ML23251A016
| ML23251A016 | |
| Person / Time | |
|---|---|
| Issue date: | 08/31/2023 |
| From: | NRC/OCIO |
| To: | - No Known Affiliation |
| Shared Package | |
| ML23251A034 | List: |
| References | |
| FOIA-2023-000163 | |
| Download: ML23251A016 (1) | |
Text
ACCELERATED LQTIUBUTION DEMONSATION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
ACCESSION NBR:8911070033 DOC.DATE: 89/10/25 NOTARIZED: NO DOCKET g
, FACIL:50-410 Nine Mile Point Nuclear Station, Unit 2, Niagara Moha 05000410 AUTH.NAME AUTHOR AFFILIATION DEAN,R.J.
Niagara Mohawk Power Corp.
WILLIS,J.L.
Niagara Mohawk Power Corp.
RECIP.NAME RECIPIENT AFFXLIATION
SUBJECT:
LER 89-026-00:on 890926,ESF initiation due to spurious trip signals caused by high frequency welding.
W/8 ltr.
DISTRIBUTION CODE: IE22T COPIES RECEIVED:LTR I ENCL (
SIZE:
TITLE: 50.73/50.9 Licensee Event Report (LER), Incident Rpt, etc.
NOTES RECIPIENT ID CODE/NAME PD1-1 LA MARTIN,R.
INTERNAL: ACRS MICHELSON ACRS WYLIE AEOD/DSP/TPAB DEDRO NRR/DEST/ICSB 7
NRR/DEST/MTB 9H NRR/DEST/RSB 8E NRR/DLPQ/HFB 10 NRR/DOEA/EAB 11 NUDOCS-ABSTRACT RES/DSIR/EIB EXTERNAL: EG!EG WILLIAMS,S LPDR NSIC MAYS,G NUDOCS FULL TXT COPIES LTTR ENCL 1
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1 RECIPIENT ID CODE/NAME PD1-1 PD BENEDICT,R ACRS MOELLER AEOD/DOA AEOD/ROAB/DSP NRR/DEST/ESB 8D NRR/DEST/MEB 9H NRR/DEST/PSB 8D NRR/DEST/SGB 8D NRR/DLPQ/PEB 10 NRR DREP/RPB 10 02 RGN1 FILE 01 L ST LOBBY WARD NRC PDR NSIC MURPHY,G.A COPXES LTTR ENCL 1
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1 NOTE TO ALL"RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM P 1-37 (EXT. 20079) TO ELIMINATEYOUR NAMEFROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!
FULL TEXT CONVERSION REQUIRED TOTAL NUMBER OF COPIES REQUIRED:
LTTR 39 ENCL 39
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7 NaAGARA
~ hAQ8AWK NMP 56892 NINE MILEPOINT NUCLEARSTATION/P.O. BOX 32, LYCOMING,N.Y. 13093/TELEPHONE (315) 343-2110 October 25, 1989 United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 RE:
Docket No. 50-410 LFR 89-26 Gentlemen:
In accordance with 10 CFR 50.73, we hereby submit the following Licensee Event Report.
LER 89-26 Which is being submitted in accordance with 10 CFR 50.73 (a)(2)(iv),
"Any event or condition that resulted in manual or automatic actuation of any Engineered Safety Feature (ESF), including the Reactor Protection System (RPS).
However, actuation of an ESF, including the RPS, that resulted from and was part of the pre-planned sequence during testing or reactor operation need not be, reported."
The 10 CFR 50.72 report was made at 1630 hours0.0189 days <br />0.453 hours <br />0.0027 weeks <br />6.20215e-4 months <br /> on September 26, 1989.
This report was completed in the format designated in NUREG-1022, Supplement 2,
dated September 1985.
Very truly yours, General Superintendent Nuclear Generation JLW/AC/lmc (1006V)
ATTACHMENT xc: William T. Russell, Regional Administrator William A. Cook, Sr. Resident Inspector qy11070033 891025 PDR p,oocy, 0~I000410 Por
NRC FOAM 366 (669)
V.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT {LER)
APPROVED OMB NO. 31504)104 E X FIR ES; 4/30/92 ESTIMATED BURDEN PER
RESPONSE
TO COMPLY WTH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FOAWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGEMENTBRANCH (F630), V.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO THE PAPERWORK REDUCTION PROJECT (31500104),
OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON, DC 20503.
FACILITYNAME (1)
DOCKET NUMBER (2) 0 5
0 0
0 PA E
3 1
OF
'"""'ngineered Safety Feature Initiation Due To Spurious Trip Signals uenc Weld EVENT DATE(5)
LER NUMBER (6)
REPORT DATE (7)
OTHER FACILITIES INVOLVED(6)
MONTH DAY YEAR YEAR
~rx Prx SEQUENTIAL iCPr rifVrsrON A".r'UMBER ROC NUMSER MONTH OAY YEAR FACILITYNAMES DOCKET NUMBERIS) 0 5
0 0
0 0 9 68 98 0
26 00 1
0 2
5 8 9 N A 0
5 0
0 0
OPERATING MODE (9)
POWER LEVEL 0
THIS REPORT IS SUBMITTED PURSUANT T 20A05(c) 50.36(cl(1) 50.36( ~l(2) 50.73( ~)(2)(l) 50.7 3(s)12 I(ii) 60.73(sl(2)(lill 20A02(SI 20AOSI ~)(1)(il 20.405(x)(1)(lil 20.405( ~I('I) 0ii) 20AOS(s) (1)(N) 20.405(sl(1)(v) 50 73(x)(2) (iv) 50,73(x)(2) (v) 50.73(s) (2)(viG 50,73(sl(2) (vill)(AI 50,73(sl(2)(vill)(BI 50,73(s) (2) (x)
LICENSEE CONTACT FOR THIS LER (12I 0 THE REQUIREMENTS OF 10 CFR (); /Cocci ons or mois of ths foilowinp/ (11) 73.71 (5) 73.71(c)
DTHER /spsciry in Aortrsct Osiow snd In Tsxt, IYRC Form 366A/
NAME Raymond J.
- Dean, Lead Engineer, System Support and Testing AREA CODE TELEPHONE NUMBER
= COMPLETE ONE LINE FOA EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)
CAUSE SYSTEM COMPONENT MANUFAC TVRER REPORTABLE TO NPRDS SYSTEM COMPONENT MANUFAC TURER IYtnF@Zk%
SUPPLEMENTAL AEPORT EXPECTED (14)
YES fffyst, compists EXPECTED SUBMISSIDhi DATE/
ABSTRACT /Limirto rcOO roscsr, Is., spproximstsiy riftrsn rinpis roses rypswrinsn hnw/ (16) dBXBhGX EXPECTED SUBMISSION DATE HSI MONTH DAY YEAR On September 26, 1989, at 1320 hours0.0153 days <br />0.367 hours <br />0.00218 weeks <br />5.0226e-4 months <br /> and at 1435 hours0.0166 days <br />0.399 hours <br />0.00237 weeks <br />5.460175e-4 months <br /> with the reactor at approximately 35X power and the mode switch in "RUNHE Nine Nile Point Unit 2 (NMP2) experienced two Engineered Safety Feature (ESF) actuations.
The first event consisted of a secondary containment isolation and the automatic initiation of the Standby 'Gas Treatment System (Trains A&B), emergency recirculation unit cooler and reactor building unit coolers.
The second event consisted of an automatic ini.tiation of Train A of the Standby Gas Treatment System.
The ESF actuations occurred on a spurious high radiation signal.
The immediate cause of the spurious signal has been determined to be electrical noi.se resulting from AC (high frequency)
Tungsten Inert Gas (TIG) welding.
The root cause has been determined to be a desi.gn deficiency.
Corrective actions consist of the following:
1.
WR 163948 was wri.tten and completed to inspect and tighten ground connecti.ons on affected radiation 'monitors.
2.
A problem report (PR 08867) has been issued to review the Instrument System Ground (ISG) design.
3.
A modification request has been issued to evaluate the need to modify the monitoring system grounds in order to isolate it from otential round nois NRC Form 366 (669)
NRC FORM 368A (64) 9)
U.S. NUCLEAR REGULATORYCOMMISSION LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION APPROVED 0MB NO. 31504))04 EXPIRES: 4/30/92 ESTIMATED BURDEN PER
RESPONSE
TO COMPLY WTH THIS INFORMATION COLLECTION REQUEST! 50J) HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE.TO THE RECORDS AND REPORTS MANAGEMENTBRANCH (F830), V.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, ANDTO lHE PAPERWORK REDUCTION PROJECT (31504)104), OFFICE OF MANAGEMENTAND BUDGET,WASHINGTON,DC 20503.
FACILITYNAME (I)
DOCKET NUMBER (2)
LER NUMBER (6)
PAGE (3)
Nine Mile Point Unit 2 TEXT ///moro 4/roco lr ror)rr/rod, oro odd/do/re/HRC Rem 36643/ (17) o 5
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YEAR 66QVSNTIAL NUMBER 026 REYrsrON NVMSER 00 02 OF 0 4
N On September 26, 1989, at 1320 hours0.0153 days <br />0.367 hours <br />0.00218 weeks <br />5.0226e-4 months <br /> with the reactor at approximately 35K power and the mode switch in "RUN", Nine Mile Point Unit 2 (NMP2) experienced an Engineered Safety Feature (ESF) actuation.
At 1435 the same day, with the reactor at approximately 35K power and the mode switch in "RUN", NMP2 experienced a second ESF actuation.
The first event consisted of a secondary containment isolation and automatic initiation of the Standby Gas Treatment System (SBGTS),
emergency recirculation unit cooler, and reactor building unit coolers.
The second event consisted of an automatic initiation of Train A of the Standby Gas Treatment System (SBGTS).
On September 26, 1989, at 1320 hours0.0153 days <br />0.367 hours <br />0.00218 weeks <br />5.0226e-4 months <br /> a series of "spikes" occurred on reactor building exhaust radiation monitors 2HVRI(IRE14A, 2HVR*RE14B, and 2HVR*RE32B.
As designed, the following occurred on a high radiation signal:
- 1) Secondary Containment Isolation, 2)
SBGTS Train "A" and Train "B" auto start, 3)
Emergency Recirculation Unit Cooler 2HVR*UC413B auto start,
- 4) Reactor Building Unit Coolers auto start.
Radiation monitors 2CMS*RElOB, 2CCP-RE131 and 2HVR-RE229 also spiked.
After verifying a high radiation condition did not exist, Operations personnel returned SBGTS Train A to standby.
The duration of this event was approximately 32 minutes.
On September 26, 1989, at 1435 hours0.0166 days <br />0.399 hours <br />0.00237 weeks <br />5.460175e-4 months <br /> a second series of "spikes" occurred on radiation monitors 2HVR*RE14A, 2HVR*RE14B and 2HVR*RE32B.
Standby Gas Treatment System Train "A" auto initiated as designed.
SBGTS Train "B",
Emergency Recirculation Unit Cooler 2HVR+UC413B,. and Reactor Building Unit Coolers were still operating from the first event.
Following the second event the Reactor Building was left in an isolated condition and
- SBGTS, 2HVR*UC413B and the Reactor Building Unit Coolers were left in operation until the cause of the spiking could be determined.
On September 27, 1989, at 0948 hours0.011 days <br />0.263 hours <br />0.00157 weeks <br />3.60714e-4 months <br /> spiking occurred again.
The spiking again caused the Reactor Building Exhaust Radiation monitors to alarm on high radiation.
At this time no ESF actuations occurred as the systems were still operating from the actuation the previous day.
Investigation revealed that AC (high frequency)
TIG welding was in process at the time of the actuations both on September 26,
- 1989, and September 27, 1989.
Upon determining the immediate cause of the event, Operations ordered all welding stopped in the Reactor Building.
Subsequently, Operations personnel secured the equipment which started September 26,
- 1989, and Reactor Building ventilation was restored to normal September 27, 1989, at 1500 hours0.0174 days <br />0.417 hours <br />0.00248 weeks <br />5.7075e-4 months <br />.
The total duration of the event was 1 day 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> 40 minutes from the start of the first event.
NRC Form 368A (84)9)
NRC FORM 388A (64)9) v U.S. NUCLEAR REGULATORYCOMMISSION LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION APPROVED OMB NO. 3)500'l04 EXPIRES: 4/30/92 ESTIMATED BURDEN PER
RESPONSE
TO COMPLY WTH THIS INFORMATION COLLECTION REQUEST: 508) HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGEMENTBRANCH (F830), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON. OC 20555. ANDTO THE PAPERWORK REDUCTION PROJECT (31504'I04), OFFICE OF MANAGEMENTAND BUDGET,WASHINGTON, DC 20503.
FACILITYNAME (1)
DOCKET NUMBER (2)
YEAR LER NUMBER (6I SEOV ENTIAL NUMBER REVISION NUMBER PAGE (3)
Nine Mile Point Unit 2 TEXT //fmore opeoe
/4 rer)rvkerf, oee erfdft/one/HRC Form 3664'4/ l(TI 0
5 0
0 0
4 1
8 9 0
2 6
00 03 OF 0 4
There were no components or systems which were inoperable and/or out of service which contributed to the event.
No plant system or component failures resulted from the event.
The immediate cause of the event has been attributed to electrical noise produced by AC TIG welding on Reactor Building El. 353.
A root cause analysis was performed using Site Supervisory Procedure S-SUP-1, "Root Cause Evaluation Program".
The results of the analysis indicate that the root cause is a design deficiency.
The current design for grounding of the Kaman Radiation Nonitors and the equipment grounds appear to. allow noise on the equipment ground system to, affect the radiation monitors.
This noise affected Div. I,, Div. II,,and non-divisional radiation monitors in the reactor building.
In reference to both events, the secondary containment isolation and initiations of the Standby Gas Treatment system and recirculation unit coolers are conservative actions and pose no adverse safety consequences at any reactor power level.
The events did not in any way adversely affect any other systems nor the operator's ability to achieve safe shutdown.
/
This event analysis is considered reportable in accordance with 10CFR50.73 (a)(2)(iv), any event or condition that resulted in automatic actuation of an Engineered Safety. Feature (ESF).
The following corrective actions were taken as a result of this event:
1.
An air sample was taken to verify a high airborne activity level did not
- exist.
The radiation history trends before and after the event were checked showing normal operation bands well below the radiation alert and high setpoints.
2.
All AC TIG welding in the Reactor Building has been suspended.
A revision to the procedure for cutting/welding/grounding permits will be made to require a review by Naintenance Engineering or System Support and Testing prior to performing AC TIG welding in the plant.
NRC Form 368A (64)9)
0
NRC FORM 388A (64) 9)
U.S. NUCLEAR REGULATORYCOMMISSION LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION APPROVED OMB NO.31504))04 6 XP IR ES: 4/30/92 ESTIMATED BURDEN PER
RESPONSE
TO COMPLY WTH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGEMENTBRANCH (F4301. U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO 1HE PAPERWORK REDUCTION PROJECT (31504))04). OFFICE OF MANAGEMENTAND BUDGET, WASHINGTON,DC 20503.
FACILITYNAME (1)
DOCKET NUMBER (2)
YEAR LER NUMBER (8)
- KN'EQUENTIAL O+<
NUMB 8 II j'EVISION
'>2:<': NUMBER PAGE (3)
Nine Mile Point Unit 2 TEXT //fmar BPoco /4 mOII98I/ 844 BI/I////ono/HRC FomI 36642/ OT) o s
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6 0 0 0 4 QF 0 4
3.
Work Request WR 163948 was issued and grounds on the affected radiation monitors were inspected and tightened.
4.
A Modification Request has been initiated to evaluate the need to modify the ground scheme for all radiation monitors required by the plant Technical Specifications.
5.
A Problem Report (PR 08867) has been issued to review the design of the Instrument System Ground (ISG) and the connected equipment grounds.
6.
A lessons learned transmittal has been prepared detailing the event and outlining precautions to be observed by personnel performing welding.
D NAL A.
Identification of components referred to in this LER:
N E
Radiation Monitor Reactor Building Ventilation (HVR)
Standby Gas Treatment System Reactor Bui'lding Emergency Recirculation Unit MON N/A N/A N/A FAN VA VA VA NG V
B.
Component failuresnone.
C.
Previous similar events there have been two similar events.
The first is described in LER 88-020.
In this event, the root cause was determined to be "contactor chattering" caused by an incorrect torque switch setting.
This chattering caused spurious high radiation trips on radiation monitors.
The corrective action was to recalibrate the torque switch.
This corrective action would not have prevented this LER.
The second similar event is described in LER 88-035.
In this event the root cause was determined to be electrical noise caused by operation of a valve on the same divisional power supply as the radiation monitor.
The corrective action was to verify proper operation of the radiation monitor and request Engineering to evaluate the sensitivity of the monitors to electrical noise on the AC distribution system.
These corrective actions would not have prevented this LER.
The noise seen in this event was due to ground induced noise versus noise induced from the AC distribution.
NRC Form 366A (64)9)
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