ML18152A996

LER 88-012-00:on 880517,individual Rod Position Indicators for Four Rods in Shutdown Bank B Differed from Rod Group Demand Counter by Greater than 12 Steps.Caused by Incorrect Rod Position Indication Due to RCS changes.W/880616 Ltr

ML18152A996
Person / Time
Site:	Surry
Issue date:	06/16/1988
From:	Benson D VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
88-027, 88-27, LER-88-012-02, LER-88-12-2, NUDOCS 8806210501
Download: ML18152A996 (4)

Text

POW 28-06-01-01

~. NRC Form 366 U.S. NUCLEAR REGULATORY COMMISSION 19-83)

APPROVED 0MB. NO. 3150-0104 EXPIRES: 8/31/88 LICENSEE EVENT REPORT (LERI FACILITY NAME 11) DOCKET NUMBER 12) I PAGE 131 TITLE 141 SURRY*POWER STATION, UNIT 2 Io I 5 I o I o I o I 2 18 11 1!0F 013 Inoperable Individual Rod Position Indicators Due to Instrument Drift EVENT DATE 15) LEA NUMBER 16) REPORT DATE 17) OTHER FACILITIES INVOLVED 18)

MONTH DAY YEAR YEAR 1:::::::,:: SEQUENTIAL :/::::: REVISION MONTH DAY YEAR FACILITY NAMES DOCKET NUMBERISI i:::::::::;: NUMBER  :;:;:;:;:: NUMBER o Is 11 7 s s s ls - o 11 I2 - oIo o I6 1 16 s Is THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check one or more of the folloY(ing) (11)

OPERATING MODE (9) 20.402(b)* 20,4051c) 73.711b)

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NAME TELEPHONE NUMBER AREA CODE I I I I I I I I I COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT 113)

CAUSE SYSTEM COMPONENT MANUFAC* MANUFAC-TURER TURER I*:*::.: .. :.* *.*:.*:* *.-:*,:.

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I I I I I I I I I I I I I I ***** .*.*  :,,..*.* I I I I I I I SUPPLEMENT~L REPORT EXPECTED 1141 MONTH DAY YEAR EXPECTED n YES (If yes, complete EXPECTED SUBMISSION DATE/

ABSTRACT (Umit to 1400 spaces, i.e., spproximstsly t;freen single-sf)Bce typewritten lines} 116) bl NO SUBMISSION DATE 115)

I I I On May 17, 1988, Unit 2 was at intermediate shutdown and proceeding to cold shutdown as required by Technical Specifications (T.S.) due to reduced auxiliary feedwater flow following a reactor trip on May 16, 1988. At 0557 hours0.00645 days <br />0.155 hours <br />9.209656e-4 weeks <br />2.119385e-4 months <br /> on May 17, 1988, the Individual Rod Position Indicators (IRPis)

[EIIS-ZI] for four rods in shutdown bank "B" differed from the rod group demand counter by greater than 12 steps. This is contrary to T.S. 3.12. The IRPis were adjusted at 0631, but during the continued cooldown, six IRPis for shutdown bank "A" drifted out of the 12 step band at 0850 hours0.00984 days <br />0.236 hours <br />0.00141 weeks <br />3.23425e-4 months <br />. The IRPis were not able to_ be calibrated, and the unit was placed in cold shutdown at 0519 hours0.00601 days <br />0.144 hours <br />8.581349e-4 weeks <br />1.974795e-4 months <br /> on May 18, 1988. Incorrect rod position indication due to Reactor Coolant System (RCS) [EIIS-AB]

temperature changes is known to be a generic Westinghouse PWR concern. A T.S. change is being prepared which will ~ccommodate the effects of RCS temperature on the rod position.indicators. A setpoint change was made which lowered the P-250 process computer rod deviation alarm to alert the operator when the rods are 10 steps out of alignment to preclude exceeding the *T.S. limit of 12 steps. The IRPis will be calibrated prior to unit criticality. ,..., ~

-cl 8806210501 g~~~81 PDR ADOCK PDR y \) 1 NRC Form 366 s  :....::...----------------------------..

POW 28-06-01-01 NRC Form 366A U.S. NUCLEAR REGULATORY COMMISSION (9-831 LICENSEE EVENT REPORT (LERI TEXT CONTINUATION APPROVED 0MB NO. 3150-0104 EXPIRES: B/31 /88 FACILITY NAME (1) DOCKET NUMBER (21 LEA NUMBER (6) PAGE (3)

SURRY POWER STATION, UNIT 2 0

15 1°1°1°121811 818 -ol1 l2 - ol c 012 °Fo 13 TEXT /ff more space is rr,quired, us,, addition*! NRC Form 3S6A's/ 1171 1.0 Description of the Event On May 17, 1988, Unit 2 was at intermediate shutdown and proceeding to cold shutdown as required by Technical Specifications (T.S.) due to reduced auxiliary feedwater flow following a reactor trip on May 16, 1988. At 0557 hours0.00645 days <br />0.155 hours <br />9.209656e-4 weeks <br />2.119385e-4 months <br /> on May 17, 1988, the Individual Rod Position Indicators (IRPis) [EIIS-ZI] for four rods in shutdown bank 11 11 B differed from the rod group demand counter by greater than 12 steps. This is contrary to T.S. 3.12.

The IRPis were adjusted at 0631, but during the continued cooldown, six IRPis for shutdown bank 11 A11 drifted out of the 12 step band at 0850 hours0.00984 days <br />0.236 hours <br />0.00141 weeks <br />3.23425e-4 months <br />. The IRPis were not able to be calibrated, and the unit was placed in cold shutdown at 0519 hours0.00601 days <br />0.144 hours <br />8.581349e-4 weeks <br />1.974795e-4 months <br /> on May 18, 1988.

2.0 Safety Consequences and Implications The IRPis provide control rod position indication in the main control room. The control rod demand counters, which indicate control rod position as demanded by the Rod Control System [EIIS-AA], remained operable during the time the IRPis were not operable. Only the shutdown banks were withdravm during this event. Inoperable IRPis will not affect the operation of the control rod assemblies, and all rods were capable of being inserted into the core if required. Therefore, the h~altp and safety of the public were not affected.

3.0 Cause Incorrect rod position indication due to Reactor Coolant System (RCS) [EIIS-AB] temperature changes is known to be a generic Westinghouse PWR concern. The decision was made to continue the plant cooldown to place the unit in the T.S.

required condition.

4.0 Immediate Corrective Action(s)

At 0519 hours0.00601 days <br />0.144 hours <br />8.581349e-4 weeks <br />1.974795e-4 months <br /> on May 18, 1988, cold shutdown was achieved.

A work request was submitted to calibrate the IRPis.

NRC FORM 366A

POW 28-06-01-01 NRC Form 366A U.S. NUCLEAR REGULATORY COMMISSION (9-83)

LICENSEE EVENT REPORT (LERI TEXT CONTINUATION APPROVED 0MB NO. 3150-0104 EXPIRES: B/31 /88 FACILITY NAME (11 DOCKET NUMBER (2) LER NUMBER (6) PAGE (JI SURRY POWER STATION, UNIT 2 01s10101012l8ll 818 -01112 -010 Ol3 OF Ol3 TEXT /If moro space is mquil'9d, USIJ odditionol NRC Form 366A's/ (171 5.0 Additional Corrective Action{s)

A Technical Specification change is being prepared which will accommodate the effects of RCS temperature on the rod position indicators.

A setpoint change was made which lowered the P-250 process computer rod deviation alarm to alert the operator when the rods are 10 steps out of alignment to preclude exceeding the Technical Specification limit of 12 steps. The IRPis will be calibrated prior to unit criticality.

6.0 Action(s) Taken to Prevent Recurrence Until the Technical Specification change is approved, the IRPis will be adjusted to agree with the step demand counters as required during RCS temperature changes below hot shutdown.

7.0 Similar Events Ul LERs: 88-010, 88-006,88-002, 86-021,85-019.

U2 LERs: 88-007, 88-003,86-019, 85-009.

8.0 Manufacturer/Model Number Magnetics Inc./Project #K9391, K9392.

NRC FORM 366A

e VIRGINIA ELECTRIC AND POWER COMPANY Surry POW9r Station P.O. lox 315 Surry, Virginia 23883 June 16, 1988 U.S. Nuclear Regulatory Commission Serial No.: 88-027 Document Control Desk Docket No.: 50-281 016 Phillips Building Licensee No.: DPR-37 Washington, D.C. 20555 Gentlemen:

Pursuant to Surry Power Station Technical Specifications, Virginia Electric and Power Company hereby submits the following Licensee Event Report for Surry Unit 2.

REPORT NUMBER 88-012-00 This report has been reviewed by the Station Nuclear Safety and Operating Committee and will be reviewed by Safety Evaluation and Control.

Very truly yours*,

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..!)OJl./lQ. "'-- .j E:/)"W..C?<...

David L. Benson Station Manager Enclosure cc: Dr. J. Nelson Grace Regional Administrator Suite 2900 101 Marietta Street, NW Atlanta, Georgia 30323