IR 05000324/1992041

Insp Repts 50-324/92-41 & 50-325/92-41 on 921109-13, 1130-1204 & 1216-18.No Violations or Deviations Noted.Major Areas Inspected:Observation of Electrical Maint & Review of Previously Identified Insp Findings

ML20127D773
Person / Time
Site:	Brunswick
Issue date:	12/31/1992
From:	George Macdonald, Moore R, Shymlock M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
Shared Package
ML20127D762	List: IR 05000324/1992041 ML20127D758
References
50-324-92-41, 50-325-92-41, NUDOCS 9301190035
Download: ML20127D773 (13)

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d#D %g UNITED ST Af f s p,, NUCLEAR HLGULATORY COMMISSloN

[(c n HLOION ll 101 MAHl0TT A $1Hf E 7. NW,

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Report Nos.: 50-325/92-41 and 50-324/92-41 Licensen: Carolina Power and Light Company P.-O. Box 1551 Raleigh, NC 27602 '

Docket Nos.: 50-325 and 50-324 License Nos.: DPR-71 and DPR-62 Facility Name Brunswick 1 and 2 Inspection Conducted: November 9-13, November 30 - December 4, r and December 16-18, 1992 Inspector OMC E. Moore

_ /2.!3a/9 E Ddte Signed-

/ M ) o P 2. L /c / f2 G. MacDonald- # '

Date Signe~d Accompanying Personnel: T. Liu Approved by: 466f -

0 3;7 N Yb ,

M. Shymlock, (Chief Date Signed 'i Plant System Section ,

Engineering Branch ,

Division of Reactor Safety SUMMARY Scope:

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This special, unannounced inspection was conducted in the areas of observation of electrical maintenance.and review of previously identified inspection-finding Results:

In the areas inspected,-: violations - or deviations were not identifie The licensee demonstrated appropriate control of i work related to emergency diesel generator maintenance.and good '

technical support involvement in these-activities. --Quality ,

Control involvement was adequate and supervisory oversight-was-goo ..

PDR -- . ADOCK 05000324-G PDR: _

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REPORT DETAILS Persons Contacted Licensee Employees

• K. Ahern, Manager, Unit 2 Operations S. Bostic, Maintenance Engineering Supervisor L. Bryant, Technical Support, Fire Protection Engineer J. Franke, Technical Support Supervisor B. Guarino, Technical Support, Electrical Engineer

• R. Helme, Manager, Technical Support

• Lucas, Vice President, Nuclear Engineering Department

• M. Jones, Manager, Training

• Leininger, Manager, NED

• Moore, Manager, Unit 1

• Morgan, Plant Manager Phillips, NED Electrical Engineer

• Richards, NED

• Thearling, Regulatory Compliance

• Water, Manager, Licensing NRC Personnel '

• R. Prevatte, Senior Resident Inspector

• Byron, Resident Inspector

• A. Gibson, Division Director, RII, Division of Reactor '

Safety i

• R. Lo, NRR, Brunswick Project Manager

• H Christensen, Projects Section Supervisor

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• Attended Exit Interview Electrical Maintenance (Components & Systems) ObservationLof Work, Work Activities, and Review of Quality Records (IP 62705)

This inspection included the observation and review of maintenance activities on Emergency Diesel Generator number 1 (EDG-1). The inspectors also reviewed the present status of all onsite EDGs, maintenance accomplished, and inspections planned during the current extended plant outage, Background *

During thisiinspection, the plant was in an extended plant-outage to address EDG building ceismic issues.- -

This-provided the licensee the opportunity for ,

performing _ complex _ maintenance and inspection- l activities on the site EDGs.: .Primarily this~ activity included an-18-month or similar 54 month periodic inspectio This inspection generally involved-crank-

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shaft defl6ction measurement, examination of engine bearings, examination of the function and integrity of support systems, visual inspection of internal

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components, and inspection of the governor and associated drive train. Prior to the outage, all EDGs met Technical Specifications' operability requirements.

The following provides a general status of the site EDGs and the licensee's planned or accomplished activity during this outag EDG-1:

A routine 54 month inspection was started in September, 1992. Due to problems encLuntered ,

during this inspection, more extensive work was ,

being accomplished which extended beyond the-original scope of the routine inspection  ;

procedure. This work was ongoing during this inspection and is discussed in detail in this  ;

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report and also in NRC Report Nos. 50-325, 324/92-20 and 92-3 The EDG was disassembled and not operable during this inspectio ;

EDG-2:

A routine 54 month inspection was completed in August, 199 No major problems were-identifie Two cylinder heads were replaced to correct a low ,

pressure condition for these cylinders which was  !

inconsistent with other cylinders of this engin After completion of the maintenance, the EDG was left in an operable condition. The licensee will return to this EDG during this outage to accomplish inspections related to problems found -

on other site.EDG .

EDG-3:

A routine 54 month inspection-was completed last .;

yea No major problems were identified. The turbocharger-was. rebuilt, during-this outage, to-

- -correct an-inlet manifold-low pressure-condition.

. After completion of maintenance, the EDG was left in an operable-condition.- An 18 month inspection and backlog maintenance work was scheduled _for .

this outag :

EDG-4:-

During surveillance testing in-November, 1992,.

the licensee identified several problems related

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to the EDG control circuits. These problems are discussed in paragraph (f) of this report. The problems were-corrected and the EDG was.left in an operable conditio Following completion of EDG 1 maintenance work the licensee planned an 18 month inspection on this EDG and performance of otLJr backlog maintenance activit b. Specific EDG-1 Issues The EDG was run for 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> loaded prior to removal from service for the routine 54 month' inspectio This run, which was a prerequisite for hot web deflection readings, demonstrated the EDG functional capability I with the existing problems later identified. Engine i inspections performed in accordance with the-  !

maintenance surveillance test procedures identified .

several deficiencie Further investigation of these  !'

deficiencies led to identification of other problem It was apparent that some of the identified problems  ;

had existed for many years. The licensee was in th l process of determining root causes for the problem i

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These causes may be related to poor maintenance, equipment installation, start-up testing, or historic operational event For example, the initial inspection identified damage  !

to the idler gear and right' camshaft gearing. The licensee indicated this may be related to maintenance- i activities of March, 1991. The initial inspection also a identified that crank shaft journal-bearing clearances 1 for some-bearings were excessive.- Further ,

investigation-identified that the number 9 journal

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bearing shell had structurally failed at some unknown dat Failure analysis indicated the bearing-failure may have occurred during maintenance on the engine driven jacket water. pump accomplished in 199 The initial inspection included bearing lift check _;

inspections and identified that crank shaft deflections -

exceeded vendor criteri The licensee' corrected-these deficiencies. -All ten  :

crank shaft--. bearings were replaced and the-shaft l alignment was adjusted with a shim under the generator 1 bearin Post maintenance engine-runs were performed and the engine was inspected again. .These inspections identified damage which had. occurred during the engine  ;

run-in The thrust bearing' surfaces on number ;

bearing were severely damaged.- The thrust bearing

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surface of the number 9 bearing restricts-the axial-  :

movement of the shaft. . The bearing damage identified  ?

after the run-in was different than the previously ,

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-identified number 9 bearing failur The previous damage was_to the portion of the bearing which supports the shaft weigh This weight bearing portion was undamaged by the post maintenance run-in. Also the flex drive gear was damaged during the run-i Further investigation of the run-in generated problems yielded more fundamental engine problem The engine block had moved along the axis, about 0.23 inches towards the generator. The date of this event had not yet been determined although it nay have occurred a early as 1982 during prestart-up testin Probable-causes could have been an attempt to parallel the generator out of phase with another. power source or original installation error. Additionally,-crank shaft deflection measurements indicated the shaft was distorted, (bent, bowed, or kinked) by 0.002 to 0.005 inches near the generator end at the number 9 bearin A wobb3e was also identified at the stub shaft on the opposite end of the crank shaft. The flexible drive assembly was found to be out of balance far beyond the manufacturer's specifications. The auxiliary systems'

motor driven pumps were found to be misaligned between motors and pumps; the jacket water pump coupling had failed during post maintenance testin The engine block was returned to its design positio Following two peening operations to correct the distortion, the shaft deflection at the number 9 bearing was-improve The stub shaft was machined to-correct an out of round-condition which contributed to the wobble. The flexible drive' assembly was replaced with a balanced component. The auxiliary pumps were realigned; the failed coupling replaced, There were potential connections between the various problems-identified and maintenance.and operational histories; however, no conclusions had yet been developed. The licensee was in the process of analyzing _ equipment histories and equipment conditions to determine root causes for the problems.. A comprehensive root cause' document wasLin progress but had-not been reviewed and approved by management prior to the close of the inspectio Control of. Work The_ inspectors reviewed the licensee's work controls related to EDG-1 maintenance activitie In 1991, the licensee implemented a. change to the control of work-activities for'EDG maintenanc Previously, EDG maintenance had been considered and controlled as'a

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simple maintenance activity with procedural controls and job oversight by the maintenance foremen. The licensee now identifies EDG ma.4ntenance as a complex evolution requiring a greater level of managemen On the current EDG maintenance activity, the licensee was using a project management concep Specific individuals were assigned to the project including a full time project manager and full time assistant project managers. The project manager was the Technical Support Supervisor, the maintenance engineering supervisor was also assigned to the projec Two shift coverage was established with at least an assistant project manager responsible for providing direction and oversight of work control activitie This structure allowed the project to be better managed and allowed the maintenance supervisor to spend more time at the job site supervising the work performed by the maintenance personnel. The project manager attended the site meetings to keep plant management informed of project statu The project management structure allowed additional personnel to track job clearances, parts availability, project documentation, and ensure that the project was receiving timely support from other required site organization Shift turnover meetings were scheduled twice each da The inspectors attended shift turnover meetings, reviewed minutes from previous meetings, and verified that activities to be accomplished during the shift were adequately preplanned. Key project personnel were in attendance including vendor support personne Specific job responsibilities were assigned and project support needs identified. The inspectors concluded that the project approach provided adequate control of EDG maintenance work activitie The licensee's investigation activities extended beyond the scope of the maintenance surveillance test procedures for the 54 and 18 month inspections. The inspectors reviewed special procedures which were developed to provide work guidanc Procedures, OSP-92-081, Norberg Diesel Crank Shaft Straightening, revision 0, and OSP-92-068, Biach Stud Tensioner Use for Cylinder Heads and Main Bearing Studs, revision 0, were reviewed. Guidance for individual tasks not addressed by procedure was provided by specific work instructions on the WR/JO documen The inspectors concluded that adequate procedural guidance was being provided for work activitie __ _ _

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Prior to break-in runs, pre-test briefings were conducted. The QC staff was present frequently during i maintenance and during all post break-in run inspection ' Technical Support Involvement The technical support provided for the EDG activities-was reviewed by the inspectors. As discussed in the previous section, a Technical Support supervisor was  ;

acting as project manager for this activity. The >

maintenance engineering supervisor was acting as a project supervisor. Engineering staff was dedicated.to provide technical support coverage for each working 1 shif In discussions of the EDG and ongoing maintenance and inspection activity, the technical staff demonstrated an in depth knowledge of the-operation, design, and current status of equipmen ,

Further technical support for this project was provided i by corporate and industry expert Several independent ,

specialista previously employed by Norberg for diesel i equipment installation, construction, and testing were ,

brought to the site. Marine diesel consultants and the present Norbarg licensed equipment manufacturer were-also used. Additionally, the licensee had contracted '

failure analysis specialists to assist in root-cause evaluation The inspectors concluded the technical support provided for this project was good, Ongoing-Licensee Activity At the close of this inspection, the licensee was continuing the initial break-in runs. These consisted of. increased run times and increased generator load

- with each ru Between' runs the EDG received visual component inspections and examinations for hot

- bearings. The inspections observed by the inspector-were thorough'and demonstrated the capability to -

identify further equipment problem In conjunction with root cause determination and

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. correction ofHEDG-1. problems, the-licensee will accomplish inspections on the other site EDGs to

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determine if these problems, and those associated.with EDG-4, are or are not unique to EDG-1. The inspector verified thatiWR/JOs were initiated to. accomplish these-additional-inspections. The following items address generic review activities for site EDGS: ,

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> 7 l Evaluate position of EDG engine blocks to .

determine if engine has moved,  ; Visual examination of flexible drive assemblies, i Examination of number 9 bearings, Examination of auxiliary motor driven pumpa'

alignment, Replacement of auto start control relays (ASCRs), Evaluation to determine whether to replace l

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existing ASCRs with hermetically sealed components or periodic replacement of non-sealed typ The licensee will complete maintenance and corrective-actions on EDG-1 then perform run-in and endurance testing to demonstrate the capability of the EDG to achieve its safety function. The NRC will-continue to review the licensee's ongoing EDG maintenance and '

testing activities during this outag Specific EDG 4 Problems On November 2, 1992, EDG-4 failed to stop following a surveillance test. The corrective action was the replacement of 2 relays in the start /stop. circuit and the ASCO solenoid stop valve. The components were sent to a lab for analysis. General licensee consensus at this time was a mechanical failure of the stop valv Formal root cause was pending lab tesult The post maintenance test on November 3, 1992, demonstrated load oscillations; the EDG was inoperabl '

On November 3, 1992, erratic load control was experienced during the EDG post maintenance run discussed above. The corrective action was the calibration of governor EGA and EGB circuits and-replacement of the EGA-circuit. Maintenance and ,

operability runs were succeosful in establishing th ,

EDG operability. The specific-root cause was not >

determine In hindsight, the cause may be related to the load oscillation event which occurred on December 12, 199 ,

On November 30, 1992, the EDG failed to-start due.to  !

equipment failure of an installed tachometer package (tac pac) which was scheduled for replacement in this plant outage.- The tac pacs were replaced with upgraded model On December 1, 1992, the EDG was inoperable due to l failure of one of the newly installed tac pace. The tac pac was_ replace ,

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On Dec. 2, 1992, the EDG was inoperable due to erratic

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load control caused by an ASCR relay failure. The $

cause was determined to be oxidation on the relay contacts which are open to the cabinet environmen The licensee determined that this potential failure mode applied to all site EDGs. Maintenance tasks were

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scheduled to replace the ASCRs on all site EDG EDG Maintenance Backlog b The inspectors reviewed the licensee's progress in reducing the maintenance backlog on EDG system Additionally, the inspectors reviewed the licensee' maintenance practices in completing various maintenance tasks, primarily related to EDG-1 activity previously discussed in this report. The licensee had completed approximately 509 WR/JOs thus far since April 21, 199 During this outage, 232 of the remaining 270 open WR/JOs were scheduled for performance. The inspector reviewed the maintenance schedule and open WR/JOs documents and concluded that all essential work ha been schedule Progress in reducing the maintenance backlog has been adequate and, based on the current resources dedicated to EDG work, it appeared that all essential work would be completed prior to plant restar Conclusion The extent of maintenance planning and appropriate use of procedures demonstrated that the licensee implemented adequate work controls for the complex maintenance evolution on EDG- QC involvement wLs adequat Technical support involvement and supervisory oversight of work has been good. Although root causes had not yet been determined, the licensee's investigation and analysis effort, thus far, demonstrated a commitment to a thorough cause evaluatio Overall, the inspectors-concluded the coordination and control of activities related.to EDG-1-maintenance had been good to this point of. revie Licensee progress on-the.EDG maintenance backlog has been satisfactory with appropriate resources dedicated to this activit . Followup on Corrective Actions for Violations .(92702)

The following violations-were reviewed to determine the adequacy of corrective action accomplished and that appropriate measures were. implemented to prevent recurrenc .

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^* (Closed) Violation 325/89-11-01, Failure to Provide i Appen31x R Separation Between HPCI and RCIC Cables in SW Corner 20 foot elevation of Unit 1 Thi'a issue identified Train A HPCl cables and Train B RC!C cables which did not meet the licensee's Appendix R fire protection requirements for cable separatio he licensee's response to the Violation dated August 18, l'J 89 , stated a modification would be developed and implemented to correct this Appendix R-deficienc The inspectors reviewed related modification, PM 89- a 080, which was completed March 6, 1991. A modification walk down was accomplisned to verify the installation of the modification and implementation of the Appendix R requirements. The inspectors concluded the corrective actions specified in the licensee's violation response had been implemented and the identified deficiency-appropriately correcte , (Closed) Violation 325,324/90-05 01, Failure to Follow Procedurt for Implementation of Modifications This violation identified the licensee's failure to '

i update uafety related 6t'awings and equipment lists following several electrical modification The licensee's response to the violation, dated March 30,-

1990, stated corrective action to include; training for l'

appropriate plant staff, procedure revision for control of regulatory required instrumentation lists, and a review of the procedure for control of drawing revisions.- i l

The inspectors reviewed documentation which verified the specified training was conducted and procedures-were reviewed and-revised as required. Further, the specific drawing and equipment list deficiencies identified in the violation had been correcte . Followup on Previous Inspection Findings (92701)- (Closed) Unresolved Item 325,324/89-02-04, Inadequate Control of Electrical Physical Separation Provided for Divisionalized Raceway-This unresolved item addressed the adequacy of the licensee's control of physical electrical separation -

requirement Two examples were identified in the Unit 2 cable spreading room which didinot meet plant specification 048-004 fire protection requirement This specification required that divisional crossings-

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with less than 18 inches separation be provided with appropriate tray cover !

The licensee evaluated the two cases and demonGtrated [

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that there is no safety concern. The licensee has enhanced the physical separation configuration contro The licensee performed a walkdown of the cable spreading rooms and developed detailed drawings showing cable tray covers to meet specification requirement Specifications 048-001, 048-004, and 048-012 were ,

revised to enhance control. The UFSAR was revised to clarify the cable separation criteri l The inspectors concluded the licensee adequately demonstrated that no safety concern existed related to  :

the identified examploa and that adequnte guidance had been established to control divisional separation and 1 cable tray covers in Unit 1 and Unic 2 cable spreading room Although plant controls have been improved, the specific physical separation deficiency identified by thin item has not been corrected. The correction of this deficiency, regarding cable tray covers for cable runs 54M/DB and 56M/DA in the Unit 2 cable spreading room, has been deferred several times and was most  ;

recently scheduled for December 18, 1992. The completion of this corrective action to install the required tray covers for this divisional crossing is i

ident111ed as inspection followup item-(IFI)-92-41-0 (Closed) Unresolved Item 325,324/89-24-01, Limitorque Motor Heater Qualification This unrecolved item involved the qualification status e of MOV operators with continuously energized motor r heater These heaters were powered from a non safety

, 120 VAC-power source. There-was no. documentation from j the vendor to support that energized motor heaters did not impact MOV motor qualification. There have been no  :

LOCA. tests performed on Limitorque operators with continuously energized motor heater "

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The URI requested that the-licensee-evaluate the

! significance the motor heaters had on the qualification of the Limitorque operators. -The licensee performed _an

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evaluation entitled "EQ Assessment of Energized Motor Heaters Installed in BSEP MOVs" dated October 30, 199 The EQ assessment _ concluded.that continuously energized

motor heaters do not impact the. qualification of the l Limitorque MOV motors and that

the MOV motors are

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2fhe motor heaters consist of small flat ceramic disks which are located within the motor endbell The >

hostere were designed for use during storage and serve l no safety-related function. The licensee determined that energized motor heaters will cause a 10 degree Celsius heat rise above ambient. This is based on '

Limitorque heater sizing practices and actual licensee testin The DC MOV motor space heaters have been disconnected via plant modification 88-014 for Unit 1 i and 88-015 for Unit MOV motor heaters are still  :

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energized on most AC MOV motor The inspectors reviewed the licensee's evaluations and plant modifications which disconnected DC MOV space '

heater The EQ Assessment reviewed the impact the motor heater had on the motor's qualified life and potential common mode failure due to heater components in the MOVs. The inspectors agreed with the assessment conclusion that the slightly elevated ambient

temperature would not prevent AC MOV motors from achieving a 40 year qualified life and that a common ,

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mode failure potential did not exist. Review of plant ,

modifications and drawings demonstrated that the MOV space heaters had been disconnected for DC MOV MOV motor failures at BSEP have been characterized as random and data does not show a history of failures due to the energized space heaters. Based on the above review the inspectors concluded that. energized MOV motor space heaters-do not impact Limitorque MOV motor-qualificatio , Exit Meeting The inspection scope and results were summarized on i November 13, and December 18, 1992, with those persons indicated in paragrap Proprietary information is not contained in this repor The inspector' described the areas

,. inspected and discussed in detail the inspection result There were no dissenting-comments received from the license .

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12 Acronyms BSEP Brunswick Steam Electrical Plant EDG Emergency Diesel Generator EQ Environmental Qualification HPCI High Pressure Coolant Injection (9ysten.)

LOCA Loss of Coolant Accident MOV Motor Operated Valve NED Nuclear Engineering Department RCIC Reactor Core Isolation Cooling (system)

UFSAR Updated Final Safety Analysis Report URI Unresolved Item VAC Volts Alternating Current WR/JO Work Request / Job Order

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