05000498/LER-1998-008, :on 980909,TS 3.0.3 Was Entered Due to Inoperable Rod Control Demand Step Counters.Caused by Inadequate Communication Between CR Staff & Maint Personnel.Detailed Discussions of Lessons Learned Held

:on 980909,TS 3.0.3 Was Entered Due to Inoperable Rod Control Demand Step Counters.Caused by Inadequate Communication Between CR Staff & Maint Personnel.Detailed Discussions of Lessons Learned Held

ML20154N766
Person / Time
Site:	South Texas
Issue date:	10/14/1998
From:	Head S HOUSTON LIGHTING & POWER CO.
To:
Shared Package
ML20154N756	List: 05000498/LER-1998-008, :on 980909,TS 3.0.3 Was Entered Due to Inoperable Rod Control Demand Step Counters.Caused by Inadequate Communication Between CR Staff & Maint Personnel.Detailed Discussions of Lessons Learned Held
References
LER-98-008, LER-98-8, NUDOCS 9810220086
Download: ML20154N766 (3)

LER-1998-008, on 980909,TS 3.0.3 Was Entered Due to Inoperable Rod Control Demand Step Counters.Caused by Inadequate Communication Between CR Staff & Maint Personnel.Detailed Discussions of Lessons Learned Held

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(viii) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(iv), System Actuation 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
4981998008R00 - NRC Website

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NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO.3150-0104 EXPIRES 0&30/3001

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! -199R) 6 Ectimated burden per response to mmply with this rnandetary information collection request: 50 hrs. Reported lessons lecrned are incorporcted into the licensing process LICENSEE EVENT REPORT (LER)

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d Co DC 20555-0001, and to the Paperwork Reduction ect (3150 0104i. Othe of (See reverse for te9tdred number of Managennt ud BudgetJashington, DC 20503. If n infwnution mllection does not display a currently valid OMB control nunter. the NRC may not conduct or d' igits/ characters for each block) spanax. and a person is not required to respond to, the information FACIUTY NAMF (1)

DOCKET NUMBER (2)

PAGE (3)

South Texas Unit 1 05000 498 1

of 3

'ITILE (4)

Entry into Technical Specifications 3.0.3 Due to Inoperable Rod Control Demand Step Counters EVENT DATE (5)

LER NUMBER (6)

REPORT DATE(7)

OTHER FACILITIES INVOLVED m)

MONTH DAY YlMR YEAR sigt nAL RE I MONH1 DAY YEAR FACILITY NAME DOCKIrr NUMBER 05000

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FACILITY NAME IX)CKET NUMBER 09 09 1998 98

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00 10 14 1998 05000 s

OPERATING THIS REPORT IS SUBMITTED PURSUANi TO THE REOUIREMENTS OF 10 CFR 5: (Check one or more) (11)

- MODE (9) 1 20.2201(b) 20.2203(a)(2)(v)

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50.73(a)(2)(i) 50.73(a)(2)(viii)

POWER 20.220HaVD 20.2203(a)OVi) 50.73(aV216i) 50.7Va)(2)(x)

LEVEL (10) 100 20.2203(a)(2xi) 20.2203(alo)(ii) 50.73(a)(2)(iii) 73.71 i

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20.2203(aV2)(ii) 20.220Ha)(4) 50.73(a)(2)(iv)

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Specify in Abstract below or in 20.2203(aW2Kiv) 50.36(cK2) 50.73(a)(2)(vii)LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPfloNE NUMBER Gnclude Area Code)

Scott Head - Licensine Suoervisor (512)972-7136 COMPLINE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE

SYSTEM COMPONENT MANUFAC.TURER REPORTABLE

CAUSE

SYSTEM COMPONENT MANUFACTURER REPORTABLE 4

TO EPIX TO EPIX n/a n/a n/a n/a N

s SUPPI WENT AI. REPORT EXPECTED (141 EXPECTED MONTil DAY YEAR lYES

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NO SUBMISSION l0f yes, complete EXPECTED SUBMISSION DATE).

DATE(15)

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

On September 9,1998, an unintentional entry into Technical Specification 3.0.3 was made when Bank D control rod step counters were inoperable for approximately 34 minutes during a troubleshooting procedure. While performing troubleshooting on the Rod Control System, additional work instructions were written into the work package to remove a relay driver card from the Rod Control System logic cabinet and place it on an extender board. Discussions during the pre-job brief did not adequately capture the effect of these changes to the work instructions. Because of three broken pins on the extender board, the driver card did not receive power after being installed. The result was that rods were moved but the control board demand position did not change. The extender card was subsequently removed and the original driver card was reinstalled in the cabinet. The step counter operation was verified and the step counters were restored to the correct position. Corrective actions include detailed discussions oflessons learned with maintenance, work control and operations personnel.

9810220086 981014 PDR ADOCK 05000498 s

PDR hkC 00RM 366 (6-1998) a

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NRC EORM 366A U.S. NUCLEAR REGULATORY COMMISSION' (6 1998)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME (1)

DOCKET LER NUMBER (6)

PAGE (3)

South Texas, Unit l' 05000 498 I "

"& JAP

"'23 2 of 3 n

98 -- 008 --

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

DESCRIPTION OF EVENT

On September 9,1998, an unintentional entry into Technical Specification 3.0.3 was made when control rod step counters for Bank D were rendered inoperable for approximately 34 minutes during a troubleshooting procedure.

Initial troubleshooting began on the Rod Control System on September 3,1998, when the C-11 indicator light (Rods at 248 Steps) was not lit with control rods at 250 steps. The work package was prepared to troubleshoot the pulse-to-analog converter on the Rod Control System. The original scope of the work did not affect the step counters. On September 9, additional instructions were written into the work package to remove a relay driver card from the Rod Control System logic cabinet and place it on an extender board.

A pre-job brief was conducted prior to starting work to discuss the work scope. The pre-job brief concentrated on the troubleshooting plan to monitor the driver card inputs and outputs to the pulse to analog converter, and whether testing could lead to generating any reactor trip signals. Since the driver card circuits are independent of each other, it was thought that problems with the test equipment connections, or a short circuit, would not have affected the step counter signals.

After the brief, the driver card from the Rod Control System logic cabinet was removed and reinstalled on the extender board. Control room personnel were requested to step Bank D control rods in. Because of three broken pins on the extender board, the driver card did not receive power after beiri installed. Control room personnel realized the problem with the step counters, when the digital rod position indication changed but both Bank D step counter; did not move, and they reviewed Technical Specifications for applicability. The extender board was remosed and the original driver card was reinstalled. Step counter operation was verified and it was determined that control rods had been moved five steps. The step counters were then restored to their correct position.

CAUSE OF EVENT

The cause of this event was less than adequate commusation between the control room staff and the maintenance personnel conducting the troubleshooting evolution.

ANALYSIS OF EVENT

Any operation or condition prohibited by the plant's Technical Specifications is reportable under 10CFR50.73(a)(2)(i)(B). Technical Specification 3.1.3.2.b allows only one step counter per bank to be inoperable.

When the troubleshooting was performed on Bank D, both step counters were inoperable for approximately 34 minutes and an unintentional entry into Technical Specification 3.0.3 was made on September 9,1998. Operability of the control rods position indicators is required to determine control rod positions and thereby ensure compliance with the control rod alignment and insertion limits. During this time control rod motion was observed on the Digital Rod Position Indication System which remained operable at all times during the troubleshooting. At no time did control rods become misaligned in the group and they were not more than twelve steps from their bank step counters.

NRC IORM 366 (61998)

NRC EORM 366A U.S. NUCLEAR REGULATORY COMMISSION p1998)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME (1)

DOCKET LER NUMBER (6)

PAGE (3)

South Texas, Unit 1' 05(XX)498 l

• 'A's"c'A*'

"'UeT 3 of 3

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nu 98 -- 008 --

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

CORRECTIVE ACTIONS

1. Operations management will discuss lessons. learned from this event as well as expectations for effective communications with alllicensed Operations personnel. (Due October 22,1998)

2. Maintenance and Work Control will discuss lessons learned from this event as well as expectations for effective communications with appropriate supervisory personnel. (Due December 16,1998) i

3. Lessons learned from this event will be included in formal Licensed Operator Requalification Training. (Due March 25,1999)

ADDITIONAL INFORMATION

There have been no licensee Event Reports submitted in the last three years by the South Texas Project to the Nuclear Regulatory Commission regarding an inoperable rod control system.

NRCIORM 366 (6-1998)