Dangerous Junk Plant Grand Gulf: Another Delayed Startup, A Host Broken Equipment and Chaos In The Control Room

Update

Dec 11 4% power: came out of refueling outage.

Dec 12 19%

Dec 13 14% core cooling safety bus failure and multiple equipment problems. 

***Basic licensed training cautions us from prolonged operation at low power levels(1-100%). The moderator void coefficient is less efficient in the low power area, than up at 100%. In other words, in the low power area, there will be less of a designed automatic feedback fuel protection mechanism than in the high power area.   


It seems a core cooling safety transformer or breaker failed beginning at 9:18. 

Then an additional core cooling system (RCIC) failed over valve issues.  

Power Reactor	Event Number: 53115
Facility: GRAND GULF Region: 4 State: MS Unit: [1] [ ] [ ] RX Type: [1] GE-6 NRC Notified By: RYAN MEYER HQ OPS Officer: STEVEN VITTO	Notification Date: 12/12/2017 Notification Time: 17:40 [ET] Event Date: 12/12/2017 Event Time: 09:18 [CST] Last Update Date: 12/12/2017
Emergency Class: NON EMERGENCY 10 CFR Section: 50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION	Person (Organization): RICK DEESE (R4DO)

Unit	SCRAM Code	RX CRIT	Initial PWR	Initial RX Mode	Current PWR	Current RX Mode
1	N	Y	16	Power Operation	16	Power Operation

Event Text

AUTOMATIC START OF EDG DUE TO LOSS OF ESF TRANSFORMER "At approximately 0918 CST on Tuesday, December 12, 2017, the Grand Gulf Nuclear Station experienced a loss of the Engineered Safety Features (ESF) Transformer 11 which was powering the Division 1 ESF bus. Subsequently, the station experienced an automatic start of the Division 1 Emergency Diesel Generator [EDG], partial isolation of the primary and secondary containment buildings and the isolation of the Reactor Core Isolation Cooling System [RCIC]. "It is not currently understood why the RCIC system isolated during this event. A team is investigating this issue separately from the loss of the ESF 11 transformer. "The cause of the event is under investigation at this time. "No other issues or unexpected events occurred. "The NRC Resident Inspector has been notified of the event."

Then approximately 4 hours later a div 3 safety battery is questioned over connectivity issues. My guess this came from a annunciator alarm in control room. I wonder if the div 3 charger was power from div 1bus. I think the div 3 charger is powered from the div 1 bus. Basically I think losing the div 1 bus took out the div 3 charger when the transformer failed that went unnoticed for four hours. This made core spray broken.

The gist of this is look at all the safety systems we lost in a short time

A enormously important bus and transformer.

A host of important primary and secondary partial isolations.    

RICI 

and one side of core spray

Power Reactor	Event Number: 53117
Facility: GRAND GULF Region: 4 State: MS Unit: [1] [ ] [ ] RX Type: [1] GE-6 NRC Notified By: WESLEY MARSHALL HQ OPS Officer: STEVEN VITTO	Notification Date: 12/12/2017 Notification Time: 20:34 [ET] Event Date: 12/12/2017 Event Time: 13:30 [CST] Last Update Date: 12/12/2017
Emergency Class: NON EMERGENCY 10 CFR Section: 50.72(b)(3)(v)(D) - ACCIDENT MITIGATION	Person (Organization): RICK DEESE (R4DO)

Unit	SCRAM Code	RX CRIT	Initial PWR	Initial RX Mode	Current PWR	Current RX Mode
1	N	Y	15	Power Operation	15	Power Operation

Event Text

HIGH PRESSURE CORE SPRAY DECLARED INOPERABLE "At approximately 1330 CST on Tuesday, December 12, 2017, Grand Gulf Nuclear Station declared Division 3 'C' Battery inoperable due to questions concerning battery terminal connection continuity. Technical Specification 3.8.4, DC Sources - Operating, Condition E, Required Action E.1, requires the station to declare the High Pressure Core Spray System inoperable immediately. The Division 3 'C' Battery and High Pressure Core Spray System was declared operable and the LCOs [Limiting condition of operation] were declared met at 1731CST on Tuesday, December 12, 2017. Based on field measurements of terminal torque and resistance, the as-found and as-left terminal resistance micro-ohm readings indicated satisfactorily all times. Formal evaluation of the as-found condition of the battery is in progress. "This report is to notify the NRC of a loss of safety function on the High Pressure Core Spray System." The NRC Resident Inspector was notified.