05000412/LER-1996-001, :on 960212,PSC Rod Bank Pulse Step Counter Positions Indicating 0 Steps.Caused by Electrical Distribution Sys Disturbance That Occurred 36 H Earlier. Performed Manual Cold Start of PCS
| ML20101D314 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 03/13/1996 |
| From: | Noonan T DUQUESNE LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| LER-96-001, LER-96-1, NPD2VPO:0446, NPD2VPO:446, NUDOCS 9603200182 | |
| Download: ML20101D314 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| 4121996001R00 - NRC Website | |
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M T.i. phone NW 393-MM Io.'*dEx ! "."pA ison oM4 snippinoport March 12,1996 NPD2VPO:0446 Beaver Valley Power Station, Unit No. 2 Docket No. 50-412, Licensee No. NPF-73 LER-96-001-00 United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555
- - In accordance with Appendix A, Beaver Valley Technical Specifications, the following Licensee Event Report is submitted:
LER 96-001-00, 10 CFR 50.73.a.2.i.B,
" Condition Prohibited by Technical Specifications - Missed Rod Position Surviellance".
W T. P. Noonan Division Vice President Nuclear Operations / Plant Manager 1
D L U nic 1
Attachment 9603200192 960313 PDR ADOCK 05000412 S
PDR w
The Nuclear Professionals 0> @f
y March 12,1996 NPD2VPO:0446 Page 2 cc:
Mr. T. T. Martin, Regional Administrator United States Nuclear Regulatory Commission Region 1 475 Allendale Road King of Prussia, PA 19406 Mr. D. S. Brinkman BVPS Licensing Project Manager United States Nuclear Regulatory Commission Washington, DC 20555 t
Mr. Larry Rossbach BVPS Senior Resident Inspector United States Nuclear Regulatory Commission i
Mr. J. A. Hultz Ohio Edison Company 76 S. Main Street Akron, OH 44308.
Mr. Mark Burns Centerior Energy Corporation 6200 Oak Tree Boulevard Independence. OH 44101-4661
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INPO Records Center 700 Galleria Parkway Atlanta, GA 30339-5957-Mr. Robert Maiers Department of Environmental. Resources P.O. Box 8469 State Office Building,13th Floor Harrisburg, PA 17105-8469 Director, Safety Evaluation & Control Virginia Electric & Power Company P.O. Box 26666 One James River Plaza-Richmond, VA 23261 l
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FORM 366 U.S. NUCLEAR REGULATORY COMMISSION
'(5 93) f ESTIMATED BURDEN PER RESPONSEMCOMPLY WTTHDHS INFORMATION COLLECDON REQUEST 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE 1DTHE INFORMATION
. LICENSEE EVENT REPORT (LER)
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Beaver Valley Power Station Unit 2 05000412 1 OF 3 Condition Prohibited by Technical Specifications, Missed Rod Position Surveillance EVENT DATE(5)
LER NUMHER (6)
REFORT DATE(7)
OTHER FACILJTIES INVOLVED (8)
EEQUENTIAL REVlblON FACILrTY NAME DUCKE'I NUMBER MONTH DAY YEAR YEAR NUMBER NUMBER MONTH DAY YEAR N/A 05000 02 12 001 00 3
13 FACILMY NAME DUCKEI NUMBER N/A 05000 OPERATING THIS REPORT IS SUDMrITED PURSUANT TO Tile REQUIREMENTS OF 10 CFR g (Check one or more)(l1)
MODE (9) 1 20.402(b) 20.405(c) 50.73(aX2Xiv) 73.71(b)
POWER 20.405(aXIXi) 50.36(cXI) 50.73(aK2 Xv) 73.71(c)
LEVEL (10) 10() -
20.405(aXIXii) 50.36(cX2) 50.73(aX2 Xvii)
OTl!ER 20.405(aXIXiii)
X 50.73( X2Xi) 50.73(aX2XviiiXA)
(Speedy m ebstmet 20.405(aXIXiv) 50.73(aX2Xii) 50.73(aX2XviiiXH) below and m Text 20.405(aXIXv) 50.73(aX2Xiii) 50.73(aX2Xx)
NRC Fonn 306A)
IJCENSEE CONTACr FOR THIS LER (12)
NAME TELEPHONE NUMBER (sulude Ana Code)
T.P. Noonan, Division Vice President Nuclear Operations / Plant Manager (412)393-7622 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN Tills REPORT (13)
CAUSE
SYSTEM COMPONENT MANUFACIURER REPORTABLE COMPONENT MANUFACTURER REPORTABLE TO NPRDS TO NPRDS B
ID XXXX XXXX N
SUPPLEMENTAL REPORT EXPECTED (14)
EXPECTED MONTil DAY YEAR YES X
NO SUBMISSION Of res. complete EXPECTED SUBMISSION DATE)
DATE(15)
ABSTRACT (Linuted to I400 spaces, i.e., approximately 15 single-spaced typewritten imes) (16)
On February 12,1996, at 1330 hours0.0154 days <br />0.369 hours <br />0.0022 weeks <br />5.06065e-4 months <br />, with Unit 2 operating at 100% power, it was discovered that the Plant Computer System (PCS) Rod Bank Pulse Step Counter Positions were indicating 0 steps. The PCS Digital Rod Position Indications (DRPI) indicated 228 steps for each Rod Bank, but no Rod Position Deviation Alarm was displayed on the PCS. A review of computer logs determined that the likely initiating event for this anomaly was an electrical distribution system disturbance that occurred 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br /> earlier. Investigation revealed that a software driven data point representing the Reactor Trip Breaker condition indicated a false " tripped" state. A trip condition on this data point results in the PCS Rod Bank Pulse Points being set to a value of zero and inhibits the Rod Position Deviation Monitor (RPDM) alarm. Control room operators immediately began manual logging of Rod Position in accordance with Technical Specifications. A manual cold start of the PCS was performed to reset all data points, and an Operating Surveillance Test was performed to verify the operability of the PCS RPDM.
Rod Position was logged once per shift until discovery of the inoperable RPDM, and every four hours thereafter. Technical Specifications require manual logging of rod position at least every four hours when the RPDM is inoperable. This event is being reported, in accordance with 10CFR50.73.a.2.i.B, as a condition prohibited by Technical Specifications.
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a NRC FORM 366 U.S. NUCLEAR REOULATORY COMMISSION (5-92)
ES11 MATED BURDEN PER RESPONSETOCOMPLY WTTHTHIS INFORMATION COLLEC'nON REQUEST $00 HRS. FORWARD COMMENTS REGARDING BURDEN ESMMATE10THE INFORMA110N LICENSEE EVENT REPORT (LER)
AND RECORDS MANAGEMENT BRANCH (MNBB 7714A U.S. NUCLEAR TEXT CONTINUATION REGULAMRY COMMISSION. WASHINOWN, DC 2053% AND M THE PAPERWORK REDUCDON PROJECTQ150 010410FFICE OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20101 FACIL.ITY NAME(1)
IXX'EET NUMBER (2)
IIR NUMBER (6) l PAGE (3)
SEQUENT!AL REVis!ON Beaver Valley Power Station Unit 2 05000412 YEAR NUMBER NUMBER 2OF3 001 00 TEXT (t/more core u repped see sanand eqpees q(ARCror= 3M (17)
Description of Event
On February 12,19%, at 1330 hours0.0154 days <br />0.369 hours <br />0.0022 weeks <br />5.06065e-4 months <br />, with Unit 2 operating at 100% Reactor Power, a Computer Engineer reviewing the Plant Computer System (PCS) status discovered that the Computer Rod Bank Pulse Step Counter Positions were indicating 0 steps.
. Digital Rod Position Indications (DRPI) indicated 228 steps for each Rod Bank, but no Rod Position Deviation Alarm was displayed on the PCS as should have occurred under these conditions. A review of computer logs determined that the likely initiating event for this computer anomaly was an electrical distribution system disturbance that occurred at 0155 hours0.00179 days <br />0.0431 hours <br />2.562831e-4 weeks <br />5.89775e-5 months <br /> on February 11,19%. This disturbance, which resulted in a fault and subsequent line breaker opening on a 138 kV distribution line, was caused by high winds. Further investigation revealed that a software driven computer data point representing reactor trip breaker condition indicated a " tripped" state. Under these conditions, the PCS Data Acquisition Program resets the Computer Rod Bank Pulse Step Counter points to a zero value. When the computer point indicates " tripped", the Rod Position Desiation
' Monitor will not alarm and is technically inoperable.
Cause of Event
A review of computer logs determined that the likely initiating event for this computer anomaly was an electrical distribution system disturbance that occurred at 0155 hours0.00179 days <br />0.0431 hours <br />2.562831e-4 weeks <br />5.89775e-5 months <br /> on February 11,19%. This disturbance, which resulted in a fault and subsequent breaker opening on a 138 kV distribution line, was caused by high winds. Numerous " false" computer and annunciator alarms were received in the Unit 2 Control Room at this time, including the field inputs to the software driven Reactor Trip Breaker Point. When the numerous computer alarms cleared the sollware driven computer point did not return to normal. The PCS Data Acquisition Program then zeroed the Rod Bank Pulse Points and the PCS Rod Position Monitor Program inhibited the Rod Deviation Alarm. The Computer Engineer apprised the Assistant Nuclear Shift Supersisor of this condition upon discovery, and Control Room Operators commenced manual logging of Rod Position.
Corrective Actions
- 1) The Assistant Nuclear Shift Supervisor and Control Room Operators were notified of the condition of the Rod Position Deviation Monitor, and commenced manual logging of Rod Position once per four hours in accordance with Tecimical Specification Surveillance Requirement 4.1.3.1.2.
- 2) A manual cold start of the Plant Computer System was performed to force a recalculation of all computer data points.
- 3) The Rod Position Deviation Alarm Operating Surveillance Test was performed to verify the operability of the PCS Rod Position Desiation Monitor.
- 4) Database modifications were implemented that will provide positive indication of the status of the PCS Rod Desiation MUnitor Alarm under the circumstances described in this event.
- 5) A procedure change was implemented to log the PCS Rod Bank Pulse Positions and compare them with bench board indications when the once per shift surveillance of the rod positions is performed by Operations.
. NRC FORM 3e6A O-92)
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ESTIMATID BURDEN PER RESPONSE TOCOMPLY Wmt THIS J
6 INFORMATION COLLECDON REQUEST: 30.0 HRS. FORWARD COMMENTS REGARDING BURDEN EFUMATE10THE INFORMATION i
LICENSEE EVENT REPORT (LER)
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MANAGFMENT AND BUDGFT, WASHINNN, DC 209D FACILITY NAME(l)
DOCKET NUMHER (2)
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SEQUENTIAL REVISION Beaver Valley Power Station Unit 2 05000412 YEAR NUMBER NUMBER
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- 6) Further investigation will be performed in an attempt to determine the cause for the false indication of the software driven computer point. Any additional recommendations will be implemented based on the results of the investigation i
Renodability i
Technical Specification Surveillance Requirement 4.1.3.1.2 requires that the position of each full length rod be verified once per four hours when the Rod Position Desiation Monitor is inoperable. This event is being reported in accordance with 10CFR50.73.a.2.i.B, as a condition prohibited by Technical Specifications.
Hafety Imnlications:
There were minimal safety implications as a result of this event. The Bench Board Rod Bank Indications and the Digital Rod Position Indication System were in senice throughout this incident. Operators complied with the once per twelve hours Technical Specification requirement by logging Rod Position once per shift
Similar Events
Beaver Valley Power Station Unit 2 has previously submitted LERs due to missed surveillances.
None of the previously rcported missed surveillances involved the Rod Position Desiation Monitor.
LER 95-005-00 " Missed Surveillance-Quadrant Power Tilt Ratio Calculation not performed" LER 92-012-00 " Missed Reactor Coolant System Dissolved Oxygen Sample" LER 92-001-00 " Operators Failed to Manually Log Axial Delta Flux" LER 90-024-00 " Chemist Failed to Perform Sample on Boric Acid Storage Tank" NCC FORM 3eoA @92)