ML20084U925

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Forwards Investigation Results of Reactor Water Recirculation 4 Inch Diameter Piping Cracks.Corrective Action & Further Investigation Listed.W/O Encl.Ltr Incomplete
ML20084U925
Person / Time
Site: Dresden, Quad Cities, 05000000
Issue date: 02/10/1975
From:
COMMONWEALTH EDISON CO.
To: Case E
Office of Nuclear Reactor Regulation
Shared Package
ML20084U927 List:
References
NUDOCS 8306290644
Download: ML20084U925 (1)


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Dre; den a nd Q u ad --C i t-i., s SLition Reac t or Wat er Ree i r< ni] a t i.on 4 - T :n:h Diameter Piping Crack I nye ; t i.g,: t i on Program, NRC_Dkts. 50-237, 50-249, k

750'Ti54 and 50-265-.7 l ;

Dear "; r. Case:

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In confor;wnce with commitments in a letter to you dated Oc te' r 21, 1974 concerning thi.s subject, attached are reports of o sults of the inv e s t i.g a t i.on s completed to date.

The one exception

i. s t.he n:'ecal F: lect ric co,

iy r.3 port <;hich is bei.:g orinted and j

till be sut.nitted by the <.nd of this onth.

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The conclus ions of the attached reports are that the mecheaism L-!@,Uc 4 of cracking is stress assisted corrosion and that certain further

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j investigation should be considered.

On the basis of the ne conclu; ions, C '

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the following corrective actions and further investigations have

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been undertaken.

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Corrective Actions

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As discussed in a letter to you dated December 27, 1974, all

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the bypass lines will be replaced.

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(a)

Dresden Unit 2 and Quad-Cities Units 1 and 2 during

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the current outages.

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(b)

Dresden Unit 3 during the next refueling outage.

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Operate with the bypass valve normally open.

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