ML101670501
| ML101670501 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 06/17/2010 |
| From: | Jacqwan Walker Entergy Operations |
| To: | NRC/NRR/DIRS/IRIB |
| Jeremy Bowen, 415-3471 | |
| Shared Package | |
| ML101670555 | List: |
| References | |
| Download: ML101670501 (18) | |
Text
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
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)
- By means specified in 10 CFR Part 50, Appendix R, Paragraph III.G.2
- Or by alternate means specified in 10 CFR Part 50, Appendix R, Paragraph III.G.3
- 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
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
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
- Transition to new risk-informed, performance-based alternative per 10 CFR 50.48(c) which endorses NFPA 805
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 Commitment Compliance Zone 98-J: Eliminate action to manually re-close 8512 X
load center breaker Zone 98-J: Eliminate action to de-energize and close X
pressurizer ERV isolation valve Zone 98-J: Eliminate actions to establish emergency X
diesel power Zone 99-M: Eliminate action to manually re-close X
B512 load center breaker Zone 99-M: Eliminate actions to establish emergency X
diesel power Zone 1 DO-N: Eliminate actions to establish emergency X
diesel power Zone 112-1: Eliminate action to de-energize and close X
pressurizer ERV isolation valve Scheduled Completion Date (If Required)
Complete Complete Complete Complete Complete Complete Complete
Complex Critical Operator Manual Actions - Unit 2 Type (Check one)
One Time Action Continuing Commitment Compliance Zone 2040-JJ: Eliminate action to de-energize and X
close sump recirculation header isolation valve Zone 2073-00: Eliminate actions for operation of X
emergency diesel generator Zone 2073-00: Eliminate action to de-energize and X
close sump recirculation header isolation valve Zone 2091-68: Eliminate action to isolate ReS inventory loss through the ECCS vent flow path Zone 2096-M: Eliminate actions for operation of X
emergency diesel generator Scheduled Completion Date (If Required)
Complete Complete Complete Delete - Eliminated by transition to NFPA 805 Complete
Complex Critical Operator Manual Actions -
Unit 2 Zone 2099-W: Eliminate actions for operation of X
emergency diesel generator Zone 2100-2: Eliminate actions to de-energize and X
close auxiliary cooling water loop isolation valve Zone 2100-2: Eliminate actions to close letdown X
isolation valve Zone 2108-8: Eliminate actions for operation of X
emergency diesel generator Zone 2108-8: Eliminate actions to close letdown X
isolation valve Zone 21 09-U: Eliminate actions for operation of X
emergency diesel generator Zone 2109-U: Eliminate actions to close letdown X
isolation valve Zone 21 11-T: Eliminate actions to close letdown X
isolation valve Complete Complete Complete Complete Complete Complete Complete Complete
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
- Use of complex OMAs
- 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