ML16223A653
| ML16223A653 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 01/06/1988 |
| From: | Gallo R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Sieber J DUQUESNE LIGHT CO. |
| References | |
| TAC-44282, NUDOCS 8801150137 | |
| Download: ML16223A653 (6) | |
Text
.ACCELERATED DISTRIBUTION DEMONSTVTION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
ACCESSION NBR:8712140257 DOC.DATE: 87/12/07 NOTARIZED: NO DOCKET #
FACIL:50-269 Oconee Nuclear Station, Unit 1, Duke Power Co.
05000269 AUTH.NAME AUTHOR AFFILIATION NORTH,P.J.
Duke Power Co.
TUCKER,H.B.
Duke Power Co.
RECIP.NAME RECIPIENT AFFILIATION
SUBJECT:
LER 87-010-00:on 871105,manual reactor trip due to component failure during startup physics testing.
W W/8 Itr.
DISTRIBUTION CODE: IE22D COPIES RECEIVED:LTR
-ENCLL SIZE:jE.
TITLE: 50.73 Licensee Event Report (LER), Incident Rpt, etc.
NOTES:AEOD/Ornstein:1cy.
05000269 S RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-3 LA 1
1 PD2-3 PD 1
1 PASTIS,H 1
1 INTERNAL: ACRS MICHELSON 1
1 ACRS MOELLER 2
2 AEOD/DOA 1
1 AEOD/DSP/NAS 1
1 AEOD/DSP/ROAB 2
2 AEOD/DSP/TPAB 1
1 ARM/DCTS/DAB 1
1 DEDRO 1
1 NRR/DEST/ADS 1
0 NRR/DEST/CEB 1
1 S
NRR/DEST/ELB 1
1 NRR/DEST/ICSB 1
1 NRR/DEST/MEB 1
1 NRR/DEST/MTB 1
1 NRR/DEST/PSB 1
1 NRR/DEST/RSB 1
1 NRR/DEST/SGB-1 1
NRR/DLPQ/HFB 1
1 NRR/DLPQ/QAB 1
1 NRR/DOEA/EAB 1
1 NRR/DREP/RAB 1
1 NRR/DREP/RPB 2
2 NRR/DRIS/SIB 1
1 NRR/PMAS/ILRB 1
1 CG-=2ILEN 02 1
1 RES TELFORD,J 1
1 RES/DE/EIB 1
1 RGN2 FILE 01 1
1 EXTERNAL: EG&G GROH,M 5
5 FORD BLDG HOY,A 1
1 H ST LOBBY WARD 1
1 LPDR 1
1 NRC PDR 1
1 NSIC HARRIS,J 1
1 NSIC MAYS,G 1
1 NOTES:
1 1
D S
A D
D S
TOTAL NUMBER OF COPIES REQUIRED: LTTR 47 ENCL 46
NRC Form 36 U.S. NUCLEAR REGULATORY COMMISS.ON (9-83)
APPROVED OMB NO. 3150-0104 LICENSEE EVENT REPORT (LER)
EXPIRES: 8/31/85 FACILITY NAME (1)
DOCKET NUMBER (2)
PAGE 3)
Oconee Nuclear Station - Unit 1 0 5 00 2
1 OF 0 4 TITLE (4)
MANUAL REACTOR TRIP DUE TO A COMPONENT FAILURE DURING STARTUP PHYSICS TESTING EVENT DATE (5)
LER NUMBER (6)
REPORT DATE (7)
OTHER FACILITIES INVOLVED (8)
MONTH DAY YEAR YEAR SEQUENTIAL EVSI MONTH DAY YEAR FACILITY NAMES DOCKET NUMBER(S) o 1510 1010111 11 0T 87 87-0 10 -
j0 012 170 1510 10101 OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check one or mare of the following) (11)
MODE (9) 20.402(b) 20.
406(c) 50,73(a(2)iv) 73.71(b)
POWER 20.406(aH)(1)(1 50.36(a)1(
[jIjI50.73(a(2)()
73.71(c)
LEVEL 0
(10) 20.405(a)(1(I) 50.36(c)(2) 50.73(a)2(0)
OTHER (Specify In Abstract I
below and in Text NRC Form 20.406(a)1i) 50.731a)(2)(1) 50.73(a)(2)HyiI(A) 366A) 20.406(aH1HIv) 50.73(a(2Hil 50.73(aH(2)(vII(B) 20.406(a1 y) 50.73(a)(2)(i) 50.73(s2xI LICENSEE CONTACT FOR THIS LER (12)
NAME TELEPHONE NUMBER AREA CODE PHILIP J. NORTH, LICENSING 7 014 317 13 -1714 1516 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)
CAUSE SYSTEM COMPONENT MANUFAC.
RTOR LE CAUSE SYSTEM COMPONENT MANEC-REPOR LE SUPPLEMENTAL REPORT EXPECTED (14)
MONTLDAY YEA X
~L4ECIBID D~lIS10.
NO..............
MONTH..DAY.YEAR EXPECTED SUBM.IR!QN YES (f yes, complere EXPECTED SUBMISSION DATE1 NO DATE.(15)
ABSTRACT (Limir to 1400 speces. I.e.,
epproximarely fifteen single-space typewritten linesl (11 On November 5, 187 Unit easine satupaphysics tstin folewngrefueling source range monitor. The pre-critical test phase had been completed and the unit was in the zero power physics test phase. During this testing phase; control power was lost to the control rods. At this time the reactor was manually tripped.
The rods were verified to be inserted and the Unit was stabilized at hot shutdown. All parameters responded to the trip as expected and there were no safety system actuations.
A workreqetwsnwritten to linvestigate and repair the loss of power problem.
A losesolerjoit a Pn #1on a control rod sequencing card was identified.
the rotcause of thsincident was determined to be a failed component due to The immediate corrective action was to manually trip the unit and stabilize the unit in hot shutdown conditions.
Subsequent corrective actions were to resume startup physics testing and to identify and repair the loose solder joint.
8712140257 871207/
PDR ADOCK 05000269 f
S DCD___________________________________
NRC Form 386 USGO18--5-8/85
NRC Form 366A U.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVEO oMB NO. 3150-0104 EXPIRES: 8/31/85 FACILITY NAME (1),
OOCKET NUMBER (21 LEA NUMBER (6)
PAGE 13)
YEAR SEQUENTIAL REVISION NUM88A NUMBER Oconee Nuclear Station - Unit a so o 2 6 9 817 -0110
-0 002 OF 0 4 TEXT (If mo" sOOM Is epW. us editW NAIC AM 1A'#) (17)
Background
At the time of this incident, Unit I was undergoing reactor physics measurements to verify the physics parameters. This program is called Zero Power Physics Testing (ZPPT). Measurements are made at zero power conditions at sufficient temperature to verify calculated worth of individual control rods [EIIS:ROD] and control rod groups, moderator temperature coefficient, boron worth, and excess reactivity of the core [EIIS:RCT].
The response of the source and intermediate range nuclear instrumentation (NI) [EIIS:JAJ are verified. All of these tests are performed at hot zero power conditions of 532 degrees-F, 2155 psig, steady Reactor Coolant System (RCS) [EIIS:AB] flow, and three or four RCS pumps
[EIIS:P] operating.
During the test, rods are withdrawn to achieve criticality, Safety Groups 1-4 are withdrawn to 100%, then regulating Groups 5-7 are withdrawn in sequence.
When Group 5 is at 75% out then Group 6 will start to withdraw. This creates a 25% overlap. This progression will continue until the desired position is achieved or all rods are withdrawn.
Control Power [EIIS:EE] for the control rods provides the ability to drive the rods in and out of the reactor. Upon loss of control power the rods do not trip and will maintain their position.
Description Of Occurrence On November 5, 1987 Unit 1 was in physics testing for Fuel Cycle 11.
At about 1300, the Control Rod Drop Time portion of the Pre-Critical Test was successfully completed. Following the Control Rod Drop Time Test, ZPPT was started at 1330. Control Rod (CR) Groups.1 through 5 were withdrawn to 100%
with no problem. CR Group 6 was pulled to 75% at which time Group 7 should have started to withdraw. When CR Group 6 reached 75% withdrawn, control power to the control rods was lost.
(
With control power lost, the rods could not be withdrawn or inserted while operating in this mode. At 1358 the Senior Reactor Operator immediately instructed a Control Operator to manually trip the reactor. At the time of the trip, the reactor was subcritical and counts were about 125 counts per second on the source range monitor. The rods fell immediately and no abnormal responses were observed. There were no safety system [EIIS:JE] actuations in response to this trip. With the unit stabilized at hot shutdown, a work request was written at 1400 to investigate and restore power to the Control Rod Drives [EIIS:AA).
The Post-Trip Review Report was completed at 1540, and clearance to restart ZPPT was granted per Performance Directives at 1624.
At 1657, the Operators began Control Rod withdrawal for Nuclear Instrumentation Overlap. However, when Control Rod Group 6 reached 75%, again Group 7 did not respond. The Instrument and Electrical Technicians continued troubleshooting the system in an effort to determine the problem. The decision was made to select "Sequence Override",
NRC FORM 366A 19-83 1
NRC Form 36A U.S. NUCLEAR REGULATORY COMMISSION 49-83)
LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVED OMe NO 3150-0104 EXPIRES: 8/3115 FACILITY NAME (11 DOCKET NUMBER (2)
LER NUMBER 181 PAGE (3)
YEAR SEQUENTIAL REVISION NUMBER NUMEER Oconee Nuclear Station - Unit 1 0 5 10 10 l0269 87 1111 0817 --0 0 013 OF 0 4 TEXT (IN rm a is ewired. useeditn NRC Form 184's) (17) which would allow the Operator to continue withdrawing rods while manually maintaining proper overlap.
At 1738, NI Overlap testing was restarted and was successfully completed.
During the troubleshooting process, the Instrument and Electrical Technicians checked for loose wires, changed the Sequencer Board, and performed several other activities in the attempt to locate the problem. On November 8, 1987 ground wire on Pin #1 on the Auto Sequencer Connector [EIIS:CON] was found to be loose, it was resoldered and the problem cleared. No other problems were observed with the Control Power after the Auto Sequencer was returned to service.
Cause of Occurrence The root cause of this event was determined to be a loose solder joint of the ground wire and Pin #1 of the Auto-Sequencer Card. There were several troubleshooting activities performed during the investigation of the loss of control power to the Control Rod Drives. Some of these involved checking all associated wiring, and changing Auto-Sequencer card. The loose solder joint was repaired and the original card was reinstalled. During the investigation of the loss of power problem, the Start Up Physics Test was restarted, but was performed in the sequence override mode. After the loss of power problem was identified and corrected, the Startup Physics testing continued and subsequently was successfully completed.
A review of the summary of incidents at Oconee Nuclear Station revealed that there has been 28 reactor trips in the past 5 years due to failed or malfunctioning equipment. One of these was during Zero Power Physics Testing.
This incident was reported in LER 270/85-02 and concerned a Reactor Trip on High Flux Indication During Zero Power Physics Testing. The event was classified as component malfunction due to the Power Range Recorder [EIIS:JR] sticking at 1%
indicated power and resulted in reactor power reaching the Reactor Protective System [EIIS:JC] 0.4% Real Power Trip Setpoint.
The corrective actions on this previous event are not similar or associated with the same components involved in this incident. This event is considered to be recurring in nature but at a low frequency.
This event involved a failed component but since the failure was at a solder joint it was not reportable to NPRDS.
Corrective Actions:
The immediate corrective action was to manually trip the unit and stabilize the unit in hot shutdown conditions.
Subsequent corrective actions were to resume Startup Physics Testing and to identify and repair the loose solder joint.
NRC FORM 386A (9-83)
NRC Form 364A U.S. NUCLEAR REGULATORY COMMISSION (943)
LICENSEE EVENT REPORT (LER) TEXT CONTINUATION APPROVED OMB NO. 3150-0104 EXPIRES: 8/31/85 FACILITY NAME III DOCKET NUMAER (2)
LER NUMBER (
I PAGE (3)
YEAR SEQUENTIAL REVISION NUMBER NUMBER Oconee Nuclear Station -
Unit 1 4
619 F7 1 0.O0 9 4 0o 014 TEXT 1H moe apw is equiwa, us NAC Fom 3114a 1171 Analysis of Occurrence:
There was no safety system actuation during this trip, and the Power Operated Relief Valves [EIIS:VI and Pressurizer Code Relief Valves were not challenged.
The reactor was subcritical with approximately 125 counts per second on the source range monitor. When the reactor was manually tripped, all systems reacted as expected. Steam generator [EIIS:SG] levels were maintained at 25 inches, and pressurizer [EIIS:PZR] level did not change.
There were no personnel injuries, personnel overexposures, or releases of radioactive material as a result of this event. This event is considered to be of no significance with respect to the health and safety of the public.
f NRC FORM 388A (9-83)
DuKE POWER GOMPANY P.O. BOX 33189 CHARLOTTE, N.C. 28242 HAL B. TUCKER ThEPHON VICE PREIDENT (704) 373-4531 NUGLEAR PRODUCTION December 7, 1987 U.S. Nuclear Regulatory Commission Document Control Desk Washington, D.C. 20555
Subject:
Oconee Nuclear Station Docket Nos. 50-269; -270, -289 LER 269/87-10 Gentlemen:
Pursuant to 10CFR 50.73 Sections (a)(1) and (d), attached is Licensee Event Report (LER) 269/87-10 concerning a manual trip of Unit 1 on November 5, 1987.
This report is submitted in accordance with 10CFR 50. 73 (a)(2)(iv).
This event is considered to be of no significance with respect to the health and safety of the public.
Very truly yours, Hal B. Tucker PJN/257/jgc Attachment xc: Dr. J. Nelson Grace American Nuclear Insurers Regional Administrator, Region II c/o Dottie Sherman, ANI Library U.S. Nuclear Regulatory Commission The Exchange, Suite 245 101 Marietta St., NW, Suite 2900 270 Farmington Avenue Atlanta, GA 30323 Farmington, CT 06032 INPO Records Center Mrs. Helen Pastis Suite 1500 U.S. Nuclear Regulatory Commission 1100 Circle 750Parkway Office of Nuclear Reactor Regulation Atlanta, GA 30339 Washington, D.C. 20555 M&M Nuclear Consultants Mr. J.C. Bryant 1221 Avenue of the Americas NRC Resident Inspector New York, NY 10020 Oconee Nuclear Stationr