ML20148F711
| ML20148F711 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 09/26/1978 |
| From: | Moriarty J COLT INDUSTRIES, INC. |
| To: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| Shared Package | |
| ML20148F701 | List: |
| References | |
| NUDOCS 7811090135 | |
| Download: ML20148F711 (2) | |
Text
Collindustries
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701 Lawto, Avenue Be'o ? W,scons,n 53511 FN 008 364 4411 o
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September 26, 1978 eTh~
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- ~#y Of fice of Inspection & Enforcement D
U. S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Ill. 60137 Attention:
Mr. James G. Keppler, Director, Region III
Subject:
Colt Industries-Fairbanks Morse Engine Division, Emergency Diesel Generators Possible Exhaust Rocker Arm Defect l
Reference:
Phone conversation reporting information contained below to U. S.
Nuclear Regulatory Commission, Mr. Bob Hei hman by Mr. J. M. Moriarty of Colt Industries-Fairbanks Morse Engine Division on September 26, 1978 Gentlemen:
A 14-cylinder PC-2 powered engine genset to be delivered for installation at b the Northeast Utilities Company's Millstone III site has been undergoing test in preparation for a customer witnessed 300-start qualification test.
During this j
pre-contract test running an axhaust rocker arm failed making the engine incper!ble I
until a new rocker arm was installed.
The failure occurred on 9/20/78 and subse-quent investigation shows the failure was caused by a stress riser from " fit up" grinding of the arm during assembly to the engine.
The hand grinder " slipped or jumped" while the operating clearance was being provided and notched the underside of the arm subject to tensile stress during operation.
In this case, the stress level from operation increased by the factor from the grinding "notc'" was high enough to cause the resulting fatigue crack.
(No additional factor such as the defective material which was concurrent with the notch on the Beaver Valley rocker arm was required to initiate the fatigue crack because the notch was more severe.)
lhare is a possibility that such grinding def ects exist in other rocker arms installed on delivered units (3 - Alabama Power and 2 - 5. Carolina at the l
customer's site plus 2 - Beaver Valley and the other Millstone unit in storage at Celcit).
The only operating PC-2 units are at Alaba.na Power Co., Farley Nuclear Plant.
We will centact Farley, advise them of this reportable incident and that an j
inspection / corrective action plan is being developed.
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The South Carolina Electric & Gas Co., Sumner Station PC-2 units have not C
been started up yet. We will notify them of this matter and inform them of our intended course of action as soon as it's established.
O g
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-,:c : T..aw.giaggriN U. S. f;uclear Regulatory Coculission
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September 26, 1973 g
Page 2 i
Those units still in Beloit will be inspected with appropriate change out, if necessary, prior to shipment.
We will keep you advised as we proceed on this matter.
Very truly yours,
. M. Moriarty MANAGER UTILI i ALES JMM:jc cc:
Mr. George Hairston Alabama Power Co.
P. O. Drawer 470 Ashford, AL 36312 Mr. Ronald B. Clary South Carolina Electric & Gas Co.
P. O. Box 764 Columbia, South Carolina 29218 C
Mr. George Buffington Stone & Webster Engineering Corp.
P. O. Box 2325 Boston, Massachusetts 02107 Stone & Webster Engineering Corp.
P. O. Cox 2325 Boston, Massachusetts 02107 Attention:
Project Engineer For Duquesne J.0. 12241 o
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