ML18100A932

LER 94-003-00:on 940204,TS 3.0.3 Was Entered Due to Inoperability of More than One Control Rod Analog Rod Position Per Control Rod Bank.Calibrated Position Indicators of Affected rods.W/940302 Ltr

ML18100A932
Person / Time
Site:	Salem
Issue date:	03/02/1994
From:	Hagan J, Pastva M Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-94-003-01, LER-94-3-1, NUDOCS 9403140103
Download: ML18100A932 (5)

Text

Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038

• Salem Generating Station March 2, 1994 U. s. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

Dear Sir:

SALEM GENERATING STATION LICENSE NO. DPR-75 DOCKET NO.50-31i UNIT NO. 2 LICENSEE EVENT REPORT 94-003-00.

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.

sincerely yours, MJPJ:pc Distribution

.if

' The power is in your hands. . 9403140103 940302 PDR ADOCK 05000311 S . . PDR 95-2189 REV 7-92

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 (9'-92) EXPIRES 5/31/95 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD LICENSEE EVENT REPORT (LER) COMMENTS REGARDING BURDEN ESTIMATE TO THE INFORMATION AND RECORDS MANAGEMENT BRANCH (MNBB 7714), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF (See reverse for required number of digits/characters for each block) MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME (1) DOCKET NUMBER (2) PAGE (3)

Salem Generating Station - Unit 2 05000 311 1OF04 TITLE (4)

T/S 3.0.3 Entry: More Than One Inoperable ARPI Per Bank.

EVENT DATE (5) LER NUMBER (6 REPORT NUMBER (7) OTHER FACILITIES INVOLVED (B FACILITY NAME DOCKET NUMBER SEQUENTIAL REVISION MONTH DAY YEAR YEAR MONTH DAY YEAR NUMBER NUMBER 05000 FACILITY NAME DOCKET NUMBER 02 04 94 94 003

-- 00 03 02 05000 94 OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check one or more (11 MODE (9) 2 20.402(b} 20.405(c) 50.73(a) (2) (iv) 73.71 (b}

POWER ?0.405 (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) x 50. 73(a}(2}(i) 50.73(a) (2) (viii) (A} (Specify in Abstract below and in Text, NRC 20.405(a)(1) (iv) 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 LER 12)

NAME TELEPHONE NUMBER (Include Area Code)

M. J. Pastva, Jr. - LER Coordinator (609) *339-5165 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

REPORTABLE REPORTABLE CAUSE SYSTEM COMPONENT MANUFACTURER CAUSE SYSTEM COMPONENT MANUFACTURER TO NPRDS TO NPRDS SUPPLEMENTAL REPORT EXPECTED (14) EXPECTED MONTH DAY YEAR I YES (If yes, complete EXPECTED SUBMISSION DATE) x NO SUBMISSION DATE (15)

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

On 2/4/94, at 0800 hours0.00926 days <br />0.222 hours <br />0.00132 weeks <br />3.044e-4 months <br />, Technical Specification (TS) 3.0.3 was entered when the Analog Rod Position Indication {ARP!) for rods 2Cl, 2C3, and 2C4 indicated greater than a + 12 step*deviation from their group demand counters. At *0858 hours, reactor shutdown was initiated in accordance with TS 3.0.3. This event resulted from output drift of the ARPI coil stacks. The most probable causes of the drift are changes in mutual inductance between rods and/or temperature changes at the ARPI coil stacks, which can result from significant changes in reactor power. At approximately 0100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> (same day) reactor power had been reduced from 93% to Mode 2. Secondary AC voltage values to the 2Cl and 2C4 signal conditioning modules were redeveloped, the modules were adjusted, and at 0915 hours0.0106 days <br />0.254 hours <br />0.00151 weeks <br />3.481575e-4 months <br />, the shutdown was terminated and TS 3.0.3 was exited. The signal conditioning module of 2C3 was adjusted in a similar manner and at 1113 hours0.0129 days <br />0.309 hours <br />0.00184 weeks <br />4.234965e-4 months <br />, the involved TS action statement exited. PSE&G will continue participation in industry Rod Control* User's Group efforts to* resolve ARPI System drift problems.

NRC FORM 366 (5-92)

.. LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station DOCKET NUMBER LER NUMBER PAGE Unit 2 5000311 94-003-00 2 of 4 PLANT AND SYSTEM IDENTIFICATION:

Westinghouse - Pressurized Water Reactor Energy Industry Identification System (EIIS) codes are identified in th.e 'text as {xx}

IDENTIFICATION OF OCCURRENCE:

Technical Specification 3.0.3 Entry; More Than One Inoperable Analog Rod Position Indicator Per Bank Event Date: 2/4/94 Report Date: 3/2/94 This report was initiated by Incident Report No.94-037.

CONDITIONS PRIOR TO OCCURRENCE:

Mode 2 Reactor Power 7E-8 amps - Unit Load -p- MWe DESCRIPTION OF OCCURRENCE:

This LER addresses a Technical Specification (~S) 3.0.3 entry due to inoperability of more than one control rod Analog Rod Position Indication (ARP!) per control rod bank {AA}.

On February 4, 1994, at 0800 hours0.00926 days <br />0.222 hours <br />0.00132 weeks <br />3.044e-4 months <br />, TS 3.0.3 was.entered when the ARPI for rods 2Cl, 2C3*, and 2C4 indicated greater than a + 12 step deviation from their group demand counters. At 0858 hours0.00993 days <br />0.238 hours <br />0.00142 weeks <br />3.26469e-4 months <br />, reactor shutdown was initiated in accordance with TS.3.0~3. At 0913 hours0.0106 days <br />0.254 hours <br />0.00151 weeks <br />3.473965e-4 months <br />, the Nuclear Regulator Commission (NRC) was notified of the shutdown initiation, in accordance with Code of Federal Regulations 10CFR50. 72 (b) ( 1) ( i) (A) . .

At 0915 hours0.0106 days <br />0.254 hours <br />0.00151 weeks <br />3.481575e-4 months <br />, the shutdown was terminated and TS 3.0.3 was exited after ARP! of control rods 2Cl and 2C4 ARPis was restored to specification. At 1113 hours0.0129 days <br />0.309 hours <br />0.00184 weeks <br />4.234965e-4 months <br />, TS 3.1.3.2.1 Action "a" was exited after the ARP! of rod 2C3 was restored to specification.

ANALYSIS OF OCCURRENCE:

ARP! operability is necessary to determine individual control rod position and ensure compliance with control rod alignment and insertion limits assumed in the accident* analyse's: .. ARP!* provides actual rod position* to the following locations: the Control Board dual channel position indicator modules, the Safety Parameter Display

LICENSEE EVENT REPORT (LER) TEXT CONTI~UATION Salem Generating Station DOCKET NUMBER LER NUMBER PAGE Unit 2 5000311 94-003-00 . 3 of 4 ANALYSIS OF OCCURRENCE: (cont'd)

System (SPDS), the main process P250 computer, and locally via the digital multimeter.

TS 3.1.3.2.1 addresses the operability requirement of the "Reactivity Control System's" position indicating systems. The indicators are determined operable by verifying agreement within_twelve (12) steps of the group demand counters. If more than one ARPI per bank is inoperable, the Limiting Condition For Operation and associated ACTION requirements of TS 3.1.3.2.1 are not met and TS 3.0.3 therefore applies.

The Limiting Condition For Operation of TS 3.1.3.2.1 was exceeded and TS 3.0.3 was entered when the ARPI of rods 2Cl, 2C3, and 2C4 became inoperable due to indication drift. This event resulted from output drift of the ARPI coil stacks. The most probable causes of the drift are changes in mutual inductance between rods and/or temperature changes at the ARPI coil stacks, which can result from significant changes in reactor power. Ambient temperatures ~t the ARPI.coil stacks and rod positions had changed as the result of reducing reactor power from 93% to Mode 2.

Secondary AC voltage values to the 2Cl and 2C4 signal conditioning modules were redeveloped and the modules adjusted. A channel check demonstrated ARPI operability and TS 3.0.3 was exited. Subsequently, the signal conditioning module of 2C3 was adjusted in a similar manner and the involved TS action statement exited.

APPARENT CAUSE OF OCCURRENCE:

The cause of these events is "Design, Manufacturing,*

Construction/Installation", as classified in Appendix B of NUREG-1022. This resulted from output drift of the ARPI coil stacks. The most probable causes of the drift are changes in mutual inductance between rods and/or temperature changes at the ARPI coil stacks, which can result from significant changes in reactor power.

Ambient temperatures at the ARPI coil stacks and.rod positions had changed as the result of reducing reactor power.

PREVIOUS OCCURRENCES:

Events, due to ARPI design concerns, have occurred on both Salem Units (see ~ERs 272/93-007-00, 272/94-001-00, 272/94-004-00, 311/94-001-00, 311/92-016-00, and_ 311/93-010-00).. As a result, system Engineering has-developed* an ARPI trending data base to identify problem electronic modules. In addition, the industry Rod Control User's Group has recognized an industry-wide problem with

-1 LICENSEE EVENT REPORT (LER) TEXT CONTlNUATION Salem Generating Station . DOCKET NUMBER LER NUMBER PAGE Unit 2 5000311 94-003-00 4 of 4 PREVIOUS OCCURRENCES: (cont'd)

ARPI System drift. Recommendations from this group and from the system vendors will be used to develop appropriate action.

SAFETY SIGNIFICANCE:

This event did not affect the health and safety of the public. With entry into TS 3.0.3, this event is reportable to the NRC pursuant to Code of Federal Regulations 10CFR 50.73(a) (2) (i) (B).

TS required actions were met for this event. 'Actual rod positions (per group demand) were correc.t.

CORRECTIVE ACTION:

The position indicators of the affected rods were calibrated and TS 3.0.3 exited.

PSE&G will continue to participate in the industry Rod control User's Group efforts to resolve problems with ARPI System drift.

nager -

at ions MJPJ:pc.

SORC Mtg.94-020