ML19246A102
| ML19246A102 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 08/22/2019 |
| From: | Woolard S Engine Systems |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML19246A102 (11) | |
Text
ENGINE SYSTEMS, INC.
175 Freight Road Telephone: 252/977-2720 Rocky Mount, NC 27804 Fax: 252/446-1134 August 22, 2019 U.S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555-0001
Subject:
10CFR21 Reporting of Defects and Non-Compliance -
Engine Systems, Inc. Report No. 10CFR21-0126, Rev. 0 EMO Fuel Injector - Cracked Spray Tip, P/N 5229250
Dear Sir:
The enclosed report addresses a reportable notification on an EMO Fuel Injector- Cracked Spray Tip, P/N 5229250.
A copy of the report has been mailed to our affected nuclear customers.
Please sign below, acknowledging receipt of this report, and return a copy to the attention of Document Control at the address above (or, fax to number 252/446-1134) within 10 working days after receipt.
Yours very truly, ENGINE SYSTEMS, INC.
Susan Woolard Document Control Please let us know if ANY of your mailing information changes
- name of recipient, name of company/facility, address, etc. Mark the changes on this acknowledgment form and send to us by mail or FAX to the number above.
RECEIVED:
93 DATE:
Quality Performance With Pride
ENGINE SYSTEMS, INC.
175 Freight Road, Rocky Mount, NC 27804 Telephone: 252/977-2720 Fax: 252/446-1134 Report No. 10CFR21-0126 Rev. O: 08/22/19 10CFR21 REPORTING OF DEFECTS AND NON-COMPLIANCE COMPONENT: EMO Fuel Injector - Cracked Spray Tip P/N 5229250 SYSTEM: Emergency Diesel Generator CONCLUSION: Reportable in Accordance with 10CFR21 Prepared By: - h__
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__,__ _ _ _ _ __ Date:
cyEngineering Manager Reviewed By: ----.illl"'-"'-=--c.-~-----'---------
Quality Manager Date: 8' /~:i./;q Quality Performance With Pride
Report No. 1 OCFR21-0126 Record of Revisions Page: 1 of 1 REV DATE PAGE DESCRIPTION 0 08/22/19 Initial issue.
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Report No. 10CFR21-0126 Revision: 0 Date: 08/22/19 Page: 1 of 2 Pursuant to 10 CFR 21.21 (d)(4), ESI is presenting the required information as follows:
(i) Name and address of the individual or individuals informing the Commission.
John Kriesel Dan Roberts Engineering Manager Quality Manager Engine Systems Inc. Engine Systems Inc.
175 Freight Rd. 175 Freight Rd.
Rocky Mount, NC 27804 Rocky Mount, NC 27804 (ii) Identification of the basic component supplied within the United States which fails to comply or contains a defect.
EMO Fuel Injector, PIN 5229250 (iii) Identification of the firm supplying the basic.component which fails to comply or contains a defect.
Engine Systems Inc. (ES/)
(iv) Nature of the defect or failure to comply and the safety hazard which is created or could be created by such defect or failure to comply.
Fuel injector, PIN 5229250, SIN R2200, was sent to ES/ for failure analysis and the spray tip was found to have a through wall crack. Inspections determined the fuel feed holes in the body of the spray tip were incorrectly drilled resulting in one of the holes not properly penetrating the reservoir.
It is in this area where the crack initiated and propagated through the full section of the spray tip.
A cracked spray tip would inhibit proper combustion of fuel within the corresponding power cylinder which could affect the load carrying capability of the diesel engine. This could impact the operability of the diesel engine and thereby prevent the emergency diesel generator set from performing its safety related function.
(v) The date on which the information of such defect or failure to comply was obtained.
July 17, 2019 (vi) In the case of a basic component which contains a defect or fails to comply, the number and location of these components in use at, supplied for, being supplied for, or may be supplied for, manufactured, or being manufactured for one or more facilities or activities subject to the regulations in this part.
ES/ Sales Customer Serial Numbers Customer Qty C-of-C Date Order P.O.
Injector wl cracked tip R2200 Remaining suspect injectors from same rebuilt lot Pooled Equipment Inventory R2159 R2145 R847 Company R2587 R2160 R2179 93870 PG00-1 20 02126/02 R2545 R2158 R4244 R2140 R2163 R2217 (end user is Exelon - Nine Mile Pt.)
R2142 R2406 R2219 R2138 R2024 R2178 R2152 The original manufacturer was contacted and stated they have not seen this anomaly nor do they have record of warranty returns due to this discrepancy. Furthermore, based on the age of the tip (repair kit PO date is 2001), if other tips contained this same discrepancy it is highly likely they would have been detected or replaced by now. For these reasons, it is ESl's belief the extent of condition is limited to this single spray tip; however, until proven otherwise the entire batch is considered suspect.
Note that while this injector was refurbished in 2002, it was only subjected to a limited number of engine run hours (approximately 10 hrs) since the rebuild. The reason for this is the injector is part of a pooled equipment inventory system that maintains spare components for use by participating companies.
Report No. 10CFR21-0126 Revision: 0 Date: 08/22/19 Page: 2 of2 (vii) The corrective action which has been, is being, or will be taken; the name of the individual or organization responsible for the action; and the length of time that has been or will be taken to complete the action.
For the end user:
- The immediate action was to remove the injector and replace with a different fuel injector.
- Given this injector was 1 of 20 reworked on the same order with the same batch of material, ES/
recommends pefforming an inspection on the remaining 19 injectors. For injectors not yet installed, this should be pefformed prior to installation. For injectors installed on the engine, this should be pefformed at the next available maintenance window. In terms of risk associated with a crack developing for an installed injector, ES/ believes the risk is low. The incorrectly drilled hole appears to be a single event issue and for remaining injectors installed at the same time as the cracked injector, credit may be taken for accumulated successful run time.
The injectors should be returned to ES/ for disassembly inspection to confirm correct drilling. This will be followed by re-assembly and full functional testing (consisting of re-calibration and 2-hour extended run time testing at 900 rpm). Upon receipt of injectors, ES/ will complete this task within 30-days.
ForESI:
- The injector repair kit (PIN 40084754) that contained the spray tip has been discontinued and is no longer utilized.
- ES/ has implemented an inspection for all new injectors to verify proper fuel feed hole drilling in the spray tip prior to assembly of the injector.
- ES/ refurbished an additional set of 20 injectors on the same customer order as the cracked tip injector (total qty of 40 injectors on customer P.O. PG00-1); however, these injectors contain rebuild kits from a different PO and the activity was pefformed 2 months prior to the cracked tip injector rebuild. ES/ has requested this batch of injectors to be removed from storage and returned for disassembly inspection to confirm correct drilling. This will be followed by re-assembly and full functional testing (consisting of re-calibration and 2-hour extended run time testing at 900 rpm).
Completion of this activity will provide additional assurance as to the isolated nature of the incorrect drilling. Upon receipt of injectors, ES/ will complete this task within 30-days.
(viii) Any advice related to the potential defect or failure to comply about the facility, activity, or basic component that has been, is being, or will be given to purchasers or licensees.
See Attachment 1 for additional discussion.
Report No. 10CFR21-0126 Revision: 0 Attachment 1 Page: 1 of 6 ATIACHMENT 1 ADDITIONAL DISCUSSION ON CRACKED SPRAY TIP The injector, P/N 5229250, was procured new in 1991 and later rebuilt in January 2002 using kit P/N 40084754 (containing spray tip PIN 40084674). The kit was purchased in November 2001. The rebuilt injector was installed and operated in an engine for approximately 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> in January 2002. It was then removed from the engine and placed in long term storage. Annually, the stored injectors were bench tested (pop testing, pressure test, rack freeness) and returned to storage to extend their shelf life for an additional year.
The injector was placed in operational service in December 2018 and failed soon afterwards. The injector failed to chatter, wouldn't build pressure, and leaked at the nozzle. Disassembly inspection revealed a cracked spray tip. Refer to injector asser:r,bly, Figure #1 .
During normal injector operation, the fuel beneath the plunger is carried to the injector spray nozzle through the check valve and through holes drilled in the spring cage. The fuel is then directed to the internal reservoir machined internal to the nozzle via three drilled passages. These passages intersect the reservoir 120° apart. As the pressure increases in the reservoir during the operation of the plunger, the valve spring lifts from its seat and fuel is emitted from the six holes machined in the tip of the nozzle.
As the fuel exits the nozzle, it is finely atomized and creates the sharp chatter sound from the injector.
With the cracked spray nozzle, the pressure is not able to properly build up and atomize the fuel. During testing on the manual injector test stand, fuel leaks through the crack during each manual stroke without developing sufficient pressure in the nozzle to lift the valve spring. It is not known if operation at normal engine speed (15 cycles/second) results in partial atomization of the fuel.
The crack was visible without magnification and extended from the machined outside diameter on one side across the tip and partially down the other side. See Photo #1 . It was decided to section the spray tip and inspect the internal machined reservoir.
The section was made to bisect the spray tip through one of the fuel feed holes, as shown below. See Photo #2 for end view of sections.
~~-~ The sectioned spray tip identified the fuel feed holes were not properly oriented.
The axis of the feed holes are supposed to be on the centerline of the body, and tilted 10° off vertical. The as-found holes are not on the body centerline
,,** .**~ *,:"::--.: ', ,~1~**:J
~-- ~*-,>~ ~ ':: l. ' ' 't as shown in Photo #3.
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K:\:\-M ~H :'-:~ The incorrect drilling resulted in one of the holes not properly penetrating the
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. ,t->* ~~<~ reservoir. A small indication is visible in the left hand section where the
\--.-. *t, *>-1 reservoir and hole have joined. It is in this area where the crack initiated and
\);\\ f::f) propagated through the full section of the spray tip. See Photos #3 through #5.
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~- ~~'-:J A visual indication of the hole axis orientation is shown in Photos #6 & #7. In
- ~ these photos a 0.062" diameter pin gage is inserted in the feed hole that doesn't penetrate the reservoir. The needle is inserted in the center of the tip to provide a reference for the centerline of the body. When properly oriented, in Photo #7 the pin gage and valve needle should appear parallel. The angle between these was measured to be approximately 8°.
Report No. 10CFR21-0126 Revision: 0 Attachment 1 Page: 2 of6 FUEL INJECTOR Followe r - - - - - - - - Follower Spring Stop Pin Spring
_,,,______ Filter Cap
~ - - - - - Gasket Body---------._,___. . ._
~5i,,:-------Filter Spring Gear r--------Filter Rack--* - -* UH Plug Locating Dowel
'---Seal Nut--------
Spill Deflector Bushing--------oot Check Valve Valve Spring Check Valve Cage - - -
Valve Spring Seat NeedleValve-----__.:L SprayTip - - - - - - - - -
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Figure #1 EMO Unit Injector
Report No. 10CFR21-0126 Revision: 0 Attachment 1 Page: 3 of 6 Crack extends into the body on one side, goes across tip and partially down the other side.
Photo #1 Cracked Injector Spray Tip Photo #2 Tip sectioned through one feed hole
Report No. 10CFR21-0126 Revision: 0 Attachment 1 Page: 4 of6 p
Sectioned tip reveals incorrectly drilled fuel feed holes.
Feed hole in this section does not penetrate the reservoir.
Indication is where wall/hole interface and where crack initiates.
See Photo #4. Photo #3 Incorrectly drilled feed holes Photo #4 Crack Initiation
.. Report No. 10CFR21-0126 Revision: 0 Attachment 1 Page: 5 of6 Photo #5 Crack at tip viewed from inside section Photo #6 Spray Tip with 0.062" dia pin gage inserted, end view
Report No. 10CFR21 -0126 Revision: 0 Attachment 1 Page: 6 of 6 Lines representing 0°, 5°, and 10° Photo #7 Spray Tip with 0.062" dia pin gage inserted, side view