ML18100A888

LER 94-002-00:on 940121,reactor Manually Tripped Due to Less than Required Operable CR Demand Position Indicators.Caused by Improper Assembly of Step Counter Lcd Display Module. Failed Counter Replaced w/spare.W/940216 Ltr

ML18100A888
Person / Time
Site:	Salem
Issue date:	02/16/1994
From:	Hagan J, Pastva M Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-94-002, LER-94-2, NUDOCS 9402230294
Download: ML18100A888 (7)

Text

-e Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038 Salem Generating Station u. s. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

Dear Sir:

SALEM GENERATING STATION LICENSE NO. DPR-70 DOCKET NO. 50-272 UNIT NO. 1 LICENSEE EVENT REPORT 94-002-00 February 16, 1994 This Licensee Event Report is being submitted pursuant to the requirements of Code of Federal Regulation 10CFR50.73(a)

(2) (i) (B). Issuance of this report is required within thirty (30) days of event discovery.

MJPJ:pc Distribution ; .. ,..-... ... r*. 8 u J Ci. 9402230294 940216 PDR ADOCK 05000272 9 PDR The power is in your hands. Sincerely yours, 95-2189 REV 7-92

, NRC FORM 366 (5-92) S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0)04 EXPIRES 5/31 /95 LICENSEE EVENT REPORT (LER) (See reverse for required number of digits/characters for each block) ESTIMATED BURDEN PER RESPONSE TO COMI LY Wr.H THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE E INFO"MATION AND RECORDS MANAGEMENT BRANCH (MNBB 771 ), U.S. l';UCLEAR REGULATORY COMMISSION, WASHINGTON, DC 55-0001, AND TO THE PAPEF\WORK REDUCTION PROJECT (3150-0 04), OFFICE OF MANAGEMENT AND BUDG.ET; WASHINGTON, DC 20 03. FACILITY NAME (1) DOCKET NUMBER (2) PAGE (3) 1OF05 Salem Generating Station -Unit 1 05000 27? NUMBER SEQUENTIAL MONTH DAY YEAR YEAR REVISION NUMBER MONTH DAY YEAR FACILITY NAME FACILITY NAME DOCKET NUMBER 05000 DOCKET NUMBER 01 21 94 94 002 00 02 Hi Q4 05000 OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR I: (Check one or more 11 MODE (9) 3 20.402(b) 20.405(c) 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) 000 20.405(a)(1)(ii) 50.36(c)(2) . 50.73(a)(2)(vii)

OTHER 20.405(a)(1

)(iii) 50.73(a)(2)(i) 50.73(a)(2)(viii)(A) (Specify in Abstract below and in Text, NRG 20.405(a)(1)(iv) x 50.73(a)(2)(ii) 50.73(a)(2)(viii)(B)

Form 366A) 20.405(a)(1)(v) 50.73(a)(2)(iii) 50.73(a)(2)(x)

LICENSEE CONTACT FOR THIS LEA (12) NAME TELEPHONE NUMBER (Include Area Code) M. J. Pastva. Jr. -LER Coordinator (nOQ)

COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13) CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE TONPRDS CAUSE SYSTEM COMPONENT MANUFACTURER REPORTABLE TO NPRDS B AA ZI Sl20 y SUPPLEMENTAL REPORT EXPECTED (14 MONTH DAY YEAR I YES (If yes, complete EXPECTED SUBMISSION DATE) x NO EXPECTED SUBMISSION DATE (15) ABSTRACT (Limit to 1400 spaces, i.e., apJJroximately 15 single-spaced typewritten lines) (16)

• On 1/21/94, at 1017 hours0.0118 days <br />0.283 hours <br />0.00168 weeks <br />3.869685e-4 months <br />, the Reactor was manually tripped, (reactor trip system breakers opened) in accordance with Technical Specifications.

During rod drop testing, the step counter readings of the Control Rod Shutdown Bank B group demand position indicators for Groups 1 and 2*did*notagree:

Group 1 demand indicated 1aa*stepsfor rod SBl while Group 2 indicated 174 steps for rod SB2. Testing was stopped, position was verified at 188 steps, and the Group 2 indicator was declared inoperable.

The cause of this event is improper assembly, by the supplier, of the indicator step counter liquid crystal display {LCD) module to the counter back plane. The counter was replaced with a spare, which was satisfactorily tested and placed into service. The indicator supplier, Science Application International Corporation

{SAIC), has been requested to provide the results of full inline inspection and failure analyses of the failed counter. The Unit 2 design change package for installing these counters will be revised to provide for visual verification/testing to confirm that the indicator LCD module is properly installed.

The PSE&G vendor manual will be revised to ensure proper operation of SAIC GRID counters prior to installation or replacement.

This event will be reviewed by Operations personnel and by the Training Department for incorporation into the Operations lesson plan. NRG FORM 366 (5-92)

BLOCK NUMBER 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 REQUIRED NUMBER OF DIGITS/CHARACTERS FOR EACH BLOCK NUMBER OF DIGITS/CHARACTERS TITLE UP TO 46 FACILITY NAME 8 TOTAL 3 IN ADDITION TO 05000 DOCKET NUMBER VARIES PAGE NUMBER UP TO 76 TITLE 6 TOTAL 2 PER BLOCK EVENT DATE 7 TOTAL 2 FOR YEAR 3 FOR SEQUENTIAL NUMBER LER NUMBER 2 FOR REVISION NUMBER 6 TOTAL 2 PER BLOCK REPORT DATE UP TO 18 FACILITY NAME 8 TOTAL-DOCKET NUMBER OTHER FACILITIES INVOLVED 3 IN ADDITION TO 05000 1 OPERATING MODE 3 POWER LEVEL 1. CHECK BOX THAT APPLIES REQUIREMENTS OF 10 CFR UP TO 50 FOR NAME 14 FOR TELEPHONE LICENSEE CONTACT CAUSE VARIES 2 FOR SYSTEM 4 FOR COMPONENT EACH COMPONENT FAILURE 4 FOR MANUFACTURER NPRDS VARIES 1 CHECK BOX THAT APPLIES SUPPLEMENTAL REPORT EXPECTED 6 TOTAL 2 PER BLOCK EXPECTED SUBMISSION DATE ..

l LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station Unit 1 DOCKET NUMBER 5000272 PLANT AND SYSTEM IDENTIFICATION:

Westinghouse

-Pressurized Water Reactor LER NUMBER 94-002-00 PAGE 2 of 5 Energy Industry Identification System (EIIS) codes are identified in the text as {xx} IDENTIFICATION OF OCCURRENCE:

Manual Reactor Protection system Actuation Due To Less Than Required Operable Control Rod Group Demand Position Indicators Event Date: 1/21/94 Report Date: 2/16/94 This report was initiated by Incident Report Nos.94-025 and 94-026 CONDITIONS PRIOR TO OCCURRENCE:

11th Refueling outage in progress with the Unit in Mode 3. Control rod drop time testing of Shutdown Bank B, was in progress in accordance with procedure Sl.IC-ST.RCS-0001(Q), "ROD DROP TIME MEASUREMENT

-HOT FULL FLOW". DESCRIPTION OF OCCURRENCE:

On January 12, 1994, at 1017 hours0.0118 days <br />0.283 hours <br />0.00168 weeks <br />3.869685e-4 months <br />, the Reactor was manually tripped, (reactor trip system breakers opened) in accordance with Technical Specification (TS) 3.1.3.2.2.

During rod drop testing, the step counter readings of the Control Rod Shutdown Bank B group demand position indicators

{AA} for rod Groups 1 and 2 did not agree: Group 1 demand indicated 188 steps for rod SB1 while Group 2 indicated 174 -steps for rod SB2. Testing was stopped and position shown by the plant P250 computer {ID} was verified to be 188 steps. The Group 2 demand position indicator was declared inoperable.

The NRC was notified of the manual actuation of the Reactor Protection System (RPS) {JC}, at 1835 hours0.0212 days <br />0.51 hours <br />0.00303 weeks <br />6.982175e-4 months <br />, in accordance with the requirements of 10CFR50. 72 (b) (2) (ii). ANALYSIS OF OCCURRENCE:

Operability of the control rod position demand indicators ensures compliance with control rod alignment and insertion limits. The indicators are determined operable by verifying that the rod position indication system agrees within twelve (12) steps of the group demand counters for a range of positions.

This permits the Operator to verify that the control rods in the bank are either fully withdrawn or LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station Unit 1 DOCKET NUMBER 5000272 ANALYSIS OF OCCURRENCE: (cont'd) LER NUMBER 94-002-00 PAGE 3 of 5 fully inserted and satisfies accident analysis assumptions concerning their position.

During control rod drop time testing of Shutdown Bank B, the Group 1 position demand indicator (step counter) showed 188 steps while the step counter for Group 2 showed 174 steps. Testing was stopped and position of the groups, as shown by the P-250 plant process computer, was verified to be 188 steps. The Group 2 step counter was then declared inoperable and in accordance with TS, the Reactor was manually tripped (reactor trip system breakers opened). The Rod Control System was functioning correctly; however, the demand position indicator counter liquid crystal display (LCD) display did not change when the counter audible clicker operated.

The subject indicator counter is one of the 14 Science Application International Corporation (SAIC) Group Rod Indicator Displays (GRID) installed, in accordance with a design change package (DCP), during the recent lRll Unit refueling/maintenance outage. Bench testing the indicator demand counter, SAIC GRID serial number (S/N) 881993-20, determined the failure resulted from improper assembly of the counter LCD display module, "SUPER SUB-CUB", supplied by Red Lion Controls.

Inspection revealed the LCD display module elastomeric strip was not making proper contact with the counter back plane (PC Board) . This resulted from the LCD display module locking pin not properly penetrating the PC Board. Consequently, the PC board under the strip was exposed to ambient conditions and the pad area developed oxidation.

This restricted electrical current flow to the LCD display module, which resulted in the erroneous LCD indications.

The failed counter was replaced with a spare, which was inspected and tested to ensure proper assembly of the LCD module to the counter PC Board, and returned to service. Non-reportable SAIC GRID counter failures, (i.e. not requiring RPS actuation) occurred on December 29,1993, and following the event reported in this LER, on January 21, 1994. Following these failures, spare GRID counters were also installed and satisfactorily tested. These non-reportable failures are also attributed to improper assembly of the LCD display module elastomeric strip to the associated PC Board. Additional testing on installed Unit 1 SAIC counters did not reveal any additional problems, with exception of the second non-reportable failure on January 21, 1994. On February 11, 1994, SAIC made 10CFR21 notification in response to these failures and other SAIC GRID failures, which are not applicable to PSE&G. SAIC has been requested to provide the results of full inline LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station Unit 1 DOCKET NUMBER 5000272 ANALYSIS OF OCCURRENCE: (cont'd) LER NUMBER 94-002-00 PAGE 4 of 5 inspection and failure analyses of the failed GRID counters described in this report. The Unit 2 DCP for installing these counters will be revised to provide for visual verification and testing in order to confirm *that the indicator LCD module is properly installed.

The PSE&G vendor manual will be revised to ensure proper operation of SAIC GRID counters prior to installation or replacement.

APPARENT CAUSE OF OCCURRENCE:

The cause of this event is "Design, Manufacturing, Construction/Installation", as classified in Appendix B of NUREG-1022.

This occurred due to improper assembly of the step counter LCD display module to the counter PC Board. PREVIOUS OCCURRENCES:

A review of documentation did not reveal a previous occurrence.

SAFETY SIGNIFICANCE:

This event did not affect the health and safety of the public and is reportable to the NRC pursuant to Code of Federal Regulations lOCFR 50.73(a) (2) (iv). During this event, control rod position was correct and the TS required action was met. In accordance with procedure Sl.IC-ST.RCS-OOOl(Q), Reactor Engineering verifies the reactor will remain sub-critical with Keff </= 0.95, when any Shutdown or Control Rod Bank is fully withdrawn from the core under hot plant conditions.

As such, this event did not affect plant safety. CORRECTIVE ACTION: The failed counter (reported by this LER) was replaced with a spare, which was satisfactorily tested and placed into service. SAIC has been requested to provide the results of full inline inspection and failure analyses of the failed GRID counters described in this report. The Unit 2 design change for installing these counters will be revised to provide for visual verification and testing in order to confirm that the indicator LCD module is properly installed.

The PSE&G vendor manual will be revised to ensure proper operation of SAIC GRID counters prior to installation or replacement.

This event will be reviewed by Operations personnel and by the LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station Unit 1 CORRECTIVE ACTION: (cont'd) DOCKET NUMBER 5000272 LER NUMBER 94-002-00 PAGE 5 of 5 Training Department for incorporation into the Operations lesson plan. MJPJ:pc SORC Mtg.94-016