ML20084R866

AO 50-249/74-32:on 741003,high Pressure Coolant Injection High Flow Switch DPIS 3-2352 Found W/Setpoint Above Tech Spec Limit.Caused by Setpoint Drift.Switch Repaired & Reset

ML20084R866
Person / Time
Site:	Dresden
Issue date:	10/09/1974
From:	Stephenson B COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML20084R868	List: ML20084R866 ML20084R870
References
735-74, AO-50-249-74-32, NUDOCS 8306150639
Download: ML20084R866 (2)

Text

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Ch CommQealth d 9:2ff2 .2:l'2Edison P S'*9 N!*? O,

, , .:.=,g Address fiep'y to: PcM C%ce Gox 767 Chicago, linnois 60690 EBS Ltr.#735-74 Dresden Nuclear Power Station R. R. #1

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Morris, Illinois 60450 October 9, 1974

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'1 o t lg Mr. Ja:nes G. Keppler, Regional Director ' -igh~

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SUBJECT:

REPO!iT OF AE!OR".AL OCCURRE!CE PER SECTION 6.6.'-- A 0F THE TFfDTICAL'Y J SPECIFICATIC J3.

HIGH LESSUE C00L.C?T INJECTION HIGH FLC/4 INSTRU:'OTP A!!O'MLY.

References:

1) Regulatory Guido 1.16 Rev.1 Appendix A

2) Motification of Region III of AEC Regulatory Operations Telephone: Fr. P. Ibura, 1320 hours0.0153 days <br />0.367 hours <br />0.00218 weeks <br />5.0226e-4 months <br /> on October 4, 1974 Telegram Id. J. Keppler,1415 hours0.0164 days <br />0.393 hours <br />0.00234 weeks <br />5.384075e-4 months <br /> on October 4,1974

3) Drawing Number: GEK 1399B Tab 3 ileport !huber: 50-249/1974-32 Report Date: October 9, 1974 Occurrence Dato: October 3, 1974 Pacility: Dresden Nuclear Power Station, Morris, Ilhnoic IDE7PIFICATION OF OCCURRD:CE .

Drecden Unit 3 high pressure coolant injection high flow cwitch DPIS 3-2352 was found with a setpoint of 155 inchen H 2O increaaing which is above the Technical Specification licit of 145 inches H;0 incrcacing.

CONDITION PRIOR TO OCCURiia!0E At the time of the occurrence, Dresden Unit 3 was in the run mode with a cteady load of 600 M!c. Routine inctrument surveillance was in progresa.

DESCRITTION OF CCCIEGE;CE DarjnC routine inctrument curveillance on Barton switch DPIS 3-2352 the cetpoint, was found to bo 155 inches H2 O increscing, which is above the o

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OCT 15 i: COPY SENT REGION / 3

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Mr. James G. Keppler ctober 9, 1974 Technical Specification limit of 150 inches H30 increasing. The switch was immediately inspected and neveral anomalies were noted. Tne actuator arm and pivots were loose, and the actuator plunger cerew was not adjusted properly.

The switch was repaired and reset to 145" H2O increasing.

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IJESIGMATIOM OF APPARE!IT CAUSE OF OCCURRENCE (Procedure)

Dresden Station han had a history of cetpoint drift on Barton sensors. A program has been underway for come time to determine the cause of this drift.

A portion of this prcgram was devoted to conculting the manufact-urer and following his recom endations. The loose and mio-adjusted parts in DPIS 3-2352 were found as a consequence of following the recoctendations made by the ITF Barton Co.

It is theorized that these anomalies were the result of an unawarenean of the inatrument mechanics involved as to what constituted a properly adjucted Earton cuitch. Thio deficiency was correctcd during the period of September 30, 1974 to October, 1974. During this tine, a reprecentative of ITf Earton Co. instructed the Dresden instrument mechanics as to the proper technique in adjusting and inspecting Barton model 203 owitchco.

AMALYSIS OF OCCURRFl!CE DPIS 3-2352 in one of two high flow sencors which function to isolate the liiCI nteam line in the event or a pipe break. The remaining sensor was found to operate within the Technical Specifications. Therefore, the cafety of plant personnel or the general public was not Jcopardized as a result of this occurrence.

CORRECTIVE ACTION The nwitch was ircnediately repaired and recot to 145" H 2 O increasing. In additicn, all Barton switches on the reactor safety cystem will be inspected, and all needed repairs made as soon as practicable.

FAILUilE DATA DPIS 3-2352 is a Barton Model 288 uith a range of -200-0-200 inches H O D:'

The switch has been found above the Technical Specificationa six times2 .

previoun to this occurrence in a cpan of approximately four years.

Sincerely, klkA4 B. B. Stephencon Superintendent hBS:'iCUlt do

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