ML18100A574

LER 93-010-01:on 930629 & 30,TS 3.0.3 Entered Due to More than One Inoperable Analog Rod Position Indicator Per Bank. Caused by Sys Design.Signal Conditioning Modules of Affected Rods Adjusted

ML18100A574
Person / Time
Site:	Salem
Issue date:	08/26/1993
From:	PASTVA M J Public Service Enterprise Group
To:
Shared Package
ML18100A573	List: ML18100A572 ML18100A574
References
LER-93-010, LER-93-10, NUDOCS 9309030251
Download: ML18100A574 (4)

Text

NRC FORM 366 (6-89) J U.S. NUCLEAR REGULATORY COMMISSION APPROVED OMB NO. 3150-0104 LICENSEE EVENT REPORT (LER) FACILITY NAME (1) Salem Generating Station -Unit 2 TITLE (4) EXPIRES:A/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGEMENT BRANCH (P-530), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104).

OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503. !DOCKET NUMBER (2)

• PAGE (3) o 1 s I o r o I o 13 I 11 1 1 loFI 0 14 T/S 3.0.3 Entries; More Than One Inoperable Analog Rod Position Indicator Per Bank. EVENT DATE (5) LEA NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (8) MONTH DAY VEAR VEAR :JJ Jt MONTH DAY YEAR FACILITY NAMES DOCKET NUMBERIS)

Salem Unit 1 o 1s1 o Io Io 12 17 12 o I 6 2 I 9 9 3 9 b ol 1 I o -o I 1 o 1 s 21 6 9 I 3 OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE RlQUIREMENTS OF 10 CFR §: (Chock one or more of th* following)

(11) MODE (9) 2 20.402(b) 20.405(c) 50.73(1)(2)(iv)

POWER I 20.40&(1)(1)(i)

--

Q 1 01 0 -20.405(1)(1)(ii) 20.406(1)(1

)(jjl) 20.40&(1)(1)(iv) 20.405(1)(1

)(v) -,__ x ,__ ,__ 60.38(c)(1)

-50.36(c)(21

"----50.73(1)(2)(i)

"----60,73(1)(2)(il)

-50.73(1)(2)(iil)

LICENSEE CONTACT FOR THIS LEA (12) NAME M. J. Pastva, Jr. -LER Coordinator 50.73(1)(2)(v) 50.7l(1)(2)(vii) 50,73(1)(2)(viii)(A) 60.73(1)(2)(viii)(B) 60.73(1)(2)(x)

AREA CODE --....__ 73.71(b) 73.71(c) OTHER (Spt1cify in Abstr*ct below *nd in Text, NRC Form 366A) TELEPHONE NUMBER 6 1019 31319 1 rs 1 11615 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13) CAUSE SYSTEM COMPONENT I I I I I I I I TURER I I I I* I I SUPPLEMENTAL REPORT EXPECTED (14) --i YES (If yes, comp/eta EXPECTED SUBMISSION DATE! ABSTRACT (Limir to 1400 spaces, i.e .. approximtJtBly fifteen single-space typewritten Jines) (16) SYSTEM COMPONENT I I I I I I I I MANUFAC-TUR EA I I I I I. I MONTH DAY YEAR EXPECTED SUBMISSION DATE 1151 I I I This LER addresses 3 Technical Specification (T/S) 3.0.3 entries due to inoperability of more than one control rod Analog Rod Position Indication (ARPI) per control rod bank. On 6/29/93, at 1200 hours0.0139 days <br />0.333 hours <br />0.00198 weeks <br />4.566e-4 months <br />, Unit 2 T/S 3.0.3 was entered for rods 1B2, 2Bl, and 2B4. At 1255 hours0.0145 days <br />0.349 hours <br />0.00208 weeks <br />4.775275e-4 months <br />, reactor shutdown was initiated in accordance with T/S 3.0.3. At 1345 hours0.0156 days <br />0.374 hours <br />0.00222 weeks <br />5.117725e-4 months <br />, the shutdown was terminated and T/S 3.0.3 was exited after control rods 2B4 and 2Bl ARPis were restored to specification.

At 1410 hours0.0163 days <br />0.392 hours <br />0.00233 weeks <br />5.36505e-4 months <br />, the T/S Action Statement was exited after rod 1B2 was restored to specification.

On 6/30/93, at 0217 hours0.00251 days <br />0.0603 hours <br />3.587963e-4 weeks <br />8.25685e-5 months <br />, Unit 2 T/S 3.0.3 was entered for rods 1SB2 and 1SB4. At 0259 hours0.003 days <br />0.0719 hours <br />4.282407e-4 weeks <br />9.85495e-5 months <br />, T/S 3.0.3 was exited when 1SB4 returned to specification due to thermal soak. At 0304 hours0.00352 days <br />0.0844 hours <br />5.026455e-4 weeks <br />1.15672e-4 months <br />, the T/S Action Statement was exited when 1SB2 was adjusted to specification.

On 7/16/90, at 2300 hours0.0266 days <br />0.639 hours <br />0.0038 weeks <br />8.7515e-4 months <br />, Unit 1 T/S 3.0.3 was entered for rods 103, 201, 203, 204 and 205. At 2350 hours0.0272 days <br />0.653 hours <br />0.00389 weeks <br />8.94175e-4 months <br />, reactor shutdown was initiated in accordance with T/S On 7/17/93, at 0330 hours0.00382 days <br />0.0917 hours <br />5.456349e-4 weeks <br />1.25565e-4 months <br />, the shutdown was terminated and T/S 3.0.3 was exited after rods 201, 203, 204, and* 205 were restored to specification.

The root cause of these events is system design. The ARP! System electronic settings experience drift due to temperature susceptibility of the system coil stacks. The signal conditioning modules of the affected rods were adjusted.

System .Engineering has developed an ARP! trending data base to identify problem electronic modules. The industry Rod Control User's Group has recognized an industry-wide.problem with ARPI System drift. Recommendations from this group and the vendors will be used to develop appropriate action. NRC Form 366 (6-89) 9309030251 930826 PDR ADOCK 05000311 S PDR 0,.

qUPPLEMENTAL LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station Unit 2 DOCKET NUMBER 5000311 PLANT AND SYSTEM IDENTIFICATION:

Westinghouse

-Pressurized Water Reactor LER NUMBER 93-010-01 PAGE 2 of 4 Energy Industry Identification System (EIIS) codes are identified in the text as {xx} IDENTIFICATION OF OCCURRENCE:

Technical Specification 3.0.3 Entries; More Than One Inoperable Analog Rod Position Indicator Per Bank Unit 2 Event Dates: 6/29/93 and 6/30/93 Unit 1 Event Date: 7/16/93 Supplement Report Date: 8/26/93 This report was initiated by Incident Report Nos.93-283, and 93-311. CONDITIONS PRIOR TO OCCURRENCE:

Unit 2 -refueling/maintenance outage completed; startup in progress; Physics testing had been completed prior to the 6/29/93 event validating control rod positions.

6/29/93: Mode 2 6/30/93: Mode 2 Reactor Power 0% Reactor Power 2% Unit 1 -startup in progress (following a 7/11/93 Reactor Trip) 7/16/93: Mode 2 Reactor Power 1.5% DESCRIPTION OF OCCURRENCES:

This LER addresses two (2) Technical Specification (T/S) 3.0.3 entries on Unit 2 and one (1) T/S 3.0.3 entry on Unit 1 due to inoperability of more than one control rod Analog Rod Position Indication (ARPI) per control rod bank {AA} (see Analysis of Occurrence).

On June 29, 1993, at 1200 hours0.0139 days <br />0.333 hours <br />0.00198 weeks <br />4.566e-4 months <br />, Unit 2 T/S 3.0.3 was entered when ARP! for rods 1B2, 2Bl, and 2B4 indicated greater than a +/- 12 step deviation from their group demand counters.

At 1255 hours0.0145 days <br />0.349 hours <br />0.00208 weeks <br />4.775275e-4 months <br />, reactor shutdown was*initiated in accordance with T/S 3.0.3. At 1314 hours0.0152 days <br />0.365 hours <br />0.00217 weeks <br />4.99977e-4 months <br />, the Nuclear Regulator Commission (NRC) was notified of the reactor shutdown initiation, in accordance with Code of Federal Regulations 10CFR50.72(b)

(1) (i) (A). At 1345 hours0.0156 days <br />0.374 hours <br />0.00222 weeks <br />5.117725e-4 months <br />, the Unit 2 shutdown was terminated and T/S 3.0.3 was exited after control rods 2B4 and 2Bl ARPis were restored to specification.

At 1410 hours0.0163 days <br />0.392 hours <br />0.00233 weeks <br />5.36505e-4 months <br />, T/S 3.1.3.2.l Action "a" was exited after the ARP! of rod 1B2 was restored to specification.

• SUPPLEMENTAL LICENSEE EVENT REPORT (LER} TEXT CONTINUATION Salem Generating Station Unit 2 DOCKET NUMBER 5000311 DESCRIPTION OF OCCURRENCES: (cont'd) LER NUMBER 93-010-01 PAGE 3 of 4 On June 30, 1993, at 0217 hours0.00251 days <br />0.0603 hours <br />3.587963e-4 weeks <br />8.25685e-5 months <br />, Unit 2 T/S 3.0.3 was entered when ARPI for rods 1SB2 and 1SB4 indicated greater than a +/- 12 step deviation from their group demand counter. At 0259 hours0.003 days <br />0.0719 hours <br />4.282407e-4 weeks <br />9.85495e-5 months <br />, T/S 3.0.3 was exited when 1SB4 returned to specification due to thermal soak. At 0304 hours0.00352 days <br />0.0844 hours <br />5.026455e-4 weeks <br />1.15672e-4 months <br />, T/S 3.1.3.2.1 Action "a" was exited when 1SB2 was adjusted to specification.

on July 16, 1993, at 2300 hours0.0266 days <br />0.639 hours <br />0.0038 weeks <br />8.7515e-4 months <br />, Unit 1 T/S 3.0.3 was entered when ARPI for rods 1D3, 2D1, 2D3, 2D4 and 2D5 indicated greater than a+/- 12 step deviation from their group demand counter. *At 2350 hours0.0272 days <br />0.653 hours <br />0.00389 weeks <br />8.94175e-4 months <br />, reactor shutdown in accordance with T/S 3.0.3. A flux map was completed verifying control rod position for the affected rods. At 0330 hours0.00382 days <br />0.0917 hours <br />5.456349e-4 weeks <br />1.25565e-4 months <br /> on July 17, 1993, the Unit 1 shutdown was terminated .and T/S 3.0.3 was exited after the ARPI of rods 2D"i, 2D3, 204, and 205 were restored to specification.

The -NRC. was notified of the reactor shutdown initiation, at 0023 hours2.662037e-4 days <br />0.00639 hours <br />3.80291e-5 weeks <br />8.7515e-6 months <br /> on July 17, 1993, in accordance with Code of Federal Regulations 10CFR50.72(b}

(1) (i} (A}. APPARENT CAUSE OF OCCURRENCES:

The root cause of these events (both Units} is "Design, Manufacturing, Construction/Installation", per NUREG-1022.

ARPI system electronic settings, associated with the Westinghouse Signal Condition Module and Control Rod coil stack on both units have a history of drift due to the analog coil stacks' susceptibility to temperature changes. During each event, actual rod positions (per group demand} were verified correct, in accordance with the Reactor Engineering Manual. -ANALYSIS OF OCCURRENCES:

ARPI operability is required to determine individual control rod position.

This ensures compliance with control-rod alignment and insertion limits assumed in the accident analyses.

T/S 3 .1. 3 .-2 .1 addresses the operability requirement of the "Reactivity Control System's" {AA} position indicating systems. The indicators are determined operable by verifying that the rod position indication syst-em agrees within twelve ( 12} steps of the group demand counters.

Respectively, on June-29 and June 30 (Unit 2) and July 17 (Unit 1), when more than one ARPI per bank became inoperable, T/S 3.1.3.2.1 Limiting Condition For Operation was exceeded and T/S 3.0.3 applied. With entry into T/S 3.0.3, these events are reportable to the NRC per Code of Federal Regulations lOCFR 50.73(a) (2) (i) (B). T/S 3.0.3 states: "When a Limiting Condition for Operation is not met except as provided in the associated ACTION requirements, within one hour

• SUPPLEMENTAL LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station Unit 2 DOCKET NUMBER 5000311 LER NUMBER 93-010-01 PAGE 4 of 4 ANALYSIS OF OCCURRENCES: (cont'd) action shall be initiated to place the unit in a MODE in which the .specif1cation does not apply by placing it, as applicable, in: 1. At least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, 2. At least HOT SHUTDOWN within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and 3. At least COLD SHUTDOWN within the subsequent 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Where corrective measures are completed that permit operation under the ACTION requirements, the ACTION may be taken in accordance with the specified time limits as measured from the time of failure to meet the Limiting Condition of Operation.

Exceptions to these requirements are stated in the individual specifications.".

PRIOR SIMILAR OCCURRENCES:

These events requiring T/S 3.0.3 entry, due to ARP! control rod equipment and design concerns, have occurred previously on both Salem Units. The most recent Unit 1 event occurred on February 26, 1993 (reference LER 272/93-007-00) and the most recent Unit 2 event occurred on November 14, 1992 (reference LER 311/92-016-00.

SAFETY SIGNIFICANCE:

T/S required actions were met for both events. Also, control rod position was correct with only ARP! indication having drifted greater than +/- 12 steps; therefore, these events did not affect the health or safety of the public. CORRECTIVE ACTION: The signal conditioning modules of the affected rods.were adjusted.

System Engineering has developed an ARP! trending data base to identify problem electronic modules. The industry Rod Control User's Group has recognized an industry-wide problem with ARP! System drift. Recommendations from this group and the ven.dors will be used to develop appropriate action. MJPJ:pc SORC Mtg.

General Manager -Salem

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