ML20086F993
| ML20086F993 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 09/19/1975 |
| From: | Ullrich W PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| AO-75-61, NUDOCS 8401090766 | |
| Download: ML20086F993 (1) | |
Text
{{#Wiki_filter:_ v/ ~ ~ PHILADELPHIA E*ECTRIC COMPANY Och3ottonAtomic Power Sta*... n Delta, Pennsylvania 17314 September 19, 1975 9rg oJ, gjr Mr. J am e s P. O'Reilly, Director {}g ft Ef f, Office of Inspection and Enforcement Region 1 United S ates Nuclear Regulatory Connission g g jsac f 631 Park Avenue King Of Prussia, Pennsylvania 19L06 Subjeet: Ab=cr=si Cecurrence PL-Your Notifiention ~ Confir=ing W. T. Ullrieb's phone conversation with Mr. Valt Baunack, Regi. United States Nuclear Regulatory Cor.=ission on Septe=ber 19, 1975
Reference:
License Number DPR kk ~ Technical Specification
Reference:
4.7.D Report No.: 50-2T7-75-61 1 Report Date: Septenber 19, 1975 -t Occurrence Date: September 18, 1975 Facility: Peach Botton Atomic Power Station - Unit 2 R. D. 1 Delta. Pennsylvania 17314 Identification of Occurrence: Failure of the auto close function of TIP machine ball valve. Conditions Prior to Occurrence ; About 55% power. Description of Occurrence: During routine operation of the No. L TIP machine, the detector stoppe. in the reactor core and woul4 not respond to either automatic or nnoua withdrawal connands. Vith the detector inserted th'e TIP isolation val-cannot be closed. . Designation of Apparent Cause of Occurrence: The shield limit zwitch 1%11ed, sending a false "in shield" signal to
- m. +-
ycl+ the centrol unit. Wh(n th-TIP is "in shield," all withdrawal control functions are disabled. "Jith the withdrawal modes inoperable and the 't. detector inserted past the isolation valve. The automatic closure yg 5.. 9 of the isointion was disablea. g }J ;g ,s..,..., Analysis of Occurrence t; ' y The ecutinuity of the shear valve circuit was verified capable of isolt 4. pv the T!? guide tube, if required. The remaining TIP nachine's i s olat io: _19 +. valves were verified to be, operational. This occurrece has minimal sa < #. V., implications. 5.'fkh Corrective Action: Logic bypass jumpers were used to retract the detector from the Reactc-y i-g-{f 6.i..bf core. The shield limit switch was inspected and adjusted to give prop. operation over the full detector travel. The XIP nachine was operated 1, J[., b successfully several times. The limit switch and the isolation valve yd? 'j ; performed correctly. $N;r.? ; f ~F'. f'i as 50-278-75-31 Failure Onta: Previous failures of this type reEor 3 50-278-75-34 50-278-75 L2 and 50 27 - ff,, ,,.e 0401090766 750919 PDR ADOCK 05000277 r > S PDR 6 i.-d '}}