ML20045D588

LER 93-006-00:on 930521,HCU 06-31 Declared Inoperable When CRD Accumulator Low Pressure/High Level Alarm Received in Cr.Hcu 02-23 Inoperable at Time.Hcu 02-23 Restored to Svc & Excess Water Drained from HCU 06-31.W/930617 Ltr

ML20045D588
Person / Time
Site:	Brunswick
Issue date:	06/17/1993
From:	Jonathan Brown, Mcgowan J CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
BSEP-93-0093, BSEP-93-93, LER-93-006-02, LER-93-6-2, NUDOCS 9306290188
Download: ML20045D588 (4)

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Carolina Power & Light Company t 't.fri, ; % _ . .; .t . \ :. , ,,  ?,,

Brunswick' Steam Electric Plant P' O. Box 10429 Southport, N.C. 28461-0429 June 17, 1993 FILE: B09-13510C .10CFR50.73.

SERIAL: BSEP-93-0093 t

E U.S. Nuclear Regulatory Commission 5 ATTN: Document Control Desk Washington, D. C. 20555 r BRU'1SWICK STEAM ELECTRIC PLANT UNIT 2 DOCKET NO. 50-324 l LICENSE NC 1RP-62 -

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LICENSEE EVENT Kt'. ORT 2-93-006 i

Gentlemen:

In accordance with Title 10 of the Code of Federal' Regulations, the enclosed Licensee Event Report is submitted. This report fulfills the requirement for a-written report within thirty (30) . days of a reportable occurrence and'is submitted in accordance with the format set forth in NUREG-1022, September 1983.

I Very truly.yours,

/.  ?> Brown, Plant Manager - Unit 1 Bru ick Steam Electric Plant [

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Enclosure cc: Mr . S . D. Ebneter ,

Mr. P. D. Milano BSEP NRC Resident Office'

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ADDCK 05000324 PDR h-

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NRC (OF)M 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED OMB NO. 3150-0104 (5/92) EXPIRES: 5/31/95 ESTIMATED BURDEN FER RESPONSE TO COMPLY WIT H THis INFORMATION COLLECTION REQUE ST: 50.0 HRS. FORW ARD LICENSEE EVENT REPORT (LER) COMMEms nEGARD,NG BURDEN ESTiuATE TO THE NFORuAriON AND RECOPDS MANAGEMENT BRANCH (MNBB 7714), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555 0001, AND TO THE PAPERWORK REDUCTION PROJECT (3160 0104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

F ACIUTY NAME (1) DOCKET NUMBER (2) PAGE (3)

Brunswick Steam Electric Plant, Unit 2 05000324 1 of 3 TITLE I4)

TWO INOPERABLE CONTROL RCD ACCUMULATORS RESULT IN ENTRY INTO TECHNICAL SPECIFICATION 3.0.3.

EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)

SEQUENTIAL REVfSION FACILITY NAME DOCKET NUMBER MONT H DAY YEAR YEAR "" ^ "*

NUMBER NUMBIR 05000-05 21 93 93 00 06 18 93 FACILITY NAME DOCKET NUMBER 05000 OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CrR 5: (Check one or more of the following1(11) 1 MODE (9) 20.402(b) 20.405(c) 50.73(aH2Hiv) 73.71(b)

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POWER LEVEL (10) 33.8% ,g ,gg,,q , g,;, gg,3g,,g,, gg,73,,g,g,,33 g7ggg 20.405(aH1Hiii) X SO 73(aH2 Hit 50.73(aH2)(viiiH A) (Specify in Abstract 3405(aH1Hw) 50.73(aH2Hii) 50.73(aH2HviiiHB) 20 405(aH1Hv) 50.73(aH2Hiii) 50.73(aH2Hx)

LICENSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER Jeanne F. McGowan, Regulatory Compliance Specialist (919) 457-2136 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

A USE SYSTE M CDMPONE NT MANUFACTURER g CAUSE SYSTEM COMPONENT M ANUF ACTURER p l

SUPPLEMENTAL REPORT EXPECTED (14) M NTH DAY MAR EXPECTED NO SUBMISSION YES X m es, v comNee E EPECTLE SUPMISSION DATE1 DATE (15)

ABSTRACT (Limit to 1400 spaces, i e. approximately fifteen single space typewritten lines) (161 On May 21, 1993, Unit 2 was cperating at approximately 33t power. Periodic Test (PT) 14.2.1, Single Rod Scram Insertion Times Test was in progress. Control Rod Drive (CRD)

Hydraulic Control Unit (HCU) 02-22 had the charging water header valved out in accordance with the PT when a CRD Accumulator Low Pressure /High Level alarm annunciated in the Control Room at 0259 hours0.003 days <br />0.0719 hours <br />4.282407e-4 weeks <br />9.85495e-5 months <br />. The alarm was due to a high water level in HCU 06-31. With two or more Control Rod Accumulators inoperable, Technical Specification 3.0.3 was entered which required placing the Unit in a six hour to Hot Shutdown condition. The Auxiliary Operator performing PT 14.2.1 was immediately instructed to open the charging j

water valve for HCU 02-23. The Accumulator was returned to service at 0300 hours0.00347 days <br />0.0833 hours <br />4.960317e-4 weeks <br />1.1415e-4 months <br /> and Technical n ecification 3.0.3 was exited. There was no intent to commence a Unit shutdown unless problems were encountered in returning HL 02-23 to service. The excess water was drained from HCU 06-31 and the Accumulator was returned to service at 0306  !

hours. l J

The cause of this event is the simultaneous inoperability of two Control Rod Drive Hydraulic Control Units. Corrective actions included valving in the charging water to HCU 02-23 and draining the excess water from HCU 06-31.

The safety significance of this event is minimal. When the reactor vessel is at operating pressure and the scram discharge volume is at atmospheric pressure, the Control Rod Accumulator is not needed to meet scram time requirements. The Standby Liquid Control system was available during this time.

. l NRC FORM 366A U. S. NUCLEAR REGULATORY COMMISSloN APPROVED OMB NO. 3150-0104 j (5/92) EXPIRES: 5/31/95 E STIM ATED BURDEN PER RE SPONSE TO COMPLY WITH THts INFORM ATION COLLECTION REQUEST: 50.0 HRS. FOPWARD LICENSEE EVENT REPORT (LER) COMMENTS REGARDING BURDEN f STIM ATE TO THE INFORMATION AND TEXT CONTINUATION RECORDS MANAGEMENT BRANCH {MNBB 7714), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON DC 20555-0001. AND TO  ;

THE PAPERWORK REDUCTION PROJE CT (3150 0104), OFFICE OF l

MANAGEMElC AND BUDGET, WASHINGTON. DC 20503.

FACluTY NAME (1) DOCKET NUMBER (2) LER NUMBER {6) PAGE (3)

SEQUENTIAL REVISION Brunswick Steam Electric Plant " " '" " " '"

05000324 2 of 3 Unit 2 93 ()()

TEXT (if more space is required, use additionalNFtC Form 366A'st (17)

TITLE TWO INOPERABLE CONTROL ROD ACCUMULATORS RESULT IN ENTRY INTO TECHNICAL SPECIFICATION 3.0.3.

INITIAL CONDITIONS On May 21, 1993, Unit 2 was at approximately 33% reactor power. Periodic Test (PT) 14.2.1, Single Rod Scram Insertion ~ _ .c Test was in progress on Control Rod Drive (CRD) Hydraulic Control Unit (HCU) 02-23. 259 hours0.003 days <br />0.0719 hours <br />4.282407e-4 weeks <br />9.85495e-5 months <br />, a high water level on HCU 06-31 caused a Control Rod Drive Accumulator Low hessure/High Level alarm to annunciate in the Control Room.

The Standby Liquid Control system was operable.

EVENT NARRATIVE On May 21, 1993, HCU 06-31 was declared inoperable when a CRD Accumulator Low Pressure /High Level alarm was received in the Control Room. The annunciator was due to a high water level in the HCU. PT 14.2.1 was in progress at this time, and HCU 02-23 was inoperable due to the charging water header isolation valve being closed. PT 14.2.1 verifies that each control rod's maximum scram insertion time is within the limits specified by Technical Specification 3.1.3.2. The accun lator charging water header isolation valve is closed for the control rod being tested to avoid erroneous scram times and unnecessary stress on the CRD mechanisms. With two or more CRD accumulators inoperable, Technical Specification 3.0.3 was invoked.

The Auxiliary Operator stationed at HCU 02-23 was immediately instructed to open the charging water header isolation valve. At 0300 hours0.00347 days <br />0.0833 hours <br />4.960317e-4 weeks <br />1.1415e-4 months <br />, HCU 02-23 was returned to service and Technical Specification 3.0.3 was exited. The excess water was drained from HCU 06-31 per Operating Procedure (OP) 08, CRD Hydraulic System Operating Procedure and the accumulator was returned to service at 0306 hours0.00354 days <br />0.085 hours <br />5.059524e-4 weeks <br />1.16433e-4 months <br />.

This event is reportable as an operation outside of Technical Specifications. Brunswick Technical Specifications do not have an Action Statement to address Unit operation with more than one accumulator incperable; therefore, the inoperability of the second HCU placed the Unit in Technical Specification 3.0.3.

_C_AMSE OF EVENT The cause of this event is the simultaneous inoperability of two Control Rod Drive HCUs.

During the performance on PT I4.2.1, the Unit is in a Limiting Condition of Operation due to a single CRD accumulator being inoperable. When a CRD accumulator Low Pressure /High Level alarm is received, the HCU causing the alarm is declared inoperable until the condition is resolved. Brunswick Technical Specifications do not address Unit operation with more than one CRD accumulator inoperable.

CORRECTIVE ACTIONS Corrective actions taken for this event included:

1. Immediately restoring HCU 02-23 to service by opening the charging water header isolation valve.

2. Draining the excess water from HCU 06-31 and returning the accumulator to service.

3. A Technical Specification change has been submitted that will address operation with more than one CRD accumulator being inoperable.

NRC FORM 366A U. S. NUCLEAR REGULATORY COMMISSION APPROVED OMB NO. 3150-0104 (E/92) EXMRES: 5/31/95 ESTNATED BUADEN PER RE SPONSE TO COMPLY . WITH THis INFORM ATION COLLECTION REQUEST: 50.0 HRS. FORWARD LICENSEE EVENT REPORT (LER) COMMENTS REGARDING BURDEN ESTN ATE TO THE INFORMATION AND REC RDS M ANAGEME NT DRANCH (MNBB 7714), U.S. NUCLEAR TEXT CONTINUATION REGULATORY COMMISS!ON, WASHINGTON, DC 20555-0001, AND TO THE PAPERWORK RfDUCTION PROJECT (3150-0104), OFFICE OF MANAGEMENT AND BUDGET, WASHINGTON. DC 20503.

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

SEQUENTIAL RE VISION swick Steam Electric Plant " # *'" ""*'"

05000324 3 of 3 93 ()0 TEXT (11 more space is required, use additional NRC form 366A's! (11)

SAFETY ASSESSMENT The safety significance of this event is minimal. When the reactor vessel pressure is greater than 800 psig and the scram discharge volume is at atmospheric pressure, the scram accumulator is not needed to meet the scram time requirements. The Standby Liquid Control system was available as a backup to Control Rod Drive Hydraulic Centrol Units in this event.

PREVIOUS SIMILAR EVENTS Previous similar events were reported in LERs 1-91-015 and 1-91-027.

EIIS COMPONENT IDENTIFICATION System /Comoonent EIIS Code CONTROL ROD DRIVE AA '

HYDRAULIC CONTROL UNIT AA/HCU ACCUMULATOR AA/HCU/ACC

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