ML20133E111

Final Part 21 & Deficiency Rept D/N 59 Re Possible Fractured or Cracked Welds on Louis Allis Emergency Standby Generators.Initially Reported on 850624.Item Not Reportable Per 10CFR50.55(e)

ML20133E111
Person / Time
Site:	Satsop
Issue date:	09/27/1985
From:	Kohler A WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	Kirsch D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
REF-PT21-85-477-000 D-N-#59, GO3-85-570, PT21-85-477, PT21-85-477-000, NUDOCS 8510090285
Download: ML20133E111 (4)

Text

- __ _ _ . -- __ _ . _ _ _ __ _ _. _

t

.- r t Washington Public Power Supply System ,

Box 1223

• Elma, Washington 98541 (206) 482-4428 g '70J g p

'I O (,4,

) OEC/cz,pl: i I

September 27, 1985 i G03-85-570 i

4

Docket No. 50-508 l

U. S. Nuclear Regulatory Commission, Region V Office of Inspection and Enforcement 1450 Maria Lane, Suite 260 i Walnut Creek, California 94596-5368 '

1 l'

Attention: Mr. D. F. Kirsch, Acting Director Division of Reactor Safety and Projects j

Subject:

NUCLEAR PROJECT N0. 3 i POTENTIAL 10CFR50.55(e) DEFICIENCY

! DIESEL GENERATOR AIR DEFLECTORS, D/N #59

! On June 24, 1985, the Supply System notified your office of .a potential

! 10CFR50.55(e) deficiency concerning the subject air deflectors. An evaluation i has determined the subject deviation not significant and not reportable under l 10CFR50.55(e).

Attached is the Supply System approved Final Report. The report provides a description of the deficiency, analysis of the safety implications and j corrective actions taken.

l 4

i I

i i

.ZE41 __

O 4

U. S. Nuclear Regulatory Commission, Region V G03-85-570 Page Two September 27, 1985 i  ;

Should you have any questions or desire further information, please contact me

directly.

. tt Jh l Jk>t A. D. Kohler m (760) l g Acting Program Director, WNP-3 i cc: Mr. J. A. Adams, NESCO j Mr. R. M. Boucher, Pacific Power & Light Company

. Mr. W. L. Bryan, Washington Water Power Company Mr. J. Crnich, Ebasco - Elma Ebasco, Elma

Mr. J. R. Lewis, Bonneville Power Administration Mr. R. V. Myers, Puget Sound Power & Light Company Mr. N. S. Reynolds (Bishop, Liberman, Cook, Purcell & Reynolds)

Mr. D. Smithpeter, BPA Mr. B. D. Withers, Portland General Electric Company l Document Control Desk - U. S. NRC 1

}

t i

I f

i

WASHINGTON NUCLEAR PROJECT N0. 3

, (DOCKET N0. 50-508)

! FINAL REPORT DIESEL GENERATOR AIR DEFLECTORS (D/N NO. 59)

DESCRIPTION OF THE DEFICIENCY Louis Allis notified the Nuclear Regulatory Commission of a potential problem involving possible fractured or cracked welds on the Emergency Standby Generators. The Supply System was identified as an end user of two (2) such generators. These were fabricated by Louis Allis and purchased by the Supply System from Colt Industries as part of the Emergency Standby Diesel Generator Sets.

The welds in question secure the conical air deflectors to the three piece coil guards located at the outboard end of each generator. As recommended by Louis Allis, a visual examination for possible cracks or fractures was performed by Ebasco's Quality Control personnel. This examination revealed some weld defects including one cracked tack and improper weld terminations in two or three welds on each generator. Two of the pieces have 1" to 1)"

long intermittent welds on approximately 5" centers and the third piece has one continuous weld. It should be noted that the weld size and spacing discussed above is different than that identified in the Interim Report, Letter G03-85-402, dated July 24, 1985. The Interim Report described the

welds as specified in the Louis Allis inspection procedure; whereas, this report describes the welds found as a result of Site inspection. The noted defects were documented on a Nonconformance Report and sent to Louis Allis for disposition. Subsequently, Louis Allis requested that the coil guard assemblies be unbolted from each generator and sent. ta their facility for further inspection and' determination of corrective action.

. )

~ _ . _ __

~ FINAL REPORT DIESEL GENERATOR AIR DEFLECTORS D/N # 59- (Continued)

SAFETY SIGNIFICANCE The subject generators supply electrical power to the 4.16KV Class IE ESF Systems in the event of a loss of offsite power. A gross failure of the welds in question could result in the air deflector falling into the internal rotating portion of the generator while it is in service. Such an event, if it were to occur, could result in generator failure.

After removal of the assemblies for shipment to the vendor, the welds were again inspected by Ebasco Engineering for determination of significance.

During this inspection it was noted that all the welds with defects are short (approximately 1)" long) intermittent welds separated by several inches of unwelded joint.

Therefore, a defect in one weld cannot propagate to another. It is our opinion that, should the few defective welds fail completely, no appreciable additional loading would be imposed on the remaining welds. Therefore, the air deflector should not become disconnected and fall into the internal rotating portion of the generator as a result of the weld defects noted.

From this, we can conclude that the subject deviation is not significant and not reportable under 10CFR50.55(e).

CORRECTIVE ACTION The coil guard assemblies were removed from the generators and sent to the Vendor's facility for repair or rework of any welds that might be suspect.

The assemblies are currently at Louis Allis. Upon completion of any necessary repair or rework, they will be shipped back to the WNP-3 Site for re-installation.

i i

l i