Another Problem At Dead Ender Palo Verde?

Is facility operations becoming more erratic?  

  

Power Reactor	Event Number: 53424
Facility: PALO VERDE Region: 4 State: AZ Unit: [ ] [2] [ ] RX Type: [1] CE,[2] CE,[3] CE NRC Notified By: DAVID HECKMAN HQ OPS Officer: HOWIE CROUCH	Notification Date: 05/23/2018 Notification Time: 17:37 [ET] Event Date: 05/23/2018 Event Time: 11:28 [MST] Last Update Date: 05/23/2018
Emergency Class: NON EMERGENCY 10 CFR Section: 50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL	Person (Organization): JASON KOZAL (R4DO)

Unit	SCRAM Code	RX CRIT	Initial PWR	Initial RX Mode	Current PWR	Current RX Mode
2	A/R	Y	100	Power Operation	0	Hot Standby

Event Text

AUTOMATIC REACTOR TRIP ON LOW DEPARTURE FROM NUCLEATE BOILING RATIO "The following event description is based on information currently available. If through subsequent reviews of this event additional information is identified that is pertinent to this event or alters the information being provided at this time a follow-up notification will be made via the ENS or under the reporting requirements of 10CFR50.73. "On May 23, 2018, at approximately 1128 Mountain Standard Time (MST), the Palo Verde Nuclear Generating Station (PVNGS) Unit 2 control room received reactor protection system alarms for low departure from nucleate boiling ratio and an automatic reactor trip occurred. Prior to the reactor trip, Unit 2 was operating normally at 100 percent power. Plant operators entered the reactor trip procedures and diagnosed an uncomplicated reactor trip. All CEAs [control element assemblies] fully inserted into the core. No emergency classification was required per the PVNGS Emergency Plan. "The Unit 2 safety-related electrical buses remained energized from normal offsite power during the event. There was no impact to the required circuits between the offsite transmission network and the onsite Class 1E Electrical Power Distribution System; the offsite power grid is stable. "No major equipment was inoperable prior to the event that contributed to the event or complicated operator response. Unit 2 is currently stable in Mode 3 with the reactor coolant system at normal operating temperature and pressure. The cause of the reactor trip is under investigation. "The event did not result in any challenges to fission product barriers and there were no adverse safety consequences as a result of this event. The event did not adversely affect the safe operation of the plant or the health and safety of the public. "The NRC Resident Inspector has been informed of the Unit 2 reactor trip." Decay is being removed via steam dumps to condenser. Units 1 and 3 at Palo Verde were unaffected by the transient and continue to operate at 100 percent power.