W3F1-2021-0026, Open Item Response, License Amendment Request to Implement a Digital Upgrade to the Core Protection Calculator (CPC) System and Control Element Assembly Calculator (Ceac) System

Open Item Response, License Amendment Request to Implement a Digital Upgrade to the Core Protection Calculator (CPC) System and Control Element Assembly Calculator (Ceac) System

ML21082A393
Person / Time
Site:	Waterford
Issue date:	03/19/2021
From:	Gaston R Entergy Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
W3F1-2021-0026
Download: ML21082A393 (7)

Text

Entergy Operations, Inc.

1340 Echelon Parkway Jackson, MS 39213 Tel 601-368-5138 Ron Gaston Director, Nuclear Licensing 10 CFR 50.90 W3F1-2021-0026 March 19, 2021 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Open Item Response - License Amendment Request to Implement a Digital Upgrade to the Core Protection Calculator (CPC) System and Control Element Assembly Calculator (CEAC) System Waterford Steam Electric Station, Unit 3 NRC Docket No. 50-382 Renewed Facility Operating License No. NPF-38

References:

1) Entergy Operations, Inc. letter to U.S. Nuclear Regulatory Commission (NRC), "License Amendment Request to Implement a Digital Upgrade to the Core Protection Calculator (CPC) system and Control Element Assembly Calculator (CEAC) system," (ADAMS Accession No. ML20205L587), dated July 23, 2020

2) NRC Meeting Summary, "Summary Of September 22, 2020, Category 1 Public Meeting With Entergy Operations, Inc. Regarding License Amendment Request To Install Digital Upgrade In Accordance With Digital Instrumentation And Control Interim Staff Guidance No. 06, Revision 2,

'Licensing Processes' (EPID L-2020-LLA-0164)," (ML20288A742), dated October 22, 2020 In Reference 1, Entergy Operations, Inc. (Entergy) submitted a proposed amendment to Appendix A, "Technical Specifications" (TS) of Renewed Facility Operating License No. NPF-38 for Waterford Steam Electric Station, Unit 3 (Waterford 3). The proposed change would revise the Waterford 3 TS to implement a planned digital instrumentation and control (DI&C) modification at Waterford 3. The DI&C modification will replace the existing digital minicomputers of the Core Protection Calculator (CPC) system and Control Element Assembly Calculator (CEAC) system with a more reliable, digital system based on the Westinghouse Electric Company (Westinghouse) Common Qualified (Common Q) Platform.

W3F1-2021-0026 Page 2 of 2 On September 22, 2020, the U.S. Nuclear Regulatory Commission (NRC) conducted a virtual Category 1 public meeting with representatives from Entergy and Westinghouse. The purpose of the meeting was to discuss Entergys license amendment request (LAR) (Reference 1). The results of that meeting are summarized in Reference 2.

During the meeting, as summarized in Reference 2, the NRC discussed a proposed process for dispositioning open items (OIs). The OIs are NRC questions regarding the LAR which the NRC would track and eventually disposition as requests for additional information, requests for confirmation of information, audits, or as needing no additional action. The OI list is an informal tool for increasing the efficiency of the NRC review, as well as promoting communication with Entergy. Enclosure 5 of the Reference 2 meeting summary provided a non-proprietary version of preliminary OIs. The enclosure to this letter provides an additional design document concerning OI No. 35.

The No Significant Hazards Consideration determination provided in the Reference 1 submittal is not altered by the information provided in this letter.

There are no new regulatory commitments included in this letter.

In accordance with 10 CFR 50.91(b)(1), "Notice for public comment; State consultation," a copy of this letter, without the proprietary attachments, is being provided to the designated State Official.

Should you have any questions or require additional information, please contact Paul Wood, Regulatory Assurance Manager, Waterford 3, at (504) 464-3786 or pwood1@entergy.com.

I declare under penalty of perjury, that the foregoing is true and correct. Executed on March 19, 2021.

Respectfully,

$%&'"(

Ron Gaston RWG/jls

Enclosure:

Westinghouse Letter LTR-TA-21-17, Revision 2, "Waterford 3 CPCS Safety Function Table - PPS Backup Trips" cc: NRC Region IV Regional Administrator NRC Senior Resident Inspector - Waterford Steam Electric Station, Unit 3 NRC Project Manager Waterford Steam Electric Station, Unit 3 Louisiana Department of Environmental Quality

Enclosure W3F1-2021-0026 Westinghouse Letter LTR-TA-21-17, Revision 2, "Waterford 3 CPCS Safety Function Table - PPS Backup Trips"

Westinghouse Non-Proprietary Class 3 LTR-TA-21-17, Revision 2 From: Transient Analysis and Licensing Engineering Phone: (860) 731-6385 Date: March 23, 2021

Subject:

Waterford 3 CPCS Safety Function Table - PPS Backup Trips To: TA (Transient Analysis) File Introduction This letter is to provide additional information that was requested from the NRC after reviewing Reference 2. The information herein lists the safety function trips for the Core Protection Calculator System (CPCS) for Waterford Steam Electric Station Unit 3 (Waterford 3) provided in Reference 2 and defines the backup Plant Protection System (PPS) trips for these functions.

The table below contains the following information to provide the response to the NRC.

1. Waterford 3 FSAR Chapter 15 Event

2. Credited Trip/Actuation Signals

3. PPS backup Trip Table A-1 in Appendix A of this letter provides this information for the Waterford-3 Core Protection Calculator System (CPCS) PPS backup trips.

The information presented in Table A-1 was compiled from reviewing several sources of information. The Waterford-3 Safety Evaluation Report, Reference 4, identified that the NRC staff has taken the operating experience of ANO-2, the previous review and acceptance of the ANO-2 CPCs, and the similarity of the Waterford 3 and ANO-2 CPCs, into account for the acceptance of the Waterford 3 CPCS. As such Reference 5, was reviewed and contained a listing of backup trips that were credited for the ANO-2 CPCS which was considered in the development of Table A-1. Then the Waterford 3 FSAR, Chapter 15, Reference 1, was reviewed to determine the events crediting the CPCS and these events were listed in Column 1 of Table A-1. The CPCS credited functions (e.g. VOPT) were identified in Reference 2 and these were listed in Column 2 of Table A-1. The Waterford 3 FSAR, Chapter 7 -

Table 7.2-4, was reviewed to determine the available trip functions in the PPS that could be credited as backup trips to the CPCS. This information along with those backup trips identified in Reference 5 was used to identify PPS trips that could be credited as analog backups to the CPCS. These are listed and identified in Column 3 of Table A-1.

2021 Westinghouse Electric Company LLC All Rights Reserved

• • • This record was final approved on 3/23/2021 1:58:16 PM. (This statement was added by the PRIME system upon its validation)

LTR-TA-21-17, Revision 2 Page 2 of 4 Westinghouse Non-Proprietary Class 3 References

1. NRC Accession Number ML19268A136, Waterford Steam Electric Station, Unit 3, Revision 311 to Final Safety Analysis Report, Chapter 15 - Accident Analyses.

2. LTR-TA-19-154, Rev. 0, Waterford 3 Core Protection Calculator System Safety Function Table, Westinghouse Electric Company, LLC.

3. NRC Accession Number ML19268A128, Waterford Steam Electric Station, Unit 3, Revision 311 to Final Safety Analysis Report, Chapter 07 - Instrumentation and Controls.

4. NRC Accession Number ML20009E071, NUREG-0787, July 1981, Safety Evaluation Report related to the operation of Waterford Steam Electric Station, Unit No. 3, dated July 1981.

5. NRC Accession Number ML102850080-2, NUREG-0308, Safety Evaluation Report for Arkansas Nuclear One Unit 2, Supplement 1 to Appendix D, Core Protection Calculator System.

Reference titles are provided for reader convenience only. Refer to the archived record in EDMS for the specific document title and approval date.

If you have any questions or concerns, please contact the undersigned.

Electronically Approved* Electronically Approved*

Warren R. Odess-Gillett, Lead Author Kim A. Jones, Verifier Licensing Engineering Transient Analysis Electronically Approved* Electronically Approved*

Allen C. Denyer, Author Amanda L. Charleroy, Manager CE Safety System Products Transient Analysis

• Electronically approved records are authenticated in the electronic document management system.

• • • This record was final approved on 3/23/2021 1:58:16 PM. (This statement was added by the PRIME system upon its validation)

LTR-TA-21-17, Revision 2 Page 3 of 4 Westinghouse Non-Proprietary Class 3 Appendix A Table A Waterford-3 CPCS PPS Backup Trips Chapter 15 Event /

PPS Backup Trip Waterford-3 SAR Credited CPCS Signals (Waterfprd-3 SAR (Reference 1) SAR Section # Trip Signals Reference 3, Table 7.2-4)

Uncontrolled CEA Bank CPCS VOPT High Linear Power Withdrawal from a critical condition SPVMIN, SPVMAX, or SAR 15.4.1.3 (at Power) DELSPV, and SUPMAX (rate of power increase for FOLLOW)

Uncontrolled CEA Bank CPCS VOPT High Linear Power Withdrawal from HZP SPVMIN or DELSPV, and High Log Power SAR 15.4.1.2 (Low Power) (Power <10-4 %)

SUPMAX (rate of power increase for FOLLOW)

CEA Misoperation - Single Rod None Not Applicable Drop / CEA Sub-group Drop SAR 15.4.1.4 Uncontrolled Boron Dilution At HFP and HZP, this event is High Linear Power bounded by the CEA Bank SAR 15.4.1.5 Withdrawals High Log Power (Power <10-4 %)

Total Loss of Reactor Coolant CPCS RPC Shaft Speed - Low Low RCS Flow Forced Flow Setpoint SAR 15.3.2.1 Increased Main Steam Flow Same as Uncontrolled CEA High Linear Power Bank Withdrawal from a Critical SAR 15.1.1.3 Condition Single Reactor Coolant Pump Shaft CPCS RPC Shaft Speed - Low Low RCS Flow Seizure / Sheared Shaft Setpoint SAR 15.3.3.1 CEA Ejection CPCS VOPT High Linear Power SAR 15.4.3.2 SPVMIN, High Log Power (Power <10-4 %)

SPVMAX, or DELSPV, and SUPMAX (rate of power increase for FOLLOW)

• • • This record was final approved on 3/23/2021 1:58:16 PM. (This statement was added by the PRIME system upon its validation)

LTR-TA-21-17, Revision 2 Page 4 of 4 Westinghouse Non-Proprietary Class 3 Table A Waterford-3 CPCS PPS Backup Trips Chapter 15 Event /

PPS Backup Trip Waterford-3 SAR Credited CPCS Signals (Waterfprd-3 SAR (Reference 1) SAR Section # Trip Signals Reference 3, Table 7.2-4)

Steam Generator Tube Rupture CPCS Hot Leg Saturation Low Pressurizer Pressure with coincident LOOP Temperature (Tsat)

SAR 15.6.3.2 Letdown Line Break CPCS Tsat Low Pressurizer Pressure SAR 15.6.3.1 CPCS Wide Band Pressure Trip Limits (Low)

Asymmetric Steam Generator CPCS Tcold Low Steam Generator 1 Pressure Transient Low Steam Generator 2 Pressure SAR 15.9.1.1 Low Steam Generator 1 Level Low Steam Generator 2 Level Pre-trip MSLB Same as Uncontrolled CEA High Linear Power with coincident LOOP Bank Withdrawal from a Critical Condition SAR 15.1.3.3 Increased Main Steam Flow with CPCS DNBR - Low High Linear Power Loss of Offsite Power SAR 15.1.2.3 Steam System Piping Failures CPCS RPC Shaft Speed - Low Low Steam Generator 1 Pressure Setpoint Low Steam Generator 2 Pressure SAR 15.1.3.1 CPCS VOPT High Linear Power SPVMIN or DELSPV, and SUPMAX (rate of power increase for FOLLOW)

Inadvertent Opening of a SG ADV CPCS Low RPC Shaft Speed - Low RCS Flow with a concurrent single failure of Low Setpoint Low Steam Generator 1 Pressure an active component Low Steam Generator 2 Pressure SAR 15.1.2.4 Low Steam Generator 1 Level Low Steam Generator 2 Level

• • • This record was final approved on 3/23/2021 1:58:16 PM. (This statement was added by the PRIME system upon its validation)