05000237/LER-1974-032, Regarding High Pressure Coolant Injection High Flow Instrument Anomaly
| ML17252A492 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 10/09/1974 |
| From: | Stephenson B Commonwealth Edison Co |
| To: | James Keppler US Atomic Energy Commission (AEC) |
| References | |
| BBS Ltr.#735-74 LER 74-032-00 | |
| Download: ML17252A492 (2) | |
| Event date: | |
|---|---|
| Report date: | |
| 2371974032R00 - NRC Website | |
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.------.:.C~.;,monw~ Edison r!,* ft a One First Nati~;aza, Chicago, Illinois
- ' \\' W Address Reply to: Post Office Box 767 Chicago, Illinois 60690 BBS Ltr.#735-74 Dresden Nuclear Power Station R. R. #1 Morris, Illinois 6o450 October 9, 1974 Mr. James G. Keppler, Regional Director Directorate of Regulatory Operations-Region III u. s. Atomic Energy Commission
! i.-
799 Roosevelt Road
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Glen Ellyn, Illinois * *60137
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SUBJEX}T:
REPORT OF ABNORMAL-OCCURRENCE PER S~TION 6.6.A OF SP~IFICATIONS.
HIGH PRESSURE COOLANT IN~TION HIGH FLOW INSTRUMENT ANOMALY.
References: 1) Regulatory Guide 1.16 Rev.l Appendix A
- 2) Notification of Region III of AEC Regulatory Operations Telephone: Mr. F. Maura, 1320 hours0.0153 days <br />0.367 hours <br />0.00218 weeks <br />5.0226e-4 months <br /> on October 4, 1974 Telegram: ~* J. Ke:PPler, 1415 hours0.0164 days <br />0.393 hours <br />0.00234 weeks <br />5.384075e-4 months <br /> o~ Octobe~ 4, 1974
- 3) Drawing Number: *G~ 1399B Tab 3.
Report Number: 50-249/1974-32 Report Date: October 9, 1974:
DOCKETED
_VSAEC Occurrence Date:-October 3, 1974 Facility: Dresden Nu.clear Power Station, Morris, Illinois IDENTIFICATION OF OCCURRENCE Dresden Unit 3 high pressure coolant injection high flow switch DPIS 3-2352 was fowid with a setpoint of 155 inches H20 increasing which is above the Technical Specification lililit of 145 inches H20 increasing.
CONDITION PRIOR TO OCCURRENCE At the time of the occurrence, Dresden Unit 3 was in the run mode with a steady load.of 600 MWe.
Routine instrument surveillance was in progress.
DESCRIPl'ION OF OCCURRENCE During routirle instrument surveillance on Barton switch DPIS 3-2352 the setpoint was found to be 155 *:11nches H2o increasing, which is above the 108/Q
- - U OCT 1 5 lffi'4
October 9, 1974 James G. Keppler Technical Specification limit of 150 inches H20 increasing. The switch was immediately inspected and several anomalies were noted. The actuator arm and pivots were loose, and the.actuator plunger screw was not adjusted properly. The switch was re~ired and reset to 145° H20 increasing.
DF.SIGNATION OF APPARENT CAUSE OF OCCURRENCE (Procedure)
Dresden Station has had a history of setpoint drift on Barton sensors. A program has been underway for some time to determine the cause of this drift. A portion of this prograin was devoted to consulting the manufact-urer and following his recommendations. The loose and mis-adjusted parts in DPIS 3-2352 were *found as a consequence of following the recommendations
- made by the I'l'I' Barton Co. It is theorized that these anomalies were the result of an unawareness of the instrument mechanics involved as to what const~tuted a properly adjusted Barton switch. This deficiency was corrected during the period of September 30, 1974 to October, 1974. During this time, a representative.of I'l'I' Barton Co. instructed the Dresden instrument mechanics as to the* proper technique in adjusting and inspecting Barton model 288 switches.
ANALYSIS OF OCCURRENCE DPIS 3-2352 is one of two high flow sensors which function to isolate the HPCI steam line in the event of a pipe break. The reJ'DB.ining sensor was
.found to operate within the Technical Specifications. Therefore, the safety of plant personnel or the general public was not jeopardized as a result of this occurrence.
CO~TIVE ACTION The switch was immediately repaired and reset to 145" H20 increasing. In addition, all Barton switches on the reactor safety system will be inspected, and all needed repairs made as soon as practicable *
. FAILURE DATA DPIS 3-2352 is a Barton Model 288 with a range of -200-0-200 inches H20 DP.
The switch has b~en found above the Technical Specifications six t:$.Ines previous to this occurrence in a span of approximately four years.
BBS:WEH:do Sincerely,
/f./Au.h-~
fr.-'B. B. Stephenson Superintendent