IR 05000413/1989025

Insp Repts 50-413/89-25 & 50-414/89-25 on 890801-28 & 0912-15.Violations Being Considered for Enforcement.Major Areas Inspected:Two Events Re Overspeeding & Tripping of Auxiliary Feedwater Pump

ML20248B705
Person / Time
Site:	Catawba
Issue date:	09/25/1989
From:	Lesser M, William Orders, Shymlock M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
Shared Package
ML20248B690	List: IR 05000413/1989025 ML20248B688
References
50-413-89-25, 50-414-89-25, NUDOCS 8910030268
Download: ML20248B705 (18)

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QEGoq*' UNITED STATES c9 '. . NUCLEAR REGULATORY COMMISslOM

$~ o,% REGION 88 5 j 101 MARIETTA STREET, N.W.

• ATLANTA, GEORGI A 30323

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Report Nos.: 50-413/89-25 and 50-414/89-25 Licensee: Duke Power Company 422 South Church Street Charlotte, Docket Nos.: 50-413 and 50-414 License Nos.: NPF-35 and NPF-52 Facility Name: Catawba Units 1 and 2 Inspection Conducted: August 1, 1989 - August 28, 1989, and September 12, 1989 - September 15, 1989 Inspector:, I76W /hr / YNA?k?

Date/ Signed M.T. Orders,SenioyResidentInspector Inspector:  ?/3// //[t/ 9h8I9 Gate' Signed

"M.S.' Lesser,ResifentInspector

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Approved by:

J W M. B. Shymlock, Chief Oate/ Signed Reactor Projects Section 3A Division of Reactor Projects SUMMARY Scope: This special resident inspection was conducted on site' inspecting two event The first event concerned the Unit 2 turbine driven auxiliary feedwater pump (CAPT) which oversped and tripped during surveillance testing,^ was returnec' to service without adequate corrective action, and subsequently oversped during a test one week later. The second event, which occurred during the performance of a

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piping flush procedure on Unit 2 involved the mispositioning of Auxiliary Feedwater system control board valve switches which control the realignment of both Unit 2 motor driven auxiliary feedwater suctions to Nuclear Service Wate Results: Two apparent violations are currently.being considered for escalated enforcemen The first involves the failure to take adequate corrective action in response to a failed surveillance test on. the Unit 2 turbine driven auxiliary feedwater pump. A maintenance work request was not written to document authorization to perform work, maintenance, and retest activities conducted on this componen Actual work conducted failed to identify the root cause of the overspee An adequate evaluation of the failure to justify operability was not performed prior to returning the pump to servic This resulted in the potential inoperability of the CAPT for a period 891003o268 890 2 ,,

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in excess of the allowed action statement. During a portion of this time, one of two motor driven auxiliary feedwater pumps was also inoperabl The second apparent violation, which occurred during the performance of a piping flush procedure on Unit 2, involved the failure to assur that the control board switches for the valves which automatically )

realign the suction of both Unit 2 motor driven auxiliary feedwater 1 pumps to the Nuclear Service Water (RN)' system, the-assured source o J makeup water, remained 'in the AUT0 position. This rendered both trains of auxiliary feedwater inoperable. A significant contributor to this event. was an inadequate flush- procedure which failed to assure that the control board. switches for the valves remained in the .j" AUTO positio .l l

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6 S REPORT DETAILS Persons Contacted I

Licensee Employees j I

• H. Barron, Operations Superintendent .l W. Beaver, Performance Engineer i

• • R. Casler, Operations Superintendent T. Crawford, Integrated. Scheduling Superintendent

• • • J. Forbes, Technical Services Superintendent

• • • R. Glover, Compliance Engineer T. Harrall, Design Engineering R. Jones, Maintenance Engineering Services Engineer F. Mack, Project Services Engineer j W. McCollough, Mechanical Maintenance Engineer '

W. McCollum, Maintenance Superintendent

• • • T. Owen, Station Manager J. Stackley, Instrumentation and Electrical Engineer B. Caldwell, Station Services Superintendent Other licensee employees contacted included technicians, operators, mechanics, security force members, and office personne Accompanying Personnel ,

• Shymlock, Section Chief, Division of Reactor Projects NRC Resident Inspectors

• • • W. Orders

• • • M. Lesser

• Attended exit interview August 24, 1989

• • Attended exit interview September 15, 1989 .i

• • • Attended both exit interviews on August 24, 1989 and i September 15, 1989 Turbine Driven Auxiliary Feedwater Pump Event Executive Summary )

On July 31, 1989 unit 2 was operating at 98% power and.in the process of performing a Technical Specification surveillance on the Turbine '

Driven Auxiliary' Feedwater. Pump (C/ PT) in accordance with-PT/2/A/4250/06, Auxiliary Feedwater. (CA) Pump Head and Valve !

Verificatio The pump initially failed the surveillance when it 4 tripped on overspeed. The test was successful on the fourth start, however, no corrective action was performed. The licensee declared !

the pump. operable based upon completing ~ the surveillance test. On August 7, the CAPT again oversped during testing which raises the question of its operability when returned to service on July 31, 198 i

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b. System Description and Design Basis The Auxiliary Feedwater System (CA) assures sufficient feedwater supply to the steam generators (S/G), .in the event of loss of the Condensate /Feedwater System, to remove energy stored in the core and primary coolant. The CA System may also be required in some other circumstances such as-evacuation of the main control room or cooldown-after a loss-of-coolant accident for a small break', including maintaining a water level in the steam generators following such a brea Three CA pumps are provided, powered from separate and diverse power sources. Two full capacity retor driven ~ pumps are powered from two separate trains of emergency-on-site electrical power, each normally supplying feedwater to two steam generators. One full capacity turbine driven pump, supplying feedwater to the B&C steam generators, is driven from steam contained in either the B or C steam generator Sufficient diversity and redundancy is provided such- that the CA System is capable of delivering the minimum required flowrate to effective steam generators during all modes of operation. The CA System is capable of delivering the required flowrate to effective steam generators at a pressure corresponding to the lowest S/G safety valve set pressure'plus 3% accumulatio Standards for nuclear safety related systems are met- for the CA System except for the condensate quality feedwater source The Standby Nuclear Service water pond serves as the ultimate long term safety related source of water for the syste The mot"r driven pumps will automatically start and provide the  ;

minimum required feedwater flow within one minute following any of '

the following conditions:

(1) Two out of four low-low level alarms in any one of the four steam generators; (2) Loss of both main feedwater pumps; (3) Initiation of the safety injection signal; (4) Loss of station normal auxiliary electric power; (5) ATWS Mitigation System Actuation Circuitry (AMSAC) start signal.

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The turbine driven pump will automatically start and provide the ]

minimum required feedwater flow within one minute following either of y the following conditions:

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(1) Two out of four low-low level alarms in any two of the four steam generators; (2) Loss of station normal auxiliary electric powe For a transient or accident condition, the minimum CA flow aust be  !

delivered within one minute of any actuation signal to start the CA pumps. The minimum flow is considered to be the flow delivered only

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to steam generators effective in cooldown and does not include flow delivered to a steam generator involved in a feedline to CA line i break. Accidents analyzed for in Chapter 15 of the Final Safety Analysis Report (FSAR) typically assume a minimum CA flow of 491 gallons per minute (gpm) delivered to two intact steam generators with no operator action for 30 minute For the postulated non-seismic event of loss of all offsite and all onsite emergency A.C. electrical power, the CA System will perform its safety related function. This assessment includes the limitation that no single failure that would prevent the single A.C. power independent turbine driven pump subsystem from functioning occurs during this limiting even The turbine driven pump (CAPT) consists of a direct coupled, single j stage Terry turbine rated at 3600 revolutions per minute (RPM) with a l Bingham horizontal seven stage centrifugal pump. The speed of the turbine is determined by the position of a steam governor valve which is controlled by a Woodward governor. The. governor is of the mechanical hydraulic type, driven by the turbine rotor through spiral reduction gears. The centrifugal force on a set of flyweights moves a spring loaded servo piston rod which. controls the flow of hydraulic fluid to the power cylinder assembly (remote servo) which provides linear motion as the output of the governor. The work capacity of the remote servo is 29 foot pound A connecting rod transmits linear motion between the power cylinder assembly and a slotted cam crank. A cam roller is connected to the end of the governor valve stem and is inserted through a bushing into the slo The slot is angled such that vertical motion of the connecting rod and cam crank is transmitted as horizontal motion to l the governor valve ste '

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~ The turbine is protected from overspeed by one electrical and one mechanical overspeed sensing device. The mechanical overspeed device setpoint is 125% (4500 RPM). Centrifugal force of the rotating turbine shaft causes displacement of the pin type trip weight outward from the shaft axi The pin strikes a ball tappet, lifting it upwards overcoming tappet reset spring force. This releases a spring loaded head lever and connecting rod which causes the turbine trip and throttle valve to close. The device must be reset locally at the turbine.

l The electrical overspeed device setpoint is approximately 4100 RPM l and consists of a photoelectric tachometer which operates a solenoid ,

l on the trip and throttle valve to close it via a separate mechanis The electrical overspeed device can be reset from the control roo _ - _ - - _ _ _ _ _ _ _ _ . ._____ ._ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ - _ _ _ _ _ _ -

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c. Event Description On July 31, 1989, Catawba Unit 2 was operating at 98% power. At 1:10 p.m. operations personnel were attempting to perform a routine surveillance test on the turbine driven auxiliary feedwater pump (CAPT). On the first two attempts to start the pump, it oversped and tripped mechanically. A Maintenance Engineering Services engineer (NES) was requested to assist in determining the nature of the overspeed problem. At 1:20 p.m. another start attempt was made which also resulted in the pump tripping on mechanical overspeed. The engineer observed during the third attempt that the governor valve control linkage did not move to control turbine speed as designe The engineer " exercised" the linkage using a screwdriver and another pump start was attempte The pump performed acceptably during this attempt, was declared operable and returned to servic It was subsequently learned that the work performed on the CAPT had been performed without' permission, with no work. request or procedure, in violation of the licensee's Maintenance Progra The residents became aware of the event on August 1, during the morning status meeting. Discussions with licensee management at that time revealed that they did not have enough information to discuss the issue in detail, that the (MES) group had been working on the issue, and that any specifics relative to the event would have to come from the aforementioned MES enginee The MES Supervisor was requested at that time to have the engineer contact the resident The system engineer called the residents the next day, August During the conversation, it was learned that:

The system engineer determined during conversations earlier that day with a representative of the company which manufactured the turbine, that the lutricant being used on the control linkage, N5000, was not recommended for that applicatio The event appeared to have been caused by the use of improper l lubricant on the governor / control valve linkag i Although the lubricant problem was germane to both units, there had been no action to verify that the unit 1 CAPT was still operabl The lubricant was to be changed out on both units beginning on or about August 1 *

Other than exercising the linkage on the Unit 2 CAPT no corrective action had been performe j The residents voiced their concerns, at that time, relative to the operability of both units' CAPT These concerns were based on the fact that the apparent root cause of the problem had apparently been identified. The problem had resulted in the inoperability of the Unit 2 CAPT, yet the licensee had not implemented immediate

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corrective actions to ensure that both units' CAPT's remained operable unt.il the lubricant could be changed, j i

On the following afternoon, representatives of the licensee's staff, i including the MES engineer, met with the residents to discuss the residents' concerns. During that meeting, it was confirmed that: 3

The apparent root cause of the problem was the use of the N5000 lubrican The licensee had, by August 3, performed a visual examination of j the linkage on the unit 1 CAPT, but had not checked the linkage i for frcedom of movement nor otherwise verified its operabilit ]

The schedule for the lubricant replacement had been moved from August 10 to on or about August ,

No additional corrective actions or testing had been performed on the unit 2 CAP l

The residents reiterated their concern over the operability of the CAPT's, in that the problem had not been resolveo, yet no immediate corrective actions or evaluation had been performe The residents !

also asked if the licensee had planned to perform pre-maintenance '

tests on the CAPT's. The licensee informed the residents they had !

not but indicated that they would consider the These tests would i verify the operability of the CAPT's from the time of the identification of the problem until the corrective maintenance was complet l On August 5 at 8:42 p.m. the Unit 1 CAPT was run successfully.for a pre-maintenance verificatio The governor valve linkage was disassembled, cleaned, lubricated with Neolube 2, and reassemble The turbine was retested and returned to service at 12:45 a.m. on j August On August 7 at 9:50 a.m. a pre-maintenance verification test was attempted on the Unit 2 CAPT. The turbine oversped and tripped on electrical overspeed. It was observed that the control linkage moved too sluggishly to control turbine speed properly. At 10:07 a.m. the CAPT was restarted at which time it ran successfully. The governor valve linkage was then disassembled, some parts replaced and lubricated with Neolube 2. It was also found that the governor valve stem had suffered corrosion attack in the area of the stem packin The valve stem was replaced and at 10:30 a.m. on the trorning of August 9, the Unit 2 CAPT was returned to servic ,

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6 Requirements (1) Technical Specification 3.7.1.2 requires in modes 1, 2, and 3 at least three . independent steam generator auxiliary feedwater pumps and associated flow paths shall be OPERABLE with:

- Two motor-driven auxiliary feedwater pumps, each capable of being powered from separate emergency busses, and

- One steam turbine-driven auxiliary feedwater pump capable of being powered from an OPERABLE steam supply syste With one auxiliary feedwater pump inoperable, restore the required auxiliary feedwater pumps to ' OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in at least HOT STANDBY within-the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in H0T SHUTDOWN within the following 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> With two auxiliary feedwater pumps inoperable, be in at least HOT STANDBY within'6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in HOT SHUTDOWN within-the.following 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> (2) The Administrative Policy Manual for Nuclear Stations, section 3.3.2.3 requires that maintenance be performed under the control of the Work Request System in accordance with written procedures which conform to applicable codes, standards, specifications and criteri Section 3.3.2.5 requires that in the event of an equipment failure, the cause shall be evaluated and equipment of the same type shall be evaluated as to whether or not it can be expected to continue to function in an appropriate manne Station Directive 3.3.7, Work Request Preparation, states that the Work Request is the basic document of the Maintenanc Management Program for corrective and preventive maintenance and that employees requesting maintenance assistance are required to comply with the provisions of the progra Maintenance Management Procedure 1.0 further defines Work Request requirements including authorization and definition of work to be performed, documentation of clearance to begin work, procedures to be used, description of maintenance activities performed and documentation of retest activities and acceptance by operation '

! (3) ation Directive 3.2.2, Development and' Conduct of the Periodic

.est Program, section 6.0 requires that if, for any reason, a surveillance test fails to meet acceptance criteria, the Compliance Engineer and the Shift Supervisor or his designee shall be notified immediately and the equipment - declared inoperable in accordance with the Technical Specification limiting' condition for operation. The Shift Supervisor shall ,

ensure that the proper - course. of action for returning the equipment to operable status is pursued.

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Station Directive 3.1.14, Operability Determination, states that i when responsible station personnel believe a component is )

operable but have concerns related to it, necessary actions I shall be taken expeditiously to resolve the concerns, identify any root cause, and confirm operability. These actions shall include additional testing, engineering evaluations, and  ;

calculations or inspections as appropriate to the circumstance '

The directive further requires an " Operability Evaluation Form" i to be completed to document the concern, the basis for the  !

evaluation and any alternate methods or compensatory measures {

needed to fulfill the component's safety functio J Contrary to the above, Administrative Policies a'nd Station Directives the steam turbine auxiliary feedwater pump was i returned to service on July 31, 1989, without adequate {

corrective actions being performed to assure the pump was in i fact operable, e. Safety Significance Issue 1 On July 31, the Unit 2 CAPT tripped on mechanical overspeed on an attempted start. An immediate attempt at a second start was 1 also unsuccessful. A third start attempt was made with an MES l Engineer, an Operations Engineer, and a Maintenance Planner observing the activity. Again, the pump tripped on mechanical overspeed and it was observed that the control valve linkage did .

not move. The CAPT control valve linkage was then manually I exercised. The CAPT was started, the linkage responded to control turbine speed, and successfully met the requirements of ,

the monthly surveillance tes Based on having passed the surveillance test, the CAPT was declared operable and returned to service. It was subsequently determined that a work request i was not initiated when the turbine trip occurred, and was not used in investigating the proble The safety significance of this issue concerns the " corrective maintenance" performed by the MES Engineer when he exercised th control valve linkag Not only war it inappropriate to simply dislodge the stuck linkage but the failure to initiate a work request circumvented the normal process of evaluating equipment operabilit It is expected that problem resolution be performed under the appropriate programs to ensure that underlying problems are identified and resolved and that an operationally reliable component is returned to service. ' Given the circumstances of this event it is not clear that the CAPT was fully operable when returned to service on July 31, 198 _ _ _ - _ _ -

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Issue 2 The CAPT oversped at 1:11 p.m. on- July 31, passed its surveillance test at 1:25 p.m. that afternoon and then oversped again at 10:00 a.m. -on August 7. The surveillance . test performed is termed a " slow start" as the turbine is started with the speed control potentiometer set at minimum' speed, then slowly increased to maximum speed by the operato The safety significance of this issue concerns the fact that normally with the CAPT in standby, a safety _ signal will cause.it to " fast start", or immediately ramp up to operating speed in approximately 30 seconds. The inspectors were concerned with the adequacy of the surveillance to demonstrate the ability of the CAPT. to perform its intended safety- function in that a fast

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start was not performed and-the governor: linkage-was exercised prior to performing the -test. Discussions with the responsible licensee engineer indicated that in this particular event, it would- not have mattered whether a slow or fast start was conducted due to the fact that the failure mechanism of. stem corrosion prevented the governor valve .from closing. Slow-starts, however, may not be appropriate for operability testing, as governor problems could potentially remain undetecte Issue 3 On July 31, 1989, the unit 2 CAPT tripped a number of times on mechanical overspeed, was returned to service and tripped on overspeed again on the next start attempt on August 7,'198 On August 1, at 4:50 a.m., the Unit 2 Motor Driven CA Pump 2B was. removed from service to repair an oil leak on the bearing housing drain plugs. Repairs were completed and the pump was returned to service at 3:00 p.m. the same da On August 2, at 3:00 a.m., Nuclear Service Water (RN) . System Train B was removed from service for repairs. With RN Train B inoperable, both Unit 1 and Unit 2 Train B Diesel Generators .

were inoperable due to RN cooling water not being availabl With the Diesel Generators inoperable, essential' power could not be provided to the Unit 1.or Unit 2 CA B Pumps, which were also considered to be inoperable. On August 4, at 8:00 p.m.., RN repair work was complete and the CA Train B Pumps were returned -

to operable statu The safety significance of this issue concerns the inoperability of 'the Unit 2 B Train CA Pump during the time the CAPT was in questionable status. Thus, the potential existed for having two auxiliary feedwater pumps inoperable.

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Issue 4 On August 1, the MES Engineer met with an MES Engineering Supervisor and the MES Manager to' evaluate the prior situatio with. the Unit 2 CAPT. Operability of the Unit 2 CAPT was discussed.- It was the view of those individuals that the Unit 2-CAPT continued to be _ operable at this tim Past problems were reviewed taking into consideration present design, repair ]j methods, procedures, and types 'of lubricants used. Of these aspects, the lubricant used 'on the control valve linkage was ~]

considered to be the major cause of the July 31 overspeed. trip .i 1 This- was confirmed the following . day when a manufacturers f representative was contacted and recommended that a dry film lubricant be used on the control valve linkage instead of the paste lubricant presently use The' safety significance of- this ' issue concerns the belief on '

August 1, by the MES Engineer, Supervisor and Nanager that the lubricant used on the CAPT control valve linkage on both units was considered to be .the major cause of the July 31 overspeed trip However, on August 2 discussions with the MES Engineer revealed that no action or evaluation had- been performed to verify that the Unit 1 CAPT was still ' operabl Issue 5 On or about August 2, licensee management determined that the work that transpired on the Unit 2 CAPT on July 31, in the ,

exercising of the linkage, had been done outside the control.of 1 the work request (WR)/ maintenance program, i The safety significance of this issue _ concerns the decision by licensee canagement to not declare the CAPT inoperable, enter the maintenance program and ensure the CAPT operable when it was determined that the work of July 31 was performed in = an I uncontrolled manner, i

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On August 3, RN Train B repairs were still in progress'and both Units' CA Pump B inoperable. Inspection of the Unit 1 CAPT was

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scheduled for ' August 6,' and the Unit 2 CAPT was scheduled for 1 l _ August The licensee felt-it was appropriate to wait and not '

L take the CAPT out of service immediately since the lubricant was l- not a short term operability concer j l

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10 The safety significance of this issue concerns the' observation that the licensee may have been influenced by the inoperability of the B trains of CA on both units to the point that they were reluctant to take immediate corrective actions to ensure that the CAPT's- remained operabl Issue 7 On - August 7, at 9:50' a.m., with Unit 2 in Mode 1, the Unit 2 CAPT tripped on electrical overspee During this start attempt, the aforementioned MES Engineer observed that th control valve linkage responded to the turbine start, but binding . slowed the response causing the electrical overspeed tri The electrical overspeed trip was reset and..- at 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br />, and a second start of the Unit 2 CAPT was successfu After securing the pump, linkage disassembly began and the control valve stem was observed to have excessive-drag in the valve assembly. Work was expanded to include rebuilding the control valv It was.at this time that it was identified that indeed the event

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of July 31 may have been caused by binding of this valve due to corrosion rather than the linkage / lubricant proble The safety significance of this issue concerns the operability of the Unit 2 CAPT during the period of July 31 through August 9,1989. In as much as no corrective maintenance was performed on July 31 and the CAPT failed to operate properly on August 7, it raises the concern about the pump's operability due to no corrective action 'being accomplished prior to returning it to service. During this_ period, the Unit 2 B train ;

motor driven CA pump was also inoperable from 4:50 a.m. until 3:00 p.m. on August 1 and -from 3:00 a.m. on August 2 until 8:17 p.m. on August f. Conclusions (1) On July 31, the Unit 2 CAPT tripped several times on mechanical overspeed, no corrective ' maintenance was performed and the l component was returned to service, l (2) On July 31, when'the Unit 2 CAPT malfunctioned, an MES engineer exercised the governor valve linkage. i.e. performed work on a safety related component without permissinn, with no procedure, l in violation of the Maintenance Progra (3) On or about August 2, licensee management determined that the work which had been performed on the Unit 2 CAPT on July 31 had been uncontrolled, yet no actions were taken to enter the maintenance program and ensure that the CAPT was operabl i

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1 (4) In as much as no corrective maintenance was performed on the l Unit 2 CAPT on or after July 31 and in as much as the component oversped again on August 7, during the next attempt to start the component, it raises concern about the pump's operabilit (5) The Unit 2 B train motor driven CA prmp was inoperable simultaneously with the CAPT, on August 1 from 4:50 a.m. until 3:00 p.m. and from 3:00 a.m. on August 2 until 8:00 p.m. on August . Auxiliary Feedwater Suction Valve Event Executive Summacy On September 12, 1989, the Resident Inspector discovered that Unit 2 ;

control board switches for ' valves which automatically align the l suction of both Unit 2 motor driven auxiliary feedwater pumps to the !

system's only safety related, assured suction source, had been '

mispositioned such that automatic realignment on a low suction pressure would not occu It was determined that the switches had been mispositioned some 30 minutes prior to discovery during the i performance of a piping flush procedure. During this time, the i turbine driven auxiliary feedwater pump was also inoperable for maintenance. The mispositioned switches were immediately identified j!

to the Shift Supervisor, and they were placed to the AUTO position l which in turn returned the motor driven auxiliary feedwater pumps to operable status, Event Description On September 12, 1989, during a routine control room tour, the Resident Inspector detected that the Unit 2 Control Room System Bypass Panel (installed in accordance with Regulatory Guide 1.47) ;

indicated that all three Auxiliary Feedwater (CA) pumps were 1 inoperable. The system is comprised of.a turbine driven pump (CAPT)- <

and two motor driven pumps. It was also determined that the CAPT was inoperable due to ongoing maintenance. The inspectar questioned the Unit 2 Operator at the Controls (0ATC) as to why br/d motor driven CA pumps indicated inoperable. The 0ATC was aware of the indications and considered the cause to be associated with valve manipulations performed to facilitate the ongoing flush of the Nuclear Service i Water (RN) to CA snction lines. The operator was not sure, however, which component realignments were causing the bypass panel indi-cations. At the inspectors request, the 0ATC reviewed applicable ,

logic diagrams and determined that the motor driven CA pump flow '

paths were inoperable due to the. control board switches for valves 2CA-15 and 2CA-18, the CA pump 2A and 2B suction isolation valves from RN, being in the "CLOSE" position. These switches have three positions: OPEN, AUT0, and CLOSE. The valves are normally closed

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i with their switches in AUTO. The safety' related function of these valves is to open automatically upon a low CA suction pressure in order to supply RN to the CA system. The four normal condensate-grade suction sources for CA are neither safety related nor seismi RN is the only safety related assured suction source.to CA. The inspector immediately informed thel Shift Supervisor of the identi--

fication that both motor driven CA pumps were inoperable'due to the inability to automatica11y' swap to RN on a low suction pressure I condition.- The Shift Supervisor concurred and had the 0ATC place the-switches for 2CA-15 and 2CA-18 in the AUTO position at approximately ;

2:10 p.m., some 35 minutes after the switches had been misa11gne I At this point the System Bypass Panel lights for Train A and Train B CA went out indicating that both trains had been returned to servic The inspuctor reviewed the ongoing flush procedure, PT/2/A/4200/59, RN to CA Piping Flush. Step 12.2.6 of that procedure requires the operator to " Ensure the following valve are closed: 2CA-15 and 4 2CA-18." At 1:35 p.m., upon performing this step, the 0ATC ensured the valves were closed by observing the control board indicating light However, she also incorrectly decided to assure the valves would not inadvertently oper by taking the aforementioned switches from AUTO to CLOS This would have prevented the automatic opening-of these valves in the event of a low suction pressure condition. It should be noted that this step was also independently verified by a-non-licensed operato Further review of the procedure revealed that both 2CA-15 and 2CA-18 are cycled open and closed after the flus The switches are then placed in AUTO. These steps were performed.at or about 12:26 the next morning, September 13. Based solely-on the time that this particular procedure step was performed, the potential existed to have all three CA pumps inoperable for a period of approximately 11 1 hours1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, had the error gone undetected. It should be noted, howeve l that it is quite probable that this error would have been detected - '

during shift turnover since the 1.47 panel is specifically referenced in the turnover procedur Requirements Technical Specification 3.7.1.2 requires in Modes 1, 2, and 3 that ,

l at least three independent steam generator auxiliary feedwater pumps '

and associated flow paths shall be OPERABLE with:

E s Two motor-driven auxiliary feedwater pumps, each capable of- ;

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One steam turbine-driven auxiliary feedwater pump capable of being powered from an OPERABLE steam supply syste j With one auxiliary feedwater pump inoperable, restore the required auxiliary feedwater -pumps to OPERABLE status J l

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within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in HOT SHUTDOWN within the following 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> With two auxiliary feedwater pumps inoperable, be in at least HOT STANDBY within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in HOT SHUTDOWN within the following 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> With three auxiliary feedwater pumps inoperable, immediately initiate corrective action to restore at least one auxiliary feedwater pump to OPERABLE status as soon as possibl Contrary to the above, on September 12, 1989, at 1:35 p.m.-with the Unit 2 Turbine Driven Auxiliary Feedwater Pump inoperable, the operator incorrectly selected the control board switches for 2CA-15 and 2CA-18, Auxiliary Feedwater Pumps 2A and 28 Suction Isolation Valves From Nuclear Service Water, to the CLOSE positio This rendered the 2A and 2B Motor Driven Auxiliary Feedwater Pumps inoperable in that it removed the ability' of 2CA-15 and 2CA-18 to automatically actuate to the full open position within 16 seconds after a loss of suction and provide a flow path from Nuclear Service Water, the assured source of. makeup wate The condition was indicated by illuminated -lights on. the Unit 2 Control Room System Bypass Panel. . Even though the operator was aware that all three auxiliary feedwater pump lights on the Unit 2 Control Room' System Bypass Panel were illuminated, the operator failed to recognize the significance of the indication The operator. therefore, failed to immediately initiate corrective action to restore at least one auxiliary feedwater pump to an operable status until 2:10 p. when the inoperability was identified by the NRC inspecto Technical Specification 6.8.1 requires that written procedures be established, implemented, and maintained covering the activities referenced in Appendix A of Regulatory Guide 1.33, Revision 2 February 1978, which includes the operation and testing of safety related equipment. These procedures are to be sufficiently detailed to support the successful completion of the applicable evolutio Further, it is required that personnel employ these procedures when performing those evolution Contrary to the above, PT/2/A/4200/59, Nuclear Service Water-(RN) to Auxiliary Feedwater (CA) Piping Flush, was inadequate in that step 12.2.6 required the operator to " Ensure the following valves are closed: 2CA-15 and 2CA-18".- However, it. failed to assure that the control board switches for the valves remained in the AUTO position.

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This contributed to the operator incorrectly selecting the switches to the CLOSE position on September 12,:1989, on Unit 2 at 1:35- This removed the ability of 2CA-15 and 2CA-18 to automatically

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actuate to the full open position within 16 seconds after a loss of suction, rendering' train A and B of the Auxiliary Feedwater system inoperabl _ _ _ _ _

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Contrary to the above, the 0ATC failed to follow procedures in that the 0ATC:

(1) was not knowledgeable of the unit status; (2) did not operate the unit in compliance with technical specifications; (3) did not ensure that the " Control Room Supervisor" was notified of the abnormal condition indicated on the R.G. 1.47 panel; (4) did not initiate prompt corrective action to a received alarm; (5) did not notify the " Control Room Supervisor" of the unexpected alar This is required by Operations Management Procedure 1-0, Section 7. Operator At the Control d. Safety Significance Issue 1 At approximately 1:35 p.m. on September 12, 1989, the Unit 2 0ATC misaligned the switches which control valves 2CA-15 and 2CA-18, the CA suction isolation valves from RN, such that the valves would not have automatically opened on a low suction pressure signal. This action rendered both motor driven CA pumps incapable of performing their intended safety function under certain conditions. The turbine !

driven CA pump was inoperable for maintenanc Thus, for some 35 minutes, all three CA pumps were inoperabl l The safety significance of this issue concerns the inoperability of !

the CA system, the inability to remove decay heat from the steam generators under certain accident conditions, and the potential for !

the system being inoperable for much longer had the error not been ;

identified by the NR Issue 2 Procedure PT-2-A-4200-59, RN to CA Piping Flush, was inadequate in ,

that step 12.2.6 requires the operator to ensure that valves 2CA-15 i and 2CA-18 are closed, but does nct caution the operator that placing the switches for these valves in the "CLOSE" position, renders the applicable pumps inoperabl The safety significance of this issue concerns the inadequacy of the procedural guidance which allowed the operator to comply with the procedure step yet render both motor driven CA pumps inoperabl Issue 3 i Although the OATC was aware that the lights on the RG 1.47 bypass panel had illuminated, indicating that both motor driven CA pumps were inoperable, and considered the reason to be associated with the '

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15-ongoing flush procedure, she did not know that placing the switches for 2CA-15 and 2CA-18 in the "CLOSE" position had made both motor driven CA pumps inoperabl The safety significance of this issue involves the apparent. lack of understanding of system design and operation.on the part of the 0AT Issue 4-During the event, the 0ATC violated Catawba Operations Management Procedure (OMP) 1-8, Section 7.2.B. which delineates, in part, the requirements and responsibilities of the 0ATC in that she did not notify the Control Room Supervisor of the abnormal condition ,

indicated on the 1.47 bypass panel.. nor did she initiate prompt-corrective action to the received alarm / indicatio The safety' significance of this issue concerns the failure of the 0ATC to identify to her co-workers or management an abnormal condition and her failure to take prompt corrective action to return the motor friven CA pumps to service once she had identified on the 1.47 status panel that.they appeared to be inoperable, Conclusions (1) At 13:35 p.m. on September 12, 1989, the Catawba Unit 2 0ATC j misaligned valve control switches for valves 2CA-15 and 2CA-18 which rendered both motor driven CA pumps inoperabl .

(2) The 0ATC failed to take prompt corrective action to return the 4 CA pumps to operable status once - she noted their apparent inoperability on the 1.47 pane (3) The 0ATC was apparently not thoroughly knowledgeable with the CA system design or interfac ;

(4) The 0ATC failed to identify the abnormality she detected on the  !

1.47 panel to her fellow operator or her operations managemen (5) Procedure FT-2-A-4200-59 was inadequate' in that - the guidance l provided to the operator did not caution her that placing the l switch for valves 2CA-15 and 2CA-18 in' the "CLOSE" , position  !

rendered the motor driven pumps inoperable.

L Exit Interview l

The inspection scope and findings were summarized on August 24, 1989, and i September 15, 1989, with those persons indicated in. paragraph 1. The i inspector described the ' areas' inspected and discussed in detail the inspection findings listed below.. No dissenting comments were received from the licensee. The licensee did not identify as proprietary any of s

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-16 the materials . provided 'to or reviewed by the . inspectors during this inspectio Findings Apparent Violation involving. inadequate corrective action associated with the return to service of the Unit-2 turbine driven auxiliary feedwater

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pump following failure of a surveillance.-

l l Apparent violation involving an inadequate procedure which failed to j assure that the CA system would automatically realign the suction of both Unit- 2 motor- driven CA pumps to the RN system. This rendered both trains of CA inoperable.

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