ML17199T487
| ML17199T487 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Quad Cities, 05000000 |
| Issue date: | 12/22/1987 |
| From: | Johnson I COMMONWEALTH EDISON CO. |
| To: | Davis A NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 4012K, NUDOCS 8801040219 | |
| Download: ML17199T487 (2) | |
Text
e Com.m.alth Edison One First National Plaza, Chicago, Illinois Address Reply to: Post Office Box 767 Chicago, Illinois 60690
- 0767 Mr. A. Bert Davis Regional Administrator.
U.S. Nuclear Regulatory Region III 799 Roosevelt Road Gleri Ellyn, IL 60137 December 22, 1987 Commission
Subject:
Dresden Station Units 2 and 3 Quad Cities Station Units l and 2 tt)+r "Piping Configuration Verification Program Status Report" NRC DQckeLN.o. 50-_?37, 249, 254 __.!i.!l<t.. 1~2.
Reference:
Letter from I.M. Johnson to A.B. Davis dated November 23, 1987.
Dear Mr. Davis:
This letter reports the status of the program to resolve apparent discrepancies found between the as-built and as-analyzed condition of certain Mark.I Torus. attached piping at Dresden Units 2 arid 3 and Quad.
Cities Units l and 2.
The previous report was submitted via the above reference letter. A previous report, "Program Description and status Report", NUTECH Document CEC-99-024, dated June 22, 1987, describes the background and the details of the program for resolution.
The purpose of the project is to demonstrate that the affected piping systems meet FSAR criteria, and if necessary, perform corrective work to return the piping to a state of FSAR compliance.
~creeninq' and Operability Compliance These activities are complete as previously reported (see above referenced letter).
FSAR Compliance
.The current focus of the project is to demonstrate FSAR compliance for the apparent discrepancies on all the piping:subsystems or analytical piping models; This effort was begun in August, 1987.
As of December 16, 1987, FSAR compliance has been demonstrated for 89\\ (25/28) of the piping models involved on Dresden, and 70\\ (26/37) for Quad Cities.
To date, FSAR compliance has been demonstrated by using manual calculations, except for five models reanalyzed for operability.
Assuming that all the remaining models can also be evaluated with manual calculations, FSAR resolution is scheduled for completion by March 15, 1988 *. If five models are assumed.to requi~e reanalysis, and worst-case assumptions are made regarding the level of analysis, the completion date for.all FSAR.resolutions could extend-to June 20, 1988.
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. 8801040219 871222 PDR ADOCK 05000237 P
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- ~iqnifican_t_:r.!?sue.~
- 1.
Operability for the piping systems within this program has been demonstrated, therefore no immediate safety concerns exist.
- 2.
At the July 30, 1987 meeting with NRR and NRC-111, Commonwealth Edison agreed to examine.the piping analyses recently performed to address pipe support and other discrepancies.
The goal was to use existing analysis information to determine the effect of pipe support location deviations on piping stresses and support reactions.
This study has been completed.
The study concludes that no clear cause-effect relationships can be drawn from these analyses due to the fact that a variety of changes made to the analysis model. tend.to obscure the effect of the pipe support relocations alone.
This underscores the need to address each discrepancy and piping model individually, as is being. done in this program.
- 3.
One method use.d to resolve discrepancies is to physically rerriove the discrepancy by corrective work in the field.
This method is used instead of analytical resolution when it is more expedient from a schedule and/or cost basis.
This approach has been discussed with members of your staff in past discussions.
~~ary To date, 22 corrective work drawings have been issued onll piping models at Dresden, and 18 drawings have been issued on 12 piping models at Quad Cities.
As.the discrepancies on the remaining models are *resolved, additional corrective work drawings will be issued.. Assuming the same rate of corrective work on future models has been experienced to date, approximately 3 additionai drawings can be expected for Dresden and 8 additional drawings for Quad Cities.
The schedule for these drawings will coincide with the resolution of piping models.
The project is proceeding smoothly through the FSAR compliance evaluation phase~ and no significant new issues are anticipated.
Therefore, it is proposed that future NRC status reports continue to be issued monthly..
Please direct any questions regarding this matter to this office.
Administrator cc: