05000244/LER-2023-003-01, Re. Ginna Nuclear Power Plant, Manual Reactor Trip Due to Degraded Condenser Vacuum from Lowering Main Steam to Air Ejectors and Auxiliary Feedwater Actuation Due to Low Steam
| ML24067A253 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 03/07/2024 |
| From: | Blankenship J Constellation Energy Generation |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| LER 2023-003-01 | |
| Download: ML24067A253 (1) | |
| Event date: | |
|---|---|
| Report date: | |
| 2442023003R01 - NRC Website | |
text
James D. Blankenship Site Vice President R E. Ginna Nuclear Power Plant 1503 Lake Rd.
Ontario. NY 14519 315-791-5200 Otfice ames.hlankenshipco:constellation.coni c:::onste((at i 0 Li W\SIW March 7, 2024 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 RE. Ginna Nuclear Power Plant Renewed Facility Operating License No. DPR-18 NRC Docket No. 50-244
Subject:
Supplement to LER 2023-003, Manual Reactor Trip due to Degraded Condenser Vacuum from Lowering Main Steam to Air Ejectors and Auxiliary Feedwater Actuation due to low Steam Generator Level The attached Licensee Event Report (LER) 2023-003-01 is submitted in accordance with 10 CFR 50.73 under the provisions of NUREG-1 022, Revision 3, Event Reporting Guidelines 10 CFR 50.72 and 50.73. There are no new commitments contained in this submittal. This submittal is for Revision 01 of the LER.
Should you have any questions regarding this submittal, please contact Justin Knowles at (315) 791-3393.
Sincerely, James D. Blankenship Attachment: LER 2023-003, Revision 01 cc:
NRC Regional Administrator, Region I NRC Project Manager, Ginna NRC Resident Inspector, Ginna (e-mail)
Attachment LER 2023-003, Revision 01
Abstract
R.E. Ginna Nuclear Power Plant, Unit 1
00244 4
Supplement to LER 2023-003-00, Manual Reactor Trip due to Degraded Condenser Vacuum from Lowering Main Steam to Air Ejectors and Auxiliary Feedwater Actuation due to low Steam Generator Level 10 12 2023 2023 003 01 03 07 2024 1
100
Justin Knowles, Regulatory Assurance Manager 315-791-3393 B
LD PCV M0120 Y
On 10/12/2023, Ginna Unit 1 experienced an uncomplicated manual reactor trip due to high Main Condenser back pressure and a valid Auxiliary Feedwater actuation due to low Steam Generator level. At 2116, Operations received a high limit alarm for Air Ejector Mass Flow Rate and observed condenser vacuum degrading and generator output beginning to lower. Field personnel began bypassing the Main Air Ejector Steam Pressure Control Valve to restore steam to the Air Ejectors. Concurrently with actions in the field, the Main Control Room (MCR) Operators began a procedurally directed downpower. At 2127, the five-minute restriction for turbine operation in the 'Back Pressure' region was exceeded and the MCR Unit Supervisor directed a reactor trip as procedurally required.
Loss of supply air to the Main Air Ejector Steam Pressure Control Valve was due to the Instrument Air (IA) Pressure Control Valve (PCV) not providing adequate output pressure to keep the valve open. The IA PCV was replaced and tested satisfactory prior to return to service. Page of
- 3. LER NUMBER YEAR SEQUENTIAL NUMBER REV NO.
052 050
V. CORRECTIVE ACTIONS
The Instrument Air Pressure Control Valve was replaced and tested satisfactory prior to return to service.
Long-term corrective actions include:
- 1. Dresser Masoneilan Model 77-20 regulators installed in single point vulnerability (SPV) locations will be replaced to prevent SCRAM recurrence.
- 2. Creation of independent, cross-functional SPV Challenge team to challenge all existing mitigation and elimination strategies.
- 3. Conduct a Leadership Training Case Study for Operations, Maintenance, and Engineering focusing on the contributing causes of this event. The training includes all Front Line Supervisors (FLS), Mid Level Managers (MLMs) and Senior Leadership Team (SLT) personnel.
- 4. Upgrade Air Ejector Steam Control AOV from Low Risk SPV to Medium Risk SPV and implement and elimination strategy.
VI. ADDITIONAL INFORMATION
LER 2023-003-00 documented the Expected Submission Dated of the Supplemental Report as 03/08/2023 and it should have been dated 03/08/2024.
A. FAILED COMPONENTS:
Instrument Air Pressure Control Valve to the Main Air Ejector Steam Pressure AOV B. PREVIOUS LERs ON SIMILAR EVENTS:
A LER historical search was conducted and no similar LER events were identified.
C. THE ENERGY INDUSTRY IDENTIFICATION SYSTEM (EIIS) COMPONENT FUNCTION IDENTIFIER AND SYSTEM NAME OF EACH COMPONENT OR SYSTEM REFERRED TO IN THIS LER:
COMPONENT - Pressure Control Valve IEEE 803 FUNCTION NUMBER - PCV IEEE 805 SYSTEM IDENTIFICATION - LD 4
4 R.E. Ginna Nuclear Power Plant, Unit 1 00244 2023 003 01