IR 05000237/1991026

Insp Repts 50-237/91-26 & 50-249/91-27 on 910916-20.No Violations Noted.Major Areas Inspected:Maint Activities Using Selected Portions of NRC Insp Procedure 62700 to Ascertain Whether Maint Was Effectively Accomplished

ML17174A933
Person / Time
Site:	Dresden
Issue date:	10/15/1991
From:	Choules N, Gainty C, Jablonski F, Walker H NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
Shared Package
ML17174A932	List: IR 05000237/1991026 ML17174A931
References
50-237-91-26, 50-249-91-27, NUDOCS 9110280046
Download: ML17174A933 (13)

Text

U. S. NUCLEAR REGULATORY COMMISSION

REGION III

Reports No. 50-237/91026(DRS); No. 50-249/91027(DRS)

I Docket Nos:

50-237; 50-249 Licenses No. DPR-19; No. DPR-25 Licensee:

Commonwealth Edison Company 1400 Opus Place Downers Grove, IL 60515 Facility Name:

Dresden Nuclear Power Station - Units 2 and 3 Inspection At:

Morris, IL.60450 Inspection Conducted:

September 16 through 20, 1991

\\ N. c. Choules Approved By:

Section Inspection Summary Inspection on September 16-20, 1991 (Reports N /91026(DRS); No. 50-249/91027(DRS))

(D- (J-91 Date

/0- I :r-<//

Date

/0-1:i**-c;;

Date Areas Inspected:

Routine announced inspection of maintenance activities using selected portions of NRC Inspection Procedure 62700 to ascertain whether maintenance was effectively accomplished and assessed by the license Results:

Based on the items inspected, overall performance in maintenance was considered satisfactor Strengths included active intervention in the work process by a maintenance foreman, the presence of training personnel at work sites to.assess training needs, and a proactive instrument maintenance departmen Significant weaknesses included the preventive maintenance (PM) procedure, which did not require a technical evaluation of the effect on system performance when PM frequencies were changed; and the audit of maintenance, which narrowly concentrated on routine work and produced results that 9110280046 911018 PDR ADOCK 05000237

.

PDR

were almost exclusively compliance oriente Minor weaknesses included housekeeping problems in the crib house and the auxiliary computer room that were not adequately corrected and prevented from recurring, a case where training was not provided on the use of new electrical measuring and test equipment, and maintenance procedures that were somewhat confusing to

• electrician Six open items were closed ou No violations of NRC requirements were identified, but there was one unresolved item identified about deferral of PM tasks on diesels without technical evaluation (Paragraph 3.5.1).

[.-*~

DETAILS 1. 0 Principal Persons Contacted*

Commonwealth Edison Company

• E. Eenigenburg, Station Manager

• G. Afflerbach, Maintenance Staff

• B. Colebank, Maintenance Staff

• J. Coonan, Maintenance Staff

• T. Gallaher, Nuclear Quality Programs Engineer

• D. Lowenstein, Regulatory Assurance Analyst

• R. Testin, Nuclear Quality Programs Engineer

• D. Van Pelt, Assistant Superintendent - Maintenance W. Wharrie, Surveillance Coordinator U. S. Nuclear Regulatory Commission

• F. Jablonski, Chief, Maintenance and outages Section

• R. Kopriva, Resident Inspector, Braidwood

• W. Rogers, Senior Resident Inspector, presden

• Indicates those individuals present at the exit meeting on September 20, 199 Other persons were contacted as a matter of course during the inspectio.0 Licensee Action on Previous Inspection Findings (Closed) Violation (237/90011-0lA; 249/90010~01A):

Failure to document non-illuminated rod position indicator lights in the*

degraded equipment lo The inspectors reviewed licensee actions taken to correct this problem, including those described in the response letter dated June 15, 199 Revision 27 of the "Unit

. 2/3 Operator's Daily Surveillance Log" was issued on August 30, 1990, to require a daily inspection of vertical panel rod position indicator In addition, the incandescent bulbs, used for rod indicator position lights, were repla'ced with more reliable light emitting diodes (LED).

This item is closed.*

(Closed) Violation (237/90011-0lB; 249/90010-0lB):

Thermal overload settings were different than specified by procedure and were made without nuclear engineering department approva The inspectors reviewed licensee actions* taken to correct this problem, including those described in the response letter dated June 15, 199 The inspector noted that changes to procedure DEP 0040-06 "Safety Related Motor Operated Valve Data and Settings" had not been made as described in the referenced respons When this discrepancy was brought to the licensee's attention, which was stated to be an oversight, a decision was made to include statements that required verification of proper overload heater position in more appropriate procedures, which included DES 8300-

01, "Inspection and Maintenance of DC operated Cutler-Hammer Reversing and Field Contactors, Models 912 and 952," Revision o, and DES 8300-02, "Inspection and Maintenance of DC operated cutler-Hammer Reversing and Field Contactors, Models 913 and 954," Revision The* inspectors discussed.the existing practices for controlling NRC commitments with the licensee, and concluded that inadvertent omissions should not recu This item is clos~d~

(Closed) Violation (237/90011-0lC; 249/90010-0lC):

A circuit breaker nuclear work request (NWR) was signed off without complete post maintenance testin The inspectors reviewed licensee actions taken to correct this problem, including those described in the response letter dated June 15, 199 The required testing was completed May 12, 1990, and documented on NWR D 19278 Additionally, QC, maintenance supervision, staff, and work analysts were reminded of the importance of complete routi-ng and thorough review of completed work package Training sessions were also held with quality control inspectors on the importance of thorough and complete work package revie This item is close (Closed) Unresolved Item (237/90011-02; 249/90010~02):

This item documented a difference between the calculated current versus time curve for 250 V de motor control center (MCC) coil for motor operated valve (MOV} 1201-3 and the generic curves supplied by the vendo The inspectors reviewed licensee actions taken to correct this problem, including those described in the response letter dated June 15, 1990. Based.on the information supplied by the licensee, the in~pectors noted that the thermal overload heater sizing for valve 1201-3 breaker was re-evaluated and the overload heater was determined to be properly size This item is close (Closed) Unresolved Item (237/90011-03; 249/90010-03):

Problem analysis data sheets (PADS) were found missing without licensee action to locate or reconstruct the The inspectors reviewed licensee actions taken to correct this problem, including those described in the response letter dated June 15, 199 The list of 78 missing PADS was reviewed and the disposition was to either cancel or rewrite the missing PAD In addition, as of April 1991, a coordinator was assigned to log and maintain control of all open PADS to prevent the further loss of document This item is close (Closed) Unresolved Item (237/90011-04; 249/90010-04):

An unauthorized change was made to the control circuitry of a valve by an electrician and the change was not noted during subsequent review The inspectors reviewed licensee actions taken to correct this problem, including those described in the response letter dated June 15, 199 Based on discussions with the licensee, the inspector noted that the central circuitry for the

• valve had been retu~ned to the original design configuratio Trainirig sessions were held with electrical maintenance work *

analysts stressing adherence to approved engineering documentation; sessions were also held with quality control inspectors on the importance of thorough and complete work package revie In addition, no unauthorized changes were noted during this inspection in the observation of maintenance *

activities or the review of completed NWR This item is close.0 Evaluation and Assessment of Maintenance The purpose *of this inspection was to evaluate and assess maintenance at the Dresden Nuclear Power Statio During the inspection, Unit 2 was operating and Unit 3 was in a refueling outag The evaluation and assessment of maintenance, with emphasis on specific system components, was accomplished by review of past operating experience results, observations of material condition and ongoing maintenance work activities, review of corrective maintenance, preventive maintenance, and predictive maintenance; review of completed maintenance activities, and evaluation of maintenance backlog The inspectors also assessed the quality verification process

• related to maintenance, which was accomplished by review of audit and sunreillance reports for implementation of corrective actions, and review of-documents, such as Licensee Event Reports (LERs), and Deviation Reports to verify that corrective actions were adequately controlle Results of the inspection are documented in the following section.1 Material Condition/Housekeeping The inspectors observed general plant areas to verify that nuclear work requests (NWRs) had been initiated for identified equipment problem The inspectors observed buildings, components, and systems for proper identification, accessibility, scaffolding, radiological controls, and unusual condition Unusual conditions included, but were not limited to water, oil or other liquids on the floor or equipment; indications of leakage through ceiling, walls or floors; loose insulation; corrosion; excessive noise; unusual temperatures; and abnormai ventilation and lightin Only Unit 2 was at operating temperatures and pressures during the inspectio The inspection results were as follows:

The plant was generally clean, well kept, and many areas appeared to have been recently painte However, housekeeping was poor in the crib house and the auxiliary computer roo The licensee had previously noted similar problems but had not taken appropriate action to either correct them or to preclude their recurrence, which was considered a minor weakness. The areas were clean before the

• .'

inspectors left the sit The inspectors also observed ground water in-leakage, which was severe in some areas such as the Unit 2 condensate pump are *

Most defective or broken equipment had been previously identified and was tagged with equipment deficiency tag Some cases were noted where the equipment deficiency tags had not been removed after work was completed as required by procedures and several loose tags were noted lying around in plant area The licensee took immediate action to remove or reattach the above tags as appropriat *

Equipment identification was good for most equipment; however, the inspectors observed a few unattached equipment identification tag Four unidentified valves were noted in the condensate pump are Unattached equipment identification tags were re-attached during the inspectio *

several small oil leaks and other minor deficiencies on Unit 2/3 diesel had been identified by the licensee some time ago but had not been repaire Licensee personnel indicated that most of these deficiencies would be repaired during the next scheduled diesel outag Except as noted above, plant housekeeping and material condition were considered goo The material condition appeared to maintain operability of components at a level commensurate with the components' function and most components in need of repair had been previously identifie.2 Maintenance Backlog Assessment and Evaluation The inspectors reviewed the amount of work accomplished compared to the amount of work schedule The review emphasized work that could affect the operability of safety-related equipm~.nt or equipment important to safety, which included some balance of plant component Maintenance backlog information was tracked to provide management with maintenance performance indicators, which would allow the detection of adverse trends in backlog level Backlogs of NWRs for corrective and preventive maintenance items were controlled and were within the capabilities of the maintenance staf The total backlog of non-outage NWRs on September 19, 1991, based on licensee reports, was 622, which did not appear to be beyond the capabilities of the existing staff to complete within a reasonable tim The inspector also noted that the number of open non-outage NWRs had remained about constant over the past yea Although some corrective maintenance was occasionally rescheduled, the inspectors did not identify any significant corrective maintenance work or backlog items that had been inappropriately delaye No backlog items appeared to affect the

• safe operation of the plant or have an adverse effect on plant availabilit Approximately 30% of mechanical maintenance PM items were past due, however, electrical and I&C over due PM items were less than 6%.

No delayed PM items were noted that would have an adverse effect on plant operability; however, the period of a diesel PM was changed without determining if equipment operability might be affecte This item is discussed in detail in Section 3.5.1 of this repor The PM program was satisfactorily managed and controlled with emphasis on PM task completio.3 Evaluation of Maintenance Activities The inspectors evaluated maintenance activities by means of direct observation of on-going work, review of the use of predictive maintenance, and review of the improvements in the instrument maintenance are. Observation of Maintenance Activities The inspectors observed ongoing work in electrical, mechanical, and I&C maintenance area These activities were selected from the daily plan and through discussions with maintenance foreme Where possible, activities on the selected systems were reviewe Priority was given to safety significant activities where work o the selected systems was not ongoing~

Maintenance was observed to determine if activities were adequately performed in accordance with required administrative and technical requirement Maintenance work activities were assessed in the. following areas:

work control and planning, management presence and involvement, quality control presence and involvement, procedure availability, adequacy, and use; personnel training and qualifications, material availability, measuring and test equipment {M&TE) application and calibration; and the adequacy of post 1,'llaintenance testing, including proper acceptance criteri The inspectors observed portions of 10 maintenance activities which were performed under the NWRs listed below:

D 00157 D 00882 D 02823

.Perform instrument calibration surveillance on # 3 emergency diesel generator (DG).

Investigate and repair all leaks into the reactor building particulate iodine noble gas monito Replace and check # 3 DG atmosphere containment air dilution/containment atmosphere inlet air flow square root extractor.*

D 82756 D 91850 D 93116 D 94372 D 98227 D 98670 D 98928 Replace # 3 DG solder joints with compression fitting Troubleshoot and list rod position indication system problems that nee~ !epair during the refueling outag Modify # 3 DG cooling water pump piping and replace existing check valve with a new dual plate discharge check valv Perform 9 and 18 month mechanical surveillance* on # 3 D Perform refueling electrical surveillance on # 3 D Perform PM on 480 V MCC breaker for the # 3 'DG vent fa Perform PM on 480 V MCC breaker for high pressure core injection (HPCI} MOV 1301- ~

During the review of mairitenance activities the following observations were noted:

D 98227 Electricians were not familiar with a new electronic multi-meter that was used to check the de control surge suppression circuit of the emergency D Based on the meter reading the electricians inappropri~tely concluded that the surge suppression circuitry had failed:

After approximately two hours, the licensee realized that the meter had been read incorrectl This problem indicated an apparent weakness in training personnel in the use of new equipmen Licensee personnel were reviewing this matter for generic applications as well as taking steps to ensure that adequate training was provided..

D 98928 --Procedures were somewhat confusing to the electricians who were working_ on 480 V breaker For example, this weakness was apparent in procedure DES 7300-08 which referred to procedure DES 7300-05 for some steps, and the procedures did not address orientation of the breaker on the bench for testin To compensate for the latter

problem, the foreman appropriately reminded the electrician as he started the test to change the position of the breaker on the bench to fuatch the position the breaker would be in

.the fiel Intervention by the supervisor was considered a strength; however, another minor problem was that the procedures were,not clear about where.the to record the calibration data for the test instrument that was used during the tes (The exact designations of the two procedures discussed above are: DES 7300-08, "Inspection and Maintenance of 480 V MCC Molded Case Circuit Breakers,",

Revision OA, and DES 7300-05, "Maintenance and Surveillance

of EQ and Safety Related 480 V MCC," Revision 02.)

The inspector noted that an individual from the plant training department was at the work site to observe the activity, assess the use of the procedures, and determine if any changes were necessary in upcoming training classe This action to develop and improve maintenance training was considered positive and a strengt Except as noted, the inspectors concluded that maintenance and surveillance activities in the areas inspected were adequate, and accomplished by skilled and knowledgeable maintenance personnel; adequate procedures and instructions were included in the NWR packages, and maintenance personnel followed the procedures and instructions while performing the maintenance activitie. Instrument Maintenance Improvements The master instrument mechanic for the instrumentation and control department had initiated an aggressive program to upgrade plant instrumentation.'

During 1990, 27 Unit 2 control room recorders had been replace _several other Unit 2 instruments had also been replace During the current Unit 3 outage several upgrades of equipment were.scheduled including replacement of 51 recorder The instrument maintenance department had taken.

action to improve the department, which included minimizing the corrective maintenance work request backlog, improving the condition of plant instrumentation, upgrading test and measuring equipment, formation of improvement committees, upgrading procedu.res, and improving communication within* the department~

These actions were cortsidered.a significant strengt.4 Review of Completed Maintenance The inspectors reviewed approximately 30 safety related/important to safety NWRs for completeness, accuracy, and technical conten Some of the specific areas evaluated.were adequacy of work instructions, engineering and technical support in the resolution of concerns identified during the performance of the work, and documentation of work performe,

Part of the NWR process required operations to assess the effect the work would have on Technical Specifications requirements, operability, and the plant in genera Thorough work instructions were generally provided and post maintenance testing was completed and appropriat In general, the work performed was adequately documente The inspectors noted that a large portion of the closed NWRs (more than 30%) had been cancele_d, which appeared to have been for valid reason No NWRs had been inappropriately cancele The inspectors concluded that the NWRs were generally satisfactory in scope and content.

9 Maintenance on Specific Systems and Components The inspectors selected specific system components for review based on safety significance and.discussions with cognizant personne Emphasis was placed on inspection of specific electrical, mechanical and instrumentation components associated with the emergency DG and s.everal containment isolation valve The inspectors evaluated material condition, maintenance backlog,*

maintenance history, corrective action, and post maintenance

• testin In the area of predictive maintenance~ several procedures were established to provide instructions for infrared thermography, vibration monitoring, and erosion/corrosion inspection The inspectors did not evaluate the results of these activities; however, use of the predictive maintenance techniques will allow for the early detection of component and equipment failures or degradatio. Emergency Diesel Generators The material condition of the Unit 2 and 2/3 rliesel was goo The different paint colors on.piping such as fuel oil, cooling water, and air was considered a strengt There were few leaks and all except one had been previously identifie A small oil leak on the scavenging pump on Unit 2 diesel was noted and a NWR was written to identify this by the end of the inspectio The inspectors reviewed the backlog of corrective maintenance NWRs on the diesels for effect on system operatio All the NWRs were prioritized as B3 and most would not be worked until an outag The amount.and type of items on the backlog list indicated that maintenance was performed as necessary to maintain the diesels in good conditio Changes were made to the frequency of scheduled PM items on the emergency DG without a technical evaluatio As reported on Deviation Report 12-2/3-90-55, the Unit 2/3 emergency DG was declared inoperable due to a broken lube oil circulation pump coupling, which had failed after 14 months of operatio In order to preclude recurrence, the licensee decided to replace the coupling at a nine month interval as stated in procedure DAMS 6600-01 "Diesel Generator 9-month (one-half fuel cycle)

Maintenance and Preventive Maintenance," Revision 0 The system engineer indicated that he believed the work was done every nine months as specified in the procedur However, the surveillance coordinator changed the established PM frequency, from nine months to every refueling outage based on a request of management, but without technical justification or approval because neither is required by.procedure DAP 11-2, "Surveillance and Periodic Task Scheduling Program," Revision 1 Replacement of the diesel lube oil filters, another task intended to be performed at a nine month interval, was also changed to every refueling outage without a technical evaluatio The Unit 3 emergency DG was down for maintenance to complete PM and the 9

and 18 month mechanical inspection Records showed that these type of inspections and periodic PM tasks were last completed 22 months ago in December 198 *

The inspectors were concerned with the interval between scheduled PM tasks and inspections, arid that the surveillance coordinator had changed the frequency of procedure DMS 6600-01 without system engineer knowledge or a technical evaluation of the effect on system performanc This item is considered unresolved until the licensee completes a technical evaluation of the PM tasks and interval that are necessary to properly maintain the diesel, and reviews the methods used to change the frequency of PM tasks (237/91026-0l(DRS); 249/91027-0l(DRS)).

3. Containment Isolation Valves The inspectors selected the following Group 3/4 containment isolation valves for review:

Unit 2 Cleanup Demineralizer System Inboard: 2-1201-1 Unit 2 Cleanup Demineralizer System Outboard: 2-1201-2 Unit 3 HPCI Turbine Steam Supply Outboard: 3-2301-4 Unit 3 HPCI Turbine steam Supply Inboard: 3-2301-5

• The inspectors reviewed the maintenance history for the last two years for the valves listed abov Most work was PM, including inspection, surveillance, lubrication, and testing, and was completed as require There were few problems noted that had required any corrective maintenanc A review of the backlog for maintenance ori these valves" ;indicated that no significant work was outstandin Documentation. was proper where required to reffect as-left condition Valve 3-2301-5 was diagnostically tested on September 20, 1990, and the torque switch was changed to meet test criteri Prodedure 0040-06 was updated,.as required, t ref le ct the new torque switch settin The inspectors also reviewed the calibration records for the instruments used to actuate the Group 3/4 containment isolation valves during accident conditions: reactor water level and

pressure, reactor water clean.up space and drain temperature, and HPCI steam flow and steam line temperatur The records indicated that the instruments were properly calibrated.. The licensee maintained a computer history of NWRs for the

.

instruments, dating back to 198 The maintenance records,

indicated that most instruments had been replaced or repaire The only outstanding NWRs for the instruments were written to replace and upgrade the valve manifolds for four reactor water level transmitters, which was outage relate The inspectors also performed a walkdown of the instruments and noted no problem The inspectors concluded that the containment

'.

isolation valves were adequately maintained to demonstrate that

• the valves would perform the safety functions as require.6 Licensee Assessment of Maintenance (Quality

• Verification)

The inspector reviewed surveillance reports, corrective action documents and one audit report to evaluate the licensee's quality verification proces The documents were reviewed tor root cause ahalysis, timely corrective action, technical assessments, and justification for close out of corrective action documents..

3. Audit and Surveillance The inspectors reviewed the audits completed since October 1990, which included a combined performance assessment of maintenance performed in January 1991, one maintenance audit. performed in July 1991, and approximately 100 field monitoring reports~

All activities included observations of work activities in progress; however, there were almost no performance based audit finding Instead,..they were almost all compliance oriente There was no evidence that the auditors had reviewed th~ broader areas of maintenance such as how maintenance, if at all, contributed to or caused reactor trips, engineered safety feature actuations, or equipment unavailability, and how well maintenance was implemented on specific systems or component The inspectors considered the narrow scope of the audits in the maintenance_ area to be a weaknes In addition to the above audits and surveillance activities, the inspectors were told that a comparative audit of maintenance at all Commonwealth Edison plants was in the process of being complete The audit was performed at Dresden from August 26-30, 1991, however, review of data and preparation of the comparative report was still in progres The inspectors reviewed the detailed audit checklist for this comparative audit and determined that the audit was an in~depth review of maintenance that appeared to be performance oriente overall, the internal evaluation of the licensee assessment of maintenance appeared to be acceptable; however, the routine audit program was considered narrow and did not produce performance oriented result. Corrective Actions The inspectors reviewed the corrective action responses to the combined performance assessment of maintenance and a draft response to the maintenance audi The corrective actions appeared to be appropriate and the responses were timel The inspectors reviewed a corrective action and non-conformance audit report that was completed during July and August 199* The audit

• r

..

--

reviewed commitments to NRC information notices, inspection reports, generic letters, INPO findings, non-conformance reports, discrepancy records and previous audit deficiencies as they applied to specific area In the area of maintenance, the auditors followed up on some prior audit findings by actually observing work to verify adherence to procedures and work request One finding of the audit identified that the station was not effectively implementirig the corrective* action for a previous finding concerning offsite review of safety evaluation.7 Conclusions Based on the results of the inspection activities described in this report, the inspectors concluded that maintenance was effective and no safety issues were identifie.0 Unresolved Items Unresolved items are matters that have been discussed with the licensee and more information is required to ascertain whether they are acceptable items, violations, or deviation An unresolv,ed item was identified during this inspection and is discussed in Paragraph 3.5.1 of this repor.0 Exit Meeting The inspectors met with licensee representatives (denoted in Paragraph 1) at the Dresden Nuclear Power Station on September 20, 1991, to summarize the purpose, scope, and findings of the inspectio The inspectors discussed the likely informational content of the inspection report with regard to documents or processes reviewed by the inspectors during the inspectio The licensee did not identify any such documents or processes as proprietar *

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