ML18005A388

LER 88-007-00:on 880309,several Alarms Received by Operators at Main Control Board Indicating Low Water Level in Steam Generator B.Caused by Failed Renewable Fuse.Fuse Replaced. W/880408 Ltr

ML18005A388
Person / Time
Site:	Harris
Issue date:	04/08/1988
From:	Schwabenbauer, Watson R CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
HO-88-007-00, HO-88-7, LER-88-007-00, LER-88-7, NUDOCS 8804130293
Download: ML18005A388 (6)

Text

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ACCELERATED IH BUTION DEMONSTIIfION SYSTEM REGULA< RY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR: 8804130293 DOC. DATE: 88/08/04 NOTARIZED: NO DOCKET 0 FACIL: 50-400 Shearon Harris Nuclear Power Planti Un'it ii Carolina 05000400 AUTH. NAME AUTHOR *FFILIATION BCHWABENBAUER Carolina. Power h Light Co.

L4ATSONi R. A. ~ Carolina Power 5 Light Co.

RECIP. NAME RECIPIENT AFFILIATION

SUBJECT:

LER 88-007-00: on'80309'lant trip occurred due to loss of.

feedwater to steam generator B.

M/8 l tr.

DISTRIBUTION CODE: IE22D COPIES RECEIVED: LTR, ENCL, SIZE:

TITLE: 50. 73 Licensee Event Report (LER)i Incident Rpti etc. D NOTES: Application for permit renewal filed. 05000408 1

RECIPIENT COPIES REC IP IENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL h PD2-1 LA 1 1 PD2-1 PD 1 BUCKLEY'S B 1 1 D INTERNAL: ACRS MICHELSON 1 ACRS MOELLER 2 2 D AEOD/DOA 1 1 'AEOD/DSP/NAB 1 1 AEOD/DSP/ROAB 2 2 AEOD/DSP/TPAB 1 1 S ARM/DCTS/D*B 1 DEDRO 1 1

'NRR/DEBT/ADS 7E 1 0 NRR/DEST/CEB 8H 1 1 NRR/DEBT/ESB 8D 1 1 NRR/DEBT/ICSB 7 1 1 NRR/DEST/MEB 9H 1 1 NRR/DEBT/MTB 9H 1 1 NRR/DEST/PSB 8D 1 1 NRR/DEBT/RBB 8E 1 NRR/DEST/SGB 8D 1 NRR/DLPG/HFB 10 1 1 NRR/DLPG/G*B 10 1 NRR/DOEA/EAB 11 1 1 NRR/DREP/R*B 10 1 NRR/DREP/RPB 10 2 2

-D.- /BIB 9A 1 1 NRR/PMAS/ ILRB 12 1 1 R G 02 1 1 RES TELFORDi J 1 1 RES/DE/EIB 1 1 RES/DRPS DIR 1 1 RGN2 FILE 01 1 R EXTERNAL: EGLG GROHi M 4 4 FORD BLDG HOYLE A 1 1

. H BT LOBBY NARD 1 1 LPDR 1 1 NRC PDR 1 1 NSIC HARRIS' 1 1 D NSIC MAYSi G 1 1 S

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TOTAL NUMBER OF COP IEB REQUIRED: LTTR 45 ENCL 44

0 NRC Form 358 US. NUCLEAR REGULATORY COMMISSION (94)3l APPROVEO OMS NO. 31600104 EXPIRES: SI31I88 LICENSEE EVENT REPORT (LER)

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

SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 0 5 0 0 0 4 0 0 1 OF 0 4 PLANT TRIP DUE TO A LOSS OF FEEDWATER TO 'B'TEAM GENERATOR EVENT DATE (5) LER NUMSEA (5) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)

.$ Nj REvteroN MONTH OAY YEAR YEAR exr SEQUENTIAL NUMBER aN NUMS4R MONTH DAY YEAR FACILITYNAMES DOCKET NUMSER(S) 0 5 0 0 0 0 3 09 88 8 8 007 0 0 0 4 0 8 8 8 0 5 0 0 0 THIS REPORT IS SUBMITTED PURSUANT T0 THE REQUIREMENTS OF 10 CFR ('I: fCheck one or more of the folfovflnp) (11 OIIERATING MODE (9) 1 20.402(b) 20.405 I c) 50.73(e) (2)(lvl 73.71(4)

POWER 20.405(e)(1)(l) 50.38(cl(1) 50.73(e)(2)(v) 73.71(c)

LEVEL (10) 20.405(e l(1 l(4) 50.38(cl(2) 50.73(e) (2)(v4) OTHER fSpsclfy ln Ahstrect trelorrrend In Text, NRC Form 20.405(e) (1)(4 I) 50.73(e) (2)(l) 50.73(e) (2) (v41) (A) 3ESAI 20AOS(e)(1) (lv) 50.73(e02)(4) 50.73(e) (2) (vl4) (8) 20AOS(e) (1)(v) 50.73(e) (2)(4ll 50.73(e) 12) (el LICENSEE CONTACT FOR THIS LER 02)

NAME TELEPHONE NUMSER AREA CODE R. SCHWABENBAUER REGULATORY COMPLIANCE TECHNICIAN 919 36 2-2 669 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRISEO IN THIS REPORT (13)

MANUFAC. REPORTABLE COMPONENT MANUFAC.

CAUSE SYSTEM COMPONENT TURER TO NPRDS CAUSE SYSTEM TURER TO NPRDS ay B S J F U B 5 6 9 YES c4 ro SUPPLEMENTAL REPORT EXPECTED (14) MONTH DAY YEAR EXPECTED SU 8 MISSION DATE RS)

YES (If yes, complete EXPECTED SUBMISSION DATE) NO ASSTAACT ILlmlt to f400 specet, I e., epproximetely fifteen slnpleepece typevrrit ten linml (15)

The plant was operating in Mode 1, Power Operation, at 100 percent reactor power on March 9, 1988. At 1654 hours0.0191 days <br />0.459 hours <br />0.00273 weeks <br />6.29347e-4 months <br />, several alarms were received by 'operators at the Main Control Board indicating low water level in "B" Steam Generator (SG).

Operators observed that the "B" Main Feedwater Regulating Valve (MFRV) had gone shut. The operators then attempted to take manual control of "B" MFRV in an effort to restore water level in "B" SG.However, the operators efforts could not restore the rapidly dropping "BH SG water level as instrument air- was lost to "B" MFRV and within 30 seconds the plant tripped due to "B" SG feedwater/ steam flow mismatch with low SG water level.

There were no safety consequences due to this event and plant response to the trip was normal. The Main Steam Isolation Valves (MSIV) were shut at 1657 hours0.0192 days <br />0.46 hours <br />0.00274 weeks <br />6.304885e-4 months <br /> in order to limit cooldown, SG water levels were restored with the Auxiliary Feedwater System, and the plant was stabilized in Mode 3, Hot Standby.

The cause of the event was a failed renewable fuse which fed the solenoid for "B"

'MFRV. The end cap on the fuse had loosened which resulted in a .loss of power to a solenoid which interrupted instrument air to the valve. The valve failed shut cutting off the feedwater supply to "B" SG.

Corrective actions include: replacing the renewable fuse with a nonrenewable type, a hold put on renewable fuses in stock, and replacing identified renewable as plant conditions permit. type'uses This event is being reported in accordance with 10CFR50.73(a)(2)(iv) as an Engineered Safety System Feature actuation.

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NRC Form 35BA US. NUCLEAR REOULATORY COMMISSION (943)

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVED OMB NO. 3(50&104 EXPIRES: 8/31/88 FACILITY NAME (11 OOCKET NUMBER (21 LER NUMBER (5) ~ AOE 13)

SHEARON HARRIS NUCLEAR POWER PLANT

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DESCRIPTION:

The plant was operating in Mode 1, Power Operation, at 100 percent reactor power on March 9, 1988. At 1654 hours0.0191 days <br />0.459 hours <br />0.00273 weeks <br />6.29347e-4 months <br /> several alarms, including feed flow/

steam flow mismatch, were received at the Main Control Board (EIIS:IB) and the operators noted no feedwater (EIIS:SJ) flow to "B" Steam Generator (SG)

(EIIS:SB), decreasing water level in "B" SG, and "B" SG Main Feedwater Regulating Valve (MFRV) (EIIS:SJ) indicating shut. The operators attempted to take manual control of "B" MFRV in an effort to restore water level in "B" SG. However, the operators efforts could not restore the rapidly decreasing "B" SG water .level, and within 30 seconds water level. reached the low l,evel setpoint of 38 percent and the plant tripped before any effective corrective action could be taken.

The plant tripped on "B" SG feedwater/steam flow mismatch with low SG water level at 1654 hours0.0191 days <br />0.459 hours <br />0.00273 weeks <br />6.29347e-4 months <br />. Subsequent to the Reactor (EIIS:AC) trip, both Main Feedwater Pumps (MFP)(EIIS:SJ) tripped, however, the motor driven Auxiliary Feedwater Pumps (AFWP)(EIIS:BA) were already activated by the low level, in the

'B'G. Actuation of the turbine driven AFWP was not required. The Main Steam Isolation Valves (MSIV) (EIIS:SB) were closed at 1657 hours0.0192 days <br />0.46 hours <br />0.00274 weeks <br />6.304885e-4 months <br /> to limit plant cooldown, SG water levels were restored with the auxiliary Feedwater System (AFW) (EIIS:BA), and the plant was stabilized in Mode 3, Hot Standby.

There were no other problems encountered during the transient.

CAUSE:

A work request was prepared to investigate and correct the problem. The repair technicians found that the negative leg fuse (BUSSMAN Model 8REN-6) had failed as indicated by a zero voltage reading. The technician pulled the fuse and obtained a continuity reading of approximately 3 ohms. He noted that the fuse was a Renewable (REN) Type and that the end. cap was loose. The technician tightened the end cap by hand approximately 1 turn" and then obtained a 0 ohm continuity reading. The fuse was returned to its holder and normal voltage to the circuit was restored.

The failed fuse was in the circuit for the Feedwater Isolation Signal to the "B" MFRV. The circuit is normally energized and allows instrument air (EIIS:LD) to be supplied to the air actuator for the 'B'FRV through a solenoid valve. (SEE ATTACHMENT). When the fuse failed the solenoid repositioned and interrupted the air supply causing the MFRV to fail shut cutting off the feedwater supply to 'B'G.

r The failed REN fuse has been replaced with a Nonrenewable (NON) type. In addition, all MFIV and Flow Control Valves (FCV) (EIIS:BA) for all 3 SG were checked and all REN type fuses were replaced with NON type fuses. The plant was then restarted and put back on line at 1917 hours0.0222 days <br />0.533 hours <br />0.00317 weeks <br />7.294185e-4 months <br /> on March 10, 1988.

NIIC POIIM SOSA oU.S.OPO:1985.0.524 538/455 (9431

NRC Form 35SA U.S. NUCLEAR REOULATORY COMMISSION (9831 LICENSEE EVENT REPORT ILER) TEXT CONTINUATION APPROVED OM8 NO. 3150&/Co EXPIRES: 8/31/85 FACILITY NAME 111 DOCKET NUMSER 121 LER NUMSER <51 PACE 13I YEAR ttovtNTrAL REV!SION NVMttll HVMttrr SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 o s o o o 40 088 007 00 03 oF0 4 TEXT Illmoro o/roco /r 0'/r 'rL rroo /r/Orr'o/ ///IC Forrrr 3//SA's/ II TI ANALYSIS:

There were no safety consequences as a result of this event and plant response to the trip was normal. The MSIVs were shut at 16S7 hours to limit plant cooldown, SG water levels were restored with the AFW System and the plant was stabilized in Mode 3, Hot Standby.

The safety consequences are bound by this event as it occurred while the plant was operating at full power.

This event is being reported in accordance with 10CFR50.73(a)(2)(iv) as an Engineered Safety System Feature actuation.

Previous events reported involving fuses include: LER-87'-037-00 where a failed fuse caused a Main Feedwater Pump to trip resulting in a plant trip, and LER-87-056-00 where a wrong fuse was pulled resulting in a plant trip.

CORRECTIVE ACTIONS/ACTIONS TO PREVENT RECURRENCE:

1. The failed REN type fuse was replaced with an NON type fuse and similar fuses for the other MFRV's were replaced.

2. A hold was put on REN type fuses in stock.

3. Upon identifying further uses of REN type fuses they'ill be replaced as plant conditions permit.

N/IC FO/IM totA *U.S.OPO:1085 0.524 538/455 15831

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Carolina Power & Light Company HARRIS NUCLEAR PROJECT P.O. Box 165 New Hill, NC 27562 APR 0 8 1988 File Number.'HF/10-13510C Letter Number'HO-88-007-00 (0)

U.S. Nuclear Regulatory Commission ATTN: NRC Document Control Desk Washington, DC 20555 SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 DOCKET NO. 50-400 LICENSE NO. NPF-63 LICENSEE EVENT REPORT 88-007-00 Gentlemen:

In accordance with Title 10 to the Code of Feder'al 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 in accordance with the format set forth in NUREG-1022, September 1983.

Very truly yours, zM~

R. A. Watson Vice President Harris Nuclear Project RJS:ddl Enclosure cc'Dr. J. Nelson Grace (NRC RII)

Mr. B. Buckley (NRR)

Mr. G. Maxwell (NRC - SHNPP)

MEM/LER-88-007/1/Osl