IR 05000413/1993031

Insp Repts 50-413/93-31 & 50-414/93-31 on 931107-1204.No Violations Noted.Major Areas Inspected:Plant Operations, Maintenance,Engineering,Plant Support & follow-up of Previously Identifed Items

ML20059B497
Person / Time
Site:	Catawba
Issue date:	12/22/1993
From:	Freudenberger, Lesser M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
Shared Package
ML20059B493	List: IR 05000413/1993031 ML20059B490
References
50-413-93-31, 50-414-93-31, NUDOCS 9401040167
Download: ML20059B497 (13)

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o UNITED STATES e

1. m fm asc ,% NUCLEAR REGULATORY COMMISSION OC . 4 REGtON 11

$ E 101 MARIETTA STREET, N.W., SUITE 2fK10 ATLANTA, GEORGIA 303230199 a ':4f

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Report Nos.: 50-413/93-31 and 50-414/93-31 Licensee: Duke Power Company ATTN: Mr. D. L. Rehn Site Vice President '

Catawba Nuclear Station 4800 Concord Road York, SC 29745 Docket Nos.: 50-413 and 50-414 License Nos.: NPF-35 and NPF-52 Facility Name: Catawba Nuclear Station Units 1 and 2 ,

Inspection Conducted: November 7, 1993 - December 4, 1993 Inspectors / St artbrEl'f3 pr-R.W Fr'eu enberger, Senior Resident Inspector ate Signed'

P. C. Hopkins, Resident Inspector, Catawba J. Zeiler, Resident Inspector, Catawba C. Yates, Reactor Engineer Intern Approved by: i /2[2*/D Mark' S. Lesser, Chief Date Signed Projects Section 3A Division of Reactor Projects  ;

SUMMARY

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Scope: This resident inspection consisted of review of plant operations, '

maintenance, engineering, plant support and follow-up of '

previously identified items. Backshift inspections were conducted on November 7, 8, 10, 12, 17, 18, and 1 Results: In the operations area, operator response to the failure of valve 2NV309 was appropriate (paragraph 3.a.). Also, an adequately implemented cold weather protection program was in place (paragraph 3.b.).

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In the maintenance area, a non-cited violation was identified regarding a failure to follow procedure which resulted in a temporary loss of a train of reactor coolant level instrumentation ;

(NCV 50-413/93-31-02, paragraph 4.c). An inspector follow-up item was opened for outage emergency diesel generator maintenance i activities (IFI 50-413/93-31-01, paragraph 4.b) Additionally, training in preparation for steam generator nozzle dam i

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- installation was judged to be weak (paragraph 4.a), and emergency core cooling system flow balance testing was performed well ,

(paragraph 4.d).  ;

In the engineering area, the decision to move forward with the permanent repair of the 2B component cooling heat exchanger flaw was appropriate for the circumstance ,

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l REPORT DETAILS i PERSONS CONTACTED Licensee Employees S. Bradshaw, Shift Operations Manager J. Forbes, Engineering Manager 3 T. Harrall, Safety Assurance Manager J. Lowery, Compliance Specialist ,

• W. McCollum, Station Manager W. Miller,-Operations Superintendent

• K. Nicholson, Compliance Specialist -

• D. Rehn, Catawba Site Vice-President

• Z. Taylor, Compliance Manager j Other licensee employees contacted included technicians, operators, mechanics, security force members, and office personne NRC Resident Inspectors ,

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• R. Freudenberger, Senior Resident Inspector P. Hopkins, Resident Inspector .

• J. Zeiler, Resident Insrector

• C. Yates, Intern

• Attended exit intervie !

Acronyms and abbreviations used throughout this report are listed in the last paragrap . PLANT STATUS

' Unit 1 Summary Unit I was in the End of Cycle (E0C) 7 refueling outage for the ,

duration of the report period. Major activities completed or underway included steam generator tube eddy' current inspections ;

and repair, reactor vessel ISI Inspection, and emergency diesel -

generator inspection and maintenanc Unit 2 Summary Unit 2-operated at or near full power for the duration of the ,

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! Inspections and Activities _of Interest Inspections were conducted by specialist inspectors from the NRC Region II Office as follows:

Report Dates Subiect Lead Insoector 93-29 11/15-19 Radiological Controls Shortridge 93-30 11/16-19 Reactor Vessel ISI Coley 93-32 11/17-12/2 Steam Generator ISI Economos 93-33 11/29-12/2 Snubbers Chou  ; Meetings With Local Officials (NRC Inspection Procedure 94600)

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During the weeks of November 8 and 22, the Senior Resident Inspector met with local elected officials from Mecklenburg and Gaston counties. The inspector discussed the role and location of the Resident Inspector's Office. On November 22, the inspector toured the Gaston County Emergency Preparedness Center with the i Gaston County Emergency Management Coordinator. The Senior Resident Inspector had previously met with elected officials in-York County and had toured the York County Emergency Response i Center with the York County Emergency Preparedness Director in October, 199 On November 29 NRC management met with Catawba Nuclear Station *

management to discuss the Systematic Assessment of Licensee Performance Report. Local government officials were invited to '

attend. Subsequent to this meeting, a meeting was held with the local official present. A general overview of NRC organization <

and purpose was discussed, NRC management and inspectors were introduced, and telephone numbers were share . OPERATIONS (NRC Inspection Procedures 71707, 71714, 40500, and 93702)

Throughout the inspection period, facility tours were conducted to observe operations and maintenance activities in progress. The tours included entries into the protected areas and the radiologically controlled areas of the plant. During these inspections, discussions were held with operators, radiation protection personnel, and instrument and electrical technicians, mechanics, security personnel, engineers, '

supervisors, and plant management. Some operations and maintenance activity observations were conducted during backshifts. Licensee meetings were attended by the inspector to observe planning and management activities. The inspections confirmed Duke Power's  !

compliance with 10 CFR, Technical Specifications, License Conditions, )

and Administrative Procedure ,

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3 Operator Response to Plant Transient On November 17, Unit 2 was at full power and Instrument and i Electrical Technicians were troubleshooting meters on the ,

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Auxiliary Shutdown Panel in accordance with work order 930841300 They identified a defective power supply. While in the process o .

replacing the power supply, power to valve 2NV-309 was interrupted '

and the valve failed to the open position. Valve 2NV-309 is the backpressure control valve in the charging system and maintains constant pressure and flow to the reactor coolant pump seal With the backpressure control valve failed open, flow to each reactor coolant pump seal reduced from approximately eight to five ,

gpm. The inspector discussed the valve failure with the control <

room operators shortly after the event. The appropriate ,

annunciator response procedure and abnormal operating procedur AP-08, Malfunction of a Reactor Coolant Pump, were referenced and 1 implemented. The valve was returned to service within approximately two hours. Control power to valve 2NV-309 was lost ~

as a result of a loose connection in the vicinity of the power supply that was- being replaced. This issue was documented by the licensee in PIP 2-C93-100 The inspector considered the operators response to the loss of '

control power to valve 2NV309 and the documentation of the issue in the PIP to be appropriat Cold Weather Preparations The inspector evaluated the licensee's cold weather protection program. This evaluation included a review of procedure PT/0/B/4700/38, Cold Weather Protection and observation of its implementation to verify that the licensee maintains an effective :

cold weather protection program for extreme cold weather. The inspector verified that the licensee has procedures in place and has inspected systems susceptible to freezing for the presence of heat tracing, space heaters (where needed), and/or insulatio The licensee in<pected for proper setting of thermostats-and to ensure that heat tracing and space heating circuits were-energized. The inspector also verified that protective measures had been reestablished for_ systems that required them and that had _

been subjected to maintenance or modification. .The licensee also t had procedures for long shutdown periods to_ ensure that an area no longer kept warm by normal plant operations would be adequately protected from cold. The inspector concluded that the licensee has an adequately implemented cold weather protection progra . MAINTENANCE (NRC Inspection Procedures 62703, 61726, 40500 & 93702) l Surveillance tests were observed to verify that approved procedures were -

being used; qualified personnel were conducting the tests; tests were l

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4 j adequate to verify equipment cperability; calibrated equipment was <

utilized; and TS requirements were appropriately implemente l In addition, the inspector observed maintenance activities to verify that correct equipment clearances were in effect; work requests and fire prevention work permits, as required, were issued and being followed; quality control personnel performed inspection activities as required; and TS requirements were being followed, Steam Generator Nozzle Dam / Channel Head Drain Plug Installation

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The Catawba Unit I steam generators (D-3) have two drains integral to each channel head. One drain connects the channel head to the manway; the other connects the low point of the channel, head bowl to its respective hot or cold leg. The Unit 2 steam generators (D-5) do not have similar drains. Concurrent with nozzle dam installation on Unit 1, plugs are installed in the channel head bowl to hot (or cold) leg drain since this drain provides a bypass flowpath past the nozzle da In preparation for steam generator maintenance activities, nozzle dams and channel head bowl drain plugs were installed in all eight steam generator nozzles. During the initial attempt to fill the reactor coolant system on November 8, the licensee observed leakage out of the steam generator manways and discovered that ;

five of the eight drain plugs were installed in the manway drain and not in the channel head bowl to hot (or cold) leg drai Transfer of the drain plugs to the proper drains resulted in an addition of approximately twelve hours of operation in reduced inventory condition In addition to initiating a PIP, the licensee conducted a meeting on November 9 to discuss the incident and develop corrective actions. The inspector observed this meeting. Based on information discussed at the meeting, the licensee identified two general areas for improvement: procedures and trainin The licensee noted that, although the procedure addressed the installation of the drain plugs,.no warnings or cautions regarding i the location of the correct drain to plug and no. detailed drawings cf the drains.sy unit were included. The inspector reviewed maintenance procedure MP/0/A/7150/099, Steam Generator Nozzle Dam :

Installation and Removal, and determined that the guidance in the !

procedure was adequate, provided that detailed mockup training was performed as would be anticipated for work of this nature -

(personnel entry into steam generator channel heads). The ,

inspector considered the licensee's proposed changes to the :

procedure to be enhancement *

The licensee's critique identified the following areas for improvement: (1) the time reserved for mockup training, (2) the mockup's simulation of the as-built configuration of Unit 1 e

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(Mockup did not include drain holes), (3) the use of experienced personnel for training, and (4) the exclusive use of experienced personnel for verification activities. The inspector considered the training issues to be major contributors to the improper .

installation of the drain plug !

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Further NRC review of this event relative to training and planning !'

for radiologically significant activities was conducted as part of a specialist radiological controls inspection during the week of November 15 and documented in inspection report 50-413, 414/93-2 b. Emergency Diesel Generator Outage Inspections and Maintenance During the unit 1 E0C-7 outage the licensee performed inspection, preventive maintenance, and repairs of emergency diesel generators ;

1A and 18. The inspectors witnessed the performance of portions of procedure IP/0/A/4974/12, Diesel Generator Maintenance and Repair. The purpose of this procedure is to ensure that emergency ;

diesel generator maintenance and repairs will be performed in accordance with design specification '

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Pedestal Resistance to Ground During performance of the annual outage maintenance and repair, the licensee discovered that the generator pedestal -

resistance to ground on the IB emergency diesel generator ;

was 10 mega-ohms. This reading indicat that resistance ha decreased since the last outage and that the insulation must be removed, cleaned, dried, and reinstalled. The emergency ;

diesel generator vendor manual guidance required a minimum -

resistance to ground for the bearing pedestal of at least 1 mega-ohm, therefore, the acceptance criterion was not exceeded. The pedestal is insulated from ground-potential to prevent circulation currents in the ger.erator rotor, ,

which potentially could cause damage to the diesel generator ,

bearing. The licensee determined that the reduction in the pedestal resistance was a result of the generator pedestal

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point. The licensee's action included disassembling the

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pedestal and thoroughly removing the paint. . After the licensee assembled the pedestal, the resistance read greater ,

than 200 mega-ohms. The 1A emergency diesel generator pedestal was inspected and no problems were foun ,

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Degraded Emergency Diesel Generator Baffle Welds On December 1, 1993, while performing outage maintenance on Diesel Generator IA, the licensee discovered that one baffle -

' located on the inside surface of the generator ventilation ,

screens was loose. The licensee determined that the quality of the welds was questionable and considered the possibility that baffle welds could be degraded on the other emergency i

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diesel generators, since an inspection of the baffles was i not proceduralized. A baffle falling into a running ;

generator could cause significant damag '

Work order 93087184-01 consisted of removing the ventilation covers and rewelding any damaged louver welds while i referring to field weld data sheets and reinstalling the '

ventilation covers in accordance with procedure IP/0/A/4974/01 Emergency diesel generator 2A was inspected next. The inspectors witnessed removal of the ventilation covers and independently inspected the bafile plates. No major problems were found. After restoring operability of the 2A ,

emergency diesel generator, the lic2nsee proceeded to inspect diesel generator 18. Train B of the control room ventilation system was aligned to the 2B emergency diesel generator, with Train A of the control room ventilation system inoperable due to maintenance activitie Because unit 1 fuel was off-loaded to the spent fuel pool and diesel generator IA was inoperable, contingency plans were developed to ensure that diesel generator 1B would be available to operate if needed to maintain spent fuel pool ,

cooling on loss of B train power during the removal and reinstallation of the ventilation cover The inspectors monitored the activities on a daily basis and observed work in progress. 'The inspectors considered the licensee's actions to inspect and repair the degraded baffle plate weld to be timely and appropriate. Contingency plans were developed to maintain spent fuel pool cooling emergency power supply availability while addressing the potential emergency diesel generator operability issu Turbo Charger High Vibration On December 3, 1993, during the IB diesel generator operability run the diesel generator tripped on high vibration in the left turbocharger 20 minutes into the ru The emergency diesel generator trip on high turbocharger vibration is a non-essential trip that is bypassed during .

emergency operation of the engine. During a second run with.. 1 additional vibration instrumentation, the engine. tripped )

again on high vibration on the same. turbocharger 30 minutes i into the operability run. The licensee replaced the turbocharger and successfully returned the emergency diesel generator to service. The turbocharger that experienced high vibration had been installed recently as a. preventive maintenance activity. The inspectors plan to monitor the l

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licensee's actions to evaluate the root cause of the  ;

turbocharger vibration. This issue is identified as part A l of Inspector Follow-up Item IFI 50-413/93-31-01: Resolution of Emergency Diesel Generator Outage Issue Output Breaker Trips during Phasing of Emergency Diesel Generators to Grid ,

I The inspector noted that on several occasions while operators were attempting to phase the emergency diesel i generators to their respective busses for load testing, the output breaker tripped. The inspector noted that this condition had no impact on the ability of the emergency diesel generators to perform their safety function; however, it represented challenges to the protective relaying associated with the output breaker and warranted followu Therefore, this issue was identified as part B of Inspector i Follow-up Item IFI 50-413/93-31-01: Resolution of Emergency Diesel Generator Outage Issues, c. Reactor Coolant System level Indication On November 11, Instrument and Electrical technicians were >

performing procedure IP/1/A/3122/02, System Calibration Procedure for ICCM External Analog Transmitters Train A and B, under work order 93054966-01. While performing pre-calibration set-up in lower containment for INC6430 (Hot Leg C Sensor Bellows Housing),

the procedure directed the closure of two process line isolation .

valves, the removal of a plug, and the opening of the process lin t test tee isolation valve to relieve system pressur ;

The two process line isolation valves were inaccessible because i

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sections of mirror insulation had been removed for other outage activities. The technicians closed .the instrumentation root' valve and loosened a fitting at a tee in the process line upstream from  :

the test tee to relieve system pressure. When a greater volume of water than expected had been drained, the technician tightened the t fitting and contacted the control roo '

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The process line for INC6430 shares a common root valve with '

INC6450 and INC6451-(one train of reactor coolant system wide- and mid-range level indication). The isolation of the root valve and draining at the process line tee resulted in a short-term (approximately ten minute) loss of one train of. reactor vessel '

level indication. The significance of'the interruption in level ,

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indication was minimized by the fact that only one train was

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affected and the work order was scheduled for performance while  ;

the refueling cavity was fille :

PIP l-093-0969 was generated as a result of this issue. The l

inspector reviewed the PIP, the work order and procedure mentioned  :

above, and discussed the issue with IAE management and plant l

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personnel with scheduling responsibility. Based on this review the inspector considered the technician's failure to follow procedure IP/1/A/3122/02, System Calibration Procedure for ICCM External Analog Transmitters Train A and B, a licensee-identified violation that will not be subject to enforcement action because the licensee's efforts to identify and/or correct the violation meet the criteria specified in Section VII.B of the Enforcement Policy. NCV 50-413/93-31-02: Failure to follow ICCM isolation procedur d. Unit 1 ECCS Flow Balance Testing During November 29 through December 1, 1993, with Unit I defueled, the licensee conducted ECCS flow balance testing in accordance with procedure PT/1/A/4400/01, ECCS Flow Balance. The purpose of this testing was to verify acceptable flow from each of the centrifugal charging, safety injection, and residual heat removal pumps when aligned for the cold leg injection phase of safety injectio Each charging pump was tested by delivering FWST water to the reactor vessel via the cold leg injection flowpath. _ Flow was balanced between the four cold leg injection lines by adjusting throttle valves in each line. During the flow balance, .a small flow anomaly occurred. The test engineers demonstrated good technical understanding of the system when it was determined through troubleshooting that the cause of the flow anomaly was due to air entrained in the piping. The flow balance was re-performed successfully on November 3 Each safety injection pump was tested while delivering FWST water to the reactor vessel via the hot leg injection line Flow data were obtained to calculate actual pump head-capacity points, which were plotted against the acceptance head-capacity curve. Data sets were taken at minimum, design, and runout flow condition At runout conditions, hot leg injection flow was balanced between the two injection lines using injection line throttle valve Cold leg injection flow was then balanced between the four lines with one pump at a time delivering runout flow from the FWST to the reactor vesse Each residual heat removal pump was tested while delivering FWST water to the reactor vessel via the cold leg injection flowpat Pump performance was analyzed at miniflow, design, and runout flow conditions. Total developed head at each flow condition was plotted on an acceptance head-capacity curve to ensure that the pump met or surpassed minimum acceptable performance requirement Pump flow was throttled using the residual heat removal heat exchanger outlet flow control valv The inspector reviewed the procedure, witnessed selected portions of testing, and independently verified selected test alignment .

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Prior to performing each section of the procedure, test engineers briefed the operations personnel and supplied briefing packages for their review. The inspectors considered these briefings to be effective in providing the operator with: 1) a summary of the i upcoming test sequence, 2) system alignments to support testing, 3) important parameters to monitor during testing, and 4)

conditions for terminating testing. As a result of adequate test pre-planning, test preparation, and effective communication between operations and test personnel, the test was executed without inciden i 5. ENGINEERING (NRC Inspection Procedures 71707 & 37828)  !

Component Cooling Water Heat Exchanger Repair  ;

On October 8 the licensee identified a small leak in the shell side of the 2B Component Cooling Heat Exchanger. Licensee .

examination revealed a through-wall crack within the - !

circumferential butt weld of two cylinders of the heat exchanger shell. This examination further indicated that the flaw was due '

to existing porosity in the weld and not due to fatigue. The '

licensee's operability evaluation revealed that the flaw in the weld would remain stable until permanent repairs could be made during the next refueling outage.- By letter dated November 15, 1993, the licensee submitted to the NRC a relief request from ,

immediate code repair of the flaw since the repair would require unavailability of safety systems supported by the component cooling water system, which was not commensurate with the safety- '

-significance of the flaw. The licensee planned to conduct monthly UT examinations to identify any unexpected growth in lieu of not :

conducting immediate weld repair On December 1, the licensee's UT examination revealed that the ,

inside diameter of the flaw had increased in length to 2.35 inches. The previous UT result on October 12 was 0.9 inche *

Since the length of the outside diameter of the flaw had not changed, the amount of leakage (a slow drip of water) remained !

about the same. Due to the significant indicated increase in flaw .

length, licensee management decided to make immediate permanen ,

repairs to the heat exchange Work order 93087407-01 was initiated to implement ' Minor Modification No. CE-4348 for an ASME Code repair of the heat ' ,

exchanger. The repair involved removing the flaw by cutting a 3- ,

inch diameter section out of t!.e heat exchanger shell, capturing l the flaw area. The heat exchanger pressure boundary was to be i restored by attaching a 3 inch pipe cap to the heat exchanger, ;

completely surrounding the hole. The inspector verified that the i

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modification package was prepared in accordance with station requirements. The inspector reviewed the 10 CFR 50.59 safety

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evaluation for the modification and determined that it adequately addressed the safety concerns associated with th repai On December 4 the licensee implemented this modification. The inspector reviewed the work order documentation and witnessed portions of the repair work, concluding that it was properly performed. Following the repair activity, a hydro test was performed that verified that the heat exchanger pressure boundary was restore ;

The licensee planned to withdraw the relief request since a permanent repair was completed and conduct analysis of the 3 inch '

section that was removed to determine the cause of the sudden indicated increase in flaw length. The inspector considered the licensee's actions to move forward with the permanent repair to be appropriate for the circumstance . EXIT INTERVIEW The insnection scope and findings were summarized on December 6, 1993, with those persons indicated in paragraph 1. The inspector described the areas inspected and discussed in detail the inspection findings listed below. No dissenting comments were received from the license The licensee did not identify as proprietary any of the materials provided to or reviewed by the inspectors during this inspectio Item Number Description and Reference ,

IFI 50-413/93-31-01 Resolution of Emergency Diesel Generator Outage ,

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Issues. (paragraph 4.b)

i NCV 50-413/93-31-02 Failure to follow ICCM isolation procedur ,

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7. ACRONYMS AND ABBREVIATIONS ASME - American Society of Mechanical Engineers ,

CE -

Exempt Change (Minor Modification)

CFR -

Code of Federal Regulations CNS -

Catawba Nuclear Station .

DPC -

Duke Power Company i ECCS - Emergency Core Cooling System _;

FWST - Refueling Water Storage Tank '

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IAC -

Instrument and Electrical ICCM - Inadequate Core Cooling Monitor  :

IFI -

Inspector Follow Item  !

ISI -

Inservice Inspection  :

LER -

Licensee Event Report  !

MMP -

Maintenance Management Procedure r

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Non-Cited Violation

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Non-Licensed Operato f HRC - -

Nuclear Regulatory Commission *

OP -

Operating Procedure  :

PIP -

Problem Investigation Process PT -

Periodic Test '

l R&R -

Removal and Restoration (Tagging Order) '

R0 -

Reactor Operator -)

SG -

Steam Generator ,

SR0 -

Senior Reactor Operator l TS -

Technical Specifica'sions t TSM -

Temporary Station Modification j URI -

Unresolved Item t UT -

Ultrasonic Testing '

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Work Order WR -

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