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Start date | Title | Description | Topic | |
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ENS 57177 | 18 June 2024 07:17:00 | Manual Reactor Trip | The following information was provided by the licensee by email: On 06/18/2024 at 0317 EDT with Unit 2 at 18 percent power, the reactor was manually tripped due to elevated secondary chemistry levels (sodium and chlorides). The trip was uncomplicated with all systems responding normally post trip. Operations stabilized the plant in Mode 3. Decay heat is being removed by auxiliary feedwater and atmospheric dump valves. St. Lucie Unit 1 was unaffected and remains at 100 percent power. This event is being reported pursuant 10CFR 50.72(b)(2)(iv)(B). The NRC Resident Inspector has been notified. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: All rods fully inserted. An investigation is underway to determine the root cause of the elevated chemistry levels.
The following retraction was provided by the licensee via email: The purpose of this notification is to retract a previous report made on 06/18/2024 at 0652 (EDT) (EN# 57177). Notification of the event to the NRC was initially made because of inserting a manual reactor trip due to elevated secondary chemistry levels (sodium and chlorides). After the initial report, Florida Power and Light has concluded that the event did not meet the reporting requirements on 10 CFR 50.72(b)(2)(iv)(B) since it was part of a normal plant shutdown. Therefore, this event is not considered an unplanned scram and is not reportable to the NRC as a Licensee Event Report per 10 CFR 50.73. The NRC Senior Resident Inspector has been notified. | |
ENS 56135 | 30 September 2022 20:08:00 | Safety System Inoperability | The following information was provided by the licensee via email: At 1608 (EDT) on September 30, 2022, it was discovered that both trains of the chemical volume and control system were simultaneously inoperable due to an unisolable piping flaw inside containment detected during plant pressurization in preparation for startup following a refueling outage. St. Lucie Unit 2 was not affected and remains at 100 percent power. This event is being reported pursuant to 10CFR50.72(b)(3)(v)(D). The NRC Resident Inspector has been notified.
The following information was provided by the licensee via email: The purpose of this notification is to retract a previous report made on 09/30/2022 at 1713 EDT (EN 56135). Notification of the event to the NRC was initially made as a result of declaring both trains of U1 Chemical and Volume Control System inoperable due to a piping flaw detected during plant pressurization in preparation for startup following a refueling outage. Subsequent to the initial report, FPL (Florida Power and Light) has concluded that the flaw identified in line 2"-CH-109 did not exceed (with sufficient margin) the allowable axial flaw size utilizing the ASME Code Case N-869 methodology, and the Chemical and Volume Control System was operable but degraded for the period of concern. Therefore, this event is not considered a Safety System Functional Failure and is not reportable to the NRC as a Licensee Event Report (LER) per 10 CFR 50.73. The NRC Senior Resident Inspector has been notified. Notified R2DO (Miller). | |
ENS 56128 | 26 September 2022 21:41:00 | Safety System Inoperability | The following information was provided by the licensee via email: At 1741 EDT on September 26, 2022, it was discovered that both trains of the chemical volume and control system were simultaneously inoperable due to an unisolable piping flaw detected during plant pressurization in preparation for startup following refueling outage. St. Lucie Unit 2 was not affected and remains at 100 percent power. This event is being reported pursuant to 10 CFR 50.72(b)(3)(v)(D). The NRC Resident Inspector has been notified.
The following information was provided by the licensee via email: The purpose of this notification is to retract a previous report made on 09/26/2022 at 2239 EDT (EN 56128). Notification of the event to the NRC was initially made as a result of declaring both trains of U1 Chemical and Volume Control System inoperable due to a piping flaw detected during plant pressurization in preparation for startup following a refueling outage. Subsequent to the initial report, FPL (Florida Power and Light) has concluded that the flaw identified in line 2"-CH(1)104 did not exceed (with sufficient margin) the allowable axial flaw size utilizing the ASME Code Case N-869 methodology, and the Chemical and Volume Control System was Operable but degraded for the period of concern. Therefore, this event is not considered a Safety System Functional Failure and is not reportable to the NRC as a Licensee Event Report (LER) per 10 CFR 50.73. The NRC Senior Resident Inspector has been notified. Notified R2DO (Miller). | |
ENS 52138 | 1 August 2016 07:42:00 | Plant Shutdown Due to Pressure Boundary Leakage Greater than Allowable Limit | On August 1, 2016 at 0342 EDT St. Lucie Unit 1 commenced a unit shutdown required by Technical Specifications due to Reactor Coolant System Pressure Boundary Leakage in excess of the allowable limit of zero leakage. The leak was initially identified on July 31, 2016 at 2115 EDT as not Pressure Boundary leakage. After further analysis, the leak was determined to be Reactor Coolant System Pressure Boundary leakage at 0123 on August 1, 2016. The leakage is estimated as less than one tenth of a gallon per minute and is not impacting the ability to shut down the unit. Additional impact of the leak is under evaluation. This report is submitted in accordance with 10CFR50.72(b)(2)(i) as 'The initiation of any nuclear plant shutdown required by the plant's Technical Specifications.' The location of the leak is on the Instrumentation piping welded connection at Flow Element FE-3311 attached to (the) Emergency Core Cooling System Injection header to Reactor Coolant System Loop 1A2. The leak activity is 0.167 microCuries per ml. The NRC Resident Inspector has been notified.
The purpose of this notification is to retract a previous report made on EN 52138. NRC notification was initially made as a result of a plant shutdown required by technical specifications (TS) for Reactor Coolant System (RCS) pressure boundary leakage. Subsequent to the initial report, St. Lucie has determined that the RCS leakage was from a seal weld on a threaded connection that was not pressure boundary leakage. However, the leak was non-isolable and required RCS depressurization to allow immediate investigation to ensure there were no faults in a RCS component body or pipe wall. The leakage was estimated to be less than one tenth of a gallon per minute and did not impact the ability to shut down the unit. No TS limits were exceeded during this event. Therefore, the plant shutdown to investigate and correct leakage past the seal weld of a threaded connection does not meet the reporting requirements of 10 CFR 50.72 or 10 CFR 50.73. The NRC Resident Inspector has been notified. Notified the R2DO (Blamey). | Pressure Boundary Leakage |
ENS 43871 | 28 December 2007 09:50:00 | Technical Specification Required Shutdown - Dropped Cea | At 0347 on 12/28/07, during plant start up from a refueling outage while In Mode 2, one control element assembly (CEA) dropped to the bottom of the core from the upper electrical limit. The reactor was not critical at the time. Technical Specification LCO 3.1.3.1 action (e) was initiated to proceed to Mode 3 at 0450 while actions are taken to repair and retrieve the CEA. This four hour non-emergency report is being made pursuant to 10 CFR 50.72(b)(2)(i), the 'Initiation of any nuclear plant shutdown required by Technical Specifications'. The licensee notified the NRC Resident Inspector.
The licensee is retracting this report based on the following: At 03:47 on 12/28/07, during plant start up from a refueling outage while in Mode 2, one control element assembly (CEA) dropped to the bottom of the core from the upper electrical limit. The reactor was not critical at the time. Technical Specification LCO 3.1.3.1 (Action E) was initiated to proceed to Mode 3 at 0450 while actions were taken to repair and retrieve the CEA. This event was reported as a four hour non-emergency report pursuant to 10CFR 50.72(b)(2)(i), 'The initiation of any nuclear plant shutdown required by Technical Specifications.' Upon further review of the event, and since the Unit was not critical in mode 2 at the time of the event, this event is not considered reportable in accordance with the guidance provide in NUREG-1022, Rev. 2, 'Event Reporting Guidelines 10CFR50.72 and 50.73,' in which 'The initiation of any plant shutdown' does not include mode changes required by TS if initiated after the plant is already in a shutdown condition. As such this notification is being retracted. The Site Resident has been notified of this retraction. | |
ENS 41018 | 4 September 2004 05:56:00 | Manual Reactor Trip Due to Steam Generator Level Oscillations | While reducing power in response to expected severe weather conditions from hurricane Frances, the reactor was manually tripped from 21% reactor power. The reactor was tripped because of significant swings in the 'B' Steam Generator level caused by erratic operation of the 'B' Feedwater Regulating Valve (FRV). All Control Element Assemblies fully inserted. Decay heat is currently being removed by Main Feedwater using the low power FRV bypass valves and Steam Bypass Control System (SBCS), maintaining RCS temperature at 532 degrees Fahrenheit. The unit will be maintained in a shutdown condition until repairs to the FRV are completed and the severe weather from Hurricane Frances abates. All primary and secondary systems performed as expected with the exception of the SBCS. The SBCS consists of five pressure control valves, PCV-8801 through PCV-8805 with PCV-8801 a larger capacity valve and designed to open first. The remaining valves are designed to open in series with overlap through their operating ranges. PCV-8801 failed to open and PCV-8802, 8803, and 8804 did not appear to properly control RCS temperature. PCV-8805 was operated in manual to control (steam generator) pressure. The Licensee notified the NRC Resident Inspector.
Florida Power and Light (FPL) is retracting this notification because the feedwater issues during the shutdown were not causal to the manual reactor trip. The St. Lucie Emergency Plan, requires that the units be taken offline prior to the onset of hurricane force winds onsite. In accordance with these requirements, St. Lucie Unit 2 was being taken offline prior to the arrival of hurricane Frances. Although automatic feedwater issues occurred during the downpower, the operators successfully took manual control of the main feedwater system. A reactor trip was not necessary to mitigate the condition, and continued operation and on-line troubleshooting would have been practical had the plant not been required to be shutdown for the approaching hurricane. The main feedwater control issues were not relevant factors during the planned plant shutdown/manual reactor trip. Therefore FPL is retracting this notification. The licensee notified the NRC Resident Inspector. Notified R2DO(Boland). | Downpower |