05000369/LER-1997-007, :on 970514,Unit 1 RT Occurred During Power Range Nuclear Instrumentation Testing.Caused by Personnel Utilizing Inappropriate Procedure for Existing Plant Conditions.Reviewed Subject & Associated Procedures
| ML20140H514 | |
| Person / Time | |
|---|---|
| Site: | McGuire  |
| Issue date: | 06/13/1997 |
| From: | Pitesa J DUKE POWER CO. |
| To: | |
| Shared Package | |
| ML20140H510 | List: |
| References | |
| LER-97-007, LER-97-7, NUDOCS 9706180291 | |
| Download: ML20140H514 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv), System Actuation 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(e)(2)(vii) 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(viii)(A) 10 CFR 50.73(a)(2)(ii) 10 CFR 50.73(a)(2)(viii)(B) |
| 3691997007R00 - NRC Website | |
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NRC FORM 366 U S NUCLEAR REGULATORY COMMISSION APPHOVED BY OMS NO. 31504104 EXPtRES 0430rD8 ESTIMATED BURDEN PER RESPONSE TO COMPLY WITH THIS MANDATORY INFORMATION COLLECTION REQUEST 500 Htt$
REPORTED LESSONS LEARNED ARE INCORPORATED INTO THE
' LICENSEE EVENT REPORT (LER)
LICENSING PROCESS AND FED BACK TO INDUSTRY FORWARD COMMENTS REGARDING BURDEN ESTMATE TO THE INFORMATION r
AND RECORDS MANAGEMENT BRANCH (T4 F33L U S NUCLEAR REGULATORY COMMISSION WASHINGTON. DC 205554001. AND TO THC PAPERV.ORK REDUCTION PROJECT (3150-0104L OFFICE OF
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MANAGEMENT AND BUDGET, WASHINGTON DC 70503 FACILITY NAME (1) ooCKET NUMBER (2)
PAGE (3)
McGuire Nuclear Station, Unit 1 05000369 1 of 5 l
TITLE (4) l Unit 1 Reactor Trip During Power Range Nuclear Instrumentation Testing j
EVENT DATE (5g LER NUMBER (6)
REPORT DATE (7)
OTHER FACILITIES INVOLVED (8)
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09 05000 l
05 14 97 97 07 0
06 13 97 N/A 05000 3
OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR (Check one or more of the followmp)(11) l MODE (9) 3 20 402(b) 20 405(c)
X 50.73(a)(2)(iv) 73.71(b) l POWE4 0%
20.405(a)(1)(t) 50.36(c)(1) 50.73(a)(2)(v) 73.71(c) l LE 20 405(a)(1)(ii) 50.36(c)(2) 50.73(e)(2)(vii)
OTHER (Specify n
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20 405(a)(1)(iii) 50.73(a)(2)(i) 50.73(a)(2)(viii)(A)
Abstract below and 20 405(a)(1)(iv)
X 50.73(a)(2)(ii) 50.73(a)(2)(viii)(B) m Text. NRC Fonn l
20 405(a)(1)(v) 50 73(a)(2)(lii) 50 73(a)(2)(x) 3664)
LICENSEE CONTACT FOR THIS LER (12)
NAME TELEPHONE NUMBER AREA CODE J. W. Pitesa (704) 875-4788 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)
CAUSE
SYSTEM COMPONENT MANUFACTURER REPORTAELE
CAUSE
SYSTEM COMPONENT MANUFACTURER REPORTABLE TO NPRDS TO NPROS
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SUPPLEMENTAL REPORT EXPECTED (14)
EXPECTED MONTH DA Y YEAR SUBMISSION YES (tyes complete EXPECTED SUBMISSION DATE')
X NO DATE(15)
ABSTRACT (Lunit to 1400 spaces, t e. approximatery fifteen smgle space typewntten lines)(16)
Unit Status: Unit 1 - Mode 3 (Hot Standby) at 0 percent power with Shutdown Rod Banks A and B withdrawn.
Event Description
On May 14, 1997, at 1104, the Unit 1 Reactor tripped during performance of Power Range (PR) Detector N42 Analog Channel Operational Testing (ACOT).
Prior to the performance of the ACOT, PR Detector channel N41 had been bypassed due to being connected to the Reactivity Computer in preparation for Zero Power Physics Testing.
The procedure chosen to bypass the N41 channel failed to bypass Permissive P-8, i
which unblocks reactor trip due to turbine trip.
During simulation of reactor power rising to 120 percent on PR Detector N42 per the ACOT, Permissive P-8 logic was met on two out of four channels which, along with the tripped turbine, tripped the reactor.
Permissive logic P-10 was met on two out of four channels, which de-energized both Source Range Detectors causing momentary entry into Technical Specification 3.0.3.
A Feedwater I
Isolation signal occurred due to a Reactor trip signal concurrent with the l
Low Tavg Bistables.
Event Cause
This event was caused by personnel utilizing an inappropriate l
procedure for the existing plant conditions.
This event is considered to be of no significance with respect to the safety of the public.
Corrective Actions
Corrective actions includea review of subject and associated procedures to determine any necessary enhancements or revisions.
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NRC FORM 368 9706180291 970611 I
PDR ADOCK 05000369 S
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APPROVLD J 3150 4104 E STIMATED BURDEN PER RESPON$E TO COMPLY WITH THIS MANDATORY INFORMATION COLLECTION REQUEST 50 0 HR$ REPORTED LESSONS LICENSEE EVENT REPORT (LER)
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DOCKET NUMBER (2)
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PAGE (3)
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NUMBER McGuire Nuclear Station, Unit 1 05000 369 97 9
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0 2 OF 5 EVALUATION:
Description of Event
Immediately prior to the event on May 14, 1997, Unit 1 was in Mode 3 (Hot Standby), stable at 557 degrees Fahrenheit and 0 percent power.
Reactor [EIIS RCT] Trip Breakers [EIIS:BKR] were closed with Shutdown Rod Banks A and B withdrawn.
Excore Neutron Flux Monitor [EIIS:JC]
System Power Range (PR) Detector [EIIS:DET) N41 was out of service and connected to the Reactivity Computer [EIIS: CPU) in preparation for Zero Power Physics Testing (ZPPT).
At approximately 1015, the Operations shift Manager directed Maintenance personnel to perform the Analog Channel Operational Testing (ACOT) on PR Detector N42 in preparation for unit startup following a Steam Generator replacement outage.
At 1030, Maintenance personnel performed steps in procedure PT/1/A/4600/01/014D, PR Detector N41 ACOT, in order to place the channel in bypass because the detector had been placed out of service for ZPPT.
This procedure allows bypass of Reactor Protection System functions for PR Detector N41.
It was not recognized that the test procedure did not address disabling Permissives P-8 and P-10.
Note:
P-8 unblocks Reactor trip on Turbine trip when two out of four PR Detectors indicate Reactor power greater than 48 percent rated thermal power.
P-10 de-energizes both Source Range (SR) indicators when two out of four PR Detectors indicate reactor power greater than 10 percent rated thermal power.
- At 1104, Maintenance personnel were performing procedure PT/1/A/4600/014E, PR Detector N42 ACOT.
Step 12.1.14 required rimulation of 120 percent power.
As the simulated power signal was increased above 10 percent power, the logic satisfying Permissive P-10 was met on both channels (N42 due to simulated signal and N41 due to being out of service defaulted above setpoint).
At 1104:33.843, as the simulated signal was increased above 48 percent power, the logic for Permissive P-8 was met on both channels (N42 due to simulated signal and N41 due to being out of service defaulted above setpoint)
As a result, a Solid State Protection
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EXPIRES 04/30/98 ESTIMATED BURCIN PER REOPONSE TO COMPLY WITH THIS MANDQTORY INFORMATION COLLECTION REQUEST 50 0 HRS REPORTED LESSONS LICENSEE EVENT REPORT (LER)
LEARNED ARE INCORPORATED INTO THE LICEN$tNG PROCESS AND FED BACK TO INDUSTRY FORWARD COMMENTS REGARDING BURDEN TEXT CONTINUATlON ESMATE TO THE INFORMATION AND RECORDS MANAGEMENT BRANCH O 4 F33). U S NUCLEAR REGULATORY COMMISSION. WASHINGTON, DC 205554001, AND TO THE PAPERWORK REDUCTION PROJECT (31504104).
OFFICE OF MANAGEMENT AND BUDGET WASHINGTON DC 20503 FACILITY NAME (1)
DOCKET NUMBER (2)
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l Signal (SSPS) of " Turbine Trip Causes Reactor Trip" was initiated.
Reactor Trip Breakers opened as expected for these conditions and Shutdown Rod Banks A and B inserted fully.
" Reactor Trip and Low Tavg" logic and all Feedwater Isolation Valves [EIIS:ISV] closed as expected.
Operators entered emergency procedure EP/1/A/5000/E-0, Reactor Trip or Safety Injection, and transitioned to EP/1/A/5000/ES-1.0, Reactor Trip Response.
At approximately 1120, CF flow was re-established and Steam Generator levels were returned to normal.
l All plant systems and equipment responded as expected except the non-safety hydraulic pump associated with CF Isolation valve 1CF-30, which continued to run in recirculation after reopening the valve.
Source Range (SR) indication was lost for less than 2 minutes (approximately 100 seconds) due to P-10 permissive being met during the performance of the N42 ACOT.
Operations personnel were aware of this loss of indication and responded appropriately using Abnormal Operating Procedures.
Conclusion:
This event did not result in any uncontrolled releases of radioactive material, personnel injuries, or radiation overexposures. This event is not Nuclear Plant Reliability Data System (NPRDS) reportable.
The event was caused by Maintenance Personnel using an inappropriate procedure for the existing plant condition to bypass PR detector N41.
The involved personnel failed to recognize that Permissives P-8 and P-10 would not be bypassed.
A review of the ACOT procedures is planned to implement enhancements to clearly delineate their purpose and use.
Review of industry and internal Operating Experience Program (OEP) and l
the Problem Investigation Program (PIP) databases for the past 24 months l
revealed that there have been no similar events associated with inadequate bypassing of channels during testing of reactor power
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EXPIRES 04/3048 ESTIMATED BUROEN PER RESPONSE TO COMPLY WITH THIS MANCu1ORY INFORMATION COLLECTON REQUEST $0 0 HRS REPORTED LESSONS LICENSEE EVENT REPORT (LER)
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DOCKET NUMBER (2)
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McGuire Nuclear Station, Unit 1 05000 369 97 A
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l monitoring instrumentation.
This event is not considered to be recurring.
CORRECTIVE ACTION
t Immediate:
- 1. N42 simulated power was reduced to 0 to re-energize Source Range indication, CF system flow was reestablished, Steam Generator levels were returned to normal, and the unit was returned to stable conditions with no problems.
Subsequent:
i
- 1. The following procedures were ple,ced on Administrative hold:
PT/1/A/4600/014D, 014E, 014F, and 014G - Analog Channel Operational i
Tests (ACOT) for all four Power Range channels - Unit 1 i
PT/2/A/4600/014D, 014E, 014F, and 014G - Analog Channel Operational e
Tests (ACOT) for all four Power Range channels - Unit 2 i
2.
Details of this event were shared with all Maintenance Personnel.
Planned:
- 1. All procedures associated with ACOT testing and bypassing (listed in Subsequent actions above) are being reviewed for enhancements which will provide appropriate barriers and guidance to ensure the proper procedures are utilized.
SAFETY ANALYSIS
Based on this analysis, this event is not considered to be significant.
At no time were the safety or health of the public or plant personnel affected as a result of the event.
i This reactor trip occurred, during Mode 3 at 0 percent power, when a simulated reactor power signal met logic for Permissive P-8 (two out of
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l NRC f OHM X6A U S NUCthAR HLGULAlGAY COMMi$SION(6-APPROVED 87 OMJ NO. 31604104 89)
EXPIRE 8 04/30me i
l ESTIMATED RURDEN PER RESPONSE TO COMPLY WITH THIS MANDATORY l
LICENSEE EVENT REPORT (LER)
INFORMATION COLLECTION REOUEST 50 0 HRS REPORTED LESSONS LEARNED ARE INCORPORATED INTO THE UCENSING PROCESS AND FED BACK TO INDUSTRY FORWARD COMMENTS REGARDING BORDEN TEXT CONTINUATION ESTIMATE TO THE INFORMATION AND RECORDS MANAGEMENT BRANCH (T4 F33). U S NUCLEAR REGULATORY COMMISSION. WASHINGTON. DC 20555-0001. AND TO THE PAPERWORK REDUCTION PROJECT (31504104).
OFFICE OF MANAGEMENT ANO BUDGFT WASHINGTON DC 20503 FAClu TY NAME (1)
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PAGE (3)
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NUMBER NUMBER McGuire Nuclear Station, Unit 1 05000 369 97 07 m
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l four Power Ranges indicating rated thermal power at greater than 48 l
percent), which unblocked the reactor trip signal due to a turbine trip (this signal was present because the turbine trip logic had not yet been reset as part of startup activities).
l Shutdown Rod Banks A and B fully inserted.
Since the unit was in Mode 3 (K effective <.99) at 0% power, insertion of the A and B Shutdown Rod banks did not alter reactor power.
During the event all required safety systems responded as expected.
A CF System isolation occurred, as a result of " Reactor Trip and Low Tavg", as expected and all equipment performed satisfactorily.
Due to the minimal feedwater flow requirements at the time, S/G levels did not change significantly and Auxiliary Feedwater was not required.
During this time, minimal heatup of the reactor coolant system occurred.
The hydraulic pump associated with valve CF Isolation valve 1CF-30 continued to run in recirculation after reopening the isolation valve but caused no safety concerns.
Source Range indication was lost momentarily due to the P-10 permissive being met.
Operations personnel were aware of the momentary loss and acted according to guidance provided by Abnormal Procedures as required.
The only changes in reactivity parameters during this time occurred due to the minimal heatup of the reactor coolant system and the insertion of the two shutdown banks.
The overall effect was a negative reactivity addition during the brief time the Source Range instruments were unavailable.
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