05000461/LER-1994-001, :on 940115,unexpected Automatic Isolation of RCIC Sys Occurred During Channel Calibr Surveillance Due to Lifting Wrong Thermocouple Lead.Labels That Are More Visible Installed to Thermocouple Terminal Strips

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:on 940115,unexpected Automatic Isolation of RCIC Sys Occurred During Channel Calibr Surveillance Due to Lifting Wrong Thermocouple Lead.Labels That Are More Visible Installed to Thermocouple Terminal Strips
ML20063K059
Person / Time
Site: Clinton Constellation icon.png
Issue date: 02/14/1994
From: Foster K, Jamila Perry
ILLINOIS POWER CO.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
JSP-071-94, JSP-71-94, LER-94-001, LER-94-1, U-602253, NUDOCS 9402280138
Download: ML20063K059 (5)


LER-1994-001, on 940115,unexpected Automatic Isolation of RCIC Sys Occurred During Channel Calibr Surveillance Due to Lifting Wrong Thermocouple Lead.Labels That Are More Visible Installed to Thermocouple Terminal Strips
Event date:
Report date:
Reporting criterion: 10 CFR 50.73(a)(2)(iv), System Actuation

10 CFR 50.73(a)(2)(v), Loss of Safety Function

10 CFR 50.73(a)(2)(i)

10 CFR 50.73(a)(2)

10 CFR 50.73(a)(2)(ii)

10 CFR 50.73(a)(2)(viii)(B)

10 CFR 50.73(a)(2)(iii)

10 CFR 50.73(a)(2)(x)
4611994001R00 - NRC Website

text

.... _.

Ithnc!s Power Company Canton Power Station P.O. Box 678 Chnton. IL 61127 Tal 217 935-0226 Fu 217 935-4632 J. Stephen Perry Senior Vice President ELLINf9lS u-602253 POWER US-940 2 - 14 )LP 2C.220 JSP-071-94 February 14, 1994 Docket No. 50-461 10CFR50.73 Document Control Desk Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

Clinton Power Station - Unit 1 Licenlee Event Report No 94-001-00

Dear Sir:

Enclosed is Licensee Event Repart No. 94-001-00: Unexpf.cted Automatic Isolation of Reactor Core Isolation Cooling System during Channel Calibration Surveillance Due to Lifling wrong Thermocouple Lead. This report is being submitted in accordance with the requirements of 10CFR50.73.

l Sincerely yours, j

i

'. Perry

-)

Senior Vice Pr.ident l

RSF/csm Enclosure cc:

NRC Clinton Licensing Project Manager NRC Resident Oflice, V-690 Regional Administrator, Region 111,'USNRC lilinois Department of Nuclear Safety INPO Records Center

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940228013s 940214

{DR ADOCK 05000461 PDR

N3c FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 (5-92)

EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS

, LICENSEE EVENT REPORT (LER)

INFORMATION COLLECTION REQUEST:

50.0 HRS.

(ORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION AND RECORDS MANAGEMENT BRANCH (MNBB (See reverse for required nunber of digits /chara *--- ror ech block)

W GTON, DC 20 55 0001, ND 0 THE APER k

REDUCTION PROJECT (3150 0104),

OfflCE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

I FACILITY NAME (1)

DOCKET NUMBER (2)

PAGE (3) i C%nton Pnwer Statinn 05000461 1OF4 TITLE (4) Unexpected Automatic Isolation of Reactor Core Isolation Cooling System during Channel Calibration Surveillance Due to Lif ting Wrong Thermocouple Lead EVENT DATE (5)

LER NUMBER (6)

_RJPORT DATE (7)

OTHER F AClllTIES INVOLVED (8)

MONTH DAY VEAR YEAR SEQUENTIAL REVISI' ' MONTH DAY YEAR TACILITY NAME DOCKET NUMBER NUMBER NUM6U None 05000 01 15 94 94 001 00 02 14 94 F ACILIM NAME DOGET NUMBER None 05000 OPE RAT ING THIS REP _QRT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR H (Check one or more) ell)

MODE (9) 1 20.402(b) 20.405(c) y 50.73(a)(2)(iv) 73.71(b)

POWER 20.405(a)(1)(i) 50.36(c)(1) 50.73(a)(2)(v)

73. 71(c )

LEVEL (10) 100 20.405(a)(1)(ii) 50.36(c)(2)

50. 73(a)(2)( vi i )

OTHER

~

20.405(a)(1)(iii) 50.73(a)(2)(i) 50.73(a)(2)(vi i i )( A)

(specify in Abstract 20.405(a)(1)(iv) 50.73(a)(2)(ii) 50.73(a)(2)(viii)(B) below and in Text, 20.405(a)(1)(v) 50.73(a)(2)(iii) 50.73(a)(2)(x)

NRC Forrn 366A)

LICENSEE CONT ACT FOR THIS LER (12)

NAME TELEPHONE NUMBER (include Area Code)

K. R. Foster, Plant Maintenance Specialist (217) 935-8881, Extension 3577 i

COMPL1TE ONE LINE FOR E ACH COMPONENT F AIf.URE DESCRIBED IN THIS REPORT (13)

CAUSE

SYSlEM COMPONENT MANUFACTURER REPORTABLE

CAUSE

SYSTEM COMPONENT MANUFACTURER REPORTABLE TO NPRDS TO NPRDS i

i SUPPLEMENT AL REPORT EXPECTED (14)

EXPECIED MONTH DAY YEAR YES y

NO SUBMISSION (If yes, complete EXPECTED SUBMISSION DATE).

DATE (15)

ABSTRACT (limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (16)

With the plant at 100 percent reactor pressure, Control and Instrumentation Maintenance (C&I) technicians were performing a channel calibration surveillance on a Reactor Water Cleanup System heat exchanger room area temperature channel. The technicians reviewed the drawing to verify the correct field thermocouple termination to be lined, but then inadvertently lined a lead from a difTerent terminal, placing the Reactor Core Isolation Cooling (RCIC) system equipment room ambient temperature channel in a tripped condition. As a result, a RCIC steam supply containment isolation valve automatically closed and the RCIC pump turbine tripped from the standby q

mode. The RCIC system was restored within sixteen minutes. The cause of this event is personnel error. The technicians performed inadequate double verification and self-checking in locating and lining the field thermocouple lead. Unusual characteristics of the work area contributed to the cause of this event. Corrective actions include the technicians understanding their error, installing improved labeling and using maxi-grabbers to identify and mark leads to be lined.

4 l

1 hRC FORM 366 (5-92) l

NRC f0RM 366A U.S. NUCLEAR REGLLATORY COMMISSICD APPROVED BY OMB NO. 3150-0104 EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATloN COLLECTION REQUEST:

50.0 HRS.

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FORWARD COMMENTS REGARDING BURDEN ESilMATE TO THE INFORMATION AND RECPRDS MANAGEMENT BRANCH (MNBB 7714),

U.S.

NUCLEAR REGULATORY COMMISSION,

WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104),

OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

FAC!LITY NAME (1)

DOCKET NUMBE R (2) trR NUMBfR f61 PAGE (3) 05000461 YEAR SEQUENTIAL REvlSION 2 OF 4 NUMBER NUMBER Clinton Power Station 94 001 00 TEXT (if more space is required, use adattional copies of NRC Form 366A) (17)

DESCRIPTION OF EVENT

On January 15,1994, the plant was in Mode 1 (POWER OPERATION) at about 100 percent reactor [RCT]

power. Control and Instrumentation (C&I) Maintenance technicians were preparing to perform a channel calibration surveillance on Reactor Water Cleanup (RWCU) system [CE] heat exchanger [HX] room area temperature channel IE31-N620B [TS). The channel calibration is performed in accordance with sulveillance procedure CPS 9432.17, "RWCU Equipment Area Temp E31-N620A(B), E31-N621 A(B,E,F), E31-N622A(B),

E31-N626A(B) Channel Calibration "

At about 0840, the C&I technicians started the calibration. The surveillance procedure requires technicians to lin field thermocouple leads from terminal strip TB001, terminal 10, in panel [PL] 1H13-P714B to allow a simulated thermocouple input into the channel As directed by the surveillance procedure, the RWCU isolation function was placed in the bypass mode to prevent an RWCU system isolation during the channel calibration.

Prior to lining the leads, the technicians noted that the label identifying terminal numbers was missing from the terminal strip Recalling that corrective action from a previous error in lifting leads requires them to verify termin numbering using the wiring diagram anytime terminal numbering is unclear, the technicians left the area to consult the drawings. Before leaving, the technicians noted that the lead to be lifted was on the bottom terminal stri (TB001). Ilowe 'er, upon returning from reviewing the drawing, the technicians mistakenly located terminal 10 on the bottom row of screws but on the top terminal strip, TB003. As required by tne suiveillance procedure, two technicians verified the terminal location (double verification) for the lead to be lilled.

At about 0858 hours0.00993 days <br />0.238 hours <br />0.00142 weeks <br />3.26469e-4 months <br />, the technicians lifled the lead from the wrong terminal strip, TB003, terminal 10, which is located directly above terminal strip TB001, terminal 10 (the correct terminal).

Lifing the wrong lead placed Reactor Core Isolation Cooling (RCIC) system [BN] equipment room ambient temperature channel lE31-N602B in a tripped condition and completed the one-out-of-two trip logic for actuatin containment isolation valves in Group 5 (RCIC). As a result, Residual Heat Removal [BO] and RCIC steam supply inboard (Division 2) containment isolation valve [ISV] lE51-F063 automatically closed and caused the RCIC pump [P] turbine [TRB] to trip off from the standby mode.

Operators immediately recognized the unexpected automatic closure of valve IE51-F063 and directed the C&l echnicians to re-land the lifled lead and stop the channel calibration. Operators declared the RCIC system t

inoperable and entered the action of Technical Specification 3.7 3, " Reactor Core Isolation Cooling System." T ction allows continued plant operation while the RCIC system is inoperable, provided the High Pressure Core a

Spray (HPCS) system [BG) is operable. It requires the RCIC system to be restored to operable status within fourteen days or a plant shutdown must be initiated. The HPCS system was operable during this event.__

~U.S. NUCLEAa REGUL ATC37 b!SSION APPQOUED BV OMB NO. 3150-0104 EXPIRES 5/31/95 ES?tMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST:

50.0 HRS.

'LICENBEE EVENT REPORT (LER)

FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE TEXT CONTINUATION INFORMATION AND RECORDS MANAGEMENT BRANCH (MNBB 7714),

U.S.

NUCLEAR REGULATORY COMMIS$10N, WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104),

OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME (1)

DOCKET NUMBER (2)

LER WUMBER f61 PAGE (3) 05000461 YEAR SEQUENTIAL REVISION 3 OF 4 NUMBER NUMBER Clinton Power Station 94 001 00 P

TEXT (If more space is required, use additional copies of NRC Form 366A) (17)

At about 0901 hours0.0104 days <br />0.25 hours <br />0.00149 weeks <br />3.428305e-4 months <br />, operators confirmed that the appropriate containment isolation valves closed by completing oft-normal procedure checklist CPS 4001.02C001, " Automatic Isolation Checklist."

By 0914 hours0.0106 days <br />0.254 hours <br />0.00151 weeks <br />3.47777e-4 months <br />, the RCIC isolation trip signals were reset, isolation valve IE51-F063 was reopened, the RCIC system was restored to the standby mode, and the action of Technical Specification 3.7.3 was exited.

Condition Report (CR) 1-94-01-030 was initiated to track a root cause analysis and corrective action determination for the event.

No automatic or manually initiated safety system responses were necessary to place the plant in a safe and stable condition. No other equipment or components were inoperable at the start of this event to the extent that their inoperable condition contributed to this event.

CAUSE OF EVENT

The cause of this event is personnel error by the C&I technicians performing the channel calibration. The technicians properly reviewed the wiring diagram to identify the correct terminal when its location was in question.

Ilowever, the technicians performed inadequate dc.able verification and self-checking in locating the correct terminal in the field and as a result lifled the wrong lead, located on the terminal strip directly above the correct terminal.

Contnbuting to the cause of this event is the difficulty of performing surveillances in Leak Detection (LD) system [UJ panels due to congestion and obstructed terminals and labeling.

CORRECTIVE ACTION

The technicians responsible for causing this event fully understand the errors they made.

To decrease the potential for lifling the wrong leads, labels that are more visible have been installed on all thermocouple terminal strips in Main Control Room panels that have wires lifled during surveillance testing. In addition, all C&I technicians will be given orange maxi-grabbers for attaching to wires prior to lifting the leads.

The grabbers will be used to identify the wires to be lifled and will enhance visibility of the wires and ensure that momentary distractions will not cause the technician to lose track of the terminal being worked. Using the grabbers will also facilitate double verification of the lead to be lifled by allowing a technician to exit the panel so a second technician can enter the panel and verify the lead to be lifted.

NRC FORD 366A U.S. NUCLEAR QEGULATC3Y COMMISSION APPROVED B7 OMB NO. 3150-0104 f 2).

EXP!RES $/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THl$

INFORMATION COLLECTION REQUEST:

50.0 HRS.

' LICENSEE EVENT REPORT (LER)

FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE TEXT CONTINUATION INFORMATION AND RECORDS MANAGEMENT BRANCH (MNBB 7714),

U.S.

NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104),

OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME (1)

DOCKET NUMBER (2)

LER NUMBER (6)

PAGE (3) 05000461 YEAR SEQUEN11AL REVISION 4 OF 4 NUMBER NUMBrR Clinton Power Station 94 001 00 TEXT (if more space is required, use additional copies of NRC Form 366A) (17)

ANALYSIS OF EVENT

This event is reportable under the provisions of 10CFR50.73(a)(2)(iv) due to the unplanned automatic closure of containment isolation valve iE51-F063, an engineered safety features actuation.

Assessment of the safety consequences and implications of this event indicates that this event was not nuclear safety significant. The RCIC system responded to the RCIC equipment room high ambient temperature signal as designed by isolating the system. The RCIC system was in the standby mode at the time of this event. The HPCS system, the alternate means of providing reactor core cooling under high reactor vessel pressure conditions, was available and operable at the time of this event.

During this event, the RCIC system was inoperable from about 0858 hours0.00993 days <br />0.238 hours <br />0.00142 weeks <br />3.26469e-4 months <br /> until about 0914 hours0.0106 days <br />0.254 hours <br />0.00151 weeks <br />3.47777e-4 months <br /> on January 15, 1994.

ADDITIONAL INFORMATION

No equipment or components failed during this event.

t A review of CPS LER history identified two events having similar circumstances. LER 87-016 discussed an unexpected automatic RCIC system isolation caused by personnel error in lifling the wrong lead. The specific cause of L.ER 87-016 was the failure to use available terminal block designation numbers when identifying the lead i

to be lifted Corrective actions included ensuring the involved personnel understood their mistake and briefmg others on lessons learned The corrective actions taken for LER 94-001 enhance the actions taken for LER 87-016.

LER 89-036 discussed an unexpected automatic RCIC system isolation caused by personnel error in failing to perform work at eye level and connecting a millivolt source to the wrong terminal. Corrective actions included ensuring that involved personnel understood their mistake; briefmg others on using ladders / stools so work is at eye level; applying difTerent color tape strips to terminal boards to enhance recognition of boards; revising procedures j

to reduce frequency of entering termination cabinets; and revising procedures to require installation of the millivolt cource in a deenergized state. The leads lifted in the event discussed in LER 94-001 were at eye level.

Corrective action for Condition Report 1-93-08-020 required labeling of terminals in the LD system panels.

Following the occurrence of LER 94-001, Illinois Power identified that this corrective action had not been completed in a timely manner. Therefore, CR 1-94-01-035 was initiated to track a root cause analysis and corrective action for this deficiency.

For further information regarding this event, contact K. R. Foster, Plant Maintenance Specialist, at (217) 935-8881, extension 3577.

hRC FORM 366A (5-92)