IR 05000445/1999011

Insp Repts 50-445/99-11 & 50-446/99-11 on 990418-0529.No Violations Noted.Major Areas Inspected:Operations, Maintenance,Engineering & Plant Support

ML20196E672
Person / Time
Site:	Comanche Peak
Issue date:	06/22/1999
From:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
To:
Shared Package
ML20196E671	List: IR 05000445/1999011 ML20196E664
References
50-445-99-11, 50-446-99-11, NUDOCS 9906280372
Download: ML20196E672 (11)

Text

-

q

.

.

ENCLOSURE 2 U.S. NUCLEAR REGULATORY COMMISSION

REGION IV

Docket Nos.: 50-445 50-446 License Nos.: NPF-87 NPF-89 Report No.: 50-445/99-11 50-446/99-11 Licensee: TU Electric Facilitv: Comanche Peak Steam Electric Station, Units 1 and 2 Location: FM-56 '

Glen Rose, Texas j

Dates: April 18 through May 29,1999 '

Inspectors: Anthony T. Gody, Senior Resident inspector Scott C.' Schwind, Resident inspector Gilbert L. Guerra, Resident inspector Don B. Allen, Project Engineer G. Michael Vasquez, Senior Enforcement Specialist Approved By: Joseph I. Tapia, Chief, Branch A Division of Reactor Projects ATTACHMENT: Supplemental Information

.

.

, 7

~

.

EXECUTIVE SUMMARY Comanche Peak Steam Electric Station, Units 1 and 2 NRC Inspection Report No. 50-445/99-11; 50-446/99-11 This inspection included aspects of licensee operations, maintenance, engineering, and plant support. The report covers a 6-week period of resident inspectio Operations

During the restart of Unit 2 following the fourth refueling outage, operators performed

' the return to full power in accordance with applicable procedures. Restoration and cleanup following the outage was completed in a timely manner, with plant equipment in good material condition and properly aligned for normal power operation *

Control room operators responded well to the loss of the Unit 2, Train A safeguards bus on May 22. The licensee was unable to determine the root cause of the event.

>

Maintenance

The conduct of maintenance and surveillance activities was good. Maintenance and surveillance activities conducted during the refueling outage and during plant startup were planned and coordinated safely and proficiently. Personnel directing surveillance tests were knowledgeable, followed the procedures, and maintained good command and control of the activitie Enaineerino e

Safety injection Accumulator 2-04 developed a small intersystem leak. System engineering provided good support to safe plant operation by promptly evaluating the impact of the leakage and identifying the source. The troubleshooting plan was

'

thorough and appropriately documented per plant procedure Plant Support i

Performance in the area of plant support remained good. Observations of radiological practices, fire protection activities, and security were consistent with past observation . )I

..

Report Details Summary of Plant Status L Unit 1 remained at 100 percent power throughout the inspection perio . Unit 2 began the r6 port shutdown for its fourth refueling outage. A reactor startup was

' performed on Apr.120,1999,' and the unit returned to 100 percent power on April 28,1999.

,

_

. Unit 2 remained at 100 percent power for the remainder of the inspection perio )

,

l. Operations 01 ~ Conduct of Operations -  !

..

i 01.1 - General Comments 171707)

' Using Inspection Procedure 71707, the inspectors conducted periodic reviews of ongoing plant operations. In general, the conduct of operations reflected a conservative decision-making policy; noteworthy observations are detailed in the sections below. The

, inspectors concluded that both units were operated by knowledgeable operators using good self-verification techniques and communication .2 Unit 2 Startuo and Return to 100 Percent Power

- Insoection Scoos (71707)

The inspectors observed Unit 2 control room operations during the reactor startup and return to 100 percent power following the fourth refueling outage, Observations and Findings

. < .

-

.

On April 20,1999, control room operators commenced startup of the Unit 2 reactor ;

following completion of the fourth refueling outage. The inspectors observed the

.

operators dilute Unit 2 to criticality. Control room activities were accomplished in a methodical manner and operators demonstrated good self-checking and independent i verification techniques.' Communications were good, as was command and control 4

within the control room. Reactor engineering provided good support for this evolution

.with the presence of a reactor engineer and the reactor engineering supervisor in the control roo .

Unit 2 operators performed the power increase and return to full power in accordance

,w ith Procedure IPO-003B, Revision 3, " Power Operations." The power increase was

- well controlled and was within the limitations for new fuel preconditioning. The reactor power was held at predefined power levels to perform calorimetric power measurements and adjust nuclear instrumentation.- Conditional surveillances were conducted at the required power levels.- The operators demonstrated clear understanding of the effects of reactivity changes on reactor power and axial flux difference and properly controlled rod positions and boron concentration to achieve the desired core conditions.

<

, _

,

1 - ,

f

, .2-I ' Conclusions ~ )

i'

Unit 2 operators performed the return to full power in accordance with applicable

. procedures. Good communications between operators was observed. Operators used

. good peer checking and self-verification techniques when manipulating control .

I O2' Operational Status of Facilities and Equipment -

- O Plant Tours and Enoineered Safety Features Walkdowns

" ~ Insoection Scoce (71707) '

The inspectors used Inspection Procedure 71707 to walk down accessible portions of

- the Unit 2, Train B, emergency diesel generato ' Observations and Findinas

. The inspectors conducted a system walkdown of the Unit 2, Train B, emergency diesel L generator utilizing the Updated Final Safety Analysis Report, lineup procedure, and plant drawings. The walkdown included the starting air, lube oil, and jacket water cooling systems. Also, included were the electrical and control board lineups. The inspectors found that the system was aligned properly as defined in the licensee's procedures and drawings. The inspectors noted that the local voltage regulator spring-loaded selector switch on the diesel generator control board was centered between the indications of normal and standby. The lineup procedure specified the switch to be in the normal

. position and position verification would be difficult without further guidance. The inspector reviewed the monthly surveillance lineup procedure and found that the i guidance listed specific annunciators for operators to verify. Completing the monthly switch position verification would result in positively verifying the position of the voltage !

regulator control switch. The inspector found this adequat ;

O2.2 ' Operational Status of Facilities and Eauioment  ! Insoection Scope (71707) '

The inspectors conducted tours of the following areas of the plant:

Units 1 and 2 safeguards buildings Unit 2 auxiliary building

- Units 1 and 2 electrical control buildings Unit 2 turbine building ' . Observations and Findinas i The inspectors noted that plant equipment was in good material condition and in its proper standby or operating condition. Scaffolding and ladders had been removed from Unit 2 following the refueling outage. Equipment and materials for the outage had been ,

- __- _ - _ -__- _ _____

3-or were being removed and work areas were being cleaned. No significant water, steam, or oilleaks were observed. Piping insulation had been restored. Pipe supports were observed to be in place and properly adjusted. Only a few contamination containment devices remaine Conclusions Unit 2 restoration and cleanup following the fourth refueling outage was complete, with plant equipment in good material condition and properly aligned for normal power operations.

02.3 Loss of Unit 2 Train A Safeauards Bus and Enaineered Safety Features Actuation Inspection Scope (71707)

The inspectors responded to the site after the Unit 2, Train A, safeguards bus lost power and verified that the operators responded properly and the engineered safety features actuation worked as designe Observations and Findinas At 7:15 a.m. CST, on May 22, the normal supply breaker (2EA1-1) to the Unit 2, Train A, safegaards bus tripped on neutral overcurrent. The neutral overcurrent trip of Breaker 2EA1-1 resulted in a lockout of the alternate supply breaker (2EA1-2) which deenergized the bus and caused an automatic emergency start of the Train A emergency diesel generator. Following the emergency start of the Train A emergency diesel generator, the blackout sequencer actuoted as designed to re-energize the bus and restore safeguards equipment to the bus. The Train A motor-driven auxiliary feedwater pump and the turbine-driven auxiliary feedwater pump both started as designed. Control room operators quickly assessed plant conditions and appropriately secured both auxiliary feedwater pumps. All plant equipment responded as designed with the exception of neutron detector well Fan 9, which failed to start. No adverse conditions resulted from this failur Relay 51N actuates on a neutral ground overcurrent condition on the bus; however, no grounds were detected on the bus or any of the equipment that was running prior to the breaker trip. After the trip, the relay remained locked-in, which prevented operators from reclosing alternate bus supply Breaker 2EA1-2 and the bus remained energized from the diesel generator for approximately 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. Further troubleshooting and inspection of the lockout relay and Breaker 2EA1-1 revealed no apparent damage or root cause for the breaker trip. As a precaution, the relay was replaced and Breaker 2EA1-1 was replaced with a recently refurbished breaker. The Train A bus remained powered from the Train A diesel generator until approximately 3:30 p.m. when the bus was shifted to its alternate Unit 1 offsite power supply through Breaker 2EA1- On May 23, at approximately 2 a.m., operators verified the reliability of the offsite power sources and returned the Train A bus to its normal offsite power suppl _ _ _ _ _ _ _

- - . - - - - - - - - - - - - - - - - - - - - - .--

.- . .

. .

i

4 Conclusions Control room operators responded well to the loss of the Unit 2, Train A, safeguards bus. The licensee was unable to determine a root cause for the normal supply breaker tri . Maintenance

,

, M1 Conduct of Maintenance M1.1 General Comments (61726. 62707)

Using inspection Procedures 61726 and 62707, the inspectors conducted reviews of ongoing maintenance and surveillance activities. In general, the conduct of maintenance and surveillance activities reflected a policy of procedure adherence and quality; noteworthy observations are detailed in the sections belo M1.2 Maintenance Observations :nspection Sqooe (62707)

The inspectors observed replacement of Cell 12 of Unit 1, Train C,125-Vdc Battery CP1-EPBTND-0 Observations and Findinas Electrical maintenance personnel replaced Cell 12 in the Unit 1, Train C,125-Vdc battery. On a loss of normal power, this battery provides power to important backup equipment, such as the de-powered main turbine lubricating oil pump. Although not a safety-related power supply, the licensee minimized the time the battery was unavailable due to the consequences of a loss of power with this equipment out of service. in spite of the desire to minimize the outage time, the mechanics were cautious and deliberate in their actions. The maintenance personnel used appropriate safety equipment,

' including face shields, acid-resistant rubber gloves, rubber aprons, and safety glasse The tools were insulated to prevent electrical arcing. The terminals were treated with approved grease as defined in the work order. The bolted connections were torqued with a calibrated and insulated torque wrench. The maintenance personnel were knowledgeable of the procedure and configuration of the batter Conclusions The conduct of maintenance activities was good. Personnelinvolved in replacement of the battery cell adhered to the work order and procedure. The mechanics were cautious and deliberate in their actions and used appropriate safety equipment. Good planning and coordination by the maintenance personnel resulted in the work being performed quickly, safely, and proficientl . _ _ _ _ _ - _ _ _ _

d i

V -5-v

,

1-

- M1.3 SurveiHance Observations

, insoection Scope (61726)

=The inspectors observed all or portions of the following surveillances:

.

. Unit 2, Train B, emergency diesel generator operability test

.

Class 1E station batteries weekly inspection -

.

Channel 35 neutron flux intermediate voltage and detector plateau

.

Zero power and power ascension test sequence

.

Movable incore detector system operation

.. Incore/excore detector calibration

.

Unit 1 turbine-driven auxiliary feedwater pump operability test Observations and Findinas The inspector observed portions of the Unit 2, Train B, emergency diesel generator monthly surveillance test. - Operators conducted a good projob briefing in the control room, which included critical portions of the procedure and coordination and communications between the control room and local operating stations. Dunng the briefing, personnel were attentive and questioning and discussed potential problems and contingencies. Plant equipment operators demonstrated good procedural adherence, self-checking techniques, and communications with the control room while starting the diesel locally. The test progressed smoothly and no problems were observe During the weekly inspection of station batteries, the inspectors noted that technicians

< were knowledgeable of their assigned tasks and closely adhered to procedural instructions. They also demonstrated a proper respect for safety which resulted in the questioning of the work conditions for a contract employee who was about to begin work in the battery rooms. The issue was resolved and the work resumed after contacting the proper individuals. The surveillances were completed satisfactoril Nuclear engineering surveillance Procedure NUC-101, "Zero Power and Power Ascension Test Sequence," was used in conjunction with operations Procedure OPT-003B, " Power Operations" to control the Unit 2 retum to full power following the refueling outage. Procedure NUC-101 specified the sequence for performing conditional surveillance tests and the plant conditions required for each test. The

' procedure prerequisites had been satisfied. The test engineer was familiar with the test procedure and test' equipment and complied with the procedure. The inspector

- observed good coordination among the reactor engineers, operators, and instrumentation technicians in ensuring the various testing activities were conducted during the proper plant condition Nuclear engineering surveillance Procedure NUC-102," Movable incore Detector System (MIDS) Operation Instructions," trovided the detailed steps to perform a flux map. The reactor engineer performing ine flux maps was also the system engineer for the movable incore detector system and was very familiar with the equipment and its t

_ _ _ - _ _ _

-

.

.

-6-condition. The engineer had the procedure and followed the procedure steps. The equipment was in very good condition and all of the incore detector paths were accessibl Nuclear engineering surveillance Procedure NUC-203,"Incore/Excore Detector Calibration," provided the directions to initiate a xenon transient in the reactor and to collect incore measurements using flux maps and excore measurements from the power range nuclear instruments. This data was then correlated to determine the proper calibration of the individual power range detectors to provide accurate indications of axial flux difference from the excore detectors. The prerequisites for the procedure were satisfied. The test engineer was very familiar with the test, had the procedure in the control room, and followed the procedure steps. The operators were very attentive to the applicable plant parameters and closely monitored and controlled the xenon transient. This ensured the test results would be valid and provided for positive operator control over core reactivity. Other control room activities were limited to reduce operator distractions during the xenon transient and restoration of stable xenon conditions. The test results indicated the power range indications required adjustments, and the necessary calibrations were performe On April 28, the inspectors observed the performance of operations surveillance test Procedure OPT-206A, Revision 16, 'AFW System," Section 8.3.3, turbine-driven auxiliary feedwater pump operability test. The operator directing the test briefed the participants in the control room prior to starting the test. The briefing included individual responsibilities, expected activities and communications, test precedure prerequisites, test steps, acceptance criteria, and past performance problems. Clear three-part communications were noted throughout the test. The operator directing the test was very familiar with the procedure, plant equipment, applicable indications, and the expected results. The test was coordinated with stroke time measurements of the associated steam admission valves, which were well within acceptable parameters. The unit supervisor provided good oversight of the surveillance and referred to plant drawings during the test to confirm the system alignment and indications were as expecte c. Conclusions The inspectors concluded that each of these surveillance activities was performed satisfactorily. The individuals directing the surveillance tests were very knowledgeable, followed the procedures, and maintained good communications and control of the activitie .

)

.

-7-111. Enaineerina E2 Engineering Support of Facilities and Equipment E Enaineerina Support of Operations and Surveillance Tests (37551 and 61726)

Using inspection Procedures 61726 and 37551, the inspectors observed ongoing engineering support of surveillance tests and the return to full power of Unit 2 following the refueling outage. Reactor engineering provided good support to operations during the startup testing and power ascension test sequence. The system engineering responsibilities for the auxiliary feedwater system had been reassigned and both the new and previous system engineers participated in the surveillance testing of the

'

auxiliary feedwater pump on April 2 E2.2 Safety Iniection Accumulator Leakaae Troubleshootina Inspection Scope i The inspector reviewed the licensee's effort to troubleshoot apparent leakage from the Unit 2 safety injection Accumulator 2-04 Observations and Findinas On May 1, the licensee identified that the level in Unit 2 safety injection Accumulator 2-04 was decreasing approximately 4 percent per day. At the time, the plant was in Mode 1 with reactor coosnt system pressure higher than the accumulator i pressure. There was also no measurable change in containment sump level or refueling water storage tank level. A containment entry was performed to inspect system piping for signs of leakage but none were found. Plant operators documented this condition on Smart Form 99-1233 for evaluation by system engineering, which resulted in a 1 I

troubleshooting plan to systematically isolate sections of piping on the accumulator sample and test lines and to install temporary pressure gauges at various points in the i system to identify the leakage path. As a result, the licensee determined that a leg of l

'

discharge piping common to the safety injection system and residual heat removal system was pressurized, which prevented a downstream check valve from seating properly. This allowed leakage from the accumulator into the safety injection test header which ties into that leg of piping. The licensee depressurized the leg of piping which reseated the check valve and stopped the accumulator leakage. In addition,

'

ultrasonic examination was performed on piping in both the residual heat removal system and safety injection system, which revealed that no gas pockets had accumulated in either syste Conclusions System engineering provided good support to safe plant operation by identifying the source of leakage from Unit 2 safety injection Accumulator 2-04. The troubleshooting plan was thorough and appropriately documented per plant procedure r 1

.

.

-8-IV. Plant Support R1 Radiological Protection and Chemistry Controls a. Insoection Scoce (71750)

The inspectors observed radiological protection activities during routine tours and observations of maintenance activities, walked down selected doors that were required to be locked for radiation protection purposes, and periodically reviewed primary and secondary water chemistry result b. Observations and Findinas The inspectors found that radiation protection technicians were present during maintenance activities in radiation areas, as expected. All of the selected doors that were required to be locked for radiation protection purposes were verified to be locked by the inspectors. The licensee closely monitored primary and secondary chemistry results, and the inspectors found that the results were within the prescribed limit V. Manaaement Meetinas X1 Exit Meeting Summary The inspector presented the results of the inspection to members of licensee management on June 9,1999. The licensee acknowledged the findings presented. No proprietary information was identifie l . 'l

.

ATTACHMENT SUPPLEMENTAL INFORMATION I PARTIAL LIST OF PERSONS CONTACTED

Licensee C. L. Terry, Senior Vice President and Principal Nuclear Officer i M. R. Blevins, Vice President, Nuclear Operations J.J. Kelly, Vice President, Nuclear Engineering and Support '

J.R. Curtis, Radiation Protection Manager R. Flores, System Engineering Manager D.L. Walling, Plant Modification Manager l D. Kross, Outage Manager i D.L. Davis, Nuclear Overview Manager l

lNSPECTION PROCEDURES USED IP 37551 Onsite Engineering IP 61726 Surveillance Observations f

IP 62707 Maintenance Observations IP 71707 Plant Operations IP 71750 Plant Support Activities ITEMS OPENED. CLOSED. AND DISCUSSED !

l Opened None i

Closed None l

l'

i Discussed None i

l

,

E