05000313/LER-1989-001, :on 881217,RCS Hot Leg Resistance Temp Detector Calibr Using Wrong Calibr Data Since Installation in May 1982.Caused by Procedural Inadequacy.Calibr Procedure for TE-1041/1042 Revised to Reflect Correct Calibr

:on 881217,RCS Hot Leg Resistance Temp Detector Calibr Using Wrong Calibr Data Since Installation in May 1982.Caused by Procedural Inadequacy.Calibr Procedure for TE-1041/1042 Revised to Reflect Correct Calibr

ML20236B160
Person / Time
Site:	Arkansas Nuclear
Issue date:	03/08/1989
From:	James M. Levine, Taylor L ARKANSAS POWER & LIGHT CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
1CAN038904, 1CAN38904, LER-89-001, LER-89-1, NUDOCS 8903200385
Download: ML20236B160 (4)

LER-1989-001, on 881217,RCS Hot Leg Resistance Temp Detector Calibr Using Wrong Calibr Data Since Installation in May 1982.Caused by Procedural Inadequacy.Calibr Procedure for TE-1041/1042 Revised to Reflect Correct Calibr

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)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(viii)(A) 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) 10 CFR 50.73(a)(2)(1)
3131989001R00 - NRC Website

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Form 1062.01A

,f l-NRC Form 366 U.S. Nuclear Regulatory Commission i

(9-83)

Approved OMB No. 3150-0104 j

Expires: 8/31/85 i

LICENSEE EVENT REPORT (L E R) i FACILITY NAME (1)

Arkansas Nuclear One, Unit One IDOCKET NUMBER (2) lPAGE (3) 10151010101 31 11 3!110Fl013 TITLE (4)

Procedure Inadequacy Caused an Improperly Calibrated Temperature Channel Resulting i

in Less Than the Required Number of Operable Reactor Protection System High Temperature Trip Channels EVENT DATE (5)

LER NUMBER (6)

REPORT DATE (7)

OTHER FACILITIES INVOLVED (8) l l. Sequential l l Revision l

l I

. Month Day l Year l Year Number Number Monthi Day lYear l Facility Names Docket Number (s) j j

l l

l 0

5 0 0 0 11 21-11 71 81 81 81 91--

01 01 11-- ' 01 0

013101818191 0

5 0 0 0 OPERATING l lIHIS REPORT IS SUBMITTED PUR5UANT '~0 THE REQUIREMENTS OF 10 CFR 5:

MODE (9) i Ni (Check one or more of the followina) (11)

POWERI l_l 20.402(b) l_l 20.405(c) l_l 50.73(a)(2)(iv) l ~l 73.71(b)

. LEVEL l l

l_l 50.36(c)(1) l _t 50.73(a)(2)(v) l i 73.71(c)

(10) 101010 _l 20.405(a)(1)(1) l_l 50.73(a)(2)(vii) l _ l Other (Specify in l]l 50.36(c)(2) l l 50.73(a)(2)(i) l_l 50.73(a)(2)(viii)(A)l Abstract below and

'i 1 20.405(a)(1)(ii)

_I 20.405(a)(1)(iii) j_j 20.405(a)(1)(iv) l_l 50.73(a)(2)(ii) l_l 50.73(a)(2)(viii)(B)I in Text, NRC Form i I 20.405(a)(1)(v) i I 50.73(a)(2)(iii) l I 50.73(a)(2)(x) l 366A)

LICENSEE CONTACT FOR THIS LER (12) i Name l Telephone Number IArea l Larry A. Taylor, Nuclear Safety and Licensing Specialist ICode l 1510111916l41-l3111010 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DFSCRIBED IN THIS REPORT (13) l l

l lReportablel l.

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l lReportablel Causelsystem! Component IManufacturerl to NPRDS I lCauselSysteml Component IManufacturerl to NPROS l l

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I I l I SUPPLEMENT REPORT EXPECTED (14) l EXPECTED l Month Day Year l SUBMISSION l l l Yes (If yes, complete Expected Submission Date) III No l DATE (15) l I l l l l

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ABSTRACT (Limit to 1400 spaces, i.e., approximately fifteen single-space typewritten lines) (16)

On December-17, 1988, plant personnel determined that a Reactor Coolant System (RCS) hot leg resistance temperature detector had been calibrated using the wrong calibration data since it was installed in May, 1982. This instrument provides one of four inputs to the Reactor Protection System (RPS) high RCS temperature trip. The calibration error would have resulted in a high RCS temperature RPS trip above the limit established by Technical Specifications for RPS channel "0".

Technical Specifications require that I

three RPS high RCS temperature trip channels be operable during startup and power operation. With channel j

"0" inoperable since May 1982, any time that another channel was out of service for maintenance or testing, there were less than three operable channels. The cause of this event was an inadequate procedure that did not require verification of the component serial number upon installation. However, this procedure had been corrected prior to discovery of this : vent. The temperature channel was correctly calibrated on December 18, 1988. The safety significance of this event is considered minimal since three of the four RCS hot leg temperature channels were operable and in service except for brief periods when a channel was out of service for testing or maintenance.

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Form 1062.018i

'HRC'Foro 366A U.S. Nuclear Regulatory Commission

. /,(9-83)

Approved OMB No. 3150-0104'

. LICENSEE EVENT REPORT (LER) TEXT CONTINUATION -

FACILITY HAME (1).

l DOCKET NUMBER (2) l LER NUMBER (6) l PAGE (3)

I l

1 ISequentiall l Revision!

Arkansas Nuclear One, Unit One l

l Year Number' Number l t

10l51010101 31 11 31 81 9 01 01 1 01 Ol01210Fl013 TEXT (If more space is required, use additional NRC Form 366A's) (17) 1.

Description of Event

A.

Plant Status At the time of discovery of this condition on December 17, 1988, Arkansas Nuclear One, Unit 1 (ANO-1) was shutdown with a Reactor Coolant System (RCS) (AB] temperature of approximately' 350 degrees Fahrenheit and RCS pressure at 800 PSIG.

B.

Component Identification The component involved in this event is RCS hot leg temperature element TE-1041/1042. This instrument is a dual element resistance temperature detector (RTD) [DET). TE-1041 provides one of four RCS hot leg temperature inputs to the Reactor Protection System (RPS) [JC].

TE-1042 provices input to the Integrated Control System (ICS). The calibration error associated with this event did not significantly affect the operation of the TCS, C.

Sequence of Events l

On December 17, 1988, Plant Maintenance personnel installed dual element RTD serial number (S/N) 4255 in the RCS hot leg temperature element location for TE-1013/1014. After installation, it was discovered that plant records indicated that RTD S/N 4255 was already installed in the RCS hot leg temperature location for TE-1041/1042. An investigation of the discrepancy determined that the RTD actually installed in location TE-1041/1042 was S/N 3444. Additional reviews also revealed that the tmperature channel associated with RTD S/N 3444 had been previously calibrated using the resistance / temperature values (RTD calibration table) for RTD S/N 4255. The use of the incorrect calibration data resulted in a non-conservative error (i.e., indicated RCS temperature lower than actual temperature) for this sensor and instrumentation string which is used as the input to RPS Channel "D" for the generation of a reactor trip on high RCS temperature.

II.

Event Cause

A.

Event Analysis

The RPS monitors selected variables associated with the nuclear reactor plant and automatically initiates protective action (generates a reactor trip) should any of these variables reach pre-established values. The RPS is a four channel system receiviag inputs from nuclear and non-nuclear instrumentation. A channel is " tripped" when any one of the variables it monitors exceeds the channel trip setpoint for that parameter. A reactor trip is initiated when any two of the four channels are tripped.

TE-1041 supplies the RCS hot leg temperature input to the RPS channel "D" high temperature trip. In May 1982, the dual element RTD for TE-1041/1042 required replacement. When the 1

replacement RTD (S/N 3444) was obtained from spare parts, the documentation provided with I

the element incorrectly indicated that the RTD was S/N 4255. Each RTD has unique

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calibration data which must be used to accurately calibrate its associated instrument channel. The procedure used by the maintenance technicians to install the RTD did not require verification of the RTD serial number prior to installation. After the RTD was installed, the temperature instrument loop was calibrated using the calibration data for RTD S/N 4255. This error would have resulted in a RPS channel "D" high RCS temperature trip of approximately 619.3 degrees Fahrenheit, instead of the required 618 degrees.

8.

Safety Significance

The safety significance of this condition is considered minimal since three of the four RCS hot leg temperature monitoring channels were calibrated correctly and normally in service during the time that the temperature instrument supplying RPS channel "D" was incorrectly calibrated. The only time that the Technical Specifications requirement of three operable channels was not. met was during brief periods when another RPS channel was removed from service for maintenance or testing. Had an actual high RCS temperature condition occurred, any two of the three operable channels would have ensured that a reactor trip occurred at or below the required 618 degrees. Additionally, channel "D" would have tripped at approximately 619.3 degrees, which is less than the value of 620 degrees assumed in the safety analysis for this protective action.

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NRC Fora 366A.

Form 1062.018 U.S. Nuclear Regulatory Commission:

f, f -(9-83).

i Approved OMB No. 3150-0104 Expires: 8/31/8S i,

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION j

FACILITY NAME (1) l DOCKET NUM?ER (2) l LER NUMBER (6) l PAGE (3)

'l l

l l l Sequential l lRevisiont

)

' Arkansas Nuclear One, Unit One l

l Year Number Number j l

1015l010l0l 31 Il 31 81 9 Oi 01 1 0l Ol01310Fl013 TEXT (If more space is required, use additional NRC Form 366A's) (17)

C.

Root Cause l

('

The root cause of this event was a procedural inadequacy it that the procedure used to install the RTD did not require verification of the components ser'11 number prior to installation or calibration of the device. Consequently, the technicians that installed the RTD in May 1982, did not verify the RTD's S/N and, therefore, did not detect the error.

1 D.

Basis for Deportability Technical Specifications Table 3.5.1-1 states that the required minimum number of operable RCS temperature channels is two and that an additional channel must be operable to establish a minimum required degree of redundancy. Technical Specifications Table 3.5.1-1, Note 6, allows the minimum operable channels to be reduced to two provided that the system is reduced i

to'one of two coincidence by tripping the remaining channel.

Following replacement of the RTO in May 1982, the RCS high temperature trip for RPS channel "D" was calibrated to trip above the Technical Specifications trip setting limit of 618 degrees. Therefore, this channel was inoperable from that time. Subsequently, any time that.

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another channel was removed from service for maintenance or testing, there would be only two operable channels. This condition has existed for brief time periods since May 1982, without an additional channel being tripped, and is reportable pursuant to 10CFR50.73(a)(2)(1)(B) as a condition prohibited by Technical Specifications.

III. Corrective Actions

4 A.'

.Immediate i

'Following discovery of the discrepancy with the RTD serial numbers, an investigation was conducted which determined that the RTD installed in the location for TE-1041/1042 was

'actually S/N 3444.

8.

Subsequent The calibration procedure for TE-1041/1042 was revised to reflect the correct calibration data and the temperature monitoring channel was properly calibrated on December 18, 1988.

A walkdown of other RCS hot leg RTDs (only hot leg RTDs provide temperature input to the

' RPS) was conducted to verify that the correct elements were installed and that their associated '

channels were correctly calibrated. No other deficiencies were identified.

j Plant procedures were reviewed, and it was determined that the " Control of Maintenance" procedure currently in use requirer the nameplate data for plant equipment to be verified and recorded whenever a component is installed-or replaced. This should prevent the recurrence of similar events.

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s C.

Future I

a There are no further corrective actions anticipated with respect to this event.

IV. Additional Information

j A.

Similar Reportable Events There have been no similar events reported at ANO-1.

B.

Supplemental Information Energy Industry Identification System (EIIS) codes are identified in the text as [XX).

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ARKANSAS POWER & LIGHT COMPANY March 8, 1989 1CAN038904 U. S. Nuclear Regulatory Commission Document Control Desk Mail Station P1-137-i Washington, D.C.

20555 j

f

SUBJECT:

Arkansas Nuclear One - Unit 1 i

Docket No. 50-313 i

License No. DPR-51 Licensing Event Report No. 313/89-001-00 1

Gentlemen:

In accordance with 10CFR50.73(a)(2)(i), attached is the subject report concerning a procedure inadequacy which caused a temperature j

channel to be improperly calibrated resulting in less than the j

required number of operable Reactor Protection System high j

temperature trip channels.

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Very truly yours j

wt J. M. Levine i

fExecutiveDirector, Nuclear Operations JML: RHS: vgh attachment cc w/att: Regional Administrator

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Region IV U. S. Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 1000 Arlington, TX 76011 INP0 Records Center 1500 Circle 75 Parkway Atlanta, GA 30339-3064 MEMBEA MIDDLE SOUTH UTILITIES SYSTEM