ML18100A768

Interim Part 21 Rept Re Discovery That Ge/Alco EDGs High Pressure Injection Tube Studs Did Not Meet Correct Matl non- Std & Not Correct Geometry.All Nonconforming Studs Identified & Replaced

ML18100A768
Person / Time
Site:	Salem
Issue date:	12/13/1993
From:	Labruna S Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
REF-PT21-93 NLR-N93200, NUDOCS 9312220220
Download: ML18100A768 (3)

Text

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Stanley LaBruna Public Service Electric and Gas Company P.O. Box 236, Hancocks Bridge, NJ 08038 609-339-1700 Vice President - Nuclear Engineering DEC 13 1993 NLR-N93200 United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Gentlemen:

10CFR21 INTERIM REPORT, EMERGENCY DIESEL GENERATOR HIGH PRESSURE INJECTION TUBE STUD MATERIAL DEFICIENCY SALEM GENERATING STATION UNITS 1 AND 2 FACILITY OPERATING LICENSE NO. DPR-70 AND DPR-75 DOCKET NOS. 50-272 AND 311 Pursuant to the notification requirements of 10CFR21, Public Service Electric and Gas Company (PSE&G) hereby provides the attached interim report concerning a potentially reportable deficiency due to the discovery that the Salem Emergency Diesel Generator (EDG) high pressure injection tube studs did not meet the correct material standard and were not the correct geometry (i.e., full-size shank vs. the required reduced size shank).

Several instances occurred between March, 1991 and May, 1993 in which non-conforming high pressure injection tube studs were found installed on the Salem Unit 1 and 2 EDGs. In two cases, a non-conforming stud was found broken during a walkdown inspection *.

Each EDG contains a total of thirty-six (36) injection tube studs, two per cylinder head. These studs are utilized to hold the high pressure fuel injection tubes in place on each cylinder head. When the EDG is running, these studs are subject to both cyclic loading (corresponding to repeated injection tube pressurization) and acceleration loading (i.e., EDG vibration).

PSE&G has determined that failure of both studs on any cylinder head will cause a failure of the mechanical seal between the injection tube and the nozzle assembly, resulting in external fuel leakage and at least partial interruption of fuel delivery to the affected cylinder. This failure may represent a fire hazard, or may result in the failure of the EDG to attain rated power or maintain required speed/frequency under rated load ..

The Salem Unit 1 and 2 EDGs were designed and manufactured by GE/ALCO. In 1990, GE/ALCO indicated that they would no longer

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provide dedicated commercial grade parts for the EDGs. During the second half of 1990, Canada-Allied Diesel Co., LTD. (CAD) was selected by PSE&G as the parts supplier for the EDGs. This included refurbishment assemblies such as the EDG cylinder heads and studs. Early in 1991, 21 new cylinder heads were received by PSE&G from CAD, each with 2 injection tube studs installed. A separate shipment of 28 injection tube studs also was received.

It is now believed that all of the injection tube studs received from CAD were non-conforming when compared to original equipment with respect to material and geometry.

At the present time, all non-conforming studs that were contained in the Salem Unit 1 and 2 EDGs have been identified and replaced.

A calculation in support of EDG operability for the two cases where a failed stud was identified concluded that a single stud was capable of sustaining the design loadings for short durations. However, fatigue analysis of the non-conforming studs has not been completed. Therefore, in order for PSE&G to determine if a Substantial Safety Hazard could have existed in accordance with 10CFR21, further analysis of the non-conforming studs is required to determine if the studs meet the design requirements necessary due to the cyclic and acceleration loading during long term operation of the EDGs. This analysis and a final determination of reportability in accordance with 10CFR21 is scheduled to be completed by February 15, 1994.

Should you have any questions, please contact us.

Sincerely, p~~

~'Document Control Desk 3 NLR-N93200 DEC 13 1993 c Mr. T. T. Martin, Administrator - Region I U. S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Mr. J. Stone - Licensing Project Manager

u. s. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Rockville, MD 20852 Mr. c. s. Marschall (SOS)

USNRC Senior Resident Inspector Mr. K. Tosch, Manager, IV NJ Department of Environmental Protection Division of Environmental Quality Bureau of Nuclear Engineering CN 415 Trenton, NJ 08625