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| {{Adams
| | #REDIRECT [[05000280/LER-1981-023-01, /01T-0:on 810709,TE-1-422D Delta T Protection Indicated Zero.To Investigate,Technician Returned Delta T Bistables to Normal w/TE-1-422D Still Indicating Zero.Caused by Incorrectly Wired Tc & Th Resistance Temp Detectors]] |
| | number = ML20009F751
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| | issue date = 07/21/1981
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| | title = /01T-0:on 810708,delta T Protection Channel T-1-422A Was Found to Indicate Zero.Caused by Incorrect Wiring of Tc & Th RTD Following Design Change.Rtd Wired Correctly
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| | author name = Wilson J
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| | author affiliation = VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
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| | addressee name =
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| | addressee affiliation = NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
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| | docket = 05000280
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| | license number =
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| | contact person =
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| | document report number = LER-81-023-01T, LER-81-23-1T, NUDOCS 8107310505
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| | package number = ML20009F730
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| | document type = LICENSEE EVENT REPORT (SEE ALSO AO RO), TEXT-SAFETY REPORT
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| | page count = 3
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| }}
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| {{LER
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| | Title = /01T-0:on 810708,delta T Protection Channel T-1-422A Was Found to Indicate Zero.Caused by Incorrect Wiring of Tc & Th RTD Following Design Change.Rtd Wired Correctly
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| | Plant =
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| | Reporting criterion =
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| | Power level =
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| | Mode =
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| | Docket = 05000280
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| | LER year = 1981
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| | LER number = 23
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| | LER revision = 1
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| | Event date =
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| | Report date =
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| | ENS =
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| | abstract =
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| }}
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| | |
| =text=
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| {{#Wiki_filter:- _ - _ _ _ _ _ _ _
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| returning to service rollowing steam generator reolacement, delta T I
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| protection channel T-1-422A was found to indicate zero as a,..
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| 1 The channel was inocerable
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| ; and not placed in the tripped mode for a total of about i
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| (804) 357-3184
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| | |
| ATTACHMENT 1 S'URRY POWER STATION, UNIT 1 DOCKET NO:
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| 50-280 REPORT NO:
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| 81-023/OlT-O EVENT DATE:
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| 07-08-81 PROTECTION DELTA T READING ZERO 1.
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| ==DESCRIPTION OF EVENT==
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| On July 8, at 1630, Unit One was returned to service following the Steam Generator Replacement.
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| Delta T protection channel T-1-422A was found to indicate zero.
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| Technicians placed the bistables in trip at 2130 as they began their investigation using the functional Periodic Test.
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| At 0045, July 9, the technicians were requested to perform the HiH1 CLS logic Periodic Test (8.5) in order to continue Power Escalation of Unit
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| : One, in accordance witt, their normal procedures, the technicians took tMe bistables out of trip and restored the circuit with T-1-422A still indicating zero.
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| The protectic'n Delta T was not piaced in trip again until approximately 0800 when the Day Shift began investigating the problem.
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| The Protection channel was inoperative and not in the tripped mode for approximately 12 hours.
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| This event is contrary to the Redundancy Requi re-ments of Technical Specification 3.7, Table 3 7-1, and is reportable in accordance wien T.S. 6.6.2a(2).
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| 2.
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| PROBABLE CONSEQUENCES AND STATUS OF REDUNDANT EQUIPMENT:
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| The Delta T trip circuits provide protection from DNB and power density in excess of-ll8%.
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| During this event the Redundant Delta T channels remained operable and therefore the health and safety of the public were not affected.
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| 3
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| ==CAUSE==
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| The Tc and TH RTD's were wired incorrectly when they were returned to service following completion of a design change during the steam generator replace-ment.
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| The failure to place and maintain the channel in trip was personnel l
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| error.
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| i l
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| k.
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| ==IMMEDIATE CORRECTIVE ACTION==
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| The Delta T bistables were placed in trip.
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| 5 SUBSEQUENT CORRECTIVE ACTION:
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| RTD's were reconnected to the correct Delto T inputs and the functional Periodic Test was performed to verify operability.
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| 5 ACTION TAKEN TO PREVENT RECURRENCE:
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| i Persennel will be reinstructed on the Technical Soecification requirements for redundant enannels.
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| 1
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| iTTACHMENT 1 SURRY POWER STATION, UHli i DOCKET NO:
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| 50-280 REPORT NO:
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| 81-023/01T-0 EVENT DATE:
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| 07-08-81 Page 2 7.
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| GENERIC IMPLICATIONS:
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| None.
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| }}
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| {{LER-Nav}}
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