IR 05000445/1997023

Insp Repts 50-445/97-23 & 50-446/97-23 on 971123-980103.No Violations Noted.Major Areas Inspected:Operations, Engineering,Maintenance & Plant Support

ML20199H777
Person / Time
Site:	Comanche Peak
Issue date:	01/30/1998
From:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
To:
Shared Package
ML20199H742	List: IR 05000445/1997023 ML20199H737
References
50-445-97-23, 50-446-97-23, NUDOCS 9802050119
Download: ML20199H777 (14)

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I ENCLOSURE

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l U.S. NUCLEAR REGULATORY COMMISClON REGION IV ,

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Docket Nos.: 50-445

. 50-446 License Nos.: NPF-87 i NPi:-89

. Report No.: 00-445/97 23 50-446/97-23 Licensee: TU Electric Facility: Comanche Peak Steam Electric Station, Units 1 and 2

. - Location: FM-56 Glen Rose, Texas Dates: November 23,1997, through January 3,1998 Inspectors: _ H. A. Freeman, Acting Senior Resident inspector R. L. Nease, Resident inspector Approved By:. J.1. Tapia, Chief, Project Branch A Division of Reactor Prcjects

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EXECUTIVE SUMMARY Comanche Peak Steam Electric Station, Units 1 and 2 NRC Inspection Report 50-445/97 23; 50-446/97 23 The reWdent inspection included aspects of licensee operations, engineering, maintenance, and plant support. The report covers a 6 week period of resident inspectio Operations _

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Operations was characterized by good command, control, and communications as observed in the reactor ceolant system drain down and vacuum fill (Section 01.2), the reactor startup from refueling (Section 01.3), and the response to the failure of a nitrogen-16 detector channel (Section 01.4).

An alarm indicating that the south wide range gas monitor sample pump had stopped was acknowledged without compensatory actions being taken (Section 04.1).

Malattaance

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Tbg licensee's troubleshootMg efforts regarding the failure of the Unit 1 safety injection stquencer were well-controlled, and included thorough management involvement (Section M1.1).

• Material condition continued to be excellent, and the licensee actively identified and corrected material condition deficiencies in a timely manner (Section M2.1).

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Operations Notification end Evaluation Form 97 787, documenting the Unit 1 Component Cooling Water Pump 1-02 failure, was closed without fully implementing the corrective actions as required by procedure (Section E8.1).

Engineering was proactive in addressing equipment and system reliability issues and provided good support during the startup of the Ur.:'t 2 feedwater heater drain tank pumps (Section E2.1).

Plant Sucoort

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Radiation protection technicians were knowledgeable of radiological requirements and took prompt and appropriate actions in response to the inspector's concerns regarding fixed contamination (Section R1.1).

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Report Details Summarv of Plant Status

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Uni Unit i began the inspection period at 100 percent power On December 13, the unit was manually shutdown to Mode 3 (hot standby) in accordance with Technical Cpecifx:ation requirements when the Train B safety injection sequencer failed to reset during recovery from a surveillance test. After the sequencer was repaired, Unit i resummi full power operations on December 15 and remain 0d there through the end of the report perio Unit 2 Unit 2 began the inspection period in Mode 6 with the reactor core being reloaded. On December 8, the reactor was taken critical and on December 10, the main generator was synchronized to the grid and the output breakers were closed, algnifying the end of the third Unit 2 refueling outage. Unit 2 achieved 100 percent power operations on December 22 and remained there through the end of the report perio LQperationa 01 Conduct of Operations

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01.1 General

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The conduct of operations was generally characterized by good command, control and

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communications. The drain down, the vacuum fill, and the startup of Unit 2 was performed in a well-controlled and professional manner. Good, conservative decision-

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making was also evident when the licensee shutdown Unit i following the Train B safety injection sequencer failure (Section M1.1).

01.2 Unit 2 Vacuum Fill Insoection Scooe (71707)

On November 2g and 30, the inspector observed the licensee conduct a prejob briefing and then drain down the reactor coolant system in accordance with Integrated Plant Operating Procedure IPO-010B, * Reactor Coolant System," in preparation for a vacuum

. fill of the reactor coolant syste Observations and Findings The inspector noted that the prejob briefing was thorough and adequately covered expected hold points and contingencies. The unit supervisor assigned a qualified reactor operator to temporarily relieve the on shift operator so that allinvolved personnel could attend the briefin l

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2 The inspector observed the licensee diain down the reactor coolant system to midloo Shift management kept distractions to the operators to a minimum and the unit supervisor maintained close observation of plant parameters. The drain down was conducted in a controlled manner and all plant Instrumentation functioned as expecte C1.3 Unit 2 Reactor Startuo Inspection Scone (ZlIDI)

On December 7 ard 8, the inspector o'> served control room operators take the Unit 2 reactor to criticality using Integrated P, ant Operating Procedure IPO-002B, * Plant Startup from Hot Standby." Observations and Findinos The inspector independently verified that the licensee hae met procedure prerequisite Throughnut the evolution, the unit supervisor routinely reinforced requirements by reading sloud the upcoming steps in the procedure and discussing expected plant response. The inspector considered this a prudent approach to procedure implementation. During the entire evolution, operators had the procedure in hand and referred to it often. The inspector observed excellent command and control and clear three part communications throughout the evolution. The inspector concluded that the licensee performed the reactor startup in accordance with procedures, demonstrated excellent command and control, and exercised good communication .4 Resoonse to Abnormal Conditions On December 12, the inspector observed control room operators support instrumentation and controls technicians adjust the nitrogen-16 channels for neutron streaming. Channel three failed low when it was retumed to service following the adjustment. Operators immediately recognized the failure and removed the channel from service. The unit supervient demonstrated excellent command and control while clearly calling out steps in the abnormal response prc:edure. Good three-part communications by all operations personnel were observed. The inspector concluded that the response to the abnormal condition was appropriate, well controlled, and in accordance with station procedure Operator Knowledge and Performance 04.1 Wide Ranoe Gas Monitor Fumo Failure Insoection Scoce (71707)

On November 19, the licensee identified that the south wide range gas monitor sample pump had been stopped for approximately 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> and that the surveillances required by

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3-the Offsite Dose Calculation Manual had not been performed as required. The inspec, tor reviewed the licensee's investigation into the cause of why the condition was not identified earlier and the resultant corrective action b. Observations and Findinas Technical Specification 6.8.3 requires the licensee to implement the requirements of the Offsite Dose Calculation Manual. Controlitem 3.3.3.5 of the Manual requires that the following equipment be operable during effluent discharges: one channel per stack of the noble gas release rate monitor, the iodine sampler, the particulate sampler, and the sample flow rate monitor. Control item 3.3.3.5 allows for effluent discharge with less than one channel per stack provided that certain actions are taken, including estimating sample flow rate once per 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> During shift turnover on the morning of November 19, the operators identified that the south wide range gas monitor sample pump had stopped at 9:44 p.m. the previous night and that the conditional surveillance requirement for continued effluent discharge (estimating sample flow rate once every 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />) had not been performed. They also noted on the display screen that the alarm appeared to have been acknowledged. Each monitor requires that the sample pump be running in order to be operable. Operators immediately restarted the sample pump and wrote a operations notification and evaluation (ONE) form documenting the missed surveillance The licensee's investigation revealed that expected radiation alarms occur simultaneous to the stopping of the sample pump and that the loss of sample flow alarm may tse acknowledged at that time. The licensee also found that instrumentation and controls technicians had performed calibrations on the south wide range gas monitor sample pump earlier in the day and may have acknowledged the alarms as part of the surveillance. The licensee also determined that since the alarm summary screens are not listed in chronological order, the alarm may have been overlooke The licensee issued a lessons learned notification on the overlooked alarm. Additionally, the operations shift manager reiterated management expectations on the acknowledging of radiation alarms by groups other than operator During the 8-hour period with the sample pump off, the inspector determined that it was unlikely that an unmonitored release could have occurred because the ventilation fans take suction from a common supply duct and exhaust to either the Train A or Train B exhaust duct. Both the Train A and Train B exhaust ducts supply both ventilation stack Ne radiation monitor alarms occurred on the north stack. Additionally, the south particulate, lodine, and gas detector was operable during the entire tim The licensee's failure to es'.imate the sample flow rate once every 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> while they continued an effluent disc'iarge with an inoperable wide range gas monitor sample pump was a violation of Techr0al Specification 6.8.3. This nonrepetitive, licensee-identified i

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-4 and corrected violation is being treated as a noncited violation, consistent with Section Vll.B.1 of the NRC Enforcement Policy (50-445(446)/9723-01).

IL Maintenance M1 Conduct of Maintenanca I M1.1 Unit 1 Safety inloction Seouencer Failure Insoection Scoon (93702. 62707) )

Following Slave Relay K-601 testing on December 12, the auto-tester indicated a Faun 55, ' output relay loss of continuity,' on the Train B sequencer. Initial troubleshooting revealed that the 15V power supply output was at 0.9V. The inspector responded to the site to observe the troubleshooting effort and to verify that the reactor had been shutdown as required by Technical Specifications.

' .Qbservations and Cindinos At 11:27 p.m. on December 12, the licensee identified a problem with the Train B safety injection sequencer. The licensee commenced troubleshooting activities while at 100 percent power. Technical Specification 3.3.2 Action 26 requires that an inoperable sequencer be restored to operable status within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> or be in at least hot standby in the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. Since the sequencer had not been restored, the licensee commenced shutdown at 4:03 a..n. The reactor was placed in hot standby (Mode 3) at 11:02 The inspector verified that the licensee had met the time limits for the shutdow The licensee initially believed that the 15V power supply had failed and replaced it with a dedicated power supply taken from a test rack. The replacement power supply exhibited the same results as the original. The licensee then replaced the logic board card frame and experienced the same results. Finally, the licensee tested the original power supply and found it was functioning normally. The licensee subsequently determined that a protective circuit had actuated when operators replaced a failed indicator bulb at the end of the K-601 slave relay test and that the protective device was the cause of the limited voltage output. This protective circuit was not discussed in the equipment technical manual. The licensee placed the original power supply back in the circuit and declared the sequencer operable. The reactor was returned to power on December 1 Conclusions The inspector concluded that the licensee's troubleshooting efforts were systematic, well controlled and had thorough management involvement even though the troubleshooting

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methodology was complicated by an inadequate description of a protective circuit in the -

equipment technical manual. A Technical Specification required reactor shutdown was completed in a controlled manne ____

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. M1.2 Eurveillance Observations Scone (61726) -

The inspector observed portions of the following work activity:

Unit 2 Turbine-driven Auxiliary Feedwater Pump Surveillance Observations and Findings The inspector found that the surveillance activity was well performed. The licensed operators used good self-verification techniques and closely followed the procedure M2 Maintenance and Material Condition of Facilities and Equipment M2.1 Review of Material Condition Durina Plant Tours

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The inspectors conoucted routine plant tours to evaluate the material condition of the plant, Observations and Findings All deficiencies noted by the inspectors during routine tours of the facility had been previously identified by the licensee for inclusion in the corrective action program. The inspector observed the startup of the Unit 2 turbine driven auxillary feedwater system following design modifications intended to minimize condensate in the steam supply lines. Whereas significant amounts of water had discharged through the sentinel valve during startups prior to the modification, the inspector did not observo^any coredensate issuing from the sentinel valv The inspector found that the material condition of the facility continued to De excellen The licensee continued to actively identify and correct material condition deficiencies in a timely manne M8 Miscellaneous Maintenance lasues (92700,02902)

M8.1 (Closed) Licensee Event Reoort 50-446/96007; reactor trip due to loss of reactor coolant pump caused by loss of electrical Bus 2A3 This event was addressed in Inspection Report 50-445/96-12;50-446/96-12. No new issues were revealed by the licensee event report.

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~6 l MB.2 (Closed) Inspection Followuo item 50-446/9616-05: nonsafety related inverter failure corrective actions. This item was left open to follow the licensee's root cause determination and corrective actions for a failure of Inverter 2C3 on December 8,199 During the recent Unit 2 refueling outage, the licensee replaced the Elgar inverters, including Inverter 2C3, with inverters from Solidstate Controls Incorporated. The inspector concluded that this corrective action should preclude any future similar failur M8.3 (Closed) Violation 50-445/9714_03; failure to perform a visualinspection of the affected area in containment in accordance with procedures after work is completed. Procedure STA-620, " Containment Entry,' required the work group supervisor to perform this visual inspection. As documented in NRC Inspection Report 50-445/97-14; 50-446/9714, dated June 30,1997, the inspector found that the work group supervisor had not entered containment on two separate occasions. Therefore, the work group supervisor could not have performed the visualinspection himself. In the response to the violation, dated July 10,1997, the licensee noted ambiguities concerning the definitions and responsibilities of the work group cupervisor and responsible work organization supervisor, in procedures STA 606, ' Control and Maintenance of Work Activities,' and STA-620. In addition, the licensee stated that delegation of this responsibility had been common practic Immediate corrective actions taken by the licensee were to document this deficiency in a ONE form and perform a walkdown of containment. The inspector witnessed the containment walkdown. The licensee's long term corrective actions included revising procedure STA-620 to clarify the definitions and responsibilities of the responsible work organization supervisor and to provide a signature block to indicate who actually performed the visual inspection. The inspector verified that the corrective actions described in the licensee's response letter were reasonable and complet tilJulgineering E2 Engineering Support of Facilities and Equipment E Egedwater Heater Drain Tank Pumo Startuo On December 15, the inspector observed the startup of the Unit 2 feedwater heater drain tank pumps following the first phase of modifications intended to make improvements to the system and to minimize water hammer. Conservative safety precautions were taken to restrict personnel access to the area where piping movement had been observed in the past. Engineering personnel actively participated in the prejob briefings. A number of engineers were stationed at strategic locations along the piping to observe piping movement. Although the engineers were not completely satisfied with the results of the modifications negating all water hammer in the heater drain pump recirculation lines, other aspects of the modification were successful. These included the addition of a warm-up line to prevent water hammer in piping to the condenser and the addition of isolation valves to make it easier to perform maintenance on the heater 1 rain pump discharge valve. Engineering continued to pursue options for reducing water hammer in the heater drain pump recirculation lines and planned to incorporate lessons learned into

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modifications scheduled for the ont Unit i refueling outage. The inspector concluded that engineering provided good support during the startup of the Unit 2 feedwater heater drain tank pumps, and that they were proactive in addressing equipment and system reliability issue E8 Miscellaneous Engineering lasues E8.1 Comoonent Coolina Water Motor Termination Failure Insoection Scone f 37551)

On November 30, during the Unit 2 refueling outage, the Train A component cooling water (CCW) pump, CCW 2-01, experienced a phase B motor termination failure during a motor start. The failure caused the 1000 horsepower Westinghouse Lifeline D motor to trip. The licensee subsequently found that the failure was a result of a loose motor termination lug. The licensee initiated ONE Form 971574 to document the failure and its resolution. The inspector reviewed the licensee's response to this issue and the procedural requirements for processing ONE Form Observations and Findinas immediate Ooerability Concerns: The licensee determined that the CCW, auxiliary feedwater, containment spray, safety injection, centrifugal charging, and residual heat removal pumps were the only Westinghouse Lifeline D pump motors installed in the i

plant. Shortly following the CCW Pump 2-01 motor failure, the licensee performed thermography on the Unit 2 CCW, auxiliary feedwater, containment spray, safety injection, and centnfugal charging pump motor leads and found no indication of degradation. The licensee concluded that there was no immediate operability concern for the Units 1 and 2 Westinghouse Ufeline D pumps, based on the thermography results and because: (1) failures had only occurred in the largest of these pump motors, the 1000 horsepower CCW pumps; (2) failures had only occurred upon starting, at which time the greatest current is drawn; (3) all three phases of CCW Pump 1-02 had been refugged in August 1997; (4) CCW Pump 1-01 was currently running and considered operable; and (5) all motor termination lugs for the residual heat removal pump motors had been recently replaced by Comanche Peak maintenance. The inspector agreed with the licensee's assessmen Previous Failurrai: The licensee identified two previous failures of Unit 1 CCW Pump 1-02 motor that were similar to the failure of the Unit 2 CCW Pump 2-01 moto The first failure occurred in 1989, when CCW Pump 1-02 failed during a start. At that time, the licensee determined that the failure was caused by deficiencies in the termination lug connection for Phase B which, over time, resulted in the lug becoming cracked. The licensee repaired the failed termination lug and performed thermography on the terminations of 19 Unit 1 and common 6.9 kV motors. Based on their analysis of

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~B-the thermography results, the licensee concluded that deterioration of termination connections was not a generic problem and routine thermography was not recommende The second failure occurred on July 27,1997, in the Unit 1 CCW Pump 1-02 motor, Phase A termination lug. The licensee immediately replaced termination lugs for all three phases of CCW Pump 1-02. The licensee's evaluation, documented in ONE Form 97 787, determined that the failure was caused by inadequate crimpinJ of the termination lug to the electrical cable coupled with loosening of the connection due to thermal cycling caused by frequent starting of the pump for routine equipment swaps. In !

reviewing industry experience, no similar failures were found. To ensure that there were no generic implications for similar pump motors, the engineering resolution for ONE Form 97 787 required that thermography and visualinspection would be performed on all Westinghouse Lifeline D motor leads, including all CCW, auxiliary feedwater, containment spray, residual heat removal, safety injection, and centrifugal charging pump Procedure STA-422, ' Processing of Operations Notification and Evaluation (ONE)

Forms,' Revision 11, states in part, that the Responsible Manager may close a ONE form prior to the actual completion of corrective actions provided those corrective actions have been initiated and are being tracked as part of another auditable, controlled and proceduralized process. Contrary to Procedure STA-422. ONE Form 97 787 was closed without the recommended thermography or visual inspections being performed or scheduled to be performed. Had the licensee properly closed ONE Form 97 787, it is l doubtful that the corrective actions would have been completed in time to prevent the November 1997 failure because the licensee had not planned to conduct these inspections until after the Unit 2 outage, This nonrepetitive, licensee-identified and corrected violation of Technical Specification 6.8.1 is being treated as a Noncited Violation, consistent with Section Vil.B.1 of the NRC Enforcement Policy (50-445/9723 ^2).

As part of the resolution of the November 1997 failure, documented on ONE .

Form 971574, the licensee issued work orders to perform thermography on all Westinghouse Lifeline D pump motors. The results of the thermography will be evaluated before determining final corrective actions. Currently, Engineering is evaluating several potential contributing factors to the failures, such as the size of the termination lug compared to the cable size, the crimping force used with respect to the cable construction, inadequate insertion of the cable into the termination lug, termination lug style (open-ended or close-ended), and thermal cycling. In addition, the licensee initiated quick turnaround lessons-learned training for all engineering personnel to reinforce the requirements for closing ONE forms. The inspector found the licensee's most recent approach to the resolution of this issue to be comprehensive and appropriat .-____..._._______.__w _ _ _. ____ _ _ . - ._ ..

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Conclualona

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ONE Form 97-787, documenting the July 1997 CCW pump failure, was closed without i

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, fully implementing and/orecheduling the corrective actions as required by procedure. _

The licensee's approach to the resolution of this issue, with respect to the most recent  :

failure of CCW 2-01 which occurred in November 1997, was comprehensive and l appropriate.= -r a

IV. Plant Support R1 Radiological Protection and Chemistry Controls

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a, inanaction Scone (71750)

! The inspector observed radiological protection activities during routine tours and

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observations of maintenance activities, inspected selected doors that were required to be

locked for radiation protection purposes, and reviewed primary and secondary water chemistry result *

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b. L Obmarvations and Findinas - -a

The inspector found th'at radiation protection technicians were present during . [

- maintenance activities in radiation areas, as expected Ali of the selected doors that -  !

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were required to be locked for radiation protection purposes were verified to be locked by

. the inspector. The licensee closely monitored primary and secondary chemistry results l and the inspector found that the results were within the prescribed limit [

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R Tour of Unit 2 Radiolaainally Contre!H Area (71750F l While touring the Unit 2 radiologically controlled area on December 17, the inspector observed a dirty swipe pad and an unattended dry bucket and mop on the 778 foo ,

elevation of the Unit 2 safeguards building. The inspector frisked the swipe pad, bucket, i and mop, and found that the radiation level on the mop was approximately 300 counts - i per minute above background radiation level. The inspector called radiation protection - 1 technicians who immediately responded to the area. The radiation protection technicians determined that the mop had fixed contamination and labeled it with a " radioactive

material" sticker. Although not required by procedure, material in the radiologically controlled area that is identified as having fixed contamination is toutinely labeled as l radioactive material, Because it was fixed and not loose, the contamination on the mop

~ handle did not pose a radiological hazard to personnel. Although, the used swipe pad

, did not show contamination, radiation protection technicians noted that.the used swipe j' pad should have been disposed of. The inspector concluded that radiation protection

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radiological requirements, and took prompt and appropriate action :

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-10-htings X1 Exit Meeting Summary The inspectors presented the resuMs of the inspection to members of licensee management on January 8,1998. The licensee acknowledged the findings presented. No proprietary information was identmed.

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ATTACHMEtil SUPPLEMENTAL.lNFORMATION PARTIAL LIST OF PERSONS CONTACTED Licensee M. R. Blevins, Vice President, Nuclear Operations  !

J.- J. Kelley, Vice President, Nuclear Engineering and Support D. R. Moore, Operations Manager D. J. Reimer, Technical Support Manager

- C. L. Terry, Senior Vice President and Principal Nuclear Officer ,

I INSPECTION PROCEDURES USED 37551 Onsite Engineering 61726 Surveillance Observations 62707 Maintenance Observations 71707 Plant Operations 71750 Plant Support Activities 92700 Onsite Followup of Written Reports of Nonroutine Events at Power Reactor Facilities 92902 Followup - Maintenance 93702 Prompt Onsite Response To Events At Operating Power Reactors ITEMS OPENED AND CLOSED Opened 50-445/9723-01;50-446/9723-01 NCV failure to implement conditional surveillance following loss of wide range gas monitor sample pump flow (Section 04.1)

50-445/9723-02 NCV failure to fully implement or schedule corrective actions prior to closure of ONE form (Section E8.1)

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2-Closed

- 50 445/9723-01; 50-446/9723-01 NCV failure to implement conditional surveillance following loss of wide range gas monitor sample pump flow (Section 04.1)

50-545/9723-02 NCV_ failure to fully implement or schedule corrective actions prior to closure of ONE form (Section E8.1) -

50-446/96007 LER reactor trip due to loss of reactor coolant pump caused by loss of electrical Bus 2A3 (Section M8.1)

50-446/9616-05 IFl nonsafety related inver1er failure corrective actions (Section M8.2) .

50-445/9714-03 VIO failurs to follow procedures for performing a -

visualInspection of containment

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(Section M8.3)

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