ML19204A268

NRR E-mail Capture - Shearon Harris Nuclear Power Plant, Unit 1 Request for Additional Information for the Escw System TS AOT Extension and Removal of an Expired Note in TS Risk Informed LAR (L-2019-LLA-0025)

ML19204A268
Person / Time
Site:	Harris
Issue date:	07/23/2019
From:	Martha Barillas Plant Licensing Branch II
To:	Earp D, Zaremba A Duke Energy Carolinas
References
L-2019-LLA-0025
Download: ML19204A268 (6)

Text

NRR-DRMAPEm Resource From: Barillas, Martha Sent: Tuesday, July 23, 2019 11:05 AM To: 'Arthur.Zaremba@duke-energy.com'; Earp Jr., Dennis Cc: Shoop, Undine; Barillas, Martha

Subject:

Shearon Harris Nuclear Power Plant, Unit 1 Request for Additional Information for the ESCW System TS AOT extension and removal of an expired note in TS Risk Informed LAR (L-2019-LLA-0025)

Attachments: HNP ESCWS TS AOT extension LAR RAI L-2019-LLA-0025.docx Mr. Zaremba, By application dated February 18, 2019 (Agencywide Documents Access and Management System (ADAMS)

Accession Number ML19049A027), Duke Energy Progress LLC, the licensee, requested to modify the Shearon Harris Nuclear Power Plant, Unit 1 Technical Specifications to permit one train of the Essential Services Chilled Water System to be inoperable for up to 7 days, from the current 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> allowed outage time. In addition, the amendment would remove an expired note previously added to the Technical Specifications by implementation of Amendment No. 153. The U.S. Nuclear Regulatory Commission (NRC) staff has determined the attached request for additional information (RAI) is needed in order to complete its review.

The RAI was e-mailed to the licensee in draft form on July 15, 2019 and a clarification call was held between Duke Energy and the NRC staff on July 18, 2019. During the clarification call, it was determined RAI 02, part a, was not needed and was removed. The revised draft RAI 02 was e-mailed on July 18, 2019. The licensee agreed to provide its response to this final RAI by August 19, 2019. A publicly-available version of this final RAI and email will be placed in the NRCs ADAMS.

Please note that if a response to this email is not received by this date, or an acceptable alternate date with a justification for an extension is not provided in writing, we may deny the application for amendment under the provisions of Title 10 of the Code of Federal Regulations, Part 2, Section 108, "Denial of application for failure to supply information."

If you have any questions, please contact me at 301-415-2760 or via email at Martha.Barillas@nrc.gov.

Martha Barillas-Project Manager NRR/Division of Operating Reactor Licensing US Nuclear Regulatory Commission 301-415-2760 1

Hearing Identifier: NRR_DRMA Email Number: 133 Mail Envelope Properties (BN8PR09MB3553B208AED47FB9C5E4DC43F2C70)

Subject:

Shearon Harris Nuclear Power Plant, Unit 1 Request for Additional Information for the ESCW System TS AOT extension and removal of an expired note in TS Risk Informed LAR (L-2019-LLA-0025)

Sent Date: 7/23/2019 11:05:11 AM Received Date: 7/23/2019 11:05:13 AM From: Barillas, Martha Created By: Martha.Barillas@nrc.gov Recipients:

"Shoop, Undine" <Undine.Shoop@nrc.gov>

Tracking Status: None "Barillas, Martha" <Martha.Barillas@nrc.gov>

Tracking Status: None

"'Arthur.Zaremba@duke-energy.com'" <Arthur.Zaremba@duke-energy.com>

Tracking Status: None "Earp Jr., Dennis" <Dennis.Earp@duke-energy.com>

Tracking Status: None Post Office: BN8PR09MB3553.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 1901 7/23/2019 11:05:13 AM HNP ESCWS TS AOT extension LAR RAI L-2019-LLA-0025.docx 43211 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received:

REQUEST FOR ADDITIONAL INFORMATION LICENSE AMENDMENT REQUEST FOR EXTENSION OF THE ESSENTIAL SERVICES CHILLED WATER SYSTEM ALLOWED OUTAGE TIME AND REMOVAL OF AN EXPIRED NOTE FROM TECHNICAL SPECIFICATIONS DUKE ENERGY PROGRESS, LLC SHEARON HARRIS NUCLEAR POWER PLANT, UNIT 1 DOCKET NO. 50-400 EPID L-2019-LLA-0025 By application dated February 18, 2019 (Agencywide Documents Access and Management System (ADAMS) Accession Number ML19049A027), Duke Energy Progress LLC, the licensee, requested to modify the Shearon Harris Nuclear Power Plant, Unit 1 (HNP) Technical Specifications to permit one train of the Essential Services Chilled Water System to be inoperable for up to 7 days, from the current 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> allowed outage time. In addition, the amendment would remove an expired note previously added to the Technical Specifications by implementation of Amendment No. 153. The U.S. Nuclear Regulatory Commission (NRC) staff has determined the following request for additional information (RAI) is needed in order to complete its review.

Request for Additional Information (RAI) 01 - PRA Model Update Section 3.3 of Reglatory Guide (RG) 1.200, Revision 2 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML090410014), provides guidance on the technical acceptability of Probabilistic Risk Assessment (PRA) to support an application and one of the aspect is the assurance that the pieces of the PRA used in the application have been performed in a technically correct manner. In addition, RG 1.200, Revision 2, states that the PRA model required to support the application is expected to represent the as-designed or as-built and as-operated plant, which, in turn, implies that the PRA model is up to date and reflects the current design and operating practice, where appropriate.

The licensee stated in Section A.2.1 of Attachment 5 to the license amendment request (LAR) that the internal events PRA model was updated in 2017 and 2018. The internal fire and high winds PRAs use the internal events PRA as the base. The licensees discussion of the Shearon Harris Nuclear Power Plant (HNP) internal fire and high winds PRAs does not provide information regarding the consistency of their development and update with the internal events PRA model updates. Therefore, the NRC staff is unclear whether the HNP internal fire and high winds PRAs incorporate the 2017 and 2018 updates performed for the internal events PRA.

a. Clarify if the internal fire and high winds PRAs supporting this application incorporate all the 2017 and 2018 updates to the internal events PRA.

b. If the internal fire and high winds PRAs supporting this application do not incorporate all the 2017 and 2018 internal events PRA updates, either justify the exclusion of updates in the context of this application or incorporate the updates, as applicable, into the internal fire and high winds PRAs supporting this application and provide the updated results (i.e., results in Table A.5.8 of Attachment 5 to the LAR).

2 RAI 02 - High Winds Section 2 of RG 1.200, Revision 2, states that one acceptable approach to demonstrate a technically acceptable PRA is by using a national consensus PRA standard that addresses the scope of the PRA used in the decision-making, and performing a peer review for the PRA using endorsed peer review guidance. Following the guidance in RG 1.200, Revision 2, may obviate the need for an in-depth review of the base PRA by NRC reviewers, allowing them to focus their review on key assumptions and areas identified by peer reviewers as being of concern and relevant to the application.

The licensee used the HNP high winds PRA model as described in Section A.2.4 of Attachment 5 to the LAR. In Section B.4 of Attachment 5 of the LAR, the licensee provided a discussion of four high winds finding level facts and observations (F&Os) that remained open and concluded that they have no impact on this application. The concerns in F&O ID: Observation #1, associated with supporting requirement WFR-B2, are dispositioned as documentation issues. It does not appear to be only a documentation issue to the NRC staff. The disposition for item 1a discusses the potential for either an updated wind pressure fragility for the Dedicated Shutdown Diesel Generator (DSDG) or the screening of the DSDG from the wind pressure fragility analysis. However, the NRC staff is unclear about the disposition and update, if any, of the DSDG wind pressure fragility analysis. If the DSDG wind pressure fragility has not been updated, or the updated value has not been included, or has been screened out in the high winds PRA supporting this application, justify the disposition of the cited F&O and discuss the impact on this application.

RAI 03 - Uncertainties and Sensitivity Studies Section 2.3.5 of RG 1.177, Revision 1 (ADAMS Accession No. ML100910008) requires that sensitivity and uncertainty analyses relating to assumptions in Technical Specification changes be evaluated. RG 1.174, Revision 3 (ADAMS Accession No. ML17317A256), states: the results of the sensitivity studies should confirm that the guidelines are still met even under the alternative assumptions (i.e., change generally remains in the appropriate region).

The licensee stated in Section A.3 of Attachment 5 to the LAR that three key assumptions are applied to the PRA analysis. The third assumption is related to the human failure events (HFEs) to open doors and implement portable fans as alternate means of cooling the Switchgear Room and Charging Safety Injection Pump (CSIP) Room. In addition, in Section A.10 of Attachment 5 to the LAR the licensee provides the uncertainty considerations of the extended CT in the internal events, internal fire, high winds and internal flooding PRA models. Based on the evaluations, three key sources of uncertainty are identified as room heat-up calculations (Table A.10.1, item 9), operability of equipment in beyond design basis environments (Table A.10.1, item 14), and HVAC performance (Table A.10.2, item 5). These three sources of uncertainty are associated with operator actions to meet the PRA success criterion. A sensitivity analysis was performed assuming the operators fail to take action to provide emergency cooling by opening doors and implementing portable fans as an alternate means of cooling the switchgear room and CSIP and an examination of the delta risk cut sets for the analysis by the licensee indicated an increase in core damage frequency (CDF) greater than 1x10-6 /year and an

3 increase in large early release frequency (LERF) greater than 1x10-8 /year. However, the impact of removal of the operator actions to provide emergency cooling on the proposed extension is unavailable.

a. Provide the results (i.e., the results in Table A.5.8 of Attachment 5 to the LAR) with guaranteed failure of operators to take action to provide emergency cooling by opening doors and implementing portable fans as an alternate means of cooling the switchgear room and CSIP in the base and the completion time extension case.

b. If the results in item (a) exceed the risk acceptance guidelines in RG 1.177, Revision 1, or RG 1.174, Revision 3, describe the approach used to develop the human error probabilities (HEPs) for the operator actions to provide emergency cooling by opening doors and implementing portable fans as an alternate means of cooling the switchgear room and CSIP. The discussion should provide numerical values of the HEPs and include sufficient detail for each of the HEPs on the following:

i. How these operator actions are credited in the internal events, internal flooding, internal fire, and high winds PRAs for the accident sequences consequential to this application.

ii. Existence of procedures and training governing the actions, the specific instructions for the actions, including the cues or indications operators will use to initiate these actions.

iii. The timeline for the actions and the basis for estimation of time available and time required to complete the actions.

iv. The HFE dependency analysis between each of the actions and other operator actions modeled in the PRAs.

v. How these actions are consistent with the supporting requirements associated with high-level requirements (HLR) HR-E, HR-F, HR-G, and HR-H of ASME/ANS RA-Sa-2009, as endorsed by RG 1.200, Revision 2.

RAI 04 - PRA Model for Auxiliary Relay Cabinet Room Section 2.3.3 of RG 1.177, Revision 1, states that specific systems or components involved in the change should be modeled in the PRA to evaluate a TS change. In addition, if the PRA does not model the system for which the TS change is being requested, specialized analyses may be necessary when requesting changes to the TS for these systems.

Section 3.2 of Attachment 1 to the LAR discusses the room heatup analysis and identifies three plant areas where operator actions may be warranted to ensure temperatures are maintained within acceptable limits should the ESCWS fail. One of these areas is the Auxiliary Relay

4 Cabinet Room. The results of the heatup analysis discussed in LAR Section 3.2 indicate that operator action may be needed to maintain acceptable temperatures in the Auxiliary Relay Cabinet Room within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> following a loss of ESCWS. This would suggest that the Auxiliary Relay Cabinet Room should be included in the PRA model based upon the heatup analysis. However, LAR Section 3.2 states, [t]he Auxiliary Relay Cabinet Room is not included in the HNP PRA Model based upon the results of the heatup analysis. Therefore, the basis and impact of the exclusion of the Auxiliary Relay Cabinet Room from the HNP PRA model is unclear to the NRC staff.

a. Justify the exclusion of the Auxiliary Relay Cabinet Room from the HNP PRAs based on the heatup analysis and the impact on this application.

b. If the exclusion of the Auxiliary Relay Cabinet Room from the HNP PRAs cannot be justified for this application, include the room in the appropriate HNP PRAs and provide the impact on this application including updated risk results (i.e., results in Table A.5.8 of Attachment 5 to the LAR).