ML25049A247

Ncsg RAI-10505-R1 (Set 5)

ML25049A247
Person / Time
Site:	Perry
Issue date:	02/18/2025
From:	Office of Nuclear Reactor Regulation
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ML25049A245	List: ML25049A246 ML25049A247
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Download: ML25049A247 (1)

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1 REQUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION PERRY UNIT 1 LICENSE RENEWAL APPLICATION REVIEW (SAFETY)

ENERGY HARBOR NUCLEAR GENERATION LLC PERRY, UNIT 1 DOCKET NO. 05000440 ISSUE DATE: 2/18/2025 NCSG RAI-10505-R1 Regulatory Basis :

Section 54.21(a)(3) of Title 10 of the Code of Federal Regulations (10 CFR) requires an applicant to demonstrate that the effects of aging for structures and components will be adequately managed so that the intended function(s) will be maintained consistent with the current licensing basis for the period of extended operation. One of the findings that the U.S.

Nuclear Regulatory Commission (NRC) staff must make to issue a renewed license (10 CFR 54.29(a)) is that actions have been identified and have been or will be taken with respect to managing the effects of aging during the period of extended operation on the functionality of structures and components that have been identified to require review under 10 CFR 54.21, such that there is reasonable assurance that the activities authorized by the renewed license will continue to be conducted in accordance with the current licensing basis. In order to complete its review and enable making a finding under 10 CFR 54.29(a), the staff requires additional information in regard to the matters described in the requests for information.

Question 1 Loss of Material Due to Wear of Fiberglass Piping Background :

As supplemented by letter dated June 27, 2024 (ML24180A010), License Renewal Application (LRA) Table 3.3.2-24 states that change in mechanical properties (cracking, loss of strength),

blistering, and flow blockage for fiberglass piping exposed internally to raw water will be managed by the Fire Water System program. For flow blockage, the aging management review (AMR) item cites plant-specific note 341, which states, Volume 1 of NUREG-2191 includes flow blockage due to fouling for fiberglass piping and piping components exposed to raw water due to potential intrusion of fouling products in raw water systems and managed by the Fire Water System program.

The staff notes that NUREG-2192, Standard Review Plan for Review of Subsequent License Renewal Applications for Nuclear Power Plants (ML17188A158), includes AMR items that address loss of material due to wear of fiberglass exposed to raw water. For example, AMR item 3.3-1, 176 (VII.C1.A-461). Table 2-6 in NUREG-2221, Technical Basis for Changes in the Subsequent License Renewal Guidance Documents NUREG-2191 and NUREG-2192 (ML17362A126), for VII.C1.A-461, indicates that loss of material due to wear from potential abrasive particles in raw water can occur for fiberglass piping.

Issue :

The LRA does not provide a technical basis for why loss of material due to wear is not an applicable aging effect for the fiberglass piping exposed internally to raw water.

Request :

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1. Please provide the technical basis for why loss of material due to wear is not an applicable aging effect for the fiberglass piping exposed internally to raw water.

Question 2 Automatic Standpipe System Flow Tests Background :

Table 4a in Appendix L of LR-ISG-2012-02, Aging Management of Internal Surfaces, Service Level III and Other Coatings, Atmospheric Storage Tanks, and Corrosion under Insulation, recommends flow tests of automatic standpipe systems in accordance with Section 6.3.1.1 of the 2011 Edition of NFPA 25. Section 6.3.1.1 of the 2011 Edition of NFPA 25 states, [a] flow test shall be conducted every 5 years at the hydraulically most remote hose connections of each zone of an automatic standpipe system to verify the water supply still provides the design pressure at the required flow.

In the letter dated December 19, 2024 (ML24354A265), the second exception in the exception table in LRA Section B.2.21 states that in lieu of flow testing at the hydraulically most remote hose connections of each zone every 5 years as specified in Section 6.3.1.1 of the 2011 Edition of NFPA 25, the applicant will perform main header flow testing in the main headers that supply the standpipe system to verify that the water supply provides the largest demand design flow plus 500 gpm [gallons per minute] for hose streams over the longest route and verifies friction losses are within values used to determine design flow at design pressure based upon the measured discharge pressure and flow of a single fire pump, will partially open hose station supply valves every 3 years to confirm no flow blockage, and will perform main drain tests on 20 percent of standpipes and risers every refueling outage (every 24 months). In addition, the applicant stated that the acceptance criteria for the main drain tests will ensure open flow and no obstructions by verifying valve operability and flow through valve and connections.

Issue :

The second exception in the exception table in LRA Section B.2.21, as supplemented by letter dated December 19, 2024 (ML24354A265), does not appear to address how many hose stations are flow tested every 3 years, where the hose stations are located (e.g., different buildings), including whether any are considered remote.

Request :

1. In order to determine whether the alternative testing is sufficient in regard to breadth in number and breadth in locations, please address the following:

a. How many hose stations are flow tested every 3 years?

b. Where are the hose stations that are flow tested every 3 years located (e.g.,

different buildings)?

c. Are any of the hose stations that are flow tested every 3 years considered remote?

Question 3 Main Drain Tests

3 Background :

Table 4a in Appendix L of LR-ISG-2012-02 recommends main drain tests for standpipe systems in accordance with Section 13.2.5 of the 2011 Edition of NFPA 25, which specifies annual main drain testing of the standpipe systems. Section 6.3.1.5 of the 2011 Edition of NFPA 25 specifies main drain testing of all standpipe systems with automatic water supplies in accordance with Chapter 13 of the 2011 Edition of NFPA 25.

In the letter dated December 19, 2024 (ML24354A265), the third exception in the exception table in LRA Section B.2.21 states that in lieu of performing annual main drain testing of all standpipe systems, the applicant will perform main drain tests of 20 percent of the standpipe systems every refueling outage (every 24 months). In addition, Enhancement 1, as supplemented by letter dated December 19, 2024 (ML24354A265), states that the Fire Water System program will be enhanced to require main drain testing of 20 percent of standpipe systems every refueling outage. The enhancement also states, [t]hese tests will occur every 10 years throughout the PEO [period of extended operation].

Issue :

Given that the main drain tests will be performed every refueling outage, it is unclear what tests will occur every 10 years throughout the PEO as indicated in Enhancement 1, as supplemented by letter dated December 19, 2024 (ML24354A265).

Request :

1. Please clarify what tests associated with the main drain testing will occur every 10 years throughout the PEO?

Question 4 Suction Screen and Suction Strainer Table 4a in Appendix L of LR-ISG-2012-02 recommends fire pump suction screen inspections in accordance with Section 8.3.3.7 of the 2011 Edition of NFPA 25, which states, After the waterflow portions of the annual test or fire protection system activations, the suction screens shall be inspected and cleared of any debris or obstructions. In the letter dated December 19, 2024 (ML24354A265), the fourth exception in the exception table in LRA Section B.2.21 states,

[d]ue to the design of the supply inlet and filtering of water from the lake to the Emergency Service Water Pumphouse Suction Bay, PNPP does not require monitoring of the suction screens on the fire pumps after the waterflow portions of the periodic tests, fire protection system activations nor during periods of unusual water supply conditions such as floods. The applicant described the design of the supply inlet, which includes traveling screens that are monitored for differential level and the high level difference is alarmed in the control room. The applicant stated that the alternative aging management activities for the traveling screens are managed by the Open-Cycle Cooling Water System program. The applicant noted that there is a basket type fire pump suction strainer and blockage of the strainer is unlikely given that the upstream traveling screen mesh size is smaller. The applicant also stated that there is no plant-specific operating experience related to flow blockage of the fire pump suction strainer.

The staff notes that LRA Table 3.3.2-22 cites AMR item 3.3.1-40 for managing loss of material of the stainless steel traveling screens by the Open-Cycle Cooling Water System program. During the audit of the Fire Water System program, the applicant described the Open-Cycle Cooling

4 Water System programs periodic traveling screen inspections and described inspections when the screen wash system is not functional.

In addition, the staff notes that LRA Table 3.3.2-24 cites AMR item 3.3.1-64 for managing loss of material of the copper alloy less than 15 percent zinc pump casing (suction strainer element) by the Fire Water System program. As supplemented by letter dated June 27, 2024 (ML24180A010), the AMR item cites plant-specific note 342 that states, Flow Blockage of the pump vertical column, suction strainer is not expected due the upstream configuration of the ESW Pumphouse Intake configuration (USAR Safety Evaluation 9.2.1.3) and the ESW Pumphouse traveling screens. See the exception taken to checking the inlet screens after every use of the pump listed in the Fire Water System AMP in LRA Section B.2.27. The staff notes that it is appropriate to manage the effects of aging of the fire pump suction strainer because Item 68 in Table 2.1-5 of Revision 2 of NUREG-1800 indicates that strainers meet 10 CFR 54.21(a)(1)(i).

Issue :

The LRA does not appear to describe the Open-Cycle Cooling Water System programs periodic traveling screen inspections. The staff notes that the traveling screens could become damaged or corrode over time, which could allow debris to pass-through and reach the fire pump suction strainer. Therefore, a description of inspections that could provide insight into whether the traveling screens are allowing debris to pass-through is requested.

The LRA does not appear to address how the Fire Water System program will manage loss of material of the fire pump suction strainer, including the frequency of the aging management activities.

The LRA does not appear to address plant-specific operating experience related to flow blockage and loss of material of the traveling screens, or loss of material of the fire pump suction strainer.

Request :

Please address the following:

1. Provide the description of the Open-Cycle Cooling Water System programs periodic traveling screen inspections, including frequency.

2. Describe the aging management activities to manage loss of material of the fire pump suction strainer under the Fire Water System program, including the frequency of the aging management activities. In addition, discuss whether the aging management activities are capable of verifying flow blockage is being adequately managed.

3. Discuss any plant-specific operating experience related to flow blockage and loss of material of the traveling screens.

4. Discuss any plant-specific operating experience related to loss of material of the fire pump suction strainer.

Question 5 Deluge Valve Trip Tests and Pre-Action Valve Trip Tests Background :

5 Table 4a in Appendix L of LR-ISG-2012-02 recommends that each deluge valve be trip tested at full flow annually in accordance with Section 13.4.3.2.2 of the 2011 Edition of NFPA 25. In the letter dated December 19, 2024 (ML24354A265), the sixth exception in the exception table in LRA Section B.2.21 states that in lieu of annually trip testing at full flow each deluge valve, the applicant will trip test at full flow open spray deluge valves every refueling outage in accordance with Section 13.4.3.2.2.3 of the 2011 Edition of NFPA 25, trip test with the supply isolation valves closed dry pipe pre-action systems with closed sprinkler heads and ventilation filter deluge spray systems with open sprays every 18 months, and the spray system protecting the Hydrogen Seal Oil System will be full flow tested every 5 years and trip tested with the supply isolation valve closed annually. The applicant stated that Any valve that fails to open is considered a failure and entered into the corrective action program to evaluate and take required corrective actions.

The staff notes that the seventh exception in the exception table in LRA Section B.2.21, as supplemented by letter dated December 19, 2024 (ML24354A265), states that the Ventilation Filter Unit Plenums cannot be tested with water and have no provisions to be tested with air.

Table 4a in Appendix L of LR-ISG-2012-02 recommends that pre-action systems be trip tested with the control valve in the full-open position every 3 years in accordance with Section 13.4.3.2.3 of the 2011 Edition of NFPA 25.

In the letter dated December 19, 2024 (ML24354A265), the eighth exception in the exception table in LRA Section B.2.21 states that in lieu of trip testing the pre-action valve with a fully open control valve every 3 years as specified in Section 13.4.3.2.3 of the 2011 Edition of NFPA 25, the applicant will trip test the pre-action valve with the isolation valves (equivalent to the control valve) closed every 18 months. The applicant stated that To ensure these systems will perform the intended function throughout the PEO, PNPP proposes trip testing and inspections that ensure the downstream piping is free of matter that might plug system sprinklers if the system were actuated, and goes on to discuss Enhancement 4 related to augmented inspections for piping segments that cannot be drained or piping segments that allow water to collect.

Issue :

The LRA does not address whether the Hydrogen Seal Oil System has provisions to be tested with air in accordance with Section 13.4.3.2.2.5 (A) of the 2011 Edition of NFPA 25. The LRA is unclear whether the inspections that ensure the downstream piping is free of matter that might plug system sprinklers if the system were actuated only refers to the augmented inspections for piping segments that cannot be drained or piping segments that allow water to collect, or whether it also includes internal visual inspections in accordance with Section 14.2 of the 2011 Edition of NFPA 25 (i.e., internal visual inspections every 5 years by removing a sprinkler head from the most remote branch line from the source of water or using the inspector's test valve (Section 14.2.1.5 of the 2011 Edition of NFPA 25)). The staff notes that Question 9 is related to Section 14.2 of the 2011 Edition of NFPA 25. In addition, the LRA is unclear whether downstream piping associated with the spray system protecting the Hydrogen Seal Oil System will also be inspected in accordance with Section 14.2 of the 2011 Edition of NFPA 25.

Request :

Please address the following:

1. Does the Hydrogen Seal Oil System have provisions to be tested with air in accordance with Section 13.4.3.2.2.5 (A) of the 2011 Edition of NFPA 25? If this system has provisions to be tested with air, what is the technical basis for not testing with air?

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2. Will the downstream piping associated with both the dry pipe pre-action systems with closed sprinkler heads and the spray system protecting the Hydrogen Seal Oil System be visually inspected internally in accordance with Section 14.2 of the 2011 Edition of NFPA 25?

Question 6 Ventilation Filter Unit Plenums Background :

Table 4a in Appendix L of LR-ISG-2012-02 recommends water discharge patterns from open spray nozzles or sprinklers be observed in accordance with Section 13.4.3.2.2.5 of the 2011 Edition of NFPA 25 to ensure plugged nozzles dont impede the spray patterns, nozzles are positioned correctly, and obstructions dont prevent discharge patterns wetting the required surfaces. The staff notes that Section 13.4.3.4.4.5 (A) of the 2011 Edition of NFPA 25 states,

[w]here the nature of the protected property is such that water cannot be discharged, the nozzles or open sprinklers shall be inspected for correct orientation and the system tested with air to ensure that the nozzles are not obstructed.

In the letter dated December 19, 2024 (ML24354A265), the seventh exception in the exception table in LRA Section B.2.21 states that the Ventilation Filter Unit Plenums cannot be tested with water and have no provisions to be tested with air. Therefore, in lieu of observing the water discharge patterns of the Ventilation Filter Unit Plenums, the applicant will visually inspect the charcoal filter plenum spray header/nozzle each time the charcoal is changed to ensure no debris that would obstruct the spray nozzles.

Issue :

The LRA does not appear to indicate the frequency of changing the charcoal. In addition, the LRA does not appear to describe the visual inspections of the charcoal filter plenum spray header/nozzle when the charcoal is changed.

The LRA does not appear to address plant-specific operating experience related to the charcoal filter plenum spray headers/nozzles.

Request :

Please address the following:

1. On what frequency is the charcoal changed?

2. Describe the visual inspections of the charcoal filter plenum spray header/nozzle that will be performed when the charcoal is changed.

3. Discuss plant-specific operating experience related to the charcoal filter plenum spray headers/nozzles.

Question 7 Mainline Strainers Background :

7 Table 4a in Appendix L of LR-ISG-2012-02 recommends water spray fixed system strainer inspections be performed every refueling outage and after each system actuation. The staff notes that Table XI.M27-1 in NUREG-2191, Volume 2, recommends water spray fixed system strainer inspections be performed after each system actuation, not every refueling outage because absent flow in the system, an inspection would not provide an effective indicator of system flow blockage as discussed in Table 2-29 of NUREG-2221 (ML17362A126). Section 10.2.1.7 of the 2011 Edition of NFPA 25 specifies removal and inspection for damaged and corroded parts of the water spray fixed system strainers every 5 years.

In the letter dated December 19, 2024 (ML24354A265), the ninth exception in the exception table in LRA Section B.2.21 states that in lieu of removing and inspecting the water spray fixed system strainers every 5 years as specified in Section 10.2.1.7 of the 2011 Edition of NFPA 25, the applicant will inspect mainline supply strainers for damage including corrosion and flow blockage from organic and inorganic debris in water spray fixed nozzle systems in scope of License Renewal every 10 years. The applicant stated that adverse findings are entered into the corrective action program for evaluation. In addition, the applicant stated that internal operating experience demonstrates that the current frequency of inspection is adequate to support fixed water system sprays. The staff notes that Enhancement 1 in LRA Section B.2.21, as supplemented by letter dated December 19, 2024 (ML24354A265), is related to this exception.

Issue :

The LRA does not appear to address whether the water spray fixed system strainers will be inspected whenever the system has been actuated consistent with Table 4a in Appendix L of LR-ISG-2012-02. While the applicant stated, internal operating experience demonstrates that the current frequency of inspection is adequate to support fixed water system sprays, it is not clear whether this statement addresses both damaged and corroded parts and flow blockage of the water spray fixed system strainers. In addition, it is not clear if current frequency indicates the mainline strainers are currently inspected on a 10-year frequency.

The LRA does not provide a technical basis for inspecting the mainline supply strainers on a 10-year frequency. Specifically, sufficient details are not provided related to the process used to determine the 10-year frequency or alternative testing (number, location, frequency) that would provide insights into whether the mainline supply strainers are blocked or are damaged or corroded.

Request :

Please address the following:

1. Will the water spray fixed system strainers be inspected whenever the system has been actuated consistent with Table 4a in Appendix L of LR-ISG-2012-02? If not, provide a technical basis for not inspecting the water spray fixed system strainers whenever the system has been actuated, or discuss revising the ninth exception and Enhancement 1 to specify inspection after each system actuation.

2. Discuss whether the statement related to internal operating experience addresses both damaged and corroded parts and flow blockage of the water spray fixed system strainers.

3. Discuss whether the current frequency statement means the mainline strainers are currently inspected on a 10-year frequency.

4. Provide a technical basis for inspecting the mainline supply strainers on a 10-year frequency that includes a description of the process followed to determine the 10-year

8 frequency and a description of alternative testing (number, location, and frequency of alternative inspections/tests) that provides insight into whether the mainline supply strainers are damaged, have corroded parts, or are blocked prior to the next mainline supply strainer inspection. Alternatively, revise the LRA to inspect the mainline supply strainers on a 5-year frequency consistent with Section 10.2.1.7 of the 2011 Edition of NFPA 25.

Question 8 Obstruction Investigations Background :

Table 4a in Appendix L of LR-ISG-2012-02 recommends an obstruction investigation in accordance with Sections 14.2 and 14.3 of the 2011 Edition of NFPA 25. Section 14.2 of the 2011 Edition of NFPA specifies inspection of piping and branch lines every 5 years by opening a flushing connection at the end of one main and by removing a sprinkler toward the end of one branch line. In the letter dated December 19, 2024 (ML24354A265), Enhancement 1 in LRA Section B.2.21 (Commitment No. 21.1 in LRA Table A.3) defines existing enhancements as the inspection scope established in other program elements or elsewhere in this program element and states that Section 14.2 of the 2011 Edition of NFPA 25 does not apply to existing enhancements.

Issue :

Enhancement 1 is unclear on what inspection scope established in other program elements or elsewhere in this program element that Section 14.2 of the 2011 Edition of NFPA 25 would not apply.

Request :

1. Please identify the specific instances where Section 14.2 of the 2011 Edition of NFPA 25 would not apply to existing enhancements (inspection scope established in other program elements or elsewhere in this program element).

Question 9 Diesel Fire Pump Heat Exchanger Background :

As supplemented by letter dated June 27, 2024 (ML24180A010), license renewal application (LRA) Table 3.3.2-24 includes aging management review items for the diesel fire pump heat exchanger tubes, noting intended functions of both pressure boundary and heat transfer with loss of material, reduction of heat transfer, and flow blockage as the aging effects requiring management. The table shows these aging effects as being managed by the Fire Water System aging management program (AMP). LRA Section B.1.4, Operating Experience, notes that Perry will continue the existing operating experience program to manage aging management program effectiveness, consistent with LR-ISG-2011-05, Ongoing Review of Operating Experience. This section also states, If there is an indication that the effects of aging are not being adequately managed, then that will be documented in the corrective action process to either enhance the AMPs or develop and implement new AMPs, as appropriate.

9 Perry condition report CR-2024-08405 documents a high temperature alarm on the diesel driven fire pump on October 25, 2024. The diesel fire pump (DFP) was emergency shut down per the alarm response. The condition report notes that the engines heat exchanger was highly fouled and was not providing adequate heat removal from the engine. Troubleshooting activities noted that the heat exchanger was fouled with sediment and high amounts of tube blockage. The CRs organizational effectiveness investigation notes that the cause of the failure was age-related degradation/fouling and identified a lack of maintenance on the heat exchanger. The CRs maintenance rule evaluation notes that the degraded heat exchanger caused a functional failure of the diesel driven fire pump. The CRs aging management evaluation states The issues identified in the CR are known aging mechanisms, and as stated in the CR, the heat exchanger on the DFP is to be replaced every 14 years as an enhancement to the Fire Water System program. As such, no further actions are required.

Issue :

Aging management review items in LRA Table 3.3.2-24, associated with the diesel driven fire pump heat exchanger tubes, identify loss of material, reduction of heat transfer, and flow blockage as the aging effects requiring management through the Fire Water System AMP.

Although the LRA includes an enhancement to replace the DFP heat exchanger on a 14-year frequency, this periodic replacement fundamentally only addresses the loss of material aging effect for the pressure boundary intended function. Previous industry operating experience had identified diesel engine heat exchanger tube leaks, which another site said they could only address through periodic replacement because they could not inspect the diesel engines heat exchanger tubes for wall thinning. While a new DFP heat exchanger will initially address the reduction of heat transfer aging effect (because it is a new unfouled heat exchanger), the staff notes that Perrys raw water heat exchanger for the high pressure core spray pump (part of the Generic Letter 89-13 program) experienced a 75 percent loss of heat transfer margin over a period of approximately 8.2 years. (Reference information discussed in CR-2022-00950 and CR-2022-01183 cited in RAI-10183-R1.)

Because the activities prescribed by the Fire Water System AMP allowed a functional failure of the diesel fire pump to occur, due to a reduction of heat transfer by the engines heat exchanger, the current activities apparently did not adequately manage the applicable effects of aging. Because the aging management evaluation did not specifically address the reduction of heat transfer due to fouling, which has also occurred in other raw water heat exchangers at Perry, it is not clear that the effects of aging will be adequately managed by only replacing the DFP heat exchanger every 14 years. Although not directly applicable to the DFP heat exchanger, the staff notes that heat exchangers managed by the Generic Letter 89-13 program are either tested or inspected/cleaned on at least a 5-year frequency.

Request :

1. Because the activities currently prescribed by the Fire Water System AMP apparently allowed a functional failure of the diesel fire pump to occur, either describe enhancements to the Fire Water System AMP to ensure that reduction of heat transfer will be adequately managed during the period of extended operation (consistent with the guidance in LRA Section B.1.4), or provide information to demonstrate that reduction of heat transfer due to fouling (as seen by other raw water heat exchangers at Perry) will be adequately managed through the 14-year periodic replacement of the DFP heat exchanger.