ML20083D771

Interim Part 21 Rept Re Failure of Fuel Injector Nozzle Tips.Initially Reported on 910723.Each Util Will Continue to Monitor Exhaust Gas Temps During Monthly Runs & Will Sample Lube Oil on Quarterly Basis for Contamination

ML20083D771
Person / Time
Site:	South Texas
Issue date:	09/20/1991
From:	Batdorf W COOPER INDUSTRIES, INC.
To:	NRC OFFICE OF ENFORCEMENT (OE)
References
REF-PT21-91, REF-QA-99900317 QCG-8434, NUDOCS 9110010232
Download: ML20083D771 (3)

Text

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COOPER Date: September 20,1991 Our Ref: OCG 8434 U.S. Nuclear Regulatory Commission Office of Inspection and Enforcement Attn: Director of Inspection and Enforcement One White Flint North 11555 Rockville Pike Rockville, MD 20852

Subject:

Fuel Nozzle Tip 10 CFR Part 21 Interim Report Gentlemen:

The following provides a status of activities and corrective actions associated with the subject 10 CFR Part 21 that have taken place since the last report dated July 23,1991.

Houston Lighting & Power (HL&P) performed a two phase supplemental audit to verify the adequacy of Cooper Bessemer supplier controls. The first phase took place at Haynes Corporation in Naples Florica on June 6 and 7,1991. The second phase of the audit was conducted at the Cooper Bessemer Reciprocating Plant in Grove City, PA. The audit cover letter, dated September 10,1991 concluded that Cooper Bessemer is ". . . now effectively controlling vendors."

During the second phase of the audit, two administrative concerns were identified and corrected.

Additionally, the audit report expressed a concern about the amount of time being taken to issue audit reports. Corrective actions are in place to improve the required time frame. Cooper Bessemer Reciprocating will comply with the NOA 1 guideline for issuing audit reports within 30 days.

The Cooper Bessemer Owner's Group Technical Committee met in Syracuse, NY August 17 19, 1991. Failure of the fuelinjector nozzle tips was discussed, and the following action items, taken from the official minutes of the meeting, were agreed to:

1. Each of the utilities willidentify the lot number and heat number for each nozzle installed in their diesel engines during their next refueling outage. They will also determine the lot numbers and heat numbers for the nozzles that they have as spares. Until the lot numbers are identified in each engine, the following three actions will be taken by each utility to look for evidence of a cracked fuel injector nozzle tip.

o Each utility will continue monitoring their exhaust gas temperatures dur.ng their monthly runs. They will be looking for a drop in temperature of about 200 degrees or more as an indication that 7 y ()(i M P, there might be a cracked fuel injector nozzle in the cylinder.

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Page 2 QCG 8434 9/20/91 Of course, there are many other possible causes for a lower tem perature in each cylinder, but, this would be an indication that it cou d be a cracked nozzle, o Each u'ility will monitor the sump level in their lube oil system during their monthly runs to check whether the level is nsing. This would be an indication that fuelis leaking from one of the cylinders and going into the lutte oil system, o Utilities will continue sampling their lube oil on at least a c uarterly basis to look for evidence of diesel fuel contamination in tio lube oil.

2. The Owner's Group agreed to perform destructive examinations of nozzles, which have been in operation from lot number 15009. The Jurpose of this testing is to determine whether the one failure found oy iL&P is an anomaly, or, whether there are other nozzles which have been in service that display a sinillar kind of cracking. If other nozzles from this lot show evidence of cracking, there is stronger evidence that this lot may also be defective. It was noted that there had been a total of four nozzles from lot 150010 tested. One of the four had cracks and other anomalies associated with it (i.e. plugged nozzle holes and inclusions in the base material), HL&P agreed to perform these examinations on two nozzles from lot #150009 for the owner's group.

3. Cooper Bessemer will verify that the emergency diesel generators can operate with one of the c done for two conditions:duringylinders out of normal service.condition operating This evaluation at a 100%will be c' rated power; and, during transient start up conditions. Results of this evaluation will be available by the next Technical Committee Meeting.

4 Cooper Bessemer will determine the status of the 10 CFR Part 21 evaluation of this fuel injection nozzle tip failure and report to Technical Committee when this evaluation will be completed.

Process controls for ensuring that future nozzles are free from defect have been tightened. HL&P specified tlat following prccurement requirement which will be implemented across the board for all future critical procurements:

NOTE TO VENDOR: For any heat lots of fuel injection nozzle tips. One tip for each lot must be examined for (1) thickness of ligaments between the center hole and the fuel ports and (2) the ligament thickness of the tip shall be 48 mils for all three ligaments. The maximum visual depth of nitriding (sum of both sides of ligament) 1/32' from the tip shall be 35% maximum as measured on one of the ligaments.

NOTE: Lots LCH 1, LCH 19/HLOO75 and LCH 19/HLOO81 manufactured by the Haynes Corporation weie examined by HL&P and may be procured without further examination.

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Page 3 OCG 8434 9/20/91 Corrective actions to prevent recurrence now appear to be in ] lace relative to this problem, investigation to determine the full scope of the 3 rob om continues. An nterim or final report will be forwarded to you as further c ovelopment occur.

Sincerely, ,

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WMB:ree cc: J. S. Baron - CES/GC A. E. Bice . CES/GC D. T. Blizzard CES/GC W. O. Ferguson - CES/GC A. D. Gillette CES/GC C. E. Hallman CES/GC W. Hanss (NRC)

J. M. Horne CES/GC R. R. Kiener - CES/GC A. Killinger (MPR Associates)

R. L. Pettis (NRC)

M. A. Schleigh CES/GC B. R. Sedelmyer CES/GC P. J. Shimek - CES/GC S. Timmaraju (HL&P)

File: K Sa 19 Fuel Nozz!e Tips Owners Group Technical Representatives

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