ML19217A325
| ML19217A325 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 08/05/2019 |
| From: | NRC |
| To: | NRC/NRO/DLSE/LB4 |
| References | |
| Download: ML19217A325 (4) | |
Text
1 Vogtle PEmails From:
Rankin, Jennivine Sent:
Monday, August 5, 2019 10:21 AM To:
Agee, Stephanie Y.
Cc:
Vogtle PEmails
Subject:
LAR 19-001: Draft RAI Attachments:
Vogtle RAIs 9698 draft Public Version.pdf Stephanie, By letter dated March 25, 2019 (ADAMS Accession No. ML19084A309), SNC submitted LAR-19-001, Request for License Amendment Regarding Protection and Safety Monitoring System Surveillance Requirement Reduction Technical Specification Revision (LAR-19-001).
Attached, please see the public version of the draft RAI for LAR-19-001 that is being entered into public ADAMS. If there is additional SUNSI information in this draft RAI, please let me know immediately.
Thank you, Jennie Jennie Rankin, Project Manager Licensing Branch 2 Division of Licensing, Siting, and Environmental Analysis Office of New Reactors
Hearing Identifier:
Vogtle_COL_Docs_Public Email Number:
465 Mail Envelope Properties (BN6PR09MB2227E9BEEBDCDA4C8C70C67C98DA0)
Subject:
LAR 19-001: Draft RAI Sent Date:
8/5/2019 10:21:12 AM Received Date:
8/5/2019 10:21:18 AM From:
Rankin, Jennivine Created By:
Jennivine.Rankin@nrc.gov Recipients:
"Vogtle PEmails" <Vogtle.PEmails@nrc.gov>
Tracking Status: None "Agee, Stephanie Y." <SYAGEE@southernco.com>
Tracking Status: None Post Office:
BN6PR09MB2227.namprd09.prod.outlook.com Files Size Date & Time MESSAGE 680 8/5/2019 10:21:18 AM Vogtle RAIs 9698 draft Public Version.pdf 174517 Options Priority:
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DRAFT Request for Additional Information Vogtle Electric Generating Plant, Units 3 and 4 Southern Nuclear Operating Company Docket No.52-025 and 52-026 Review Section: 16 - Technical Specifications Application Section: LAR 19-001 plant-specific TS changes digital I&C safety system QUESTIONS 16-01 10 CFR 50.36(c)(3) requires technical specifications for a utilization facility to include surveillance requirements, which "are requirements relating to test, calibration, or inspection to assure that the necessary quality of systems and components is maintained, that facility operation will be within safety limits, and that the limiting conditions for operation will be met." In addition, BTP 7-17, "Guidance on Self-Test and Surveillance Test Provisions" (ADAMS Accession No. ML16019A316) states in part, "If automatic test features are credited with performing surveillance test functions, provisions should be made to confirm the execution of the automatic tests during plant operation" as an acceptable means to meet regulatory requirements in 10 CFR 50.55a(h) and relevant GDCs.
The licensee for VEGP Units 3 and 4 submitted license amendment request (LAR)19-001, "Request for License Amendment Regarding Protection and Safety Monitoring System [PMS]
Surveillance Requirement Reduction Technical Specification Revision" (ADAMS Accession No. ML19084A308). The amendment request proposed to remove TS manual surveillance requirements (SRs) specified for (1) the PMS instrumentation functions: CHANNEL CHECK and CHANNEL OPERATIONAL TEST (COT); and (2) PMS actuation logic functions: ACTUATION LOGIC TEST (ALT) and ACTUATION LOGIC OUTPUT TEST (ALOT) by crediting the PMS platform continuous self-diagnostic functions and several self-tests of the PMS application software.
The licensee is requested to provide additional information that either (1) justifies not including provisions to confirm the execution of the automatic tests during plant operation, such as those described below, or (2) proposes appropriate SRs that can provide assurance of PMS operability.
The staff has previously approved SRs that provide assurance of digital instrumentation and control (I&C) protection system operability for self-diagnostic systems in digital I&C plant protection systems. Such SRs have specified (1) manual review of digital I&C system event logs to provide positive confirmation that unalarmed events do not go unnoticed and that the self-testing features are functioning as intended; and (2) manual verification of trip setpoint values in digital memory to provide positive confirmation that trip setpoints have not changed and that the associated reactor trip and engineered safeguards features instrumentation and actuation logic functions are operable. Such SRs also specify performance at appropriate surveillance frequencies during the operating cycle between unit shutdowns for refueling. In lieu of new SRs, such manual verifications could be specified as a part of existing SRs through digital-system-appropriate changes to the definitions of CHANNEL CHECK, COT, ALT, and ALOT.
((Proprietary Information))
16-02 10 CFR 50.36(c)(3) requires technical specifications for a utilization facility to include surveillance requirements, which "are requirements relating to test, calibration, or inspection to assure that the necessary quality of systems and components is maintained, that facility operation will be within safety limits, and that the limiting conditions for operation will be met." In addition, BTP 7-17, states in part, "If automatic test features are credited with performing surveillance test functions, provisions should be made to confirm the execution of the automatic tests during plant operation."
In a previous license amendment for VEGP Units 3 and 4, the staff approved a change to the ACTUATION LOGIC TEST so that the portion of the PMS logic containing just the local coincidence logic (LCL) and its input and output communication processors is included in the surveillance scope. A new defined term, ACTUATION LOGIC OUTPUT TEST (ALOT) was created and verifies safety logic pathways associated with the ESF integrated logic cabinets, each of which contains two redundant integrated logic processors (ILPs), and for each of the division's actuated components, two redundant safety remote node controllers (SRNCs) and one component interface module (CIM).
In LAR 19-001, the licensee proposed to remove the ALOT SRs from the plant-specific TS for most engineered safeguards features (ESF) automatically actuated components. The basis for SR removal is that the PMS Common Q platform self-diagnostics for the ILPs and the FPGA platform self-diagnostics for the SRNCs and CIMs provide adequate hardware monitoring to detect faults in system components. These faults are reported to the operators as a division fault alarm.
The 24-month Frequency ALOT is normally performed by the CIM output is as expected. The NRC staff understands that all safety logic pathways are exercised. The 24-month Frequency SR to verify actuation of an ESF component on a simulated or actual actuation signal and the 24-month Frequency SR to verify the component stroke time is within its actuation response time limit, is also performed using the MTP in essentially the same way.
The licensee is requested to (1) provide additional information that either justifies not including in these ESF component surveillances the explicit requirement, that the surveillance must be performed by injecting a test actuation signal from the MTP to the ILP input and verifying that the actuated device actuates and that its actuation response time is met, or (2) include this requirement in these ESF component surveillances to provide assurance of PMS actuation output logic operability by exercising a subset of the possible safety logic pathways through the ILPs, SRNCs, and CIM each time the associated ESF component automatic actuation SR and actuation response time verification SR are performed. This is consistent with how performance of the ALOT SR and the associated component actuation SRs were previously accepted by the NRC staff in the ALOT license amendment. Over a set number of ESF component surveillance intervals, the staff would expect that all safety logic pathways in each ILC will have been exercised.
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