ML19319B788
| ML19319B788 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 09/12/1977 |
| From: | Lingerfelter J, Vallade S TOLEDO EDISON CO. |
| To: | |
| Shared Package | |
| ML19319B691 | List: |
| References | |
| NUDOCS 8001270256 | |
| Download: ML19319B788 (2) | |
Text
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LICENSEE EVEtr REPORT
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@l89inoperable. The indicator light for Rod 4 showed that it was 100%
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8 189withdrawn, but the indicator itself had a fluctuatine readine. This is l E Lnot a repetitive occurrence. OTP-33-77-63) 1 7 89 8L -
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[NJ 43 44 47 48 CAUST DESCRIPiioN l9 Instru:nent and_Cggt.r_o_1 Technicians found that a relay in the Position I e9 l Indicator Panel was defective. It was replaced by the vendor.
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,,, Jacque Lingenfelter/ Sue Vallade (4197'259-5000, Ext. 251 DVR # 095-1,129-1 -
8001270
( TOLEDO EDISON COMPANY
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/ DAVIS-BESSE UNIT ONE NUCLEAR POWER STATION SUPPLEMENTAL INFORMATION FOR LER NP-33-77-63
_DATE OF EVENT: August 12, 1977 F_ACILITY: Davis-Besse Unit 1
_IDE!TIIFICATION OF OCCURRENCE:
Rod 4 of Group 4 was inoperable.The Absolute Position Indicator (API) for Control Conditions Prior to Occurrence: The plant was in Mode 2, with Power (MWT) = 0 and Load (M Tr) = 0.
Description of Occurrence: At 1910 hours0.0221 days <br />0.531 hours <br />0.00316 weeks <br />7.26755e-4 months <br /> on August 12, 1977, the Absolute Position Indicator (API) for Control Rod 4 of Group 4 was inoperable. The Control Room operator could not determine Control Rod 4 position within + 6.5%
This placed the Station in Action State =ent (a) of Technical Specification , 3.1.3.3.
The 100%indicator withdrawn, light but (relative position indicator) for Rod 4 showed that it was the API reading fluctuated frem 70-100% withdrawn. Since the indicator lights and API readings for the other reds in Group 4 shewed 100%
thdrawal, it was suspected that the API for Rod 4 was defective .
Designation of Aeoarent Cause of Occurrence:
Upon investigation, Instrument and Control Technicians round that a relay in the Position Indicator Panel was defective.
Dianond Controls.The relay, along with connecting cable, was replaced by the vendor, Analysis of Occurrence:
public or Station personnel.There was no danger to the health and safety of the The cont nl red was m-+= Thy aligned with the group, and relative indication was still operable.
properly. The cvuisol rod was operating t
Corrective Action: On August 13, 1977 !
operability to the API for Control Rod 4the relay was replaced, returning .
Statenent (a) of Technical Specification 3.1.3.3.This removed the Station from Action ;
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5 I ; I Failure Data: *i There have been no previous similar occurrences. .e l
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