IR 05000369/1993022

Insp Repts 50-369/93-22 & 50-370/93-22 on Stated Date. Violations Noted.Major Areas Inspected:Plant Operations, Surveillance Testing,Maintenance Observations,Ler & Followup on Previous Insp Findings

ML20059K733
Person / Time
Site:	Mcguire, McGuire
Issue date:	11/09/1993
From:	Lesser M, Maxwell G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
Shared Package
ML20059K719	List: IR 05000369/1993022 ML20059K718 ML20059K722
References
50-369-93-22, 50-370-93-22, NUDOCS 9311160166
Download: ML20059K733 (10)

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UNITED STATES

.[#p asoh -4 NUCLEAR REGULATORY COMMISSION REGloN 11 3 g ,)y S 101 MARIETTA STREET, N.W., SUITE 2900 :p ATLANT A, GEORGIA 303234199

\...../Report Nos. 50-369/93-22 and 50-370/93-22 Licensee: Duke Power Company 422 South Church Street Charlotte, NC 28242-1007 Facility Name: McGuire Nuclear Station 1 and 2 Docket Nos. 50-369 and 50-370 License Nos. NPF-9 and NPF-17 Inspection Conducted: September 26, 1993 - October 16, 1993 Inspectors: [ $ 2'Eub NNalW9/f8

'D~ ate . Sigifed

/rG.LMaxwell,SeniorResidentInspector J. Zeile , Resident Inspector Approved by: 18/f[93 M. S':' Lesser, Section Chief Date Signed Projects Section 3A Division of Reactor Projects SUMMARY Scope: This routine, resident inspection was conducted in the areas of plant operations, surveillance testing, maintenance observations, licensee event reports, followup on previous inspection findings, and meeting with local officials. Backshift. inspections were l performed on October 6, 7, 13 and 1 Results: In the areas inspected, one violation was identified for an inadequate procedure for the abnormal operation of the letdown charging system (paragraph 7.c.). One non-cited. violation was identified in the area of configuration control of a letdown system vent and drain valve 2NV-464 (paragraph- 7.c.). One unresolved item was identified for an incomplete weld for a plugged tube in the unit 1 "A" steam generator-(paragraph 4.b).

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REPORT DETAILS Persons Contacted Licensee Emplovees T. Arlow, Safety. Review Group 0. Baxter, Support Operations Manager

• A. Beaver, Shift Operations Manager

• R. Bostian, Mechanical Maintenance Manager-

• J. Boyle, Work Control Superintendent R. Branch, General Supervisor, Mech. Main D. Bumgardner, Unit 1-Operations Manager B. Caldwell, Training Manager M. Cash, Engineering Supervisor

• W. Cross, Compliance Security Specialist T. Curtis, System Engineering Manager F. Fowler, Human Resources Manager

• E. Geddie, Station Manager

• G. Gilbert, Safety Assurance Manager P. Guill, Compliance Engineer

• R. Hall, Engineering Manager

• B. Hamilton, Superintendent of Operations

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• F. Hayes, Manager, Human Resources

• T. McHeekin, Site Vice President

• M. Nazar, Station Manager Staff

• M. Pacetti, Mechanical / Nuclear Engineer

• T. Pederson, Safety Review Supervisor

• N. Pope, Instrument & Electrical Superintendent

• R. Sharpe, Regulatory Compliance Manager B. Travis, Component Engineering Manager

• H. Vanpeiet, Engineering J. Washam, Safety Review Group

Other' licensee employees contacted included craftsmen, technicians, operators, mechanics, security force members, and office personne .

NRC Resident Inspectors  !

• G. Maxwell, Senior Resident Inspector q J. Zeiler, Resident Inspector j

• Attended exit interview L Acronyms and abbreviations used throughout this report are listed in the last paragrap . Plant Operations (71707) Observations The inspection staff reviewed plant operations during .the report

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period to verify conformance with applicable regulatory ;

, requirements. Control room logs, shift supervisors' logs, shift turnover records and equipment removal and restoration records

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were routinely reviewed. Interviews were conducted with plant !

l operations, maintenance, chemistry, health physics, and '

performance personnel.

, Activities within the control room were monitored during shifts L

and at shift changes. Actions and/or activities observed were conducted as prescribed in applicable station administrative'

directive Plant tours taken during the reporting period included, but were not limited to, the turbine buildings, the auxiliary building, electrical equipment rooms, cable spreading rooms, and the station yard zone inside the protected are During the plant tours, ongoing activities, housekeeping, fire-

, protection, security, equipment status and radiation control practices were observe Unit 1 Operations t

The unit began this report period shut down in Mode 5 following a steam generator tube leak. On October 5, the unit was returned to power and operated at 22% power. On October 6, the unit was shut down when a primary to secondary leak occurred in the "A" steam generator. The unit remained shut down for the remainder of the period for the leak repairs. Details pertaining to this leak repair are discussed in paragraph ; Unit 2 Operations  ;

On September 27, 1993, the unit was shut down due to an unidentified primary coolant leakage in excess of one gallon per ,

minute. An unusual event was declared and the plant was cooled down to Mode 5 for repairs to the leak, which was identified as a seal leak on valve 2NC-14, and so that an evaluation of the unit j steam generator tubes for potential leaks could be conducted, j Additionally, the licensee had committed to plug a population of tubes that had been identified, based upon unit I tube ,

inspections, as vulnerable to cracking. The tube inspection had l been conducted in response to concerns identified during the unit-- -)

I tube leak repairs made prior to October 5. On October 15 the unit was returned to powe No violations or deviations were identifie l

3. Surveillance Testing (61726) ' Observed Surveillance Tests i

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The resident inspectors reviewed and/or witnessed selected I surveillance tests to assess the adequacy of procedures and performance as well as conformance with the applicable T Selected tests were witnessed to verify that (1) approved ;

procedures were available and in use, (2) test equipment in use l was calibrated, (3) test prerequisites were met, (4) system

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restoration was completed, and (5) acceptance criteria were me ;

On October 12 the inspectors reviewed and witnessed in detail the licensee's performance of procedure PT/2/A/4208/01A, Containment Spray Pump 2A Performance Test. The purpose of this test was to verify the operational readiness of the Spray pump in accordance ,

with the TS 4.6.2.b and the in-service test requirements of ASME '

Boiler and Pressure Vessel Code,Section XI. The test required that the pump operate in recirculation to the Refueling Water Storage Tank for approximately 15 minutes. During operation, pump operating parameters were measured and recorded. These parameters .

were then compared with acceptance criteria for the pump. The -1 inspectors verified that (1) instrumentation was calibrated, (2) ,

required data were taken-in accordance with the test procedure, I and (3) test results were satisfactory. No discrepancies were i

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identifie i 4. Maintenance Observations (62703) j Resident Inspectors reviewed and/or witnessed maintenance activities to ;

assess procedural and performance adequacy and conformance with the

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applicable T The resident inspectors witnessed selected activities to verify that, i where applicable, approved procedures were available and in use, i prerequisites were met, equipment restoration was completed, and ;

maintenance results were adequat !

l The following maintenance activities were reviewed or witnessed in '

detail:

1 Replacement of Outboard Seal on IB Charging Pump j I

On September 27, while unit I was in Mode 5, the outboard seal on j the IB charging pump failed. Work orders 93069838, 93070025, and ;

93071290 were initiated to repair or replace the seal as j necessary. Measurements were taken and it was determined that apparently the pump shaft had warped and replacing its seal would j not complete the repair. Instead, the pump's rotor, including a new seal, was replaced. On September 30, the staff ran the pump after the rotor was replaced and found that the new seal demonstrated unstable temperatures, at higher than expected values. The outboard seal on the new rotor was replaced, and on October 1 the pump was tested and the seal temperatures stabilized. The pump was then returned to service. Throughout l

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these seal and rotor repair activities the inspectors observed l maintenance work activities, including removal of the seals,  !

evaluation of the old seal and rotor conditions,'and test runs on -!

the pump. The inspectors verified that work was completed in '

accordance with the work order _

The inspectors also verified, that prior to its return to. service, --

the' pump was properly vented, run and tested to ensure '

operabilit :

! Defective Weld on Unit 1 Steam Generator Tube Plug -

On October 5, with Unit 1.in Mode 1 at approximately 10 percent i power and increasing, chemistry samples of the secondary system ,

indicated that there was a potential primary to secondary leak, 3 although, at this power level, the leak rate was not easily

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discernable. Subsequent sampling at 22 percent power' revealed a .

primary to secondary tube leak in the "A" steam generator. This

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leak was estimated to be 200 to 400 gpd. Although this was less- 1 than the TS limit of 500 gpd, the licensee's administrative' limit '

of 50 gpd was exceeded. Therefore, a shutdown to Mode'5 was-initiated at 10:10 p.m. Mode 3 was reached the following day at 2:15 Subsequent investigation revealed that the hot leg tube plug i steam generator was leakin '

located in position 39-72 in the "A" This plug was installed on September 9 after a sleeve pull was performed on the associated tube. The defective plug was removed, ,

as well as a second welded plug in location 7-78 that was - y installed at the same- time as the, plug in 39-72. The licensee: -

indicated that this plug was removed because its. quality could not  !

be guaranteed. New plugs were welded in these locations and each'

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weld was visually inspected by licensee QC personnel and Babcock '  ;

and Wilcox inspectors. Following these inspections, the steam 3 generator was pressure-tested to verify .that the new plugs were i leak tigh l In analyzing the circumstances associated with this event, the:

inspectors noted that the initial- post-weld visual inspection of '

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the tube plug was performed remotely using a video camera. The  ;

inspectors reviewedithe video recording of the QC inspection for; a this weld and noted irregularities in the. weld pattern.- Th .

licensee had previously determined that the weld was faulty q because there was insufficient weld overlapL at' the weld start and 1 stop point. The poor. quality. of the weld. was not: identified - 1 during the post-weld, remote,- visual QC inspectio j t

At the end of this inspection period, licensee personnel were l investigating the contributing factors that led to the poor quality of ~ the weld and other corrective actions that could be implemented to prevent-recurrence. The licensee initiated PIP 1- l M93-964 to address this issue. The inspectors will review these- 1

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corrective actions upon completion of the corrective action This issue will be carried as an unresolved item pendinn completion of this revie This item is documented as URI 369/93-22-01: Incomplete Weld for Steam Generator Tube Plu ,

c. Reactor Vessel Internal Cladding Gouged - Unit 2  ;

The inspectors reviewed an evaluation that was conducted by the ;

licensee engineering staff in response to a Problem Investigation ,

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Process report PIP-2-M93-0687. The evaluation was provided to determine the reactor vessel's operability for the licensed life of McGuire Unit 2 without any repairs to the gouged are Background: As a result of the 10 year in-service inspection of the reactor vessel, which was conducted during the most recent Unit 2 outage (2-EOC-8), a gouged area was identified in the reactor vessel internal cladding. The vessel inspection was- -

conducted to satisfy the requirements of ASME Boiler & Pressu Vessel Code,Section XI,1980, IWB-2500 (specifically, Table au-2500-1). The gouged area was in the cladding of the lower vessel interior at 290*, approximately two feet up from the incore :

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Evaluation: The gouge was initially discovered on July 22, 1993, ,

through the use of color video equipment contracted from B&W-Nuclear Services. The colored video was especially helpful because it showed a distinctive, bright orange indication in the deepest section of the gouge. The location of the gouge was more_ ,

accurately identified as being at 290* circumferentially and two ,

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to three inches above the bottom head to bottom head spherical shell weld (W01). After the gouge was identified, video ;

inspections were performed at various angles and elevation i Because of the camera size a profile view could not be attaine '

Initial assumptions were that the gouge penetrated into the low alloy steel base metal. An ultrasonic test (UT) using Automatic Reactor Inspection System test probes was used to determine if any l cracks existed under the gouge. A smaller camera (black and white !

video) was used to attain a close-up, profile view of the are Special measurement scales were used to visually determine the !

dimensions of the gouge, which were as follows: the length'was ,

1 3/4", the depth was 5/32", and the height was 1/2". Afterwards, a " Dental Impression" was taken to obtain exact measurements. The :

length was 1.64", width was .40", and depth was .055". According ;

to the vessel manufacturer's drawing RDM-30738-1536, minimum ;

dimensions for clad thickness is .126". This indicated that the flaw was entirely in the claddin Site records revealed that, on August 16, 1976, during construction, a mechanic accidentally dropped a 20-foot length of

! small diameter piping into the vessel while attempting to lower it ,

into the vessel. At the time no visible damage was identifie i The manufacturer's records did not indicate that any damage was

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found near weld WOI prior to the vessel's shipment. This weld was also examined by UT on September 8, 1978, and visually on November 10, 198 Neither examination revealed any gouges in the claddin Conclusions: Westinghouse developed an analysis of corrosion rates and assumed the exposure of the base metal. The analysis revealed that the expected corrosion rate will not cause stress intensity limits to exceed the ASME code used for fabrication (Section III, 1971 edition addenda through Summer of 1971) for the remainder of the service life. Nor will the corrosion rate create l any structural deficiency in the vessel. The dark " rust-colored" section on the colored video was attributed to accumulation of corrosion products from other sources in the gouged are Observations: The inspectors interviewed several individuals who-were involved with the inspection and evaluation of the gouge and j subsequent formation of conclusions. The NRR Project Manager, the '

NRR Technical Staff, the resident inspectors and Region II management were frequently apprised by the licensee concerning the identification, inspection and conclusions. The inspectors found that the engineering conclusions were conservative and demonstrated good engineering judgmen No violations or deviations were identifie . Information Meetings With Local Officials (94600)

On October 12, the Senior Resident Inspector attended a meeting that was conducted between site personnel, representativ_es of the state of North i Carolina, and members from the emergency management organizations I

representing counties near the McGuire plant site. During the meeting, the inspector and the various representatives discussed, in general, the role and location of the Resident Inspector's Office. The focus of the 4 meeting was an annual site energency exercise that was scheduled to be !

conducted during the week of October 18, 199 !

l l 6. Licensee Event Report (LER) Followup (90712, 92700)

The following LER was evaluated to determine if the information provided met NRC requirements. The inspectors considered the adequacy of description, verification of compliance with Technical Specifications l and regulatory requirements, corrective action taken, existence of l potential generic problems, fulfillment of reporting requirements, and i the relative safety significance of each event. Additional in plant reviews and discussion with plant personnel, as appropriate, were conducted. The following LER is closed:

l (Closed) LER 369/91-08: Under certain postulated conditions, the diesel generators could be rendered inoperable because of a design deficiency defined as insufficient pipe wall thickness of steam and feedwater i piping in the vicinity of the diesels. The inspectors verified that the '

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piping erosion measurements were completed under work request 890315 on ;

September 26, 1991. No excessive erosion was noted. The piping was ,

added to the station's erosion / corrosion program for continued- :

monitoring. The inspectors reviewed documentation from modifications MG-12393 and MG-22393 for upgrading the 2" main steam drain lines and ;

the 4" feedwater tempering lines to seismic grade piping. The unit 2 '

modification was completed during the 1992 EOC7 outage and the unit 1-modification was completed during the 1993 EOC8 outag . Followup on Previous Inspection Findings (92701, 92702, and 71707)

The following previously identified items were' reviewed to verify _ that the licensee's responses, where applicable,- and actions.were in _

compliance with regulatory requirements and corrective actions have been i implemented. This verification included record review, observations, and discussions with licensee personne , (Closed) Violation 369/91-31-01: Failure to provide adequate procedures for volumetric leak rate calibration resulting in i inoperability of both trains of annulus ventilation. The-licensee ,

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responded to this violation in a letter dated March 2,1992. The inspectors verified that the volumetric' leak rate calibration procedures have been revised to include instructions for control = y of the annulus doors. The inspectors observed that the contro room alarms were installed during the E0C8 refueling outages 3 Training in the use of the new alarms, the procedure changes, and the control program for the annulus doors has been completed, (Closed) Violation 369/91-22-02: Failure to follow pro':edure for removal of lower reactor internals. The licensee responded to ;

this violation in letters dated December 17, 1991, and June 3, 1993. The inspectors verified that the licensee revised ,

procedures for the handling of the lower internals. A procedure

adherence group was created to develop guidelines for implementation of procedure requirements. The inspectors verified l that these guidelines have been incorporated into the y administrative procedure ; (Closed) Unresolved Item 50-370/93-18-03 Maintaining system

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configuration control - 2NV-46 The inspectors reviewed the records for the letdown system ,

following a hydrostatic test that was conducted on the system i during the last outage just before responsibility for the system !

was returned to operations. Records indicated that, following the l hydrostatic test, valve 2NV-464 was returned to its normally l closed position and verified closed by a second person. After the- -I water hammer event, the handwheel for 2NV-464 was found j approximately 1/4 turn open, allowing a leak path through .its j downstream " cracked" pipe nipple. Initially, the inspectors were !

informed that this valve was 1-1/4 turns open. No other records !

indicate that the position of this valve was changed prior to the

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water hammer even The licensee provided a viable explanation for this slight mispositioning, indicating that it could have occurred when clean .p of shielding material (lead) was being conducted, just prior to the placement of the plant systems back into service. Another explanation was that the force experienced during the system water hammer may have caused the valve hand wheel to move 1/4 turn. The inspectors determined that, even >

though 2NC-464 was not fully closed, the effect of the condition :

did not significantly impact reactor safety since system leakage was identified and the letdown system was isolated within eight -

minutes after 2NV-2 was opened. The worst-case leakage was estimated to be between 10 and 15 gallons per minute. In the afternoon of September 10, plant management required teams of operations personnel to conduct walkdowns inside Unit 2 containment. The resident inspectors accompanied these teams and ;

observed their actions. The teams were given lists of all system valves that acted as vent or drain paths that should normally be closed and capped. Each of these valves were checked tight. As a result, no valves were found mispositioned and only one pipe cap -

required more than " snugging up." The worst-case leaks found were three caps dripping at a rate of about one' drop every 15 second ;

In view of the minimum safety significance of the impact of vent !

and drain valve 2NV-464 being only 1/4 turn open and the actions 3 observed by the teams of operators inside containment within 12 l hours after finding 2NV-464 not fully closed, the inspectors ;

viewed this Unresolved item (50-370/93-18-03, maintaining system ,

configuration control - 2NV-464) as a non-cited violation. The inspectors informed the licensee that, because the criteria specified in Section VII.B of the NRC Enforcement Policy were satisfied, this item would be identified as a non-cited violation, 3 50-370/93-22-02, Loss of configuration control, letdown system valve 2NV 46 d. (Closed) Unresolved Item 50-370/93-18-02, Operation of unit 2 systems and equipment - water hammer in letdown system, will be closed and is upgraded to a violation. The abnormal operating procedure that affected the letdown system immediately before and following the water hammer event, AP/2/A/5500/12, Loss of Normal Letdown Charging or Seal Injection Flow, was evaluated. This ;

procedure did not contain any cautions, instructions, guidance, or controls associated with the electrical interlock between 2NV-2 :

and 2NV-458. The procedure did not alert the operators to the l potential for system voiding if 2NV-458 was not closed upon the closure of 2NV- ,

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The violation was caused by operators not having adequate procedural controls over the letdown system. Specifically, ,

abnormal operating procedure, AP/2/A/5500/12, did not provide l cautions, instructions guidance, or controls to verify that the l interlock between 2NV-2 and 2NV-458 functioned. The inspectors ;

interviewed personnel from the site operations training department j I

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and evaluated the training provided to plant operators on the -

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interlocks associated with 2NV-2 and 2NV-458. The inspectors determined that the operators should have been aware of how this interlock works and its purpose. This item will be identified as a violation 50-370/93-2.2-01, Inadequate abnormal procedural guidance to alert operatior,s personnel of potential voiding in the letdown pipin .

8. Exit Interview j The inspection scope and findings were summarized on October 18, 1993, with the Station Manager and members of his staff. The following items '

were discussed in detail:

Violation 50-370/93-22-01: Inadequate abnormal procedure guidance to alert operations personnel of potential voiding the letdown piping, (paragraph 7.d.).  !

Non-cited Violation 50-370/93-22-02: Loss of configuration i control - letdown system valve 2NV-464, (paragraph 7.c.). -

Unresolved Item 50-369/93-22-01: Incomplete weld for steam generator tube plug, (paragraph 4.b.).

The licensee representatives present offered no dissenting comments, nor did they identify as proprietary any of the information reviewed by the inspectors during the course of their inspection. The licensee informed '

the inspectors that the items discussed in paragraphs 6 and 7 were close ;

9. Acronyms and Abbreviations ASME - American Society of Mechanical Engineers EOC -

End-of-Cycle 3 gpd -

gallons per day  ;

LER -

Licensee Event Report {

NC -

Reactor Coolant System NCV -

Non-cited Violation  ;

NOV -

Notice of Violation l NRC -

Nuclear Regulatory Commission j NRR -

Nuclear Reactor Regulation .

PIP -

Problem Investigation Process 1 QC -

Quality Control )

TS -

Technical Specification -l URI -

Unresolved Item UT -

Ultrasonic Test i

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