ML19339B682
| ML19339B682 | |
| Person / Time | |
|---|---|
| Site: | Fermi, 05000452, 05000453 |
| Issue date: | 11/03/1980 |
| From: | Hines E DETROIT EDISON CO. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, EF2-49-826, NUDOCS 8011070454 | |
| Download: ML19339B682 (2) | |
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p Edward Hines Ass s a-r 5 ce p es :ect ourr, AS%>&^ce Detroit 2000 sacyc Av bCJ3Cn samr"w=
November 3, i980 a
a EF2-49,8.16 13 Mr. James G. Keppler, Director El Reglon iII tE Ci f5U @E U. S. Nuclear Regulatory Commission 799 RooseveIt Road w
Glen Ellyn, IL 60137
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Dear Mr. Keppler:
.a 10CFR50.55(e) Report on Agastat Relay Bases This is submitted as Detroit Edison's final report on the Agastat relay base problem (reported per.50.55(e) requirements.
The problem was originally reported to Mr. Dick Knop by Mr. H. A. Walker in a telephone call November 9, 1979 It had been noted in performing checks on the Primary Containment Monitoring System that some circuits through the Agastat relays were open when they should have been closed.
I nvest ig.t i on revealed that pins in the relay mounting brackets connecting to the relays were loose and if a good alignment of relay connector pins to mounting bracket terminal was not obtained, then the mounting bracket terminal was pushed away from the relay resulting in an open or intermittently open circuit. At the time of the report, the problem had been noted only in the two panels of the Containment Monitoring Systems (panels Hll-P914 and Hil-P9i5).
Subsequent investigation has revealed that this type relay base is also used in five additional panels which were supplied by General Electric.
Detroit Edison has ordered a different model of relay mounting base for panels Hil-P914 and Hil-P915 which will replace all forty bases now in these panels.
General Electric has submitted a proposal to modify the relay bases in the five G.E. supplied panels to eliminate the pin push out problem.
This proposal has been evaluated by Detroit Edison Engineering, and the Edison conclusion is contained in the following paragraph.
Edison accepts the General Electric proposal, with slight modification, as a suitable solution to the pin push out problem.
Each Agastat relay base of the type in question in the five above-mentioned G.E. supplied pane.ls will be modified by the insertion of a micarta spacer under the relay base.
This spacer will have the desirable effect of holding relay mounting bracket terminals in place and preventing tendency for movement of same when the relay is inserted.
New Installations or modifications to Agastat circuits of this type will incorporate the newer style relay mounting. Additional details are available from the Generation Engineering Department.
If you have any questions concerning this matter, please contact Mr. H. A.
Walker of our Construction quality Assurance Organization.
Very truly yours,
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i Mr. James G. Keppler November 3, 1980 Page 2 EF2-49,826 s
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Mr. Victor Stello, Jr.,' Director Office of Inspection and Erforcement Division of Reactor inspection Programs j
U. S. Nuclear Regulatory Commission j
'20555 Mr. Bruce Little, Resident inspector U. S. Nuclear Regulatory Commission-Resident inspectors.0ffice 6450 North Dixie Highway Newport, MI 48166 l
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