ML19339B240

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Responds to NRC 800815 Ltr Re Const Rework Noted in IE Insp Repts 50-454/80-13,50-455/80-12,50-456/80-07 & 50-457/80-07. Program Initiated to Determine Extent & Causes for Rework in Six General Areas
ML19339B240
Person / Time
Site: Byron, Braidwood  Constellation icon.png
Issue date: 08/22/1980
From: Reed C
COMMONWEALTH EDISON CO.
To: James Keppler
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
NUDOCS 8011060560
Download: ML19339B240 (2)


Text

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[/ b' i Comm:nwe:lth Edison Ore First Nat:cnal Plaza Cmcap m.no s

Accress Aeply to Post Oftce Bon 767 Chicago I!hnois 60690 August 22, 1980 Mr. James G. Keppler, Director Directorate of Inspection ano Enforcement - Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137

Subject:

Byron Statico Units 1 and 2 Braidwood Station Units 1 and 2 Construction Re-work NRC Docket .v o s . 50-454, 50-455, 50-456, and 50-457 Reference (a): August 15. 1980 letter from G. Fiorelli to C. Reed transmitting IE Inspection Report Nos. 50-454/80-13, 50-455/80-12, 50-456/80-07, and 50-457/80-07.

Dear Mr. Keppler:

As indicated in Reference (a), a meeting was held between NRC Region III and Commonwealth Edison Company personnel to discuss NRC concerns regarding significant construction re-work at Byron and in part, at the Braidwood and LaSalle power plants. At this meeting Commonwealth Edison committed to perform an in-depth examination and evaluation of its design / engineering organization and function, and to provide a comprehensive evaluation of the conditions and circumstances which have led to certain areas of significant construction re-work at Byron Station. The scope of tnis examination and evaluation including current status follows.

SuDsequent to the aforementioned meeting, Commonwealth Edison began a two phase program to determine the extent of and causes for re ork on safety-related systems. The initial phase consisted of examining the Safety Injection (SI) System. O f tne 158 spools installed, 80 (51%) have been reworked.

the rework indicates that the reasons for rework Acan detailed review of be categorized into six general areas divided among these areas. with the amount of rework nearly equally The general areas are:

1) Field interference;
2) Design changes; 1

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Mr. James G. Keppler, Director August 22, 1980 Page 2

3) Field error;
4) Hanger lugs;
5) Convenience cuts; and
6) Other, such as instrument connections, faorication of piping in tne field, etc.

Of these general areas only two can ne attributed to design - design changes and field interference. Although field interference coul0 be related to field installation, for purposes of this evaluation all reworx due to field interference nas assumed to relate to design proolems. Thus, in summary about one-third or 17% of the rework associated with the SI system coulo De attributed to the design function.

In order to insure that a sufficient data base exists oefore drawing any conclusions regarding causes for rework, Commonwealth Edison intends to perform a similar examination of tne rework on two auditional systems - tne Component Cooling (CC) System and Reactor Coolant System (RCS). These two systems were chosen Decause the CC system, which has a large number of spools installed (364), has a significant rework rate, 66%; whereas the RCS system, which has a smaller number of spools installeo (91), has a lon rework rate, 14%. In addition, all three of these systems have a variety of piping including carbon and stainless steel.

Currently, Commonwealth Edison expects this examination and categorization to be completec within two or three months. Once the categorizations have been made, the second phase of this program will be inaugurated. This phase n'i l l involve two paralle2 efforts oy Engineering and Quality Assurance. Engineering will examine the reaors items associated nith cesign to ascertain their causes. The original drawings through all revisions will ce reviewed. The QA oepartment will verify, in parallel, that all the rework followed the appropriately required documentation through both the design control and design change phases.

Commonwealth Edison will review the results of Dotn phases of this review and will initiate appropriate changes, if deemed necessary.

Please address any questions that you may have concerning this matter to this office.

Very truly yours,

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Cordell Reed Vice President Nuclear Operations 6230A