ML101670501

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Discussion of Screening Criteria - Arkansas Nuclear One (ANO)
ML101670501
Person / Time
Site: Arkansas Nuclear  Entergy icon.png
Issue date: 06/17/2010
From: Jacqwan Walker
Entergy Operations
To:
NRC/NRR/DIRS/IRIB
Jeremy Bowen, 415-3471
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Download: ML101670501 (18)
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Enclosure 2 Arkansas Nuclear One Presentation Meeting Summary of the 6/8/2010 Meeting with NRC/SNC/FPL/SCE&G Dated June 17, 2010

Discussion of Screening Criteria Arkansas Nuclear One (ANO)

Jessica Walker ANO Fire Protection

Overview

  • Background
  • Screening Criteria

- NRC Working Group Results

- Arkansas Nuclear One (ANO) Review

  • Conclusions

Arkansas Nuclear One (ANO)

Background Information

  • 2001 Triennial Fire Protection Inspection - Resulted in White Finding

- Failure to ensure that cables and equipment of redundant trains of systems necessary to achieve and maintain hot shutdown conditions would remain free of fire damage (in the event of a fire)

  • Fire Areas 98J and 99M in Arkansas Nuclear One, Unit 1 (ANO-1)

- ANO initiated a Manual Action Review Project to identify potential changes to plant systems and components in order to reduce the complexity of safe shutdown manual actions

Arkansas Nuclear One (ANO)

Background Information

  • June 30, 2004 - Entergy Operations, Inc. (Entergy) provided the results of the ANO, Units 1 and 2 10CFR50, Appendix R Manual Action Review Project
  • December 17, 2004 - Entergy provided the schedule for completion of modifications and analyses to eliminate the time critical complex manual actions at ANO, Units 1 and 2
  • March 31, 2005 - NRC closed the White Finding based on the results of Supplemental Inspection 50-313/05-11; 50-368/05-11
  • November 2, 2005 - Entergy submitted a letter of intent to adopt NFPA 805

Arkansas Nuclear One (ANO)

Background Information

  • Current state of Fire Protection at AND

- Modifications completed to eliminate time-critical, complex recovery actions

- Revised Operations Fire Procedures

  • Prescriptive response to notification of a severe fire

- Non-Compliances addressed since white finding

  • Compensatory actions
  • Tracked in the corrective action process

- NFPA 805 Project Plans

  • Coordinating with Pilot Plant transition activities
  • Participating in NEI NFPA 805 Task Force activities

Screening Criteria

  • NRC Working Group Results

- Potential issues with protection or separation for safe shutdown equipment

- Relatively large number of Operator Manual Actions (OMAs)

- Limited documentation of cable routing

- Use of complex OMAs

- Symptom-based fire response procedures with complex OMAs

Potential Issues with Protection or Separation

Relatively Large Number of Operator Manual Actions

- Risk analysis

- Realistic Fire Modeling

- Modifications

  • Compensatory measures
  • Current OMAs feasible

Cable Routing Documentation

  • Since construction, cable routing data has been maintained electronically

- ANO cable routing data was initially turned over electronically from the Bechtel Circuit and Raceway schedule after construction

  • Electronic Databases have been in use since the 1980's containing the cable to raceway and raceway to fire zone relationships

- The Plant Data Management System (PDMS) is the current repository for the safe shutdown equipment list and the relationship of equipment to safe shutdown cables

- PDMS provides for configuration control of cable and raceway data by tracking changes from design through as-built configuration

- A high level of confidence in the accuracy and integrity of data is provided by PDMS

Use of Complex Operator Manual Actions

  • June 13, 2007 - Entergy provided the results of the completed modification and analysis to eliminate the time critical complex manual actions

- One modification was eliminated by the risk evaluations associated with the transition to NFPA 805

- The analyses and modifications to eliminate the other identified manual actions statused as complete

  • These modifications reduce overall fire risk
  • In addition, AND has a safe shutdown review process that reviews modifications and procedure changes to ensure ongoing control of the required manual actions

OMA Elimination Examples

  • U1 OMA - Manual action to re-close 8512 load center breaker in 98-J and 99-M

- To restore offsite power at LC bus 85 without the need to take operator actions, the breaker 8512 control cables, specifically cables RC8512C and RCD 11 09A that were re-routed

OMA Elimination Examples

  • U-2 OMA: Eliminate action to de-energize and close sump recirculation header isolation valve 2CV-5649-1

- Potential existed for a "hot short" to cause 2CV-5649-1 to spuriously open

  • A spurious open signal to the Refueling Water Tank (RWT) outlet valves had potential to drain the RWT to the containment sump

- The "hot short" issue was resolved by replacing the "hot" conductor with a new cable routed in new conduit between cabinets Control Room

Complex Critical Operator Manual Actions - Unit 1 Type (Check one)

One Time Action Continuing Scheduled Completion Date Commitment Compliance (If Required)

Zone 98-J: Eliminate action to manua lly re-close 8512 X Complete load center breaker Zone 98-J: Eliminate action to de-energize and close X Complete pressurizer ERV isolation valve Zone 98-J: Eliminate actions to establish emergency X Complete diesel power Zone 99-M: Eliminate action to manually re-close X Complete B512 load center breaker Zone 99-M: Eliminate actions to establish emergency X Complete diesel power Zone 1DO-N: Eliminate actions to establish emergency X Complete diesel power Zone 112-1: Eliminate action to de-energize and close X Complete pressurizer ERV isolation valve

Complex Critical Operator Manual Actions - Unit 2 Type (Check one)

One Time Action Continuing Scheduled Completion Date Commit ment Compliance (If Required )

Zone 2040-JJ : Eliminate action to de-energize and X Complete close sump recirculation header isolation valve Zone 2073-00: Eliminate actions for operation of X Complete emergency diesel generator Zone 2073-00: Eliminate action to de-energize and X Com plete close sump reci rculation header isolation valve Zone 2091-68: Elimi nate action to isolate ReS Delete - Eliminated by inventory loss th rough the ECCS vent flow path tra nsition to NFPA 805 Zone 2096-M: Eliminate actions for ope ration of X Complete eme rgency diesel genera tor

Complex Critical Operator Manual Actions - Unit 2 Zone 2099-W: Eliminate actions for operation of X Complete emergency diesel generator Zone 2100-2: Eliminate actions to de-energize and X Complete close auxiliary cooling water loop isolation va lve Zone 2100-2: Eliminate actions to close letdown X Complete isolation valve Zone 2108-8: Eliminate actions for operation of X Complete emergency diesel generator Zone 2 108-8: Elim inate actions to close letdown X Complete isolation valve Zone 21 09-U: Eliminate actions for operation of X Complete emergency diesel generator Zone 2 109-U: Eliminate actions to close letdown X Complete isolation va lve Zone 21 11-T: Eliminate actions to close letdown X Complete isolation va lve

Symptom Based Fire Response Procedures

  • Safe shutdown procedures have evolved since the identification of the original white finding
  • Since 2004, safe shutdown procedures are prescriptive upon notification of a severe fire

Screening Criteria Conclusions

  • AND Screening Results Only two screening criteria apply
  • Potential issues with protection or separation for safe shutdown equipment
  • Relatively large number of OMAs Three screening criteria do not apply
  • Limited documentation of cable routing

- A high level of confidence in the accuracy and integrity of data is provided by PDMS

- Analyses and modifications to eliminate identified complex, critical manual actions complete

  • Symptom-based fire response procedures with complex OMAs

- Safe shutdown procedures are prescriptive upon notification of a severe fire

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