Used to reduce reactivity in the Core. Used during a Scram.
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| | Site | Start date | Title | Description |
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| ENS 55973 | Grand Gulf | 30 June 2022 19:45:00 | Manual SCRAM Due to Loss of Transformer | The following information was provided by the licensee via phone and email:
At 1445 (CDT) on June 30, 2022, with Grand Gulf Nuclear Station in Mode 1 and at 100 percent power, the reactor was manually tripped due to the loss of balance of plant (BOP) transformer 23. All control rods fully inserted into the core and all systems responded appropriately.
Reactor level is being maintained with condensate and feedwater. Reactor pressure is being maintained with turbine bypass valves. The cause of the loss of BOP transformer 23 is under investigation at this time.
Standby Service Water 'A' and 'B' were manually initiated to supply cooling to Control Room A/C, ESF switchgear room coolers, and plant auxiliary loads.
This event is being reported under 10 CFR 50.72(b)(2)(iv)(B) as an event or condition that resulted in actuation of the Reactor Protection System and 10 CFR 50.72(b)(3)(iv)(A) due to the actuation of Standby Service Water.
The NRC Senior Resident Inspector was notified. | | Inspection Manual Change Notice 22-014, Table of Contents for Inspection Manual Change Notice 22-014 | | 28 June 2022 | Table of Contents for Inspection Manual Change Notice 22-014 | | | ML22131A372 | Armed Forces Radiobiology Research Institute | 27 June 2022 | Safety Evaluation by the Office of Nuclear Reactor Regulation Related to Amendment No. 26 to Renewed Facility Operating License R-84 | | | ML22131A371 | Armed Forces Radiobiology Research Institute | 27 June 2022 | Armed Forces Radiobiology Research Institute - Issuance of Amendment No. 26 to Renewed Facility Operating License No. R-84 | | | ML22174A324 | | 27 June 2022 | NRC Presentation: NRC Harvesting Strategy, Coordination, and Activities | | | ML22174A323 | | 27 June 2022 | NRC Presentation: Harvesting, an Overview and Historical Perspective | | | ENS 55964 | Fermi | 25 June 2022 03:38:00 | Automatic Reactor SCRAM Due to Main Turbine Trip | The following information was provided by the licensee via email:
At 2338 EDT, on June 24, 2022, with the unit in Mode 1 at 100 percent power, the reactor automatically scrammed due to an RPS actuation following a Main Turbine Trip. The cause of the turbine trip is not known at this time. The scram was not complex, with systems responding normally post-scram.
Operations responded and stabilized the plant. Reactor water level has been recovered and maintained at the normal level. Decay Heat is being removed by the Main Steam system to the main condenser using the Turbine Bypass Valves. All Control Rods inserted into the core. The transient occurred with no surveillances or activities in progress. Investigation into the cause of the Turbine Trip is in progress.
Due to the reactor protection system actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B). The low reactor water level caused an isolation of Primary Containment (Groups 4/13/15) as expected. The Primary Containment Isolation Event is being reported under 10 CFR 50.72(b)(3)(iv)(A). There was no impact to the health and safety of the public or plant personnel. The NRC resident has been notified. | | ENS 55963 | Waterford | 25 June 2022 01:12:00 | Automatic Reactor Trip Due to Main Steam Isolation Valve Closure | The following information was provided by the licensee via email:
At 2012 CDT, Waterford 3 Steam Electric Station, Unit 3 was operating at 100 percent power when an automatic reactor trip occurred due to Main Steam Isolation Valve MS-124B going closed unexpectedly. Subsequently, both main feedwater isolation valves shut. Emergency Feedwater (EFW) was automatically actuated. Preliminary evaluation indicates that all plant systems functioned normally after the reactor trip. The unit is currently stable in Mode 3. All control rods fully inserted as expected and all other plant equipment functioned as expected. This was an uncomplicated scram.
This event is being reported as a 4-hour non-emergency notification in accordance with 10 CFR 50.72(b)(2)(iv)(B) as an actuation of the reactor protection system (RPS) when the reactor is critical and as an 8-hour non-emergency notification in accordance with 10 CFR 50.72(b)(3)(iv)(A) as valid actuation of the EFW system.
The NRC Resident Inspector has been notified. | | ML22173A081 | | 24 June 2022 | Memo - OGC Review of Framatome Topical Reports, ANP-10340P-A, Revision 0, ANP-10335P-A, Revision 0, ANP-10333P-A, Revision 0 | | | RS-22-082, Defueled Safety Analysis Report Update, Revision 11 | Dresden | 22 June 2022 | Defueled Safety Analysis Report Update, Revision 11 | |
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