ML112220610

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Meeting Presentation Prairie Island Pre-Decisional Enforcement Conference
ML112220610
Person / Time
Site: Prairie Island Xcel Energy icon.png
Issue date: 08/02/2002
From:
Nuclear Management Co
To:
NRC/RGN-III
References
EA-02-068
Download: ML112220610 (35)
v • d • e


Text

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Prairie Island Nuclear Generating Plant Pre-Decisional Enforcement Conference August 2, 2002 NMC)

!f-.--- _Agenda_.~_._._____.. _.. ~__.

  • Introduction
  • Factual Summary
  • Lessons Learned
  • Corrective Actions
  • Conclusions NM~

__....~.~ct~aLSllJ)1mar____'1_

  • Calvert Cliffs event review
  • 06 operating and maintenance history prior to April 2001
  • April 9 06 surveillance problems and NOEO request
  • Events subsequent to April 16 grant of NOED

1996

  • May - July 1996 - OE Report screened at PINGP

- PINGP lube oils have Total Base Number(TBN) and sulfated ash properties similar to Calvert Cliffs

- No immediate action: fuel sulfur content high (0.18%), no scuffing noted during Preventive Maintenance (PM)

- Corrective actions: Discuss need to change oil with vendors, obtain recommendations for oil change by 1/1/97 to include in PM if required

  • Nov 1996 - PINGP engineer attends SACM conference

- Summarized Calvert Cliffs experience as an "incompatibility between an entirely synthetic oil with a high TBN (> 15), high CD classification, and a low sulfur fuel"

- No problems with extensive use of mineral or synthetic lube oil and low sulfur fuel in Sweden, Germany, Switzerland & France

- SACM conclusion was "not enough experience" to "express formal statements about the lubricant-fuel influences"

.~~--~---~

NMC) 3

1996 - 1999

  • Late 1996 - Mobil and SACM contacts
  • Nov 1998 - 06 5-yr inspection and rebuild (530 hours0.00613 days <br />0.147 hours <br />8.763227e-4 weeks <br />2.01665e-4 months <br />)

- Some carbon buildup, rings move freely, no indications of blow-by

- BG&E experienced engineer involved

  • Feb 1999 - PINGP attends SACM Owners Group meeting

- Calvert Cliffs solution included switch to mineral oil

- PINGP engineers report on high temperature in one 06 cylinder

- No linkage of 06 cylinder problem to oil incompatibility

  • Nov 1999 - 06 24-hr load test completed successfully NM~

4

2000 - 2001

  • Jan 2000 - Revised OE due date to Nov 2000

- Sulfur content dropping slowly, PINGP perceived that the industry and vendors did not agree with Calvert Cliffs root cause analysis

  • May 2000 - 05 5-yr inspection and rebuild (450 hrs)

- No abnormal indications

  • Jul 2000 - OE closed

- PINGP inspections of D5 and D6 found no ring problems, no scuffing, no blow-by, and "exceptional results" after 450 and 530 operating hours

- Calvert Cliffs reported hard deposits under rings, liner scuffing at 140-170 operating hours

Conclusions:

(1) Lube oil change not recommended; (2) Current performance monitoring and PMs adequate to identify condition

  • Aug 2000 - Jan 2001

- Monthly surveillance runs and inspections satisfactory

- No data suggesting oil incompatibility NMC) 5

~u m ma~Y-l~96

~_~______

__.-_2_~OO1_____

  • Complex technical issue, conflicting operating data
  • Disagreement over Calvert Cliffs conclusion
  • No evidence at PINGP after four years
  • Continuing to look for indications

-\\

NM~

6

~_ Februar-y - April?~Q01

  • Feb 2001 - Monthly run

- "Fuel oil" leak reported

  • Mar 2001 - Monthly run

- Elevated crankcase pressure noted in log

  • Apr 9, 2001 - Monthly run

- 0930 - entered TS LCO for 06 monthly run

- 1330 - terminated engine run -- elevated crankcase pressure

- 1500 - SACM recommends full borescope inspection

- 1526 - 05 Operability run

  • Apr 10, 2001

- 1600 - Borescope identified bore polishing and blow-by on 06 E2-B1

- 1719 - Initiated a work order to repair D6

.:It:

NM~

7

,..----______1:)6 E2-B 1 H i~_~~ I~j_~_~'lY--a __ pr()~b ~em

  • Sep 1997 D6 E2-B1 high exhaust temperature
  • Feb 1998 Calibrated 06 E2-B1 exhaust temperature instrument - no change
  • Feb 1999 Swapped 06 E2-B1/B5 fuel injection pumps
  • Apr 1999 Returned 06 E2-B1/B5 fuel injection pumps
  • SACM Unable to correct
  • Apr 2001 Blow-by in same cylinder NMC>

8

Draft NOED Pr~p_~_raJion_...____

  • Apr 11, 2001

- Management considers contingency need for NOED to complete engine re-assembly Condition Report initiated to assess cylinder problem

  • Apr 12, 2001

- Licensing prepares initial draft NOED following guidance in NRC Inspection Manual and previous PINGP NOED request

  • Apr 13, 2001 0730 - SACM Tech Rep arrives to support re-assembly 1300 - OC reviews draft NOED, oil incompatibility not raised as issue 1400 - Draft NOED request faxed to NRC 1430 - Conference call with NRC Staff to discuss NOED NMC:>

"/

9

First Conference Call With NRC

  • April 13, 2001

- Focus on PRA and compensatory measures

- Mr. Carlson substitutes for system engineering

  • Site responded to NRC Staff questions

- History of D6 problem requiring NOED

- Apparent cause - high crankcase pressure from blow-by in a single cylinder Cause of blow-by not known No indication affecting other cylinders/other engines

  • Collective engineering judgment: problem limited to E2-B1 Single problematic cylinder exhibiting limited blow-by

- No basis for tie to D5 or Calvert Cliffs

  • Result of call

- Additional PRA information requested

- Follow-up callan April 16, 2001, to confirm need for NOED, PRA changes, NMC) 10

~_

Weekenq_t:!_~~~J~WQrk_______~____

  • Apr 14, 2001

- 1308 - 06 reassembled

- 1835 - Start 06 break-in run

  • Apr 15, 2001

- 0448 - Started 06 24-hr load test

  • Apr 16, 2001

- 0449 - Completed 06 24-hr load test

- 0630 - OC meeting to approve NOED request

- 0730 - NRC conference call -- NOED verbal approval NM~

11

Second Conference Call

  • April 16, 2001
  • NOED needed - engine not re-assembled
  • Revised PRA discussion per April 13 call
  • NRC Staff verbally granted NOED
  • 06 Successfully Completed 34 hours3.935185e-4 days <br />0.00944 hours <br />5.621693e-5 weeks <br />1.2937e-5 months <br /> of Operation

- Break-in period

- Load test

- No unusual operating parameters, no blow-by

  • All indications were that problem limited to single cylinder NMC) 12

Context of the NOED

  • PINGP did not suspect credible common mode failure mechanism before or during the NOED
  • Site experience supported preliminary conclusion of an isolated cylinder problem of unknown cause

- Focus was on problematic E2-81

  • Available information did not point to oil incompatibility

- Single cylinder

- D5 apparently unaffected

- Did not find any "sticky rings"

- Questionable validity of Calvert Cliffs conclusion

- Different type of oil (mineral v. synthetic)

NMC) 13

Re~urn to O~erability "--"----------

Apr 16, 2001

- 0930 - NOED effective

- 1100 - Conference call with SACM (France)

Purpose to discuss engine condition Agreement on 12-hr run and borescope to confirm "break in" marks Many potential root causes discussed No root cause matched all PINGP conditions Oil incompatibility discussed -- SACM could not explain limitation of symptoms to a single cylinder

- 1300 - PINGP personnel and tech rep discuss status, pursue investigation

  • Apr 17, 2001

- 0047 - Started D6 12-hr load test

- C/C pressure normal E2-B1 temperature w/in 50 degrees of others

- 1410 - Completed 06 12-hr load test

- 1500 - Performed borescope inspection - no degradation 1900 - Vendor representative concurrence with D6 condition

- 2331 - Completed TS required fast start test -- 06 declared operable NM~

14

Post-NOED Period

  • Apr 18, 2001

- E-mail from engine vendor stating "suspect there could be incompatibility problem between fuel and lube oil"

- Root cause team forming to evaluate information

  • Apr 23, 2001

- Requested Root Cause Report of Calvert Cliffs incident from BG&E

  • Apr 30 - May 1, 2001

- Calvert Cliffs report received by PINGP engineer

  • May 2,2001

- Calvert Cliffs report issued to Root Cause team

  • May 9,2001

- D5 and 06 declared inoperable, Unit 2 shut down NMC>

15

Calvert Cliffs Root Cause Reoort

  • First reviewed April 30 - May 2
  • Identified technical parallels between events

- Problem initially found in one cylinder

- Established mineral - synthetic distinction not relevant to oil incompatibility issue

- Discussed independent analyses and unanimous conclusion of cause

  • Provided root cause team with technical bases for oil incompatibility as the potential cause NMC) 16

Statement of Dennis Carlson

  • No vendor recommended oil change
  • No information indicated oil incompatibility in April 2001
  • Limited role in 06 issue and NOEO
  • Provided complete and accurate responses NMC) 17

Statement of Scott H iedeman

  • Before reading the full Calvert Cliffs report had concluded oil incompatibility problem would not develop at PINGP because:

- Vendors did not recommend oil change and assured PINGP engines would not experience oil incompatibility

- PINGP used mineral-based rather than synthetic lube oil

- Absence of operating problems, especially during rebuilds

- Potential problems could be detected in preventive maintenance

- April 2001 incident was limited to a single cylinder NM~

18

StatemeoLof_S~9ttJ~iiedemClIl1 cont)

  • The full Calvert Cliffs report changed view about the potential for an oil incompatibility problem:

- Realized SACM agreed oil incompatibility was root cause for Calvert Cliffs (contrary to statements made by SACM's U.S. representative)

- Realized symptoms of oil incompatibility could develop in a single cylinder

- Realized significance of "Total Base Number" NMC) 19

SIT Document Timeline

  • May 14, 2001

- Document removed from SIT production stack

- Document later retrieved by concerned employee

  • May 16, 2001

- Concerned employee determines document appears relevant

  • May 17, 2001

- Document returned to NRC production process

- Document produced to SIT

- ECP investigation

- ECP manager informs SIT of investigation results and confirms SIT receipt of document

.. ~~

NM~

20

SIT Document Production

  • Company Actions

- Promptly investigated individual's action

- Reported incident to SIT/Senior Resident

- Ensured SIT had document

  • Determined there was no intent to withhold significant information by individual or PINGP NMC) 21

Statement of Scott Hiedeman -- SIT

~,,----

"-----~

  • Did not intend to mislead the NRC or withhold information
  • Removed the Lube Notes article because thought it was inaccurate and misleading
  • Removing the document was an error of judgment NMC) 22

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Lessons Learned

  • Complacency
  • Roles and responsibilities
  • Lack of formal processes
  • Management expectations, standards, accountabi I ities
  • Quality validation/verification (QV&V) weaknesses
  • Sense of ownership/urgency/follow-through NM~

25

OE Im~rQy~ments_~~_~_~~___

  • Developed very comprehensive processes for review of external OE
  • Assigned resources
  • Integrated OE into our daily work
  • Formed OE oversight process/team NM9

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26

EngineeriQA~Or~n_~zatiQn Improvements

  • Role/responsibility changes
  • Training improvements
  • Formal turnover process
  • Communication standards
  • Organization changes NM~

27

N9ED R~~~est Pro~_e_s_s___~___

  • Formalized Process
  • Management Involvement
  • Operations Committee Improvements
  • Ownership
  • Expectations for Site Organization
  • Complete and Accurate Information
  • Operation Under NOED
  • Plant Event Investigation and Recovery Process NMC:>

28

NRC Communications

  • Complete and Accurate
  • Verification and Validation Process
  • Regulatory Compliance Organization
  • Inspection Support Process
  • NRC Confidence in our Communication NMC) 29

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Overall Sum_mary______

... PINGP provided NRC with as complete and accurate information as possible
... Lack of aggressive OE investigation inhibited root cause analysis and technical conclusions
... Prompt action when new information raised questions with initial technical conclusions
... PINGP provided all relevant documents to NRC NM9 32

Broader Initiatives

  • Performance Improvements

- Management changes

- Staff realignment

- Formal processes

- Clear management expectations, standards, accountabilities

- Process assessment

  • Priority Issues
  • Long-term Goals NM~

'.f-*. _

33

Conclusion

~Actions were not willful violations

~Corrective actions are in place

~NRC enforcement action is not warranted

~Enforcement discretion is warranted NM~

34

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