IR 05000482/1993018

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Insp Rept 50-482/93-18 on 930607-11 & 21-25.No Insp Findings Opened or Closed.Major Areas Inspected:Erosion/Corrosion Monitoring Program & Associated Activities,Per GL 89-08
ML20056C938
Person / Time
Site: Wolf Creek Wolf Creek Nuclear Operating Corporation icon.png
Issue date: 07/13/1993
From: Powers D
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
To:
Shared Package
ML20056C937 List:
References
50-482-93-18, GL-89-08, GL-89-8, NUDOCS 9307300118
Download: ML20056C938 (12)


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APPENDIX U.S. NUCLEAR REGULATORY COMMISSION

REGION IV

Inspection Report: 50-482/93-18 Operating License: NPF-42

Licensee: Wolf Creek Nuclear Operating Corporation P.O. Box 411  ;

Burlington, Kansas 66839 ,

facility Name: Wolf Creek Generating Station (WCGS)

Inspection At: Wichita and Burlington, Kansas  ;

Inspection Conducted: June 7-11 and 21-25, 1993 -

Inspector: L. D. Gilbert, Reactor Inspector, Maintenance Section i Division of Reactor Safety ,

Approved: # < SW 7//3)73 ;

Dr. Dale A. Powers, Chief, Maintenance Section Date Division of Reactor Safety Inspection Summary Areas Inspected: Routine, announced inspection of erosion / corrosion monitoring prcgram and associated activitie ,

Results:

  • The licensee had developed an upgraded program for the detection of component degradation in high-energy piping resulting from  ;

erosion / corrosion that adequately addressed the concerns identified in l Generic Letter 89-08 (Section 2.1.1).

  • The licensee had developed an aggressive schedule for upgrading the

program to include complete CPECMATE computer modeling of all trains of each susceptible system by end of 1993 (Section 2.1.1.1).

- * The administrative procedures clearly defined responsibilities for the j erosion / corrosion program (Section 2.1.1.1).

  • The licensee committed to updating the response to Generic Letter 89-08 within 45 days to address its upgraded long-term erosion / corrosion monitoring program (Section 2.1.1.1).  ;

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  • The inspector concluded that the quality of the licensee's audit was good. The licensee's identification and planned corrections to program deficiencies were notable (Section 2.1.1.1).
  • Independent engineering review of data input to an analysis for a non-safety system was weak and did not ensure the identification of all inconsistencies (Section 2.1.1.2).
  • The licensee committed to completing clarifications to the quality control procedure by September 15, 1993 (Section 2.1.1.3).
  • Prior to 1993, the licensee's program implementation was marginal; however, subsequently, personnel were effectively implementing the ,

monitoring program (Section 2.1.1.3).

  • The responsible engineer was knowledgeable of industry experience and the program requirements for monitoring piping degradation. The planned i training for program personnel was appropriate (Section 2.2). .

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Summary of Inspection Findinas:

  • No inspection findings were opened or close Attachments:
  • Attachment 1 - Persons Contacted and Exit Meeting
  • Attachment 2 - Other Documents Reviewed

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DETAILS

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1 PLANT STATUS During this inspection period, the plant was operating at powe INSPECTION OF EROSION / CORROSION MONITORING PROGRAMS (49001)

The objectives of this inspection were to ascertain whether (a) licensee activities relative to the long-term erosion / corrosion monitoring program were in acen Gance with Generic Letter 89-08, " Erosion / Corrosion-Induced Pipe Wall Thinning"; (b) management control problems or weaknesses exist in the implementation of the program; and (c) the program had been independently reviewe .1 Discussion 2. Program Development The inspector reviewed the licensee's response to Generic Letter 89-08. The response was documented in a letter to NRC dated July 21, 1989. The licensee notified the NRC in this letter that a formalized long-term erosion / corrosion l program, equivalent to the Nuclear Utility Management and Resources '

Council (NUMARC) guidelines referenced in Generic letter 89-08, had been implemented. The program was to provide assurance of the structural integrity of carbon-steel piping systems designed to carry high-energy water in single-phase flow and steam in two-phase flow. In the response, the licensee i confirmed that: 1

= A formalized long-term erosion / corrosion program had been developed and documented in Procedure ADM 08-212, " Erosion / Corrosion Monitoring Program," which was issued on July 17, 1987;

  • The program was implemented in accordance with NUMARC and Electric Power Research Institute (EPRI) guidelines to monitor the effects of erosion / corrosion in both single-phase flow and steam in two-phase flow; and

that erosion / corrosion would not affect the structural integrity of carbon steel piping system The inspector was informed that prior to 1988, the basis for selection of piping components for evaluation was engineering judgement and industry experience. In 1988, the EPRI CHEC computer program was used for analyzing single-phase flow systems and selecting additional components for monitorin Then in 1990, the licensee partially upgraded the erosion / corrosion program to l

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include the EPRI CHECMATE computer program for predicting component wall thinning in two-phase flow, carbon-steel, high-energy piping systems. The inspector was informed that the licensee was a member of the CHECMATE Users'

Group and engineering personnel attended their meetings. For those engineers that had not received the EPRI training, instructions on the CHECMATE computer program were given by an engineering contractor. The licensee had recently scheduled engineering and quality control and assurance personnel into upcoming EPRI training courses (which will be on CHECWORKS). The inspector ,

concluded that the planned training was appropriat !

2.1. Licensee Program Audit

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At the request of its flow-accelerated corrosion task force, the licensee ,

performed an in-depth audit of the component wall thinning program. The audit ,

was performed with the assistance of a contract specialist with industry ,

experience in the use of the EPRI computer programs. The audit was performed in January and February of this year and the report was issued on February 24, .

1993. The audit focused on three major areas, computer program analysis, !

selection of inspection locations, and content and implementation regarding ,

quality control activities associated with the flow-accelerated corrosion :

progra The area of computer program analysis received an evaluation rating of ,

marginal based on the following:

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  • The CHEC and CHECMATE computer program modeling and analysis had only been used to a limited degree (i.e., components analyzed) and that which had been performed was not independently verifie * The computer programs were not updated to include ey. amination result feedback and replaced plant component .

The area of selection of inspection locations received an evaluation rating of marginal for not utilizing the CHECHATE ccaputer analysis for selecting components to monito The area of content and implementation regarding quality control activities associated with the flow-accelerated corrosion program received an evaluation rating of satisfactory, j i

The audit report contained the following four recommendations for improvemen I i

  • Engineering should develop an input data package that contained the !

required information and verificatio !

  • Engineering should establish a formal method for notification to the responsible engineer of changing plant conditions that affect the flow-accelerated corrosion monitoring program and computer modeling and analysi l

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  • Engineering personnel involved in the CHECMATE analysis should receive !

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formal trainin * Quality control should establish a consistent grid pattern on components for improved correlation of thickness measurements and evaluation of wea ;

In response to the audit findings and other program enhancements identified by the flow-accelerated corrosion task force, the licensee issued Administrative Procedure KGP-1264, " Component Wall Thinning Monitoring Programs," Revision 0, and revised Engineering Guidelines WCNOC-84, " Flow Accelerated Corrosion Monitoring Program," Revision 1. Procedure KGP-1264 described the component ;

wall thinning program, assigned responsibilities for development and implementation of the program, and established a component wall-thinning steering committee and task force. The revised guidelines in WCN0C-84 provided clear instructions for complete CHECMATE modeling and analysis for all normally operating lines in systems that are susceptible to flow-accelerated corrosion. The complete CHECMATE modeling of the 103 subsystems identified in WCNOC-84, which included all trains of each susceptible system, had been aggressively scheduled for completion by the end of 1993. This modeling will be used in selecting components for the next refueling outage (Fall 1994).

Licensing informed the inspector that the response to Generic Letter 89-08 will be updated within 45 days of the inspection to address the upgraded long-term erosion / corrosion monitoring program. This supplemental response is not required but will be complementary. The inspector concluded that the quality of the audit was good. The licensee's identification and planned corrections (

to program deficiencies were notabl .1.1.2 Current Program Implementation The inspector reviewed the engineering evaluation in WCNOC-84 that identified i the following piping systems as being potentially susceptible to erosion / corrosion: main steam, main turbine, condensate, feedwater, feedwater heater extraction drains and vents, steam generator blowdown, gland seal steam, auxiliary steam generator, auxiliary steam, and auxiliary turbine. The ,

inspector verified that the carbon-steel piping systems, which would be i susceptible to erosion / corrosion, that were specified in Section 3 of the Wolf !

Creek Final Safety Analysis Report as high-energy lines, were included in the erosion / corrosion program.

The inspector was informed that the new CHECMATE modeling had been completed for the high pressure extraction steam lines and had been partially completed i for the moisture separator reheater drain and vent lines for the main turbine system. Since the remainder of the systems were scheduled for modeling later, the inspector reviewed the completed CHECMATE input forms for a segment of piping from the extraction steam lines and the muisture separator reheater drain lines. The segment from the extraction steam lines included the piping i

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-6-from the high pressure turbine to the Feedwater Heater 7A. The segment from the moisture separator reheater drain lines included the piping from the Second Stage Moisture Separator Reheater A to Drain Tank For each of the lines, the inspector compared the engineering input data and plant conditions to the database in the computer program. The dattbase parameters reviewed included the pipe size, schedule, length, material, and geometry factors, and operating conditions regarding flow rate, water

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chemistry, temperature and pressure, and hours of operation. ihe CHECMATE input forms and data base were derived from, and for the most part in i

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agreement with, the piping isometric drawings, the heat balance diagram, the pipe class summary, pipe class sheets, and the CHECMATE User's Manual, as well -

as information provided by operations and chemistry. However, a few inconsistencies were noted by the inspector during the review of the input forms for the extraction steam line (non-safety) that was documented in <

Attachment E of Calculation XX-M-014, Revision 0. For example, the pipe schedule for Line AC-444-GAD should have been Standard Weight not Schedule 40; the material code for Component AC-078-GBD-18-4E should have been 18 not 21; and the pipe diameter for Component AC-078-GBD-18-8T8-4E should have been 16 not 18 inche These inconsistencies had not been identified in the independent engineering review. The inspector concluded that the review process was weak in ensuring the correctness of input data. The inspector concluded that two of these inconsistencies would have skewed the predictions of erosion / corrosion degradation nonconservatively. The inspector war informed that these errors would be corrected in the next revision of the calculation, which was ,

scheduled for December. The calculation had been scheduled for revision and another review in order to incorporate plant modifications performed during the last outage and input other data needed to upgrade the program to CHECWORX. The inspector considered this to be appropriate corrective actio The inspector also reviewed the engineering documentation for the selection of .

inspection locations in large bore piping that were monitored during the last :

refueling outage (Refuel VI). The piping locations selected for monitoring i were identified by engineering and included 33 previously inspected piping segments and 77 new inspections of piping segments. The licensee identified  ;

each piping segment, which usually included more than one component, by an i inspection activity number. The inspector concluded that the documentatinn  ;

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was excellent, in that, it included a detailed evaluation of each piping subsystem for the following:

  • New inspection points based on a programmatic review of the l susceptibility analysis performed in accordance with instructions in WCNOC-84;
  • Reinspection locations based on the results of analysis of ultrasonic ihickness measurements from previous inspections; and l

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  • h w inspection points based on industry or operating experienc l 2.1.1.3 Sample Review cf Inspection Activities j In order to review the implementation of the erosion / corrosion monitoring program, the inspector selected a number of inspection activities from four piping systems: main feedwater, steam generator blowdown, feedwater heater ;

extraction drains and vents, and main turbine. The piping components selected from the main feedwater system were identified as Activities 2272 and 113 The piping components selected from the steam generator blowdown system were .

identified as Activities 0181, 2264, and 3008. The piping components selected '

from the feedwater heater extraction drains and vents system were identified as Activities 1231, 2008, and 3002. The piping components selected from the main turbine system were identified as Activities 0291, 0299, 0303, 0329, 2100, and 219 For each of the activities, the inspector reviewed the thickness measurement reports and engineering evaluations. The approved procedure for performing thickness measurements was QCI 12.1-503, " Ultrasonic Examination for Component Wall Thinning," Revision 7. The minimum measured thickness for each component was reviewed against the criteria established by engineering. For the samples selected, the inspector verified that the results had been evaluated and satisfactorily dispositioned by engineering. For those components with unacceptable thicknesses, the inspector verified that the components had been replaced or scheduled for an examination within the specified number of refueling cycles in accordance with engineering guidance in WCNOC-84. For component replacement in the extraction steam system, the inspector verified

, that an upgr6de material had been used and other components had been examined to satisfy program expansion requirements of guidance in WCNOC-8 In addition, the inspector walked down a portion of the feedwater and extraction steam piping systems for a comparison of the installed piping configuration to the latest piping isometric drawings. For the feedwater system, the piping installed in the plant from Feedwater Pump A to High Pressure Heaters SA, 6A, 7A, 58, 68, and 7B was inspected and found to be consistent with the Isometric Drawings M-13AE01-RO, M-13AE02-R4, and M13AE03-R For the extraction steam system, the piping installed in the plant from the high pressure turbine to High Pressure Heaters 6A and 6B was inspected and found to be consistent with the Isometric Drawings M-13AC07-R1 and WI-M-13AC07-00- The inspector also reviewed the certification of the ultrasonic equipment, the calibration blocks, and the nondestructive examination personnel who performed the thickness measurements. The equipment and personnel met the calibration interval and certificat an requirements, respectively, of Procedure QCI 12.1-50 One anomaly was identified by the inspector that the licensee corrected regarding the lack of-quality assurance review of the contractor-provided certification documents for a qualified contract quality control inspector. A performance improvement request, PIR-93-0571, was )

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-8-initiated to document the oversight. The inspector concluded that the actions taken were appropriate. During review of calibration requirements in Procedure QCI 12.1-503, the inspector discussed areas of the procedure and related documentation which could be clarified to provide clear instructions '

for performance and documentation of the examinations. The inspector was informed by the quality control supervisor that the procedure would be revised to clarify the following:

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  • Calibration block material and identification requirements,
  • Documentation requirements for denoting time of calibration and temperature of calibration block and component,
  • Tolerance limits for ultrasonic system calibration checks and documentation requirements, and
  • Transducer size and frequency limitation The licensee documented proposed actions to address the above procedure enhancements in Interoffice Correspondence QC 93-0105 dated June 24, 1993, and established September 15, 1993, as the completion date. The inspector ,

concluded that the licensee had effectiveiy implemented the erosion / corrosion monitoring progra .2 Conclusions

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The administrative procedures clearly defined responsibilities for developing, maintaining, and implementing the erosion / corrosion program. The licensee had developed a program, for the detection of component degradation in high-energy piping resulting from erosion / corrosion, that adequately addressed the ,

concerns identified in Generic Letter 89-08. The licensee had developed an aggressive schedule for upgrading the program to include complete CHECMATE computer modeling of all trains of each susceptible system by end of 199 The response to Generic Letter 89-08 will be updated within 45 days of the inspection to address the upgraded long-term erosion / corrosion monitoring progra The responsible engineer was knowledgeable of industry experience and the ;

program requirements for monitoring piping degradation. The planned training '

for personnel involved in the erosion / corrosion monitoring program was appropriate. The inspector concluded that the cuality of the licensee's audit was good. The licensee's identification and planned corrections to program deficiencies were notable. The inspector determined the independent engineering review of data input to an analysis for a non-safety system was weak and did not ensure the identification of all inconsistencie For those sampled components with a measured thickness less than the specified acceptable thickness, the licensee properly evaluated and satisfactorily dispositioned those results. Prior to 1993, the licensee's program

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-g-implementation was marginal; however, subsequently, the licensee was '

effectively implementing the erosion / corrosion monitorir.g program and upgraded piping system components, where appropriate, to reduce the effects of flow-accelerated corrosion on piping integrity. Quality control documented proposed actions to address procedural clarifications and established September 15, 1993, as the completion dat F

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ATTACHMENT 1 )

1 PERSONS CONTACTED i i

1.1 Licensee Personnel  !

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  • D. Adams, Modifications Engineer l
  • R. Benedict, Manager, Quality Control
  • J. Bloomer, Systeins Engineer
  • A. Clason, Supervisor, Maintenance Engineering
  • T. Deddens, Jr., Outage Manager
  • H. Dingler, Manager, Nuclear Plant Engineering Support
  • C. Fowler, Manager, Maintenance and Modifications
  • G. Grell, Inspector, Quality Control
  • C. Gukeison, Flow-Accelerated Corrosion Engineer P. Gupta, Supervisor, Engineering
  • S. Hedges, Supervisor, Engineering
  • L. Holloway, Supervisor, Engineering
  • C. Holman, Auditor
  • W. Lindsay, Manager, Quality Assurance
  • V. MacTaggart, Supervisor, Engineering
  • K. Moles, Manager, Regulatory Services
  • W. Norton, Manager, Technical Services K. Parthasarathy, Manager, Facilities Engineering and Analysis A. Prakash, Supervisor, Engineering
  • T. Riley, Supervisor, Regulatory Compliance
  • B. Smith, Manager, Modifications
  • C. Swartzendruber, Manager, Technical Services l A. Viswanathan, Flow-Accelerated Corrosion Senior Engineer .
  • B. Withers, President and Chief Executive Officer l
  • J. Yunk, Compliance Specialist 1.2 NRC Personnel

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  • J. Whittemore, Acting, Senior Resident Inspector l

In addition to the personnel listed above, the inspector contacted other l personnel during this inspection perio j i

  • Denotes personnel that attended the exit meetin #

2 EXIT MEETING An exit meeting was conducted on June 25, 1993. During this meeting, the inspector reviewed the scope and findings of the report. During the meeting, the licensee committed that the response to Generic Letter 89-08 will be

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updated within 45 days to address the upgraded long-term erosion / corrosio , ,

monitoring program. The licensee also committed to a September 15, 1993, l completion date for completing the proposed actions to address the procedural 1 enhancements discussed in paragraph 2.1.1.3. The licensee did not identify as I

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proprietary any information provided to, or reviewed by, the inspecto i .

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. l ATTACHMENT 2 .

OTHER DOCUMENTS REVIEWED

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Document WCNOC-106, " Engineering Evaluation of Wolf Creek Generating Station Pipe-Wall- Thickness UT Inspections for Refuel 6," Revision 0 Document WCNOC-96, " Engineering Evaluation of Wolf Creek Generating Station

"' Pipe-Wall Thickness UT Inspections for Refuel 4 and 5," Revision 0 Document WCNOC-98, " Selection of Inspection Locations in Large Bore Piping for Refuel VI," Revision 0 Document MS-01, " Pipe Class Summary," Revision 32 l Document MS-02, " Pipe Class Sheets," Revision 40 l

Design Document Change Notice MS-02-40-7

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