ML22172A214
| ML22172A214 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 07/11/2022 |
| From: | Stephanie Devlin-Gill Plant Licensing Branch II |
| To: | |
| Williams S | |
| References | |
| EPID L-2022-LRM-0044 | |
| Download: ML22172A214 (3) | |
Text
July 11, 2022 LICENSEE:
Southern Nuclear Operating Company, Inc.
FACILITY:
Joseph M. Farley Nuclear Plant, Units 1 and 2
SUBJECT:
SUMMARY
OF JUNE 16, 2022, PUBLIC MEETING WITH SOUTHERN NUCLEAR OPERATING COMPANY, INC., REGARDING A PROPOSED LICENSE AMENDMENT REQUEST TO MODIFY THE TECHNICAL SPECIFICATIONS REGARDING PRESSURIZER SAFETY VALVE SETPOINTS AT THE JOSEPH M. FARLEY NUCLEAR PLANT, UNITS 1 AND 2 (EPID NO.
On June 16, 2022, an Observation Public Meeting was held between the U.S. Nuclear Regulatory Commission (NRC) and representatives of Southern Nuclear Operating Company, Inc. (SNC, the licensee). The purpose of the meeting was for SNC to describe its plan to submit a license amendment request (LAR) to propose modifications to the Joseph M. Farley, Units 1 and 2 (Farley), Technical Specifications (TS) regarding the Limiting Condition for Operation (LCO) for Pressurizer Safety Valves.
A list of attendees is provided as an Enclosure.
On May 31, 2022 (Agencywide Document and Access Management System (ADAMS)
Accession No. ML22151A116), the meeting was noticed on the NRC public webpage for the meeting to be held on June 16, 2022.
The NRC staff opened the meeting with introductory remarks and an introduction of the attendees.
SNC discussed the following topics: (1) background, (2) proposed license amendment request, (3) analysis, (4) precedent, and (5) schedule.
SNC presented slides contained in ML22159A177.
=
Background===
SNC described that the pressurizer safety valves (PSVs) provide, in conjunction with the reactor protection system, overpressure protection for the reactor coolant system. SNC stated that Farleys PSVs are enclosed pop type, spring loaded, self-actuated valves with backpressure compensation. SNC stated that Farleys PSVs are designed to prevent the system pressure from exceeding the system safety limit of 2735 pounds per square inch gauge (psig).
SNC described that the relief capacity for each PSV is 345,000 pounds per hour and is based on postulated overpressure transient conditions resulting from a complete loss of steam flow to the turbine. SNC stated that that event results in the maximum surge rate into the pressurizer, which specifies the minimum relief capacity for the PSVs. SNC stated that Farleys self-actuated safety valves are sized on the basis of steam flow from the pressurizer to accommodate this surge at a setpoint of 2485 psig and a total accumulation of 3 percent.
Proposed License Amendment Request Reason for the Proposed LAR SNC stated that it would request a license amendment to change the Farley TS revising LCO 3.4.10, Pressurizer Safety Valves to decrease the low setpoint tolerance value. SNC stated that SNC plans to propose the change in order to reduce an unnecessarily restrictive LCO. SNC stated that there have been six instances since 2015 where the PSVs were tested and found outside the +/-1 percent tolerance limits and that all the out of tolerance test results were outside the low end of the setpoint tolerance (-1 percent). SNC stated that the as-found results did not exceed -3 percent of the pressure setpoint. SNC stated that, based on the lift pressure meeting the Inservice Test (IST) program requirements, no IST scope expansion testing was needed and the PSVs are performing within the design analysis assumptions. SNC stated that generating a licensee event report for a PSV that is performing satisfactorily within the design analysis assumptions is an unnecessary burden for both the licensee and the NRC.
Overview of the Proposed LAR SNC stated that the proposed LAR would change the Farley TS LCO 3.4.10, Pressurizer Safety Valves as follows:
Current LCO 3.4.10 Three pressurizer safety valves shall be OPERABLE with lift settings 2460 psig and 2510 psig.
Proposed LCO 3.4.10 Three pressurizer safety valves shall be OPERABLE with lift settings 2423 psig and 2510 psig.
Analysis SNC described that for the proposed LAR, SNC evaluated the following:
accidents that could result in overpressurization if not properly terminated; accidents that are affected by a change in the setpoint low side PSV tolerance; analyses not impacted (PSVs not modeled or not credited);
margin between PSVs and pressurizer power operated relief valves (PORVs); and margin between PSVs and high-pressure reactor trip.
Precedent SNC stated that Exelon Generation Company, LLC (Exelon) proposed a similar TS modification to change its PSV setpoints, as described in ML031810344, and that the NRC approved Exelons TS modification in ML042250516.
Schedule SNC stated that it plans to submit the proposed LAR in June 2022, and request a 1-year review schedule.
NRC Questions to SNC The NRC staff asked questions of SNC and requested that SNC provide clarifications in its submittal.
On slide 11, the NRC staff asked SNC if it plans to include the results of its analyses investigating the accidents that are affected by a change in the setpoint low side PSV tolerance in the upcoming LAR. SNC responded that no analyses are impacted because all analyses were previously performed with a -3 percent lower tolerance limit, while the proposed LAR will revise the lower tolerance limit down from -1 to -2.5 percent.
On slide 13, the NRC staff asked SNC if it believes that the reduction in the margin between PSVs and PORVs actuation setpoints from 77 to 40 pounds per square inch (psi) is sufficient.
The NRC staff requested that SNCs justification for the reduction in margin be included in the LAR.
On slide 14, the NRC staff asked SNC if the calculated uncertainty associated with the Pressurizer Pressure - High reactor trip was determined to be +28.8 psi had previously been approved by the NRC. The NRC staff requested that SNC include a reference in SNCs upcoming LAR to the document that describes the analysis from which the +28.8 psi was obtained and any previous NRC approval of the +28.8 psi calculation.
On slide 16, the NRC staff asked SNC about the assumptions and decisions made in the precedent LAR in comparison to the assumptions and decisions being proposed by SNC. The NRC staff noted that the precedent documents describe that Exelon used both the industry-wide experience as well as the plant-specific experience to inform its PSV setpoint modifications, while SNC only described Farley-specific experience in its presentation. The NRC staff also noted that in the precedent documents, Exelon revised down both the upper and lower PSV lift pressure tolerances as well as the nominal PSV lift setting, while SNC plans to request only a change to the lower PSV lift setting while keeping the nominal PSV lift setting unchanged.
On slide 18, the NRC staff asked SNC if its request for a 1-year review schedule includes the Acceptance Review, or if it does not. The NRC staff noted that it would prefer the 1-year review schedule not include the Acceptance Review.
At the end of the presentation, the NRC staff asked SNC about the percent setpoint tolerance for as-found versus as-left values.
Public Questions to NRC There were no members of the public in attendance.
Closing The NRC staff made no regulatory decisions during the meeting.
Once received, the NRC staff will perform a thorough review of the proposed LAR and make any regulatory decisions in writing in a timely manner.
The meeting adjourned at 10:30 am (Eastern time).
Please direct any inquiries to me at 301-415-5301 or Stephanie.Devlin-Gill@nrc.gov.
/RA/
Stephanie Devlin-Gill, Project Manager Plant Licensing Branch, II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-348 and 50-364
Enclosure:
List of Attendees cc w/encls: Listserv
Enclosure LIST OF ATTENDEES JUNE 16, 2022, PUBLIC MEETING WITH SOUTHERN NUCLEAR OPERATING COMPANY, INC.
REGARDING A PROPOSED LICENSE AMENDMENT REQUEST JOSEPH M. FARLEY NUCLEAR PLANT, UNITS 1 AND 2 ATTENDEE REPRESENTING Stephanie Devlin-Gill U.S. Nuclear Regulatory Commission (NRC)
Syed Haider NRC Dawnmathews Kalathiveettil NRC John Lamb NRC Yueh-Li (Renee) Li NRC Peter Meier NRC Steve Smith NRC Ian Tseng NRC Hang Vu NRC Jose E. Cedeno Southern Nuclear Operating Company, Inc. (SNC)
James Bradley Chamberlain SNC Ryan Joyce SNC Wesley Sparkman SNC
ML22172A214 OFFICE NRR/DORL/LPL2-1/PM NRR/DORL/LPL2-1/LA NRR/DSS/SNSB/BC NAME SDevlin-Gill KGoldstein SKrepel DATE 06/21/2022 06/23/2022 06/23/2022 OFFICE NRR/DSS/STSB/BC NRR/DEX/EICB/BC NRR/DEX/EMIB/BC NAME VCusumano MWaters SBailey DATE 06/23/2022 06/23/2022 06/27/2022 OFFICE NRR/DORL/LPL2-1/BC NRR/DORL/LPL2-1/PM NAME MMarkley SDevlin-Gill DATE 07/01/2022 07/11/2022