ML20084J355

Ro:On 730213 & 22,sample of Discharge Bay & Mississippi River Downstream of Diffuser Pipe Showed Chlorine Residual Bay in Excess of Tech Spec Limit.Caused by Condenser Relay Failure.Frequency of Injection Increased

ML20084J355
Person / Time
Site:	Quad Cities
Issue date:	03/12/1973
From:	Stephenson B COMMONWEALTH EDISON CO.
To:	Giambusso A US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20084J323	List: ML20084J321 ML20084J332 ML20084J355 ML20084J366
References
BBS-73-41, NUDOCS 8305120565
Download: ML20084J355 (2)

Text

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.B Comm Post Othee Box 216 g $2 Cordova, Illinois 61242 Telephono 309/654-2241 s

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

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Reference:

Quad-Ci' ties Nuclear Power Station Docket Numbers 50-254 - and 50-265 DPR-29 and 30, Appendix B, Section 1.1 and 3.1.A.

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Dear Mr. Giambusso:

The purpose of this letter is to report chlorine residual cor g ations in the discharge Tay in excess _of___the_

ITmiting condTUpns_f_pt operation liJ tee non-radiolorric_al

-tECHni" cal sp_e ci_fi cations, ,

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The limit of 0.1 ppm free and

' combined cElorine in the discharge bay was exceeded on several occasions since my last report to you on this subject dated February 9,1973 On February 13, 1973, Bio-Test Laboratories sampled the discharge bay and the Mississippi Riv,er downstream of the diffuser pipe. The total chlorine residual in the river was less than 0.1 ppm at all times, however, the discharge bay total chlorine residual registered as high as 0. 41 ppm. A total of 192 gallons of sodium hypochlorite was injected.

From February 13th to February 22, 1973 the system was operated in automatic with the circulating water flow direction from north to south. During this time, it was discovered that the feed cycle to the Northeast section of the unit one condenser was inoperable due to a relay failure. On February 22, 1973, station personnel sampled the discharge bay for free and combined chlorine during the injection of 252 gallons of sodium hypochlorite. The maximum free chlorine level was 0.2 ppm, while the maximum combined chlorine level was 2.2 ppm.

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Mr. A. Giambusso March 12, 1973 Between the evening of February 22 to Febr'uary 28, 1973 the entire sodium hypochlorite system was shutdown to repair the service water hypochlorite injection pumps.

During a condenser tube leak outage on Unit 2 on February 24, 1973, the tubes were inspected by chemists from the Commonwealth Edison Central Efficiency office. The amount of bacterial slime detected by sampling led them to con-clude that chlorination in the past had been insufficient to prevent a build up. Based on their recommendation the frequency of injection was increased from once a day to three times a day and the injection rate fixed at 7 rpm.

7his program was initiated on March 3,1973 Since each condenser half is chlorinated for 10 minutes, the total cycle consists of 40 minutes of injection every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

During the inj ection period residual chlorine levels in the discharge bay of 1.0 to 1.5 ppm have been observed.

Although these residuals exceed the Limiting Condition for Operation, lower injection rates have proven to be ineffective. The frequency of injection is such that the LCO will be exceeded for less than 10 per cent of each day.

Very truly yours, COMMONWEALTH EDISON COMPANY Quad-Citi s Nuc1/ar Power Station \

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. h Station /uperintendent S

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