ML20217J474
| ML20217J474 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 10/13/1997 |
| From: | Mitchell T PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 50-277-97-05, 50-277-97-5, 50-278-97-05, 50-278-97-5, NUDOCS 9710210115 | |
| Download: ML20217J474 (6) | |
Text
Thomas N.Mitchsil Vice Presklent 4
Peach Bottom AtorTuc Fbwer Station Y
.PECO NUCLEAR Peiir,4,P""'
A Unit of PECO Energy
${7 f 5 }7y 32 Fax 717 456 4243 Docket Nos. 50-277 50-278 License Nos. DPR-44 DPR-56 October 13, 1997 U. S. Nuclear Regulatory Commission Attn.: Document Control Desk Washington, DC 20555
Subject:
Peach Bottom Atomic Power Station Units 2 & 3 Response to Notice of Violation (Combined Inspection Report No.
50-277/97-05 & 50-278/97-05)
Gentlemen:
In response to your letter dated September 12,1997 which transmitted the Notice of Violation conceming the referenced inspection report, we submit the attached response. The subject report concerned a Residents' Integrated Safety Inspection which was conducted June 8 through August 9,1997, i
If you have any questions or desire additional information, do not hesitate to contact us.
hl Thomas N. Mitchell Vice President, Peach Bottom Atomic Power Station Attachments cc:
. W. T. Henrick, Public Service Electric & Gas R. R. Janati, Commonidalth of Pennsylvania
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g H. J. Miller, US NRC, Administrator, Region i R. S. Barkley, US NRC, Interim Senior Resident inspector T. M. Messick, Atlantic Electric R. l. McLean, State of Maryland A. F. Kirby Ill, DelMarVa Power CCN-97-14060,n1';Q'
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.OEAP Coordinator 62A-1, Chesterbrook Correspondence Control Program 618-3, Chesterbrook NCB Secretary (11) 62A-1, Chesterbrook D. M. Smith 63C-3, Chesterbrook G. R. Rainey 63C-3, Chesterbrook T. N. Mitchell SMB4-9, Peach Bottom J. B. Cotton 62C-3, Chesterbrook T. J. Niessen 53A-1, Chesterbrc9k E. J. Cullen S23-1, Main Office E. W. Callan SMB4-6, Peach Bottom G. A. Hunger 62A-1, Chesterbrook J. G. Hufnagel 62A-1, Chesterbrook C. J. McDermott S13-1, Main Office i
G. 9. Edwards A4-1S, Peach Bottom
-V. Cwietniewicz PB-TC, Peach Bottom R.A.Kankus 61C-1, Chesterbrook G. J. Lengyel A4-4S, Peach Bottom R. K. Smith A4-5S, Peach Bottou 4
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RESPONSE TO NOTICE OF VIOLATION 97-05-02 Restatement of Violatiori Technical specification 5.4.1 requires, in part, that written procedures be established and maintained covering the bypass of safety functions.
Contrary to the above, PECO did not properly maintain written procedures for the bypass of the main control room (MCR) ventilation system isolation when a Division 1 MCR radiation monitor was inoperable. Specifically, Procedure GP-25 Appendix 13, MCR Ventilation isolation, Division 1, failed to provide complete instructions for maintaining radiation monitor RIS-0760A in a tripped condition.
Consequently, on or about July 10,1997, a PECO technician removed the monitor from a tripped condition, contrary to technical specifications.
This violation represents a Severity Level IV problem (Supplement I).
Backaround Information On July 8,1997, Maintenance Instrument and Control (l&C) technicians contacted the instrument manufacturer of the "A" channel Main Control Room Emergency Ventilation (MCREV) radiation monitor RIS-0760A concerning a problem where l
the monitor was indicating higher than three other channels. This monitor samples the main control room air intake for radiation and initiates a trip on a high radiation
@nal. After discussion with the manufacturer, l&C personnel determined that the pre-amplifier was the most probable cause of the monitor indicating high. Although the readings were higher than the other instruments, the instrument was still within the operating band. The higher readings actually put the monitor in a more conservative direction with the instrument operating closer to the trip point. A routine calibration check and quarterly functional test had also been recently performed successfully.
Maintenance Planning created a work order to evaluate and replace the pre-amplifier if necessary. Shift Management declared the MCREV sub-system inoperable on July 9 at 5:30 p.m. to allow l&C to investigate and perform work activities. Technical specifications 3.3.7.1 allowed six hours before the channel would need to be placed in the trip condition. The pre-amplifier was replaced j
within this time frame, but troubleshooting following the replacement revealed that l
the higher than normalindication had not changed.
At approximately 10:30 p.m., I&C technicians informed the control room of their results and that they cc,uld not continue due to working hour limitations. Since the six hour tech spec limit was running out, the Operations shift decided to enter GP-25 Appendix 13 - MCR Ventilation isolation, Division I and placed the "A" MCREV radiation monitor RIS-0760A in the trip condition by turning the key lock switch to
- OFF" locally at the monitor. Tags were placed on the redundant MCREV channels as a precaution in the main control room, but were not placed on the local monitor that was tripped. These actions were in compliance with the procedure as it was written.
The on-shift I&C technicians continued to summarize their troubleshooting activities with the Operations shift who afterwards requested to talk with the l&C subject matter expert (SME). At app:oximately 10:45 p.m., the I&C SME was called to the control room. The shift discussed the activities with the l&C SME and 4
questioned if any further troubleshooting could be performed, it was determined that the instrument grounds were the only item that had not been previously checked. The l&C SME communicated to the shift that he was going to continue work and check the radiation monitoring instrument grounds to see if there could be excessive noise affecting the instrument. Although the shift questioned the I&C SME on how the grounds were to be checked, they were not aware that this testing would involve taking the lomi radiation monitor out of the trip condition.
- Following the control room briefing, the l&C SME went to the local panel for the "A" MCREV radiation monitor RIS-0760A The l&C SME placed the key-lock switch to "ON" and initiated troubleshooting activities. During these activities various grounds where checked within the monitor, but no appreciable differences in the readings were noted. At approximately 12:45 a.m. on July 10,1997, the l&C SME concluded troubleshooting activities. The I&C SME notified the control room that he had completed work and that troubleshooting would resume on day-shift.
At 3:00 a.m., while resetting an unrelated alarm, a Plant Reactor Operator (PRO) observed the MCREV radiation moNtor alarm reset. The PRO immediately '
recognized that the alarm should not have cleared and notified control room 4
supervision. An investigation was initiated and the I&C SME was called at his home to determine why the MCREV radiation monitor had reset. At approximately 3:25 a.m. it was determined that the local key-switch for MCREV radiation monitor RIS-0760A had been placed back in service for troubleshooting and was left in the "ON" position. The key-lock switch was then placed in the "OFF" position and the GP-25, Appendix 13 trip was re-established.
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Reason For the Violation
~GP-25, Appendix 13, "MCR Ventilation isolation, Division l' was not adequate to j-ensure the radiatio _n monitor would be maintained in the trip condition. The procedure allowed the tripped unit to be either removed or placed in service by the -
- use of a local key-lock switch rather than a jumper or other mechanical device. As
!1 a result, the key lock switch was taken to the "OFF" position to implement the trip, i
When the unit was retumed to the "ON" position to perform troubleshooting, the F
trip was negated.. The procedure did not provide a serviceable method to insert the trip. Additionally,'even though the procedure required redundant components -
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- to bs tagged in the control room as a precaution, the actual local component that was administratively removed from service was not required to be tagged.
Therefore, there was no local indication to indicate that the radiation monitor had been placed in the tripped condition per procedurei-Communications between Operations and Maintenance l&C was less than adequate. Although Operations was aware that the l&C SME was performing troubleshooting and work ac'ivities on the radiation monitor, they were not aware that the instrument was required to be re-energized to suppon this testing. Better communication of the activities planned should have identifuxi the procedural inadequacy where troubleshooting could not be performed with the radiation monitor in the "OFF" position or in the tripped condition.
The l&C SME was so focused on troubleshooting the instrument grounds that he did not realize at the time that by placing the local radiation monitor key-lock switch to_the "ON" position for troubleshooting that he was negating the trip implemented per GP-25, Appendix 13.-
i Corrective Steps That Have Been Taken and the Results Achieved -
' At 03:25 a_.m. on July 10,1997, the key-lock switch for Radiation Monitor RIS-0760A was placed in the "OFF" position in accordance with GP-25, Appendix 13, 4
1which re-established the trip for the MCREV Division 1 Radiation Monitoring. A local equipment status tag was placed on MCREV radiation monitor RIS 0760A to prevent further manipulation of the switch. All work activities on the radiation monitor were suspended. In addition, later that day, GP-25, Appendix 13 was temporarily changed to trip the channel using a jumper, which maintained power to
! the radiation monitor in the trip mode to allow troubleshooting activities.
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A review of other GP-25 Appendices was conducted to ensure that no other similar conditions existed where channel trips could be removed by the single action of positioning key-lock switches.
A Performance Enhancement Program (PEP) was initiated on July 10 to investigate this event. Results of that investigation have been used to develop this response.
Review cithis event determined that although the MCREV "A" channel was administratively declared inoperable per GP-25, Appendix 13, the radiation monitor was functional and capable of monitoring the radiation levels and providing a trip function to MCREV. The testing that l&C performed during the troubleshooting evolution verified that the radiation monitor was able to respond to input signals and provide correct indications. Additionally, the instrument was tested by the equipment manufacturer and found to be within specifications. The vendor testing of the detector and pre-amplifier determined that the radiation monitor that had been placed back into service for troubleshooting was in calibration and capable of l
l performing its function in the event of a high radiation signal tJ the "A" radiatior monitor. As a result, the "A" channel of the MCREV Radiation Monitor was functional and would have performed appropriately.
Corrective Steos That Will Be Taken to Avoid Further Violations A revision to GP-25 Appendix 13 and 14 (for channels B and D) will be implemented to incorporate the temporary changes which have been initiated.
This revision is the next step in the progression of the temporary change process.
This change will incorporate the use of some type of mechanical device to provide the capability to energize equipment for troubleshooting or testing without removing equipment from a tripped condition. This revision will be completed by November 21,1997.
Additional information concerning this event will be provided to appropriate Operations and Maintenance l&C personnel by November 30,1997.
Date When Full Comoliance Was Achieved Full compliance was achieved on July 10,1997, when a temporary change (TC) was implemented on GP-25, Appendix 13 to trip the appropriate channel using a jumper instead of the appropriate key-lock switch. This change enabled the equipment to remain energized for troubleshooting without affecting the trip.
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