ML20344A108
| ML20344A108 | |
| Person / Time | |
|---|---|
| Site: | Perry, Vogtle, Comanche Peak  |
| Issue date: | 12/04/2020 |
| From: | Darrell Roberts Engine Systems |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML20344A108 (6) | |
Text
1111 02:43:02 p.m. 12-04-2020 1 /6 ENGINE SYSTEMS, INC.
175 Freight Road Telephone: 252/977-2720 Rocky Mount, NC 27804 Fax: 252/446-1134 TELEFAX Date: December 04, 2020 Company: NRC Operations Center Fax Number: 301 /816-5151 Verification No.: 301/816-5100
Reference:
Report No. 10CFR21-0114, Rev. 1 From: Dan Roberts Page: 1 of 6
Dear Sir/ Madam:
Following this cover is a copy of our report 10CFR21-0114, Rev. 1, for a 10CFR21 reportable notification on a subcover assembly P/N 1A-7846 and machined subcover PIN 03-362-04-AH.
A copy of this report will be mailed to the NRC Document Control Desk and to our affected nuclear customer.
Should you have questions, please let us know.
Sincerely, ENGINE SYSTEMS, INC.
[2alJr--
Dan Roberts Quality Manager Quality Performance With Pride
1111 02:43:16p.m. 12-04-2020 2 /6 ENGINE SYSTEMS, INC.
175 Freight Road, Rocky Mount, NC 27804 Telephone: 252/977-2720 Fax: 252/446-1134 Report No. 10CFR21-0114 Rev. 0: 12/28/16 Rev. 1: 12/04/20 10CFR21 REPORTING OF DEFECTS AND NON-COMPLIANCE COMPONENT: Subcover assembly P/N 1A-7846 and machined subcover P/N 03-362-04-AH SYSTEM: Emergency Diesel Generator CONCLUSION: Reportable in Accordance With 10CFR21 Prepared By: -~__k--=+-"'--"'VJ.A-'-'*=--=-------- Date: IZ IL/ Izozo
(}Engineering Manager Reviewed By: ___ {l_ec....,c.-=-_{4U;-,__,<....:..:=------- Date:
Quality Assurance Manager Quality Performance With Pride
1111 02:43:28 p.m. 12-04-2020 3 /6 Report No. 10CFR21-0114 Record of Revisions Page: 1 of 1 REV DATE PAGE DESCRIPTION 1 12/04/20 Cover In Component section, added machined subcover 03-362-04-AH.
1 In Component section, added machined subcover 03-362-04-AH.
3 In Affected Users and Shipments table, added column for part number and added last row.
It was discovered that ES/ supplied qty 2 machined subcovers, PIN 03-362-04-AH, to Comanche Peak that were not captured in the revision 0 notification. PIN 1A-7846 is the typically supplied subcover assembly whereas PIN 03-362-04-AH is the bare machined subcover.
1111 02:43:40 p.m. 12-04-2020 4/6 Report No. 10CFR21-0114 Revision: 1 Date: 12/04/20 Page: 1 of 3 COMPONENT:
Subcover assembly, P/N 1A-7846, including machined subcover, P/N 03-362-04-AH.
SUMMARY
Engine Systems Inc. (ESI) began a 10CFR21 evaluation on November 18, 2016 upon notification of an issue with a subcover assembly at Perry Nuclear Plant. Attempts to install the subcover on their Enterprise diesel engine revealed two issues that prevented successful installation. First, one of the bolt holes was not fully machined through the entire depth of the subcover. Though the bolt could be inserted into the top of its corresponding hole, it would not pass completely through. The second issue was an interference between the rocker arm shaft and its mating pedestal. It was found that incomplete machining of the pedestal prevented the shaft from sitting flat on the pedestal.
The evaluation was concluded on 12/21/16 and it was determined that this issue is a reportable defect as defined by 10CFR21. The figures and photos below and on the following page provide visual detail of the deficiencies.
. .,, , Item #2: Location of incomplete I machining of pedestal I
I Item #1: Location of II inadequately drilled \
bolt hole '
Figure 1: Outline Drawing of Subcover
1111 02:44:05 p.m. 12-04-2020 5/6 Report No. 10CFR21-0114 Revision: 1 Date: 12/04/20 Page: 2 of 3 Photo 1: Visual Depiction of Inadequately Photo 2: Attempted Bolt Install Drilled Bolt Hole Item #2:
I 'I
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I I',
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I Correct Machining (note radius)
Photo 3: Actual Machining Figure 2: Ideal Pedestal Machining
1111 02:46: 18 p.m. 12-04-2020 6 /6 Report No. 10CFR21-0114 Revision: 1 Date: 12/04/20 Page: 3 of 3 DISCUSSION:
The subcover is a device that is fastened to the top of the cylinder head and provides support for the rocker arms and rocker shafts and encloses the valve stem area. There is one subcover per cylinder head and thus for a model DSRV-16-4 Enterprise engine there are 16 subcovers. Failure of a subcover would impact the ability of either of the corresponding rocker arms to provide the mechanical force to actuate the intake and exhaust valves. Without valve actuation, that particular power assembly would be unable to generate power which would reduce the output of the emergency diesel generator (EOG).
Failure of the EOG to produce its nameplate rated power could prevent the safe shutdown of the nuclear power plant during an emergency situation.
The issue regarding the inadequately drilled bolt hole would be detected during installation since it would prevent the bolt from passing through the hole. Therefore, it is determined this issue would have no impact on operability since the cover could not be installed with an incompletely drilled bolt hole.
With regard to the incompletely machined pedestal, there is the potential that a customer could install the rocker arm shaft without detecting this issue. In this situation, the shaft will partially fit on the pedestal and the bolt will !head into subcover; however, the shaft will not seat fully on the pedestal.
This prevents full contact with the pedestal and inhibits adequate preload throughout the bolted joint.
If a customer were to install the rocker arm shaft (with mating rocker arms, pushrods, etc) onto the engine without realizing this issue, operability and durability of the engine would be compromised.
This could present a substantial safety hazard.
AFFECTED USERS AND SHIPMENTS:
All of the subcovers listed below are subject to the pedestal machining discrepancy and may subject to the inadequately drilled bolt hole.
ESI Sales Order Order Date Customer Part ESI Certification Customer PO Qty Number Date 8001930 12/19/2011 First Energy - Perry 45307431 1/30/2013 (qty 1) 1A-7846 4 (AFW#3168) 7/2712013 (qty 3) 3006881 (qty 14) 7127/2013 (qty 14) 8001963 *1tv 1l 2/412010 Korea - Yonggwang Y090528171 1A-7846 15 10/18/2013 lntv 1\
3009694 2/23/2012 Korea - Yonggwang NYG1-02M0007-550 1A-7846 2 7127/2013 3009847 41512012 First Energy - Perry 45389292 1A-7846 7/2712013 (qty 5) 8 9127/2013 ;~,;. 3i 3009695 2123/2012 Korea - Yonggwang Y050089101 1A-7846 2 10/18/2013 3015101 12/29/2015 Georgia Power - Vogtle SNG10122963 1A-7846 2 4121/2016 3012736 4121/2014 EFH - Comanche Peak B 0209108 171 03-362-04-AH 2 816/2014 CORRECTIVE ACTIONS:
Customers may elect to perform corrective machining to restore the subcover to its design dimensions.
Otherwise, return the affected subcovers to ESI for inspection and rework. If customer rework is desired, perform the following:
a) Inspect for the bolt hole (item #1 ). If rework is necessary, drill through to a diameter of 13/16".
b) For the incomplete machining of the rocker arm pedestal (item #2), first remove the installed dowel which has 0.000" to 0.001" clearance. Then machine a 2" radius relief at the affected area. All other dimensions such as pedestal height shall remain unchanged.
The root cause analysis determined the cause to be machining errors that were not detected during ES l's dedication activities. As subcovers are returned, they will be re-machined at the vendor's facility, inspected by ESI, and returned to customers within 60 days of receipt. ESI will also incorporate revisions to the dedication report prior to the supply of any new or reworked subcovers to further clarify the inspection of these features during the dedication process, thereby preventing reoccurrence.