ML20084S773

From kanterella
Jump to navigation Jump to search
Provides Addl Info Re Removal of Recirculation Pump Discharge Valve Bypass Piping Due to Crack Indications in B Loop Bypass Line Upper weld-o-let.Mod & Repair Program Acceptable
ML20084S773
Person / Time
Site: Quad Cities Constellation icon.png
Issue date: 01/05/1976
From: Kalivianakis N
COMMONWEALTH EDISON CO.
To:
Office of Nuclear Reactor Regulation
Shared Package
ML20084S771 List:
References
NJK-76-3, NUDOCS 8306170243
Download: ML20084S773 (2)


Text

'

A 1E FILE COPE K cg

< .~

~

$,pg Ccmn ,wnith Ecisan Quad-Citiec Generating Station hw 9 ',W^!.o  !

L w~, Post Office Box 216 f

/ (s {~ X/ .N Cordova,lltinois 61242 /S)'

c 'I , Y -

Telephone 309/654-2241

@ 'W ~) l97G p  ;[

" % ,'!O3 g w cer  !

NJ K-76-3 D "'*"'"

p, January 5, 1976

(

Director of Office of Nuclear Reactor Regulation U. S.'Hucicar Regulatory Commission Washington, D. C. 20555

Reference:

Quad-Cities Nuclear Power Station Docket No. 50-265, DPR-30 Unit 2 Abnormal Occurrence Report No. A0 50-265/75-38 The purpose of this letter is to provide you with further information concerning the removal of the Quad-Cities Unit 2 recirculation pump dis-charge valve bypass piping during the recent core maintenance outage.

The removal was brought abcut as a result of crack indications in the "B" loop bypass 1ine upper weld-o-let. This occurrence had been reported in Abnormal Occurrence Report No. A0 50-263/J_f-38.

Based on evaluation of the various alternatives available and the results of a special test performed on Quad-Cities Unit 1, the existing discharge bypass piping and motor operated bypass valve were removed. Sixteen inch long stainless steel spool pieces were installed at both weld-o-lets on each recirculation loop with caps welded on the outboard end of the spool pieces. Piping work on the "B" loop was completed on October- 31, 1975 and the "A" loop was finished on November 1. All Non-Destructive Testing was completed on November 1, and a hydrostatic test was performed in conjunction with the reactor pressure vessel hydro on November 4 and 5 The details of the piping repair and replacement are given in work package 4031-75 and the line removal is documented in modification package M 2-75-27 A Reactor Recirculation Piping Stress Analysis from Sargent &

Lundy Engineers, Inc. and a Hanger Analysis from General Electric Company are included in this package. _0n-Site and Off-Site Reviews have concurred with this change and safety evaluation. Region lll of the NRC has re-viewed the modification and repair program and found it to be satisfactory.

l This review was conducted on November 6, 1975 and is documented by lE Inspection Report No.050-265/75-23 A new wiring scheme was developed-to climinate the control and Interlock-function'of the removed recirculation discharge bypass valves, and to provide for a recirculation pump trip upon >10% closure from full open of the pump discharge valve. This change is included in the modification package for the line removal and work details are given in work package 4150-75 8306170243 751014' PDR ADOCK 05000265 171 S _

PDR COPY SENT REGION _ m e