ML24325A440
| ML24325A440 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 11/26/2024 |
| From: | John Lamb NRC/NRR/DORL/LPL2-1 |
| To: | |
| Shared Package | |
| ML24325A442 | List: |
| References | |
| EPID L-2024-LRM-0128 | |
| Download: ML24325A440 (6) | |
Text
November 26, 2024 LICENSEE:
Southern Nuclear Operating Company, Inc.
FACILITY:
Vogtle Electric Generating Plant, Units 3 and 4
SUBJECT:
SUMMARY
OF NOVEMBER 19, 2024, OBSERVATION PRE-SUBMITTAL MEETING HELD WITH SOUTHERN NUCLEAR OPERATING COMPANY, INC.,
REGARDING A PROPOSED LICENSE AMENDMENT REQUEST FOR MODES 5 AND 6 FOR VOGTLE ELECTRIC GENERATING PLANT, UNITS 3 AND 4 (EPID NO. L-2024-LRM-0128)
On November 19, 2024, an Observation 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) for Vogtle Electric Generating Plant (Vogtle), Units 3 and 4.
SNC is proposing changes to current TS action statements in MODES 5 and 6.
A list of attendees is provided as an Enclosure.
On November 7, 2024 (Agencywide Documents and Access Management System (ADAMS)
Accession No. ML24312A248), the meeting was noticed on the NRC public webpage.
The NRC staff opened the meeting with introductory remarks and a roll call of the attendees.
The SNC representative presented slides contained in ML24317A223.
The SNC representative discussed the following topics: (1) description, (2) technical evaluation, (3) mark-up examples, and (4) schedule.
The SNC representative stated that the following types of Technical Specification (TS) MODE 5 and 6 Required Actions that can present conflicts or restrictions in moving between MODES 5 and 6 are:
Initiate action to establish 20% pressurizer level with the reactor coolant system (RCS) pressure boundary intact.
Initiate action to establish RCS VENTED.
Initiate action to establish RCS VENTED and establish 20% pressurizer level.
Initiate action to open RCS pressure boundary and establish 20% pressurizer level.
Initiate action to open the RCS pressure boundary.
Initiate action to establish water level 23 feet above the top of the reactor vessel flange or Initiate action to establish a pressurizer level above the P-12 interlock.
Initiate action to remove the upper internals.
Open a containment air flow path 6 inches in diameter.
Open containment equipment hatch or containment airlock.
The SNC representative said that the following are impacted actions:
TS 3.3.8 Functions 1, 7, 14, 15, 16 & 18, Actions J, K, L, M, N and P TS 3.3.9 Functions 2, 6, 7, 8, 9 & 15, Actions G, H, I, J, K, and L TS 3.3.10 Functions 1 and 2, Actions C, D, and E TS 3.3.16, Action B and C TS 3.4.12, Action D TS 3.4.13, Actions C and D TS 3.5.3, Action E TS 3.5.5, Action E TS 3.5.7, Action F TS 3.5.8, Action F TS 3.6.4, Action C TS 3.6.5, Action C TS 3.6.6, Actions E and F TS 3.6.7, Action B TS 3.6.9, Action G The SNC representative stated that the proposed LAR will be submitted to the NRC in fourth quarter of 2024, requesting that the NRC staff complete its review by the first refueling outage for Vogtle, Unit 4, which is scheduled for late third quarter of 2025.
The NRC staff stated that it will have to assess the schedule once the LAR is submitted; however, it appears that the proposed LAR may be complex based on the discussions during this pre-submittal meeting.
The NRC staff raised the following questions and comments:
What is the problem statement indicating the need for the proposed LAR?
What is safety benefit of the proposed changes?
Are the proposed changes providing intended primarily for outage relief (i.e., reducing the outage schedule)?
Is SNC using the guidance contained in NUMARC 91-06, Guidelines for Industry Actions to Assess Shutdown Management?
Is SNC considering the recommendations contained in Generic Letter 88-17, Loss of Decay Heat Removal?
Has SNC read SECY-97-0168, Issuance for Public Comment of Proposed Rulemaking Package for Shutdown and Fuel Storage Pool Operation, dated July 30, 1997?
To date, has SNC experienced any of the postulated TS conflicts described in its presentation?
The scenarios described in SNCs presentation involve failure of passive safety systems required by GDC 34which should be unlikely to happen. SNC postulating two specific systems (CMT and IRWST) being inoperable at the same time at either Vogtle, Units 3 or 4, with concurrent failures to restore either system to operable status within the specified Completion Times. In the licensees hypothesized scenario, the plant operators would be presented with conflicting Required Actions. The NRC staff pointed out that the operators always have the option of placing the plant in a MODE or Condition where the limiting condition for operation (LCO) does not apply. In the case of the scenario described by SNC, with the conflicting requirements, the operators can place the unit in MODE 6. Once MODE 6 is entered, then the MODE 5 actions are no longer required to be met per LCO 3.0.2 of the Vogtle, Units 3 and 4, TS.
Once MODE 6 is entered, then the MODE 5 actions are no longer required to be met per LCO 3.0.2 of the Vogtle 3 and 4 TS.
SNC is proposing to remove the specified Required Actions from the Vogtle 3 and 4 TS for the scenarios described in its presentation and rely on the operators implementing risk management actions in accordance with the maintenance rule. The NRC staff asked what options do the operators have and how will the operator select the safest option?
Would the operators be expected to make choices on the fly?
A low power probabilistic risk assessment (PRA) was submitted with SNCs Combined License (COL) application. Has SNC used any risk insights in the proposed LAR?
SNC clarified that they are only considering removal of the MODE 5 applicability. The licensee indicated it plans to retain other MODE 5 requirements, such as those for shutdown margin and the control room envelope.
Does SNC plan to perform a full-blown maintenance rule a(4) shutdown risk assessment for the circumstances proposed in the LAR?
Has SNC considered how to address potential, future changes in the methodology to assess 10 CFR 50.65a(4) risk assessments in relation the proposed LAR justification?
The NRC staff noted that, rather than removing the Required Actions SNC listed in their presentation from the Vogtle 3 and 4, another option would be for SNC to add a Condition and Required Actions to specify the actions to be taken if the operators find themselves in the explicit situation described to have conflicting TS actions.
What is the linkage between the conflicts and the NUMARC guidance?
For the instrumentation LCOs listed in the SNC presentation, would the operators have the option of placing the inoperable channels in trip or bypass?
Has SNC considered whether the modified language in the TS Bases could create a conflict with the No Significant Hazard Consideration (NSHC) language concerning probability and consequences?
The NRC staff expressed a concern that the proposed TS changes are not characterizing the plant conditions sufficiently to understand the conflicting operator actions and the operator decision options.
There was one member of the public in attendance.
The NRC staff did not make any regulatory decisions during the meeting. Once received, the NRC staff will perform a thorough review of the proposed LAR. The NRC staff will make any regulatory decisions in writing in a timely manner. Public Meeting Feedback forms were available, but no comments were received.
The meeting adjourned at 1:50 pm Eastern Time (ET).
Please direct any inquiries to me at John.Lamb@nrc.gov or 301-415-3100.
/RA John G. Lamb, Senior Project Manager Plant Licensing Branch, II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos.52-025 and 52-026
Enclosure:
List of Attendees cc w/encls: Distribution via Listserv
Enclosure LIST OF ATTENDEES NOVEMBER 19, 2024, PRE-SUBMITTAL MEETING WITH SOUTHERN NUCLEAR COMPANY REGARDING A PROPOSED LICENSE AMENDMENT REQUEST TO MODES 5 AND 6 VOGTLE ELECTRIC GENERATING PLANT, UNITS 3 AND 4 ATTENDEE REPRESENTING John G. Lamb U.S. Nuclear Regulatory Commission (NRC)
Mike Markley NRC Charley Peabody NRC Logan Gaul NRC Raul Hernandez NRC Rob Elliott NRC Nichols Soliz NRC Jay Robinson NRC John Hughey NRC Norbert Carte NRC Alissa Neuhausen NRC Marie Pohida NRC Daniel Silverstein NRC Keith Tetter NRC Michael Swim NRC Ken Lowery Southern Nuclear Operating Company (SNC)
Ryan Joyce SNC Jim Chamberlain SNC Thomas Joseph SNC Jeremiah Gilbreath SNC Eddie Grant SNC Dan Williamson SNC Mariam Ismail Public
ML24325A442 (Package)
ML24312A248 (Meeting Notice)
ML24325A440 (Meeting Summary)
ML24317A233 (SNC Slides)
OFFICE DORL/LPL2-1/PM DORL/LPL2-1/LA DSS/SNSB/BC DORL/LPL2-1/BC DORL/LPL2-1/PM NAME JLamb KGoldstein DMurdock (A)
MMarkley JLamb DATE 11/19/2024 11/21/2024 11/25/2024 11/26/2024 11/26/2024