ML030770555

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Point Beach Nuclear Plant - 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 Committed to NuclearExcellence Auxiliary Feedwater I.

September 23, 2002 I

V. ,

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I INTRODUCTION Fred Cayia

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.4 Committed to Nuclear Excelle " 2

I AGENDA

/ 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 NuclearExcellenc ' 3

Iri 00 00 z Zf

'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 4.

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2L-I OVERVIEW OF AFW PROBLEM Richard Flessner NMC Committed to Nuclear Excellenc 7

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."

N m.e NMC-'

Committed to Nuclear Exce~lle* P 8

F 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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Committed to NMC NuclearExceIIence I,

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-- T-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 L ý4 //: k

> Root Cause Evaluation initiated SMultidiscipline RCE Team established NM ~nc~

Committed to Nuclear Ece 10

"EXTENT OF (CONDITION REVIEW I

'C NiMiCi Committed to Nuclear Excellence 11

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I 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 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 two additional for _ Y'"

high-actions completed for operator risk systemrs, comprising -80% of CDF risk Committed to NuclearExcellenc1 p 12

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 cel E

Committed to NucMlear 13 i,,

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

'7 Formalize I PRA interfaces 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 t

Committed to Nuclear Excellenc r 1 14 I.

f1 CORRECTIVE ACTIONS To'Improve Operational Response SPeriane ahPnges made to EOP-0,EOP-0.1, and PECA-i.c k spd AFW oack-up supply provided toSPneumatic recirculatio'h valves

> Updated thc PBNP Simulator to model AFW pump failure due 'to less than required minimum recirculation flow (Degraded AFW) t.he response to SEN 174 SReviewed 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

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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

CORRECTIVE ACTIONS Initiated Expanded Extent of Condition Reviews Brainstornung identified alternate approaches for evaluating, extent of condition V,/"*-

> Feasibility and scope being evaluated ProcedureiReview t using FMEA and procedure timing Modeling Pf consequential failures on the Simulator Focus is the impact of support systems on plant operations' -4 NMe- C Committed to NuclearNEcellenc 17 i

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-. -. - *'tt4< '

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PRA Program 1

II Jim Masterlark iNMC Committed to Nuclear Excellenc 18

Z 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 M!

19 Committed to Nuclear Excellence

jp PRA UPDATE PROJECT Use of Failure Modes and Effects Analysis 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 NMCl l Committed to NucleNE cellenc "*Supp ort system failure 20

~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

-i NMC earExce Committed to NuclM Excllene" Nclea Commttedto 2 21

I CORRECTIVE ACTION PROGRAM Scott Pfaff

-A NMCitec Committedto NuclearExcellenc I, 22 I;

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PROB1LEM IDENTIFICATION &

____ REPORTING It Pre&.1997 Post 1997 SAveraged 89(6 Condition > Averaged 4130 Condition Reports per year 1991 - 1996 Reports per year 1997 - 2001

> 206 SCAQs identified 1998 44 SCAQs identified 1996 > 147 SCAQs identified 1999

> 132 SCAQs identified 2000

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

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Comm;ted to Nuclear Excellen2 23

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PROBLEM IDENTIFICATION &

REPORTING t

.! CAP History Total # CRs Initiated r #&tions Created Alssues I

  • -L--Level 250 200 150 100 50 0

NMClr-ec Committed to Nuclear "ExcetlenceJ

PROBLEM EVALUATION SRO SCREENING Pre-1997 2002

> SRO Screening captured: > SRO Screening captures:

"* Immediate actions taken

"* DocumerIt SSC operability

"* Document SSC operability (Yes/No/Non-Safety), no basis, for determination (Operable, Inoperable, OBD, NA) required

"* Basis for operability

"* LCO Enty.y Required

"* Compensatory actions to (Yes/No), . r support SSC operability

"* Reportabue (Yes/No)

"* Document unplanned LCO

"* SRO Coraiments Action Statement entry

"* Document external agency notification-,

"* SRO Comments Committed to NuclearExcellenc2 25

4 PROBLEM EVALUATION rn urn.

MANAGEMENT REVIEW Pre-1997 2002

> No formal sdreening committee > CAP Screen Team comprised of a multi-disciplinary team chaired by the Plant Manager

> Significance assigned by CAP

> Significance,,determined by Screen Team using a Corrective Action group determination matrix Two levels, SCAQ & non

"* Level A - SCAQ SCAQ

"* Level B - CAQ

"* Level C - Detrimental

"* Level D- Improvements Committed to NuclearExcellence 26 iE

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PROBLEM EVALUATION MAXNAGEMENT REVIEW CONT.

Pre-1997 cont. 2002 cont.

Managers discussed all > CAP Screening Team performs:

SLine SCAQ events and reviewed "* Review Operability call &

others for: basis

"* Immedia!te/interim actions

= Review Reportability call

"* Determine level of effort

"* Operability required

" Reportability

"* Establish scope of RCEs

"* Responsible work group

"* Assign responsible group rd

"* Call for industry notification

"* ID Good Catch CAPs

"* ID any unit mode change restraints <'

Committed to Nuclear Excellenc 27 I

4 A

PROBLEM EVALUATION-i EVALUATIONS Pr- 1997 2002

> General Reqg"irements General Requirements Required prioritization (0 "* All evals have 30 day due

99) date

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

"* Wfin 7 days of creation, evals should be assigned to individual t

NIMC Committed to Nuclear Excellenc 28 I

1 PROBLEM EVALUATION-i t

EVALUATIONS t CONT.

Pr'e-1997 2002

> Root Cause Evaluations Root Cause Evaluations

"* Managers requested RCE "* RCE methodology meets for SCAQ CRs when industry standards desired, iio criteria or "* RCE guideline w/specific justification content criteria ()41*)

"* Required4due date of 30 "* Safety assessment days

"* Extent of condition

"* No Root Cause content assessment guidance!

"* Quality grading of RCEs

"* RCE mefhodology did not meet indt'stry standards NMC Committed to NuclearExcellenc , 29

i PROBLEM EVALUATION EVA] LUATIONS CONT.

Pre-1997 2002

> Apparent Ca'use Evaluations > Apparent Cause Evaluations Not available " Event Description

"* Extent of Condition Assessment

"* Required Corrective U

Actions i "* Corrective Actions to I

.1 Prevent Recurrence (optional)

"* Apparent Cause Statement

"* Quality grading of ACEs

-. L- S NMC

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PROBLEM EVALUATION EVALUATIONS t

CONT.

Pre-1997

  • 2002 ,,

> Condition Evaluationis > Condition Evaluations Jý

"* No guidance for; "* Scope of problem requirements "* Potential solutions

"* Due date determined by "* Corrective action to resolve Supervisor (up tb 300 days)

Maintenance Rule Evaluations

-A NMC Committed to Nuclear Excellence

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PROBLEM EVALUATION

- - EVALUATIONS CONT.

i t

Pm-,1997 2002 V'-*l.

> CARB Revie'ws > CARB Review">}';

reviews all completed Level A evaluations & RCEs

> Effectivenes-s Reviews

  • Not performed

> Effectiveness Reviews

  • Effectiveness reviews required for all RCE CATPRs

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'I Nuc Committed to Nuclear "Excellenc -I 32

ýs Xir PROBLEM RESOLUTION CORRECTIVE ACTION Pre-1997 2002 Corrective Action group > Prioritized w/graduated scheme determined work group most based on significance qualified to perform required > Due date assigned in work. accordance with specific criteria priority by Supervisor

> Flagged if unit mode restraint Due date &pnriority (0- 99) > Utilize QA or Licensing review assigned at C(iscretion of where appropriate Supervisor SW/in 7 days of creation, the I,

Activity should be assigned to

4. an individual

> Minimum requirements for acceptable documentation of completed work 4

NMCear Committed to Nuclear Excellenc 33

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, t CORRECTIVE ACTION PROGRAM

SUMMARY

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

i

> Continuou's Programmatic Improvement

> Continuou's Senior Management Support & Reinforcement of Expectations

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> Continuous CAP Oversight Improvement lqOo.v;;i r J-~

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-A Committed to NuclearExcellen>

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CONCLUSION

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Fred Cayia NMC--[&

Committed to Nuclear Excell:> 35

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