ML18152B082

LER 88-024-00:on 880711,16 Individual Rod Position Indicators for Eight Rods in Each Shutdown Bank a & B Differed from Group Demand Step Counter by Greater than 12 Steps.Caused by Drift in Subj indicators.W/880809 Ltr

ML18152B082
Person / Time
Site:	Surry
Issue date:	08/09/1988
From:	Benson D VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
88-038, 88-38, LER-88-024, LER-88-24, NUDOCS 8808190280
Download: ML18152B082 (4)

Text

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NRC Form 366 19-83) - LICENSEE EVENT REPORT (LER) e POW 28-06-01 U.S. NUCLEAR REGULATORY COMMISSION APPROVED OMa NO. 3160-0104 EXPIRES: 8/31/88 FACILITY NAME 111 DOCKET NUMBER (21 PAGE 131 Surry Power Station. Unit 1 015IOIOIOl">laln 1loF~h TITLE 141 Inoperable Individual Rod Position Indicators Due To Instrument '

n ... if't EVENT DATE ISi LER NUMBER 161 REPORT DATE (71 OTHER FACILITIES INVOLVED (Bl MONTH DAY YEAR YEAR {ft SE~~~~r~AL ( ) ~~1~~~ MONTH DAY YEAR FACILITY NAMES DOCKET NUMBERISI o I1 , I 1 a a aIa - o I 2 I 4 - olo o I s o 19 s Is OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Chock on* or more of th* fol/OV(lng/ (111 N

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LICENSEE CONTACT FOR THIS LER (121 I--

60.73(all2llvlll)(BI 60.73(all211xl NAME TELEPHONE NUMBER AREA CODE D. L. Benson, Station Manager 81 0 I 4 3 I 5 I 7 r 13 11 I 8 14 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (131 CAUSE SYSTEM COMPONENT MANUFAC*

TURER X A1A 21 I I I MI 01 31 5 N I I I I I I I I I I I I I I 1!!111!!!!!!!:!i!!i!!!!l!l!i!l!lil!i!ill!l!i!l!i!l!l! I I I I I I I SUPPLEMENTAL REPORT EXPECTED 114) MONTH DAY YEAR EXPECTED

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SUBMISSION DATE 1151

- - , YES (If yas, compl*t* EXPECTED SUBMISSION DATE/ NO . I I I ABSTRACT (Limit~. 1400 SPl1C8S, i.*., approxim*t*ly fift**n singlB*SPllC* tyP11Wrimn Jinas/ (161 on July 11, 1988, Unit 1 was at intermediate shutdown and proceeding to cold shutdown. At 1105 hours0.0128 days <br />0.307 hours <br />0.00183 weeks <br />4.204525e-4 months <br />, 16 Individual Rod Po.sition Indicators ( IRPis) for eight rods in each shutdown bank "A" and "B" differed from the group demand step counter by greater than 12 steps. This is contrary to Technical Specification (T. S.) 3.12.E. The IRPis were adjusted at 1245 hours0.0144 days <br />0.346 hours <br />0.00206 weeks <br />4.737225e-4 months <br /> and the unit reached cold shutdown at 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br />. Incorrect IRPI indication due to primary temperature changes is known to be a generic Westinghouse concern. A Technical Specification change is being prepared which will accommodate this phenomenon and the P-250 process computer alarm setpoint has been changed to alert the operator when IRPis are 10 steps out of alignment.

8808190280 880809 PDR ADCICK 05000280 S PDC NRC Form 366 IQ.R11 _ -----*

POW 28-06-01 NRC Fprm 368A U.S. NUCLEAR REGULATORY COMMISSION (9-83)

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVED 0MB NO. 3150-0104 EXPIR.ES: 8/31 /B8

'I' FACILITY NAME 11) DOCKET NUMBER 12) LER NUMBER 16) PAGE (3)

SEQUENTIAL ::::::::::: REVISION YEAR ."."."."." NUMBER  :::::::::: NUMBER Surry Power Station, Unit 1 o 1s Io Io Io I 218 IO 8 IS - o I 2 I 4 - o I o oI 2 OF nI ~

TEXT (ff mom space is n,quimd, U/19 *dditiona/ NRC Form 366A 's) 117) 1.0 Description of the Event On July 11, 1988, Unit 1 was at intermediate shutdown and proceeding to cold shutdown due to leakage through a containment isolation valve. At 1105 hours0.0128 days <br />0.307 hours <br />0.00183 weeks <br />4.204525e-4 months <br />, 16 Individual Rod Position Indicators (IRPis) {EIIS-ZI}

for eight control rods in each shutdown bank 1 A' & 'B' differed from the group step demand counter by greater than 12 steps. This is contrary to Technical Specification (T.S.) 3.12.E.

The IRPis were adjusted at 1245 hours0.0144 days <br />0.346 hours <br />0.00206 weeks <br />4.737225e-4 months <br /> and the unit achieved cold shutdown at 1300 hours0.015 days <br />0.361 hours <br />0.00215 weeks <br />4.9465e-4 months <br /> on July 11, 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 the control rod group position as demanded by the rod control system {EIIS-AA}

remained operable during the time the IRPis were not operable. In addition, inoperable IRPis will not affect the operation of the control rod assemblies.

All rods were capable of being dropped into the core, if required. Therefore, the health and safety of the public were not affected.

3.0 Cause The cause of the event is due to the drift in IRPI indication as a result of primary coolant temperature changes. This is known to be a generic West.inghouse PWR concern.

4.0 Immediate Corrective Action(s)

The IRPis were adjusted to within the required T. s. tolerance.

5.0 Additional Corrective Action(s)

None required.

NRC FORM 366A *u.s. GPO: 1988-520-589100070 19-831

POW 28-06-01

"'. NRC Form 368A ** U.S. NUCLEAR REGULATORY COMMISSION (9-83)

• LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVED 0MB NO. 3150--0104 EXPIRES: 8/31 /88

\ FACILITY NAME (1) DOCKET NUMBER (2) LER NUMBER (6) PAGE (3)

Surry Power Station, Unit 1 o 1s1010101 21810 818 -01214 - 010 013 oF o 13 TEXT (ff more space is required, use sddiliofllJI NRC Form 366A 's) 117) 6.0 Action(s) Taken to Prevent Recurrence A setpoint change has been made which lowered the P-250 process computer rod deviation alarm to alert the operator when the IRPis deviate from the group demand position by 10 steps. This will aid in initiating corrective action prior to exceeding the T. s. limits.

A Technical Specification change is being prepared which will accommodate the effects of primary coolant temperature changes on the IRPis. Until the T. s.

change is approved, the IRPis will be adjusted to agree with the step demand counters as required during primary temperature changes.

7.0 Similar Events Unit 1 LERs .: 88-010, 88-006,88-002 86-021,85-019.

Unit 2 LERs: 88-012, 88-007,88-003, 86-019,85-009.

8.0 Manufacturer/Model Number Magnetics Inc./Project #K9391, K9392 NRC FORM 366A *U.S. GPO, 1988-520-589100070 (9-83)

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e e VIRGINIA ELECTRIC AND POWER COMPANY Surry Power Station P. 0. Box 316 Surry, Virginia 23883 August 9, 1988 U.S. Nuclear Regulatory Commission Serial Ho.: 88-038 Document Control Desk Docket Ho.: 50-280 016 Phillips Building Licensee No. : DPR-32 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 1.

REPORT NUMBER 88-024-00 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, V

jha~. f:~

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