IR 05000348/2011012

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Summary of Public Meeting with Joseph M. Farley Nuclear Plant, to Discuss Safety Significance of Preliminary White Finding Associated with One Apparent Violation Documented in NRC Inspection Report 05000348-11-012 and 05000364-11-012
ML111960460
Person / Time
Site: Farley  Southern Nuclear icon.png
Issue date: 07/15/2011
From: Scott Shaeffer
NRC/RGN-II/DRP/RPB2
To: Stinson L
Southern Nuclear Operating Co
References
IR-11-012
Download: ML111960460 (46)
v • d • e


Text

UNITED STATES NUCLEAR REGULATORY COMMISSION uly 15, 2011

SUBJECT:

PUBLIC MEETING SUMMARY - JOSEPH M. FARLEY NUCLEAR PLANT -

DOCKET NOS. 50-348 AND 50-364

Dear Mr. Stinson:

This refers to the Regulatory Conference conducted on July 12, 2011, in Atlanta, GA. The purpose of the Regulatory Conference was to provide opportunities to discuss the safety significance of the preliminary White finding associated with one Apparent Violation that was documented in NRC Inspection Report 05000348/2011012 and 364/2011012 (ML111590912).

The findings dealt with the failure to maintain the configuration of the 1A reactor coolant pump (RCP) oil lift pump system in accordance with plant design and drawings. This resulted in an electrical short on November 10, 2010 that caused a fire on the Unit 1 main control room (MCR)

1A RCP board handswitch. This conference also addressed whether enforcement action is warranted for the associated Apparent Violation.

In accordance with 10 CFR 2.390 of the NRC's "Rules of Practice," a copy of this letter will be available electronically for public inspection in the NRC Public Document Room (PDR) or from the Publicly Available Records (PARS) component of NRCs document system (ADAMS).

ADAMS is accessible from the NRC Web site at http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).

Should you have any questions concerning this meeting, please contact me at (404) 997-4521.

Sincerely,

/RA/

Scott M. Shaeffer, Chief Reactor Projects Branch 2 Division of Reactor Projects Docket Nos.: 50-348, 50-364 License Nos.: NPF-2, NPF-8

Enclosures:

1. List of Attendees 2. NRC Agenda 3. SNC Powerpoint Presentation

REGION II==

245 PEACHTREE CENTER AVENUE NE, SUITE 1200 ATLANTA, GEORGIA 30303-1257 FARLEY REGULATORY CONFERENCE Atlanta, GA July 12, 2011 Name (Print) Title and Organization

_____________J. Munday_____________ Division Director NRC RII/DRS

_____________R. Nease ______________ _Branch Chief NRC RII/DRS/EB2_______

_____________G. McCoy______________ _Branch Chief NRC RII/DRP/RPB5______

_____________L. Suggs ______________ _Inspector NRC RII/DRS/EB2__________

_____________R. Fanner______________ _Inspector NRC RII/DRS/EB2__________

_____________G. Wiseman____________ _Senior Inspector NRC RII/DRS/EB2____

_____________D. Chung______________ NRC NRR/DRA/PRA Operational Support

_____________E. Crowe______________ _Senior Resident Farley NRC RII/DRP___

_____________W. Rogers_____________ _SRA NRC RII/DRP/RPB7_____________

_____________W. Jones______________ _Deputy Division Director NRC RII/DRP_

_____________R. Croteau_____________ _Division Director NRC RII/DRP _______

_____________L. Wert________________ Deputy Regional Administrator NRC RII_

_____________S. Sparks______________ Senior Enforcement Specialist NRC RII__

_____________S. Shaeffer____________ _Branch Chief NRC RII/DRP/RPB2______

_____________S. Rose_______________ Sr. Project Engineer NRC RII/DRP/RPB2

_____________T. Lighty______________ _Project Engineer NRC RII/DRP/RPB2__

Enclosure 1

UNITED STATES NUCLEAR REGULATORY COMMISSION

REGION II

245 PEACHTREE CENTER AVENUE NE, SUITE 1200 ATLANTA, GEORGIA 30303-1257 FARLEY REGULATORY CONFERENCE Atlanta, GA July 12, 2011 (Via Teleconference)

Name (Print) Title and Organization

_____________M. Ashley___________________ NRC HQ/NRR

_____________S. Meng Wong_______________ _NRC HQ/DRA____________________________

_____________A. Klein_____________________ _NRC HQ/DRA/AFPB______________________

_____________S. Lee______________________ _NRC HQ/DRA____________________________

_____________J. Hyslop___________________ _NRC HQ/DRA/FRB_______________________

_____________N. Coleman_________________ _NRC HQ/OE_____________________________

_____________J. Circle____________________ _NRC HQ/NRR/DRA/APOB_________________

_____________R. Gallucci__________________ _NRC HQ/NRR/DRA/APLA__________________

_____________B. Martin___________________ _NRC HQ/NRR/DORL______________________

_____________D. Harrison_________________ _NRC HQ/DRA____________________________

________________________________________ _________________________________________

________________________________________ _________________________________________

________________________________________ _________________________________________

________________________________________ _________________________________________

________________________________________ _________________________________________

________________________________________ _________________________________________

Enclosure 1

Enclosure 1 Enclosure 2

REGULATORY CONFERENCE AGENDA SOUTHERN NUCLEAR OPERATING COMPANY JULY 12, 2011 NRC REGION II, ATLANTA, GEORGIA I. OPENING REMARKS AND INTRODUCTION II. NRC REGULATORY AND ENFORCEMENT POLICY III. STATEMENT OF ISSUE AND APPARENT VIOLATION IV. SOUTHERN NUCLEAR OPERATING COMPANY V. TRANSITION TO CLOSED SESSION (If Required)

a. PUBLIC QUESTIONS b. NRC REMARKS/BREAK c. SOUTHERN NUCLEAR OPERATING COMPANY VI. BREAK/NRC CAUCUS VII. NRC FOLLOW UP QUESTIONS VIII. CLOSING REMARKS IX. PUBLIC QUESTIONS (If Not Previously Performed)

Enclosure 2

Farley Nuclear Plant NRC Regulatory Conference July 12, 2011 Mark J Ajluni, PE Nuclear Licensing Director John D Lattner, PE Principal Engineer - Fire Protection Ken McElroy RIE Program Manager Enclosure 3

Agenda

  • Introductions
  • Objectives
  • Presentation
  • Wrap-Up and Conclusion Enclosure 3

Objectives 1. To provide new information about the event 2. To prove the handswitch fire that occurred on Nov. 10, 2010, in the Unit 1 control room was a non-challenging fire per the guidance of NUREG/CR 6850 3. To demonstrate that the event is not risk significant and should be characterized as green Enclosure 3

The Event

  • Calibration of 1A RCP oil lift system
  • Broken conduit found
  • Repairs made under PM processes versus CM
  • Operators later attempted start of the 1A RCP and detected burning inside the handswitch
  • Operator responded by opening panel and blowing on the switch box enclosure
  • At the same time the circuit opened and the burning stopped Enclosure 3

Enclosure 3

Handswitch Internals Spade Terminals Spade Terminal Region Contacts Normally Open Enclosure 3

Handswitch in Closed Position Contacts Closed Enclosure 3

Handswitch Spring Returns to Open Arcing Enclosure 3

Handswitch Damage Enclosure 3

Testing Results Because we are dealing with a specific wiring arrangement and switch all seven SNC tests of handswitch fault indicate the same location for damage and the repeatable nature of failure for this particular fault.

Enclosure 3

Handswitch Construction

  • Fire resistive construction of switch block
  • Does not melt or drip plastic
  • Fire resistive construction of switch housing
  • Objective of testing was to confirm how the switch responds to shorted conditions Enclosure 3

Main Control Board Handswitch Enclosure 3

Main Control Board Handswitch Enclosure 3

Main Control Board Handswitch Enclosure 3

Operator Intervention

  • The operator action had no impact on putting out the fire
  • Switch is well placed in fire retardant enclosure making direct air flow to the point of combustion impossible
  • The Condition Report assumes what the operator initially believed at the time, that he blew out the fire
  • Switch will self-extinguish when current path becomes interrupted
  • Operator action was inconsequential, testing shows the fire will self-extinguish anyway Enclosure 3

Main Control Board Enclosure 3

No Potential for Fire Spread

  • Handswitch fire self-extinguishes
  • Confirmed by testing
  • Handswitch fire not of sufficient duration or intensity to ignite secondary combustibles
  • Test thermocouples
  • CHRISTIFIRE test results
  • Fire resistive properties of cables and handswitch materials
  • No hot gas layer formed within panel
  • Conclusion: No potential for fire spread Enclosure 3

NUREG/CR-6850 Appendix C Objective Classification Criteria If any one of the following exist, the event is challenging NUREG/CR-6850 Objective Criteria FNP Event A hose stream, multiple portable fire No automatic or manual suppression used extinguishers, and/or a fixed fire suppression system (either manually or automatically actuated) were used to suppress the fire One or more components outside the No evidence of any collateral damage boundaries of the fire ignition source outside of the fire ignition source were affected Combustible materials outside the No ignition of secondary combustibles boundaries of the fire ignition source were ignited Enclosure 3

NUREG/CR-6850 Appendix C Objective Classification Criteria If any two of the following exist, the event is challenging NUREG/CR-6850 Objective Criteria FNP Event Actuation of an automatic detection Event did not produce sufficient smoke to system actuate the main control room detection system. An ionization smoke detector is located on the ceiling directly behind Section C of the MCB A plant trip was experienced Event did not cause a plant trip. The unit was in cold shutdown.

A reported loss of greater than $5,000 Physical damage limited to the handswitch (< $1,000)

A burning duration or suppression time of Burning duration was less than two 10 minutes or longer minutes Enclosure 3

NUREG/CR-6850 Appendix C Subjective Classification Criteria If any of the following exist, the event is Challenging NUREG/CR-6850 Subjective Criteria FNP Event It is apparent that active intervention was Operator blowing on the switch enclosure needed to prevent potential spread was insignificant intervention. Test data demonstrates the handswitch fire self-extinguishes There are indications that heat was No evidence of heat damage to any generated of sufficient intensity and components outside of the fire ignition duration to affect components outside source the fire ignition source There are indications that flames or heat No ignition of secondary combustibles was generated of sufficient intensity and duration to cause the ignition of secondary combustibles outside the fire ignition source Substantial smoke was generated Insignificant amount of smoke Enclosure 3

NUREG/CR-6850 Appendix C Subjective Classification Criteria If any of the following exist, the event is Challenging NUREG/CR-6850 Subjective Criteria FNP Event It is apparent that active intervention was Operator blowing on the switch enclosure needed to prevent potential spread was insignificant intervention. Test data demonstrates the handswitch fire self-extinguishes There are indications that heat was No evidence of heat damage to any generated of sufficient intensity and components outside of the fire ignition duration to affect components outside source the fire ignition source There are indications that flames or heat No ignition of secondary combustibles was generated of sufficient intensity and duration to cause the ignition of secondary combustibles outside the fire ignition source Substantial smoke was generated Insignificant amount of smoke Enclosure 3

NUREG/CR-6850 Appendix C Objective Classification Criteria If any two of the following exist, the event is challenging NUREG/CR-6850 Objective Criteria FNP Event Actuation of an automatic detection Event did not produce sufficient smoke to system actuate the main control room detection system. An ionization smoke detector is located on the ceiling directly behind Section C of the MCB A plant trip was experienced Event did not cause a plant trip. The unit was in cold shutdown.

A reported loss of greater than $5,000 Physical damage limited to the handswitch (< $1,000)

A burning duration or suppression time of Burning duration was less than two 10 minutes or longer minutes Enclosure 3

Non-Challenging Control Room Fires From Fire Events Database Involving Intervention Fire Description Type of Intervention Incident No 374 SDV high level RPS relay burned Control room personnel extinguished the burning relay 425 A relay burned due to its old age Portable CO2 extinguisher used 815 A relay burned up in the primary Portable CO2 extinguisher containment isolation panel used 2224 Defective insulation on windings led to Portable fire extinguisher fault within current protection relay used 2266 Small fire found in control panel Operator blew out flame transformer Enclosure 3

Conclusion: Non-Challenging

  • None of the objective or subjective criteria was met
  • Event is non-challenging Enclosure 3

SNC Risk Significance Determination Enclosure 3

SDP Factors HRA Control Room Abandonment Dominated Unit 1 MCR Panel (Unit 2)

Suppression Non-Fire Ignition Will Fire before Fire Severity Shutdown propagation to Suppression Probability Propagate? Factor outside MCR cable bundle Probability No Risk Not Significant Unit 2 Enclosure 3

Phase III Summary Fire Propagation Suppress before MCR Shutdown CCDP Ignition Probability propagation to Abandonment outside Probability cable bundle Probability MCR NRC 1.0 0.5 1.0** 1.1E-3 (upper) 9.9E-3 5.5E-6 (white)

5.6E-4 (lower) 2.8E-6 (white)

SNC 1.0 0.5* 1.0** (upper) 6.3E-5 3.1E-3 1.0E-7 (green)

0.01 (realistic) 6.4E-4 1.0E-8 (green)

    • SNC Position - fire not challenging
      • Considered in MCR abandonment probability Enclosure 3

MCR Abandonment - HVAC

- HVAC allows Main Control Room (MCR) to remain manned for larger fires

- Larger fires are less likely to occur

- Risk of Abandonment reduced by a factor of 20

MCR Abandonment (cont.)

  • SNC determined HVAC was operating normally and would continue to operate
  • HVAC controls/circuitry physically separated from fire location
  • Operators and Fire Brigade would not trip HVAC Enclosure 3

Farley Common MCR Fire Location HVAC Controls Enclosure 3

Shutdown from Outside MCR NRC Value SNC Value Comments 9.9E-3 3.1E-3 *Dominated by loss of aux feedwater due to human error

  • Equipment failure of AFW negligible
  • Difference is due to modeling of human error Enclosure 3

SDP Summary

  • Even assuming a challenging fire and an event probability of 1.0, the CCDP is green

- HVAC was a operating normally making the likelihood of control room evacuation less

- SNC performed a more realistic HRA reducing the calculated risk Enclosure 3

Corrective Actions Enclosure 3

Root Cause of the Event

  • No written work package generated for the replacement of the flex conduit. We stepped out of process mixing CM with PM
  • No lift sheet
  • No pre-job brief
  • Management has not been successful in getting Maintenance to internalize Human Performance tool usage 100% of the time.
  • No discussion of human performance tools when problem identified
  • Skill-of-the-craft is accepted behavior Enclosure 3

Corrective Actions

  • Revised fleet procedures to define allowable work scope for minor maintenance, tool pouch work, and CR initiation.
  • Maintenance personnel were trained using dynamic training methods.
  • Implemented leadership action plan for Maintenance Superintendents. Accomplished with the assistance of leadership expert.

Enclosure 3

Conclusion and Wrap-Up

  • The event is non-challenging as it does not meet the NUREG / CR 6850 criteria for challenging
  • Tests revealed that the handswitch consistently fails at the same location, resulting in a self-extinguishing condition
  • Target cables will not catch fire because heat rates are low.
  • Modeling control room HVAC results in green risk.
  • The event is not risk significant
  • The event should be characterized as green Enclosure 3
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