ML20084K498

Updates AOs 50-265/74-3,50-265/74-13,50-265/74-16 & 50-265/74-19 Re low-low Reactor Water Level Switch LIS-2-263-728 Failure.Surveillance Interval Changed to Monthly.Switch Installation Delayed Pending Analog Trip Sys

ML20084K498
Person / Time
Site:	Quad Cities
Issue date:	10/05/1976
From:	Kalivianakis N COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
AO-50-265-74-13, AO-50-265-74-16, AO-50-265-74-19, AO-50-265-74-3, NJK-76-369, NUDOCS 8305190444
Download: ML20084K498 (2)

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Qua, . ties Nuclear Power Station -

Post Office 216 Cordova. it Telephone 61242 654 2241 O

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NJ K-76-369 E

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O l/ c pr ,m b October 5, 1976 6 k O T(p/u.&@n.

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f' %cy29g W J. Keppler, Regional Director

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Office of Inspection and Enforcement f

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Reglon i11 hj,II NDZ~

U. S. Nuclear Regulatory C.ommission 799 Roosevelt Road -

Glen Ellyn, Illinois 60137

Reference:

1) Quad-Cities Nuclear Power Station -

Docket No. 50-265, DPR-30, Unit 2 Appendix A, Section 3.2.B, Table 3.2.2

2) quad-Cities Station Abnormal Occurrence IWports A0 50-265/74-3, A0 50-265/74-13, A0 50 '

465/749 62 and A0 50-265/74-19

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The purpose of this letter is to provide you with information concerning the present status of Unit Two Low-Low Reactor Water Level Switch LIS-2-263-72D. This Yarway Model 4418C switch had experienced several

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failures in 1974, and these occurrences were reported in the referenced -

Abnormal Occurence Reports. Details regarding corrective actions to be taken were itemized in report A0 50-265/74-13 These proposed actions consisted of replacing the defective switch, and performing the functional surveillances weekly instead of quarterly. By agreement with your representative, the failures given by occurrences A0 50-265/74-16 and A0 50-265/74-19 would be reported with written followup after the new switch was installed. ,

Following the ordering of a new switch, a lengthy time period wa's required to obtain the necessary parts. Since an outage was required to install the switch, it was decided to schedule this installation during the Unit Two Fall, 1976 Refueling Outage.

in reviewing the perforraance of LIS-2-263-72D over the last 26 months of continuous weekly surveillance testing, this switch has not failed to properly actuate at its required setpoint. The last failure of

, this switch was reported on August 2, 1974. Based on this reliable performance over the past two year period, the survelliance interval

, for LIS-2-263-72D was changed to monthly on September 1,1976.

8305190444 761005 4 PDR ADOCK 05000265 1QVG7t-S PDR r DCT 121976 _

- - - - - ,_ _ _ - - - - - _m-

%ddi,tionally, insta Ion of a new switch has been erred pending

'tha forthcoming Installation of a new analog trip system for ECCS Initiation and, Reactor Protection System level instrumentation. The Commonwealth Edison Co. Station Nuclear EngineeringtDepartment is presently designing this system. Action item 4-75-25 was issued to Engineering to assure completion of this project. The Station has recently begun similar investigations regarding the Unit One EHC Low 011 Pressure Switches. An experimental analog trip setup has been constructed and data are being gathered to determine the reliability of such a system. This experiment is documented by'Special Test No.

1-21.

The replacement of the existing Yarway level switches with the analog ,

type system will be documented by Modification Packages M-4-1-76-34 and M-4-2-76-34, and Special Project Request No. QC-119 ,

Very truly yours, COMMONWEALTH EDISON COMPANY QUAD-CITIES NUCLEAR POWER STATION

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/ /d i N. J. Kallvianakis Station Superintendent NJK/LFG/1k cc: G. Abre11

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