ML030770555

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Potential Common Mode Failure Auxiliary Feedwater
ML030770555
Person / Time
Site: Point Beach  NextEra Energy icon.png
Issue date: 09/23/2002
From:
Nuclear Management Co
To:
Office of Nuclear Reactor Regulation
References
FOIA/PA-2003-0094
Download: ML030770555 (35)
v • d • e


Text

Poii'It Beach Nuclear Plant Potential Common Mode Failure NMC Auxiliary Feedwater Committed to Nuclear Excellence I.

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September 23, 2002 V.

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INTRODUCTION Fred Cayia

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AGENDA

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Inatroduction (Fred Cayia)

V ArW System Design (Tom Kendall)

V Overview of AFW Problem (Rich Flessner)

V Extent of Condition Review (Rich Flessner)

V"FRA (Jim Masterlark)

V" Corrective Action Program (Scott Pfaff)

V" Conclusion (Fred Cayia)

Committed to Nuclear Excellenc 3

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'AFW DESIGN BASIS SSupply water to SG to remove decay heat and replenish SG inventoury

> Safety-Reli.ted Functions:

"* Supply FW during accidents with main steam safety valve opening

"* Supply TFW during accidents which require rapid RCS cooldown

"* Isolate flow to a faulted or ruptured S/G NMC Committed to Nuclear Excellence5

AFW System - Major Flow Paths 2AOV-4002

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I OVERVIEW OF AFW PROBLEM Richard Flessner NMC Committed to Nuclear Excellenc 7

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VIOLATION S"Procedui:es EOP-0.1 Unit 1, 'Reactor Trip Response,' Revision 24, and EOP-0.1 Unit 2,

'Reactor Trip Response,' Revision 23, did not provide adequate operator instructions to verify that the aixdliary feedwater (AFW) pump minimum' flow recirculation valves were open while cont'trolling AFW flow upon low instrumernt air header pressure."

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ROOT CAUSE The original EOP validation process failed to identify that specific operator actions were needed to properly control or stop AFW flow under a loss of instrument air condition.

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  • 6 NMC Committed to Nuclear ExceIIence 9

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IMMEDIATE ACTIONS TAKEN Informatio:n tags placed Shifts briefed and trained on issue

> Notification made to NRC

> Simulator" training for each crew

> Procedure changes -o, s.r

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> Root Cause Evaluation initiated SMultidiscipline RCE Team established NM Committed to Nuclear Ece

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NiMiCi Committed to Nuclear Excellence "EXTENT OF (CONDITION REVIEW I

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  • .m.., m Original I')RA Model was based primarily on design functions and actions taken to mitigate failures

> Detailed review of PRA model completed on four high-risk I'systems and a review of assumptio'ns for Y'"

operator actions completed for two additional high- _

risk systemrs, comprising -80% of CDF risk Committed to Nuclear Excellenc1 p 12 RCE EXTENT OF CONDITION EOP validation process did not adequately evaluate effects of loss of instrument air

> Reviewed operator actions associated with a loss of instrumerit air (AOP-5B) to ensure consistency and timeliness of actions in emergency procedures

CORRECTIVE ACTIONS To lkddress Extent of Condition Issues

  • Developed and implemented a matrix of Xat events considered risk-significant for each EOP to be used during the EOP validation process

> Revised the EOP verification/validation process to formally inAclude PRA involvement

> Detailed PRA model reviews of other risk significant, systems are continuing NMC Committed to NucMlear E

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'7 Formally provided training and operations with list of highest"risk HEPs and with a description of human error reduction methods used in PRA models Added hujfnan error reduction methods into training process ar~d EOP/AOP procedure process 3 Reviewedtraining materials and EOPs/AOPhs for the highest-ri~2k HEPs against human error reduction methods fbr possible CDF reduction opportunities 1

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Committed to Nuclear Excellenc r

! i CORRECTIVE ACTIONS To Improve Integration of PRA into Training and Procedures Formalize I PRA interfaces

CORRECTIVE ACTIONS To'Improve Operational Response SPeriane ahPnges made to EOP-0,EOP-0.1, and PECA-i.c k

spd SPneumatic oack-up supply provided to AFW recirculatio'h valves

> Updated thc PBNP Simulator to model AFW pump failure due 'to less than required minimum recirculation flow SReviewed t.he response to SEN 174 (Degraded AFW) and verified that procedures exist for maintaining adequate p;ump flow Added OPNIN safety function to the AFW recirculation valves Committed to Nuclear Excellence 15 f

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CORRECTIVE ACTIONS Other Actions

> Revised t1..e AFW PRA model to accurately reflect system performance

> Revised tfije design process to include consideration of human action induced failure modes

> Reviewed'AFW design documents for consistency in describing the recirculation line function J,

NMC Committed to Nuclear Excellence 16 Ii

Brainstornung identified alternate approaches for evaluating, extent of condition V,/"*-

> Feasibility and scope being evaluated t

ProcedureiReview using FMEA and procedure timing Modeling Pf consequential failures on the Simulator Focus is the impact of support systems on plant operations' NMe-C Committed to NuclearNEcellenc

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CORRECTIVE ACTIONS Initiated Expanded Extent of Condition Reviews

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PRA Program 1

II Jim Masterlark iNMC Committed to Nuclear Excellenc I.-

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2PRA UPDATE PROJECT

> Self initiatcId voluntary project

> Ongoing formal evaluation of PRA model

> Most risk s'ignificant systems evaluated first

> Revalidates model assumptions SFour primary reasons for.update

"* Validates changes in plant since original PRA model

"* Adds sophistication for better use of on line Safety Monito:.

"* Update'reliability and availability data

"*Expand "Human Reliability Analysis N\\MC Committed to Nuclear Excellence 19 M!

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PRA UPDATE PROJECT Use of Failure Modes and Effects Analysis NMCl l C ommitted to NucleNE cellenc Determines possible failure modes

  • Rigorouts evaluation for each component
  • Capture failure mode in fault tree, or e DochUment reason that it is not included
  • Analyz'* to determine effect of failure modes on system operation
  • Determination of how component could get to each pisition analyzed

"* Equipment failure

"* Opegrator action

"* Supp ort system failure 20 jp

~1 PRA EMERGENCY PROCEDURE VALIDATION INTEGRATION PRA Group is a formal reviewer for changes to the Emergency Procedures

  • Affect~on Human Error Calculations
  • Optimi7zation of Wording and Format
  • Opporttunities to recover from human errors identified
  • Timing of actions appropriate to plant response
  • Risk Significant entry conditions identified

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21 NMC Committed to NuclM ear Exce

I Scott Pfaff

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NMCitec Committed to Nuclear Excellenc 22 CORRECTIVE ACTION PROGRAM

PROB1LEM IDENTIFICATION &

REPORTING It Pre&.1997 SAveraged 89(6 Condition Reports per year 1991 - 1996 44 SCAQs identified 1996 Post 1997

> Averaged 4130 Condition Reports per year 1997 - 2001

> 206 SCAQs identified 1998 147 SCAQs identified 1999

> 132 SCAQs identified 2000

> 99 SCAQs identified 2001 S28 SCAQs identified 2002 (YTD)

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CAP History Total # CRs Initiated r

  1. &tions Created *-L--Level A lssues I 250 200 150 100 50 0

NMClr-ec Committed to Nuclear "ExcetlenceJ PROBLEM IDENTIFICATION &

REPORTING t

Pre-1997

> SRO Screening captured:

"* DocumerIt SSC operability (Yes/No/Non-Safety), no basis, for determination required

"* LCO Enty.y Required (Yes/No),

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"* Reportabue (Yes/No)

"* SRO Coraiments 2002

> SRO Screening captures:

"* Immediate actions taken

"* Document SSC operability (Operable, Inoperable, OBD, NA)

"* Basis for operability

"* Compensatory actions to support SSC operability

"* Document unplanned LCO Action Statement entry

"* Document external agency notification-,

"* SRO Comments Committed to Nuclear Excellenc2 PROBLEM EVALUATION SRO SCREENING 25

PROBLEM EVALUATION MANAGEMENT REVIEW Pre-1997

> No formal sdreening committee

> Significance,,determined by Corrective Action group Two levels, SCAQ & non SCAQ 2002

> CAP Screen Team comprised of a multi-disciplinary team chaired by the Plant Manager

> Significance assigned by CAP Screen Team using a determination matrix

"* Level A - SCAQ

"* Level B - CAQ

"* Level C - Detrimental

"* Level D-Improvements Committed to Nuclear Excellence 4



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PROBLEM EVALUATION MAXNAGEMENT REVIEW CONT.

Pre-1997 cont.

SLine Managers discussed all SCAQ events and reviewed others for:

"* Immedia!te/interim actions

"* Operability

" Reportability

"* Responsible work group rd Committed to Nuclear Excellenc 2002 cont.

> CAP Screening Team performs:

"* Review Operability call &

basis

= Review Reportability call

"* Determine level of effort required

"* Establish scope of RCEs

"* Assign responsible group

"* Call for industry notification

"* ID Good Catch CAPs

"* ID any unit mode change restraints 27 I

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PROBLEM EVALUATION-EVALUATIONS Pr-1997

> General Reqg"irements Required prioritization (0 99)

General Requirements

"* All evals have 30 day due date

"* Prioritized (1 - 5) w/graduated scheme based on significance

"* Wfin 7 days of creation, evals should be assigned to individual NIMC Committed to Nuclear Excellenc 2002 t

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PROBLEM EVALUATION-EVALUATIONS CONT.

Pr'e-1997

> Root Cause Evaluations

"* Managers requested RCE for SCAQ CRs when desired, iio criteria or justification

"* Required4due date of 30 days

"* No Root Cause content guidance!

"* RCE mefhodology did not meet indt'stry standards NMC Committed to Nuclear Excellenc 2002 Root Cause Evaluations

"* RCE methodology meets industry standards

"* RCE guideline w/specific content criteria ()41*)

"* Safety assessment

"* Extent of condition assessment

"* Quality grading of RCEs 29 1

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Pre-1997

> Apparent Ca'use Evaluations Not available U

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LUATIONS CONT.

2002

> Apparent Cause Evaluations

" Event Description

"* Extent of Condition Assessment

"* Required Corrective Actions

"* Corrective Actions to Prevent Recurrence (optional)

"* Apparent Cause Statement

"* Quality grading of ACEs

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PROBLEM EVALUATION

PROBLEM EVALUATION EVALUATIONS CONT.

Pre-1997 *

> Condition Evaluationis

"* No guidance for; requirements

"* Due date determined by Supervisor (up tb 300 days) 2002

> Condition Evaluations Jý

"* Scope of problem

"* Potential solutions

"* Corrective action to resolve Maintenance Rule Evaluations NMC Committed to Nuclear Excellence

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PROBLEM EVALUATION EVALUATIONS CONT.

Pm-,1997

> CARB Revie'ws

> Effectivenes-s Reviews

  • Not performed 2002 V'-*l.

> CARB Review">}';

reviews all completed Level A evaluations & RCEs

> Effectiveness Reviews

  • Effectiveness reviews required for all RCE CATPRs

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PROBLEM RESOLUTION CORRECTIVE ACTION Pre-1997 Corrective Action group determined work group most qualified to perform required work.

Due date &pnriority (0- 99) assigned at C(iscretion of Supervisor I,

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2002

> Prioritized w/graduated scheme based on significance

> Due date assigned in accordance with specific criteria priority by Supervisor

> Flagged if unit mode restraint

> Utilize QA or Licensing review where appropriate SW/in 7 days of creation, the Activity should be assigned to an individual

> Minimum requirements for acceptable documentation of completed work 4

NMCear Committed to Nuclear Excellenc 33

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CORRECTIVE ACTION PROGRAM

SUMMARY

Since mid-1907 the Point Beach Corrective Action Program has undergone significant'!change and continuous improvements:

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> Continuou's Programmatic Improvement

> Continuou's Senior Management Support & Reinforcement of Expectations

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Fred Cayia NMC--[&

Committed to Nuclear Excell :>

35 CONCLUSION

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