ML20084J268

Ao:On 730216,during Calibr,Setpoint Drifts of PS-2-261-30A, B & D Found Below Tech Spec Limits.Setpoint Increased

ML20084J268
Person / Time
Site:	Quad Cities
Issue date:	02/26/1973
From:	Stephenson B COMMONWEALTH EDISON CO.
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20084J247	List: ML20084J244 ML20084J251 ML20084J255 ML20084J262 ML20084J268 ML20084J271
References
BBS-73-33, NUDOCS 8305120293
Download: ML20084J268 (2)

Text

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• ComgCa.a e:lth Edison Nuct:ar Pow:r Stition Outd- V('~T Post Offica Box 216 Cordova. lilinois 61242 Telephone 309/654-2241 /hg  %

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February 26, 1973 t-

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Mr. Angelo Giambusso Deputy Director of Reactor Projects Directorate of Licensing U. S. Atomic Energy Commission Washington, D. C. 20545

Reference:

Quad-Cities Nuclear Power Station, Unit 2 Docket No.C5027331 License DPR-30, Appendix A Section 1.0. A.2 and 3 2. A.

Dear Mr. Giambusso:

The purpose of this letter is to inform you of the details concerning the setpoint drifts of PS-2-261-30 A, B, and D. The setpoints of these switches were found to be__846 psig, 847_psig, and 848 psig, decreasing respectively during'a routine calibration on February 16, 1973 This is contrary tc Section 2.2. A, of the Technical Specification which requires the switches to trip at 850 psig. These switches are Barksdale Model B2T-M12SS with a range of 0-1200 psig and an accuracy of 1 per cent.

Instruments 30A and 300 are in the "A" logic and 30B and 30D are in the "B" logic of the Primary Containment Isolation system. Thus if a Main Steam Line Low Pressure condition existed, the isolation would have occurred at 848 psig.

This is considered to be an insignificant variation from the Limiting Condition for Operation which is intended to prevent a rapid depressurization of the reactor vessel.

Drif t problems have been encountered before with these instruments. This occurrence is identical to the drift of the Unit 1 low pressure switches reported to you in my 8305120293 730427 DR ADOCK 05000254 PDR 1404

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Mr. Angelo Giambusso February 26, 1973 .

,k letter dhted February 26, 1973, for Docket No. 50-254.

As stated in that letter the corrective action will be to increase the setpoint further from 858 to 864 psi and continue calibration on a monthly vice quarterly basis.

Very truly yours, COMMONWEALTH EDISON COMPANY QUAD-CITIES NUCLEAR POWER STATION ar d4 #

pfg. B. B. Stephenson ~

Superintendent BBS/zm t

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Comh.ase:lth Ourd-C Edison Pow;r Nuclear Station C Post Office Box 216 .

Cordova,Ilknois 61242 Telephone 309/654-2241 /

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BBS-73-33 (wkr4WV[{,2 1 M(gg' 44 W8 s C l6 "

February 26, 1973 ,

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N e N 01 Mr. Angelo Giambusso Deputy Director of Reactor Projects Directorate of Licensing U. S. Atomic Energy Commission .

Washington, D. C. 20545

Reference:

Quad-Cities Nuclear Power Station, Unit 2 Docket No. 50-265, License DPR-30, Appendix A Section 1.0. A.2 and 3 2. A.

Dear Mr. Giambusso:

The purpose of this letter is to inform you of the details concerning the setpoint drif ts of PS-2-261-30 A, B, and D. The setpoints of these switches were found to be 846 psig, 847 psig, and 848 psig, decreasing respectively during a routine calibration on February 16, 1973 This is contrary to Section 2.2. A, of the Technical Specification which requires the switches to trip at 850 psig. These switches are Barksdale Model B2T-M12SS with a range of 0-1200 psig and an accuracy of 1 per cent.

Instruments 30A and 300 are in the " A" logic and 30B and 30D are in the "B" logic of the Primary Containment Isolation system. Thus if a Main Steam Line Low Pressure condition existed, the isolation would have occurred at 848 psig.

This is considered to be an insignificant variation from the Limiting Condition for Operation which is intended to prevent a rapid depressurization of the reactor vessel.

Drif t problems have been encountered before with these instruments. This occurrence is identical to the drif t of the Unit 1 low pressure switches reported to you in my s 2 - -

\p p ~p p 1404

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.  : 1 Mr. Angelo Giambusso February 26, 1973 ,

i letter dated February 26, 1973, for Docket No. 50-254.

As stated in that letter the corrective action will be to increase the setpoint further from 858 to 864 psi and continue calibration on a monthly vice quarterly basis .

l Very truly yours, COMMONWEALTH EDISON COMPANY QUAD-CITIES NUCLEAR POWER STATION jgk;. B. B. Stephenson s Superintendent BBS/zm

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