ML053250417

Preliminary Issue List, with Handwritten Notes

ML053250417
Person / Time
Site:	Palo Verde
Issue date:	11/15/2005
From:	NRC Region 4
To:
References
FOIA/PA-2004-0307
Download: ML053250417 (2)

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Preliminary Issue List Palo Verde Nuclear Generating Station Augmented Inspection Team NOTE: This is NOT an all-inclusive list.

230 kV Liberty Transmission Line, Tower#73, Phase "C"Insulator Failure C - single phase to ground fault resulted in loss of offsite power and three unit trip E Auxiliary Relay, Liberty Transmission Line Fault Detection/Protection System Failure q , A inadequate design resulted in single failure vulnerability d>

• additional single failure design issues identified and corrected to extent practical

• licensee also did not appear to make resolution of this issue a startup issue until the concern was raised by the AIT

• 4Jnit I Atmospheric Dump Valve 185 Fail e n:rooe ristra ction with minimal impact on event response

• apparent cause being determined

• Unit 1 Letdown Heat Exchanger Isolation Failure

• licensee performance deficiency associated with understanding implications of temporary modification installed in plant

• little impact on control room response to event

• some potential impact on fire response being reviewed by AIT

• UiUtlancdL3General-Electric-Magne Blast Circuit Breaker Failures (J complicated event recovery efforts taii t ereturn of offsite power to ESF

{ZieQ determined apparent cause as "breaker not cycled frequently enoug!P VA AlThl lctse een-apparent caseara ncern regaaigttrret

5gtrj %functionality of breakers resident staff following as potential operability issue

• Vnit 2 Train "A" Emergency Diesel Generator Failure resulted in a loss of power to Train "A" ESF busses following loss of offsite power

'e .fapparent cause wa ode ure n e er circuit -7 ,-,xA _

• Unit 2, Train "E" Positive Displacement Charging Pump Trip a

• operator error resulted in suction line isolation and protective trip of pump

• AIT identified that auxiliary operator was delayed approximately 10 minutes at the RCA access point even after the operator explained he was on a time critical mission

• *when RCA access delay was discussed with licensee, AIT determined that the licensee was unaware of delay information in this record was deleted in accordance with the reedOM1 of InfoFMation

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• Unit 3 Bypass Valve/Control Cabinet Malfunctions

-S good operator actions minimized impact on plant, was operator distraction O-C potential design modification issue being reviewed by AIT as apparent cause

• Unit 3 Reactor Coolant Pump Lube Oil Lift Pump Breaker Thermal Overload Trip

• no impact on trip but some minor impacts on recovery

• potential design issue associated with set point of thermal overloads

• Unit 3 Low Pressure Safety Injection System In-leakage (Check Valve V217)

• little impact on event, operator distraction to take manual actions to prevent over

_pressurization

• apparent cause was Borg-Warner check valve leakage, potential maintenance issue a* -nit 3Variable Over PowerTrD-ReactorCoolant Pump Speed Increase to 67 Hz license- in stigating potential impacts o I A; . AIT-raisudiqest-ios aboutydrrauic affects, if any

'-:> Technical Support Center Emergency Diesel Generator Failure

• apparent cause was test switch out of position

• maintenance personnel failed to use restoration procedure six days prior to event following testing

• some Impact on emergency response organization which needed to use alternate TSC

• Procedure Issue Associated with Minimum Amperage for Reactor Coolant Pumps

• complicated recovery efforts by delaying RCP restoration

• appears minimum amperage basis'involved NPSH limits

• high voltage in switchyard resulted in low amperage J1X i~ Emergency Response Organization Notification Issues

• some delay in notification occurred but little impact

• apparent cause associated with procedure adequacy and communication failures

• Initial Notification of State and Local Official Issues

• Unit I and Unit 3 did meet their guidelines on timeliness of initial notification

• little overall impact because Unit 2 Alert Notification was timely

• apparent cause being reviewed