and, in the case of steam systems, a visible plume or condensation in the area of the leak. Audible indications that could indicate a leak are the sounds of leaking gaseous contents escaping from the system. In addition, system engineers review operations logs, deficiency lists, and system parameters such as pressure, flow, and temperature which could indicate a system leak.

Based on these activities and considerations, signs of leakage of clear gaseous fluids are detected from bolted closures included in the Bolting Integrity Program, and ensure that the detection of loss of material and loss of preload occur before there is a loss of intended function.

Follow-up (Set 1) RAI B.1.3-1a

Background:

As amended by letter dated October 13, 2016, LRA Section B.1.3, Buried and Underground Piping and Tanks Inspection, and LRA Section A.1.3 (associated Updated Final Safety Analysis Report (UFSAR) Summary Description) state that the external surfaces of buried piping components subject to aging management review will be managed for loss of material and cracking. In addition, LRA Section B.1.3 states that components included in the program are fabricated from metallic or concrete materials.

GALL Report AMP XI.M41 and the associated UFSAR Summary Description issued in License Renewal Interim Staff Guidance (LR-ISG)-2015-01 state that the program addresses the aging effects of loss of material, cracking, and changes in material properties (for cementitious piping only).

Issue:

It is unclear to the staff why changes in material properties is not an applicable aging effect for concrete (i.e. cementitious) piping.

Request:

State the basis for why changes in material properties is not an applicable aging effect for concrete piping.

to W3F1-2016-0077 Page 3 of 5 Waterford 3 Response Change in material properties was not identified as an applicable aging effect for the exterior of concrete pipe exposed to soil/groundwater at WF3 because the groundwater is not aggressive.

The groundwater at WF3 meets the criteria for non-aggressive raw water and ground water/soil as described in NUREG-1801 XI.S7, Element 4, specifically, pH > 5.5, chlorides < 500 parts per million [ppm], and sulfates < 1500 ppm. As described in LRA Section B.1.3, the exterior of the concrete pipe will be inspected for loss of material and cracking. As indicated in XI.M41 (described in ISG-LR-2015-01) changes in material properties due to aggressive chemical attack for cementitious piping can be evidenced by visual indications of cracking and loss of material, such as, exfoliation, spalling, scaling, or residue or deposits from leaching of the concrete. Thus, while change in material properties is not considered an aging effect requiring management, visual inspections to manage cracking and loss of material would be expected to identify aging effects, if any, resulting from a change in material properties.

In addition to the above, LRA Section 2.1.3 reads; LR-ISG-2015-01 (Draft) Changes to Buried and Underground Piping and Tank recommendations This ISG provides proposed guidance related to managing loss of material for the external surfaces of buried and underground piping and tanks. Due to the draft nature of the ISG and the timing of its issuance, it was not feasible to include recommended activities from this ISG into the Waterford 3 LRA.

In response to RAI B.1.3-1, the above should have read with additions underlined and deletions lined through; This ISG provides proposed expanded guidance for managing the effects of aging related to managing loss of material for the external surfaces of buried and underground piping and tanks. This guidance is presented as a revision to NUREG-1800 (Ref.2.1-2) and NUREG 1801 (Ref.2.1-3), as revised by LR-ISG-2011-03. The revised guidance has been considered in the integrated plant assessment and is reflected in the aging management results in Section 3 and the aging management program description presented in Appendix B, Section B.1.3, Buried and Underground Piping and Tanks Inspection. Due to the draft nature of the ISG and the timing of its issuance, it was not feasible to include recommended activities from this ISG into the Waterford 3 LRA.

to W3F1-2016-0077 Page 4 of 5 Follow-up (Set 1) RAI B.1.1-1a (submerged bolting)

Background:

LRA Section B.1.1 describes the existing Bolting Integrity Program as consistent with an exception and enhancements, with GALL Report AMP XI.M18, Bolting Integrity. The GALL Report AMP XI.M18 recommends periodic inspections (at least once per refueling cycle) of closure bolting for signs of leakage to ensure the detection of age-related degradation due to loss of material and loss of preload. The staff noted that a submerged environment limits the ability to detect leakage of submerged bolted connections and, by letter dated September 15, 2016, issued RAI B.1.1-1 requesting the applicant to describe the frequency and method(s) of inspection to be used to detect loss of material and loss of preload on Waterford Steam Electric Station, Unit 3 (WF3) submerged closure bolts. In its response to RAI B.1.1-1, dated October 13, 2016, Entergy Operations, Inc. and Entergy Louisiana, LLC (Entergy or the applicant) stated, in part, the following:

Aging management activities will include opportunistic inspection of the normally inaccessible submerged bolted connection on each [dry cooling tower] DCT area sump pump. [] In addition, each DCT area sump pump is flow-tested at least once every seven years. An acceptable flow test indicates that the submerged bolted connection is not degraded due to loss of material or loss of preload such that the intended function cannot be met. [] A review of operating experience and maintenance records dating back to 1987 identified no indication of loss of intended function of submerged bolting associated with the DCT sump pumps.

Therefore, the monitoring methods and frequency of pump flow testing and opportunistic inspections have been shown effective in managing the applicable aging effects to prevent significant age-related degradation of the submerged DCT area sump pump submerged bolting.

Issue:

Standard Review Plan for License Renewal (SRP-LR) states that for aging management of structures and components (SCs), method and frequency of inspections may be linked to plant specific or industry wide operating experience and the program should include justification that the method and frequency are adequate to detect the aging effects before there is a loss of SC intended function. The SRP-LR also states that the detection of aging effects should occur before there is a loss of SC intended function and that [a] program based solely on detecting

[SC] failure should not be considered as an effective AMP for license renewal. Although the applicant stated that a review of operating experience and maintenance record shows no loss of intended function to date, the staff notes that absence of loss of intended function to date does not demonstrate the program effectiveness for adequate and timely detection of aging effects for long-lived passive SCs. The SRP-LR requires the staff to verify that an adequate AMP demonstrates that it will be effective in the timely detection of the aging effects before there is a loss of intended function.

It is not clear to the staff whether plant-specific operating experience has shown that opportunistic inspections have occurred such that the staff can assess whether the proposed opportunistic inspections are adequate to manage aging of submerged closure bolts during the period of extended (PEO). Considering the possibility that opportunistic inspections may not be performed during the PEO, the staff does not consider that pump flow tests performed once to W3F1-2016-0077 Page 5 of 5 every 7 years will allow for adequate and timely detection of degradation of the submerged closure bolts. The program including only opportunistic inspection in conjunction with testing of pump flow every 7 years may result in inspections and/or testing not done frequently enough to detect the aging effects of loss of material and loss of preload of the submerged bolts before there is a loss of intended function. Additional information is needed to demonstrate that the Bolting Integrity Program frequency and method(s) of inspections will be adequate to detect loss of material and loss of preload in submerged bolts before there is a loss of intended function.

Requests:

Provide the technical basis (e.g., operating experience, related maintenance history, analyses, inspection results, other applicable methods of performance monitoring) to demonstrate that the aging management programs methods and frequency of inspections will ensure that the aging effects of loss of material and loss of preload for the submerged bolts will be timely detected and adequately managed before there is a loss of intended function.

Waterford 3 Response As stated in the response to RAI B.1.1-1 (W3F1-2016-0063), a review of operating experience and maintenance records dating back to 1987 identified no indication of loss of intended function of submerged bolting associated with the four dry cooling tower (DCT) area sump pumps. A review of maintenance records indicates that two of the four DCT area sump pumps have been replaced since 1987.

As part of their rounds, operations personnel inspect the two dry cooling tower (DCT) area sumps every shift.

In addition, sump levels are monitored and alarm in the control room, alerting operators if the DCT area sump pumps are not maintaining acceptable sump levels.

The monitoring methods and frequency of pump flow testing and opportunistic inspections, along with the daily sump monitoring and control room equipment monitoring by operations personnel have been shown effective in managing the applicable aging effects to prevent a loss of intended function of the DCT area sump pump submerged bolting.