ML20002A223

Interim Deficiency Rept 3 Re Failures in Diesel Generator Assemblies.Injection Pumps on Engines Have Been Replaced, Rocker Arms Reworked & Placed in Satisfactory Condition & Lubricating Oil Header Redesigned

ML20002A223
Person / Time
Site:	Millstone
Issue date:	08/29/1980
From:	Counsil W, Foster E NORTHEAST NUCLEAR ENERGY CO.
To:	Grier G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20002A175	List: ML20002A223
References
10CFR-050.55E, 10CFR-50.55E, AEC-MP3-217, B10063, NUDOCS 8011050219
Download: ML20002A223 (3)

Text

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f040cEcoNNECTICUT 06:01 am) mii Mr. B. H. Grier, Director August 29, 1980 Office of Inspection and Enforcement United States Nuclear Regulatory Commission Region I Docket No. 50-423 631 Park Avenue AEC-MP3-217 King of Prussia, Pennsylvania 19406 B10063 Gentlemen:

Millstone Unit No. 3 Reporting of Deficiencies in Design and Construction Deficiency Report No. 3 is forwarded for your infor=ation as required by Title 10 Code of Federal Regulation Part 50 Paragraph 55(e) .

Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY

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A rm W. G. Counsil Senior Vice President Attachment cc: Nuclear Regulatory Commission Office of Inspection and Enforcement Division of Reactor Operations Inspection Washington, D.C. 20555 4

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• Deficiency Report (10 CFR Part 50, Paragraph 55(e))

Report 3 Unit Millstone Unit 3 Final Interim X

Reference:

(1) W.G. Counsil (Northeast Utilities) letter to B. H. Grier (NRC Region I, Office of Inspection and Enforcement) dated November 3, 1978.

In the referenced letter, Northeast Utilities reported three significant deficiencies on the Millstone Unit 3 Emergency Diesel Generators, in final approved design, which were subsequently released for manufacturing.

1) Fuel injection pump failures - During the 300 start qualification test, several barrel to plunger seizures occurred caused by improper design /

manufacturing leaving the associated fuel injection pump inoperable.

2) Exhaust rocker arm failure - During the 300 stare qualification test, one exhaust rocker arm failed due to a manufacturing error leaving the engine inoperable.

3) Lubricating oil header failure - During the 300 start test, catastrophic failure of the lubricating oil header caused by an improper design change left the engine inoperable.

Since our previous interim report, our constructive action plan has been finalized.

1) Fuel injection pump failures - The injection pumps on both engines have been replaced with those manufactured by L' Orange. The pump barrels and plungers provided by L' Orange were satisfactorily qualified during the Seabrook Project Engine 300 start test, with no pump failures.

2) Exhaust rocker arm failure - All rocker arms on the Millstone engines were inspected, reworked where necessary, and placed in satisfactory condition.

All rocker arms were magnafluxed to detect any possible flaws. In addition, the calculated design stress levels were checked against a rocker arm test installation. The results of .he test indicated adequate margin in the yield strength of the rocker arm.

3) Lubricating oil header failure - The lubricating oil header has been re-  !

designed and the design has been tested with a model. The model was '

fitted with strain gages and pressure tested to one and one half (1.5)  ;

times the working pressure. l

i We consider the chcnges and testing performed on these three items to satisfactorily resolve the significant deficiencies described above.

Subsequent to the notification and resolution of the above deficiencies, Northeast Utilities has been notified of two additional significant deficiencies. As required by 10CFR50.55(e), we are reporting two significant deficiencies in final approved design, which were released for manufacturing.

1) Failure of crankshaft thrust bearing - A failure of the crankshaf t thrust bearing occurred on one of two Colt diesels at South Carolina's Electric & Gas Company Summer Station. Preliminary evaluation revealed the most likely cause of failure to be the omission of plugs in the oil supply system for the bearing.

2) Failure of crankshaf t thrust bearing - A failure of the crankshaft thrust bearing has occurred during shop tests of the Number 4 diesel generator set for the SNUPPS con-tract. It was determined that the detail

• drawings pro-vide inadequate clearance between the thrust bearing halves to allow for thermal expansion.

Both these items are not yet resolved. Colt has indicated that an inspection of the Millstone engines will be performeu when they are removed from storage for preparation for shipment. We will report to the NRC on our proposed corrective action in the near future.

C La E. R. Foster Project Manager Millstone Unit 3 RPN/cle j

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