ML18059A423

Rev 0 to Palisades Plant Pressurizer Safe End Crack Repair Action Plan.

ML18059A423
Person / Time
Site:	Palisades
Issue date:	10/07/1993
From:	CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:
Shared Package
ML18059A421	List: ML18059A420 ML18059A422 ML18059A423 ML18059A424 ML18059A425
References
PROC-931007, NUDOCS 9310120434
Download: ML18059A423 (14)

Text

ENCLOSURE 2 Consumers Power Company Palisades Plant Docket 50-255 PRESSURIZER SAFE END CRACK ACTION PLAN October 7, 1993

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9310120434 931007 PDR ADOCK05000255 5 . . PDR

PALISADES PLANT PRESSURIZER SAFE END CRACK REPAIR ACTION PLAN REVISION 0 10/07/93

• APPROVALS:

Action Plan Revision 0: xS~~h/z_:i Plant General Manager Date PURPOSE:

The purpose of the Pressurizer Safe End Crack Repair Action Plan is to provide a document which identifies responsibilities, ensures necessary actions are completed prior to the plant startup, and ensures assignments for long term actions are made.

The Action Plan may only be modified with the approval of the Plant General Manager or his designated alternate .

Page 1 of 5 Action Plan

1. Conduct an engineering evaluation of the failure.

The specific elements of this engineering analysis include the following:

a. Metallurgical analysis of the failed safe end to identify the cause of the crack.

Metallurgical Analysis Complete and Crack Cause Evaluated NECO Mechanical, Civil, and Structural Manager

b. Analysis of factors contributing to PWSCC in the pressurizer nozzle safe end. This includes evaluation of material properties and stresses that may have contributed to the failure. Piping stresses and weld residual stresses are being evaluated and will be reviewed by an independent third party .

Analysis of Material Properties and Stresses Complete and Third Party Review Complete NECO Mechanical, Civil, and Structural Manager

c. Evaluation of other nozzles safe ends in the primary coolant system, based on the engineering evaluation of the failure, to identify other locations which may be susceptible to the same failure cause. This evaluation includes both nozzles with Inconel 600 safe ends and other safe end materials. Contributing factors to PWSCC will also be evaluated for the safe ends that are identified as being susceptible to the same failure cause. This will include evaluation of material properties and stresses.

Nozzle Safe End Evaluation Complete

• NECO Mechanical, Civil, and Structural Manager

Page 2 of 5

• d. Evaluation of appropriate non-destructive examination techniques to identify similar flaws in other susceptible safe ends.

Evaluation of NDE Predictive Testing Services Supervisor

2. Identify corrective actions for the specific safe end that failed.

An engineering evaluation of the repair to the pressurizer safe end, based on the root cause analysis of the failure, has shown that. the lifetime of the repaired safe end well exceeds the length of the next operating cycle.

Corrective Actions of Safe End Failure Identified NECO Mechanical, Civil, and Structural Manager

3. Identify corrective actions for other safe ends that may be susceptible to the same failure.

Other safe ends that may be susceptible to the same failure will be inspected for flaws using appropriate non-destructive examination techniques.

NDE for Additional Safe Ends Identified, Documented, and Evaluated Satisfactorily Predictive Testing Services Supervisor

Page 3 of 5

• 4. Complete necessary corrective actions to ensure safe operation of Palisades during the next operating cycle prior to returning the plant to service.

a. Repair of the failed pressurizer safe end.

Repair Complete Maintenance Manager

b. Non-destructive examinations of other safe ends potentially susceptible to the same failure cause.

Repair Complete and Acceptance NDE Satisfactory Predictive Testing Services Supervisor

5. Identify corrective actions necessary to ensure long term safe operation of Palisades.

a. Engineering evaluation of additional repairs which may be necessary for long term operation of the pressurizer safe ends will be performed and additional repairs and corrective actions, if required, will be completed by the end of the next refueling shutdown.

Assign Action for the Above Corrective Actions for Next Refueling Outage NECO Mechanical, Civil, and Structural Manager

Page 4of5

• b. Further evaluation of non-destructive examination techniques in light of the pressurizer safe end crack will be conducted. Enhanced ultrasonic techniques will be employed in an augmented inspection program for safe ends beginning in the next refueling shutdown. To provide assurance that we are performing the most effective NDE possible the following actions will be completed:

Assign Action to Evaluate NDE Techniques and Employ Them in Augmented Inspection Program in Next Refueling Outage Predictive Testing Services Supervisor

6. Technical Report Prepared, Finalized.

NECO Mechanical, Civil and Structural Manager

7. Send Report to NRC.

Safety and Licensing Manager

8. Hold Meeting with NRC to Review Technical Report.

Safety and Licensing Manager

9. Provide NRC with crack tip sample for independent sample analysis.

Predictive Testing Service Supervisor

Page 5 of 5

• 10. PRC Review of Technical Report and Recommended Approvals.

PRC Chairman

11. Authorization For Leaving Cold Shutdown.

Plant General Manager I

. I

• ENCLOSURE 3 Consumers Power Company Palisades Plant Docket 50-255 PRESSURIZER SAFE END CRACK NDE

SUMMARY

October 7, 1993

~

WALL THICKNESS SURFACE PROFILE RT OD ID IGSCC CODE WELD # DIA PIEL SEIF N ID OD CIL PT PT UT UT COMMENTS PORV #1 6" 1.5" 1.8" Smooth Moderate Done Done Done No* No* *Configuration SE TO Bore Transition precludes UT NOZZLE 4-6" .438" 1.5" Taper Heavy Done Done Done No* No* . New Weld WELD #lA Bore Transition *Configuration SE TO PIPE I

precludes UT SPRAY #20 4" .625" .625" As No Done Done No No* No* *Configura-ELBOW TO Welded Transition ti on SE #21 precludes UT

1. 21 NOZZLE 4-8" .625" 2. 5" Smooth Heavy Done Done No No* No* *Configura-tion TO SE Bore Transition precludes UT RELIEF VALVES RV-1039 #1 6" 1.3" 1. 6" Smooth Moderate Done Done Done Done No NOZZLE TO Bore Transition IN FLANGE RV-1040 #1 6" 1. 3" 1. 6" Smooth Moderate Done Done Done Done No NOZZLE TO Bore Transition IN FLANGE RV-1041 #1 1. 3" 1. 6" Smooth NOZZLE TO IN FLANGE I 6"

Bore IModerate Transition Done Done Done Done ifo Do = Scheduled But Not Complete P/EL = Pipe or Elbow Done = Completed *

• SE = Safe End No = Decision Made Not To Examine N Nozzle F = Flange Effective as of October 7, 1993

WELD #

• DIA P/EL WALL THICKNESS SEIF N ID SURFACE PROFILE OD RT C/L OD PT ID PT IGSCC UT CODE UT

-=*

COMMENTS PORV PIPING WELDS WELD #2 4" .438 As- No Done Done No No No New Weld PIPE TO Welded Transition PIPE WELD #3 4" .438 As- No Done Done No No No New Weld PIPE TO Welded Transition ELBOW WELD #4 4" .438 As- No Done Done No No No ELBOW TO Welded Transition PIPE WELD #5 4" .438 As- No Done Done No No No PIPE TO Welded Transition ELBOW WELD #6 4" .438 As- No Done Done No No No ELBOW TO Welded Transition PIPE Do = Scheduled But Not Complete P/EL = Pipe or Elbow Done = Completed SE = Safe End No = Decision Made Not To Examine N Nozzle F Flange Effective as of October 7, 1993

PRESSlJRl2ER ~ELIEF VALVE

~ OZZLE ASSEt16l Y IMCDMNEL 1

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WELD *2 r J.

WELD #6 r1Jf1Ti'1

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(0 WELD # 1-----.....__ ---

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_z PORV NOZZLE ASSEMBLE

• SPRAY NOZZLE ASSEMBLE

October 8, 1993 THE ATTACHED TWO DOCUMENTS (ONE OF WHICH IS PROPRIETARY) AR.E REFERENCES LISTED IN CONSUMERS 10/7 /93 LETTER FROM SLADE TO NRC DOCUMENT CONTROL DESK. THESE DOCUMENTS WERE SENT TO NRC AT NRC'S REQUEST AND

• SHOULD BE DOCKETED ALONG WITH THE INCOMING LETTER.

THANK YOU.

,CAROLE JAMERSON, PD3-1

-,* *' :' 504-1337' *, .. ,

• ,, '.*. i

' ~. . .'

OUTLINE

• PRESENT SITUATION

• CORRELATION ANALYSIS

• PRESSURIZER NOZZLES

• TUBE MATERIAL

• THEORETICAL MODEL

• WEIBULL FAILURE MODEL

• EST/MA TION OF PARAMETERS

• DEVELOPMENT OF EXTREMAL MODEL

• ESTIMATION OF BOUNDS FOR FIRST FAILURES

• APPL/CATION TO CROM LIFE PREDICT/ON ANALYSIS

• CASE 1 : 50 KS/ MATERIAL

• CASE 2: 36 KS/ MATERIAL

• CONCLUSIONS

• I ALLOY600

PRESENT

• SITUATION

• RECENT HISTORY

• STATUS OF PRESSURIZER NOZZLES

• FIELD FAILURES EVEN IN LEAST SUSCEPTIBLE HEATS

• STATISTICAL QUANDRY

• ONLY INITIAL FAILURE INFORMATION AVAILABLE

• DIFFICULTY IN DEVELOPING OVERALL ASSESSMENT

• I ALLOY600