ML20072E685
| ML20072E685 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities  |
| Issue date: | 06/15/1983 |
| From: | Rybak B COMMONWEALTH EDISON CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| 6777N, NUDOCS 8306270108 | |
| Download: ML20072E685 (2) | |
Text
N Commonwealth Edison
[
) one First Natim;f Plata. Chicago, lil%ois
( j/ 7 Address Reply to: Post Othee Box 767 C
Chicago, Illinois 60690 s
June 15, 1983 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555
Subject:
Quad Cities Station Unit 1 Request for Extension of Mark I Containment Program Completion Date NRC Docket No. 50-254-References (a):
T. A.
Ippolito letter to J. S. Abel dated January 13, 1981.
(b):
D. M.
Vassallo letter to L. DelGeorge dated January 19, 1982.
Dear Mr. Denton:
The subject letters contained NRC Orders and extension of exemptions for the Mark I containment work.
These Orders provided specific exemptions and schedular extensions to comply with General Design Criterion 50 of Appendix A to 10 CFR Part 50.
The schedule as noted in reference (b) for Quad Cities Unit 1 is to complete all work by July 1, 1983.
During the process of performing final load calculations and analyses of the structural components for Quad Cities Unit 1, it was found that some of the initial modifications, as installed, did not have a margin of safety as required by Mark I Owner's Load Definition Report and the Mark I Owner's Structural Acceptance Criteria.
Final loading information became available too late to complete designs, procure material, and install all modifications prior to the end of the fall 1982 outage.
The following modifications have yet to be installed at Quad Cities Unit 1:
1)
Stiffeners for the Safety Relief Valve Discharge (SRVD) line penetration of the vent pipe.
2)
Stiffeners for the ring girder and the ring girder web extension.
3)
Changes to the T-quencher guide plate bolts.
4)
Reinforcement of the SRVD line below the vent penetration.
5)
Redesign of the SRVD line rigid support in the vent pipe.
6)
Target Rock SRVD line shear lugs.
Ei306270108 830615
//0 PDR ADDCK 05000254 P
O O'
H. R. Denton June 15, 1983 These additional modifications are considered to be minor modifications.
It is expected that all will be completed during the next unit outage, currently scheduled for Spring, 1984.
An analysis of this systems as currently installed has been performed by our Architect-Engineer.
The results are being evaluated and will be included in an operability report to be completed by June 22, 1983.
It is expected the report will demonstrate that the system as presently installed meets established operability criteria and is safe to operate at least until the next refueling outage.
If you have any questions concerning this matter, please contact this office.
One (1) signed original and forty (40) copies of this transmittal are enclosed for your use.
Very truly yours, B. Rybak Nuclear Licensing Administrator 1m cc:
R. Bevan - NRR R. Gilbert - NRR NRC Resident Inspector - Dresden 6777N I
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