ML12061A052
| ML12061A052 | |
| Person / Time | |
|---|---|
| Site: | Perry  |
| Issue date: | 02/22/2012 |
| From: | Homer T Engine Systems |
| To: | NRC/FSME, Office of Nuclear Reactor Regulation |
| References | |
| 47685 | |
| Download: ML12061A052 (8) | |
Text
02/22/2012 U.S. Nuclear Regulatory Commission.Operations CenterEvent Report Part 21 (PAR) Event# 47685 Rep Org: ENGINE SYSTEMS, INC Notification Date I Time: 02/22/2012 17:21 (EST)
Supplier: ENGINE SYSTEMS, INC Event Date /Time: 02/17/2012 (EST)
Last Modification: 02/22/2012 Region: 1 Docket #:
City: ROCKY MOUNT Agreement State: Yes County: License #:
State: NC NRC Notified by: TOM HOMER Notifications: PATTY PELKE R3DO HQ Ops Officer: PETE SNYDER PART 21 - REACTORS EMAIL Emergency Class: NON EMERGENCY 10 CFR Section:
21.21 UNSPECIFIED PARAGRAPH MISSING UPPER MOUNTING PADS ON SUBCOVER ASSEMBLIES "Engine Systems Inc. (ESI) began a 10CFR21 evaluation on 12/20/11 upon notification of an issue with four subcover assemblies at Perry Nuclear Power Plant., It was reported that Perry was performing a maintenance activity whereby they were replacing four cylinder head subcover assemblies on their Enterprise diesel engine.
During installation, it was noted that qty. 2 of 11 bolt holes were missing an upper mounting pad. This was visually apparent once the customer attempted to install the bolts, which have a 6" length. The two areas missing the upper landing pad did not have an area for the underside of the bolt head to rest upon.
"The evaluation was concluded on 2/17/12 and it determined that this issue is a reportable defect as defined by 10CFR21.
"DISCUSSION:
"Lack of the mounting pads alone will not result in a failure, however if a customer attempts to install the subcover without recognizing.the missing material, there is the possibility that two of the eleven hold down bolts will provide no clamping function. This may result in loosening of the subcover mounting which could allow the cover to separate from the cylinder head.
"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 reducethe output of the emergency diesel generator (EDG). Failure of the EDG to produce its nameplate rated power could prevent the
02/22/2012 U.S. NuclearRegulatoro Commission OperationsCenter Event Report Pake 2 Part 21 (PAR) Event # 47685 safe shutdown of the nuclear power plant during an emergency situation.
"AFFECTED USERS AND SHIPMENTS:
"ESI has supplied subcovers with the incorrect mounting pad to the following customers [in USA]:
"Perry; Qty: 4; Date: October 2011.
"Note: The subcovers returned by Perry are the subject of this evaluation.
"CORRECTIVE ACTIONS:
"Customers may elect to justify use of a shorter bolt to facilitate installation of in-stock covers. Otherwise it is ESI's recommendation that customers return the subcovers for replacement.
"The root cause analysis determined that the cause of this issue was that the pattern for the casting is missing the portions that would ultimately form this upper mounting pad. In addition, the machining drawing was unclear in showing these locations. As a result, ESI's inspections did not specifically check for these locations and the non-conforming subcovers were shipped to the customer.
"The pattern is now being corrected to ensure the presence of the upper mounting pads. Also, ESI's dedication report is being revised to add specific checks to inspect for the presence of these pads. This will be completed prior to any future shipments of this item."
Re ceived at: 02/22/2012 16:34 02-22-12;04:42PM; # 1/ 6 EENGINE S1 175 Freight Road SYSTEMS, INC.
Rocky Mount, NC 27804 Telephone: 252/977-2720 Fax: 252/446-1134 TELEFAX Date: February 22, 2012 Company: NRC Operations Center Fax Number: 301/816-5151 Verification No.: 301/816-5100
Reference:
Report No. IQCFR21-0105, Rev. 0 From: Tom Homer Page: 1 of 6
Dear Sir:
Following this cover is a copy of our report 10CFR21-0105, Rev.0, for a 10CFR21 reportable notification on a subcover assembly, P/N 1A-7846.
A copy of this report will be mailed to the. NRC Document Control Desk and to our affected nuclear customers Should you have questions, please let us know, Sincerely, ENGINE SYSTEMS, INC.
Tom Homer Quality Assurance Manager
.Quality Performance With Pride
02-22-12;04:42PM; # 2/ 6 ENGINE SYSTEMS, INC.
ESI 175 Freight Road, Rocky Mount, NO 27804 Telephone: 2521977-2720 Fax: 2525446-1134 Report No. 10CFR21-0105 Rev. 0: 02/22/12 10CFR21 REPORTING OF DEFECTS AND NON-COMPLIANCE COMPONENT: Subcover Assembly, P/N 1A-7846 SYSTEM: Emergency Diesel Generator CONCLUSION: Reportable in Accordance With 10CFR21 Prepared By: Date: a. .
e ication ngineering Supervisor Approved By: Date:_________
7~r Engineering Manager Reviewed By: Date: 2-22 -/Z Quait Assurance Manager Quality Performance With Pride
02-22-12;04:42PM; # 3/ 6 Report No. 10CFR21-0105 Record of Revisions Page: 1 of 1 REV DATE PAGE DESCRIPTION 0 02/22/12 Initial issue.
02-22-12;04:42PM; # 4/ 6 Report No. 10CFR21-0105 Revision: 0 Date: 02/22/12 Page: 1 of 3 COMPONENT:
Subcover assembly, P/N 1A-78a46.
SUMMARY
Engine Systems Inc. (ESI) began a 10CFR21 evaluation oa12/20/11 upon notification of an issue with four subcover assemblies at Perry Nuclear Plant. It was reported that Perry was performing a maintenance activity whereby they were replacing four cylinder head subcover assemblies on their Enterprise diesel engine. During installation, it was noted that qty 2 of the 11 bolt holes were missing an upper mounting pad. This was visually apparent once the customer attempted to install the bolts, which have a 6" length. The two areas missing the upper landing pad did not have an area for the underside of the bolt head to rest upon. See photos 1 and 2 below showing an incorrect vs. correct subcover, The evaluation was concluded on 02/17/12 and it was determined that this issue is a reportable defect as defined by 10CFR21.
Upper mounting Upper mounting ..
p.adis present pad is missing
- I Photo 1: Subcover Returned by Perry Photo 2: Previously Installed Subcover (Incorrect) (Correct)
02-22-12;04: 42PM; # 5/ 6 Report No. 10CFR21-0105 Revision: 0 Date: 02/22/12 Page: 2of3 Figure 1 and photo 3 below show the positions within the subcover where the pads are missing.
r, I Figure 1: Overhead View of Subcover Photo 3: Locations of Missing Landing Pads
02-22-12; 04:42PM; # 6/ 6 Report No. 100FR21-0105 Revision: 0 Date: 02/22/12 Page: 30o 3 DISCUSSION:
Lack of the mounting pads alone will not result in a failure, however if a customer attempts to install the subcover without recognizing the missing material, there is the possibility that two of the eleven hold down b6lts will provide no clamping function. This may result in loosening of the subcover mounting which could allow the cover to separate from the cylinder head.
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 (EDG). Failure of the EDG to produce its nameplate rated power could prevent the safe shutdown of the nuclear power plant during an emergency situation.
AFFECTED USERS AND SHIPMENTS:
ESI has supplied subcovers with the incorrect mounting pad to the following customers:
Description ESI Job Customer Customer PO ci1yESI Certification I Number Number t Date 102126 Korea - Yonggwang Y050089101 2 April2003 3001279 Korea - Yonggwang NYG1-02M0007-550 2 July 2005 3006073 Perry Y090528171 4(1) October 2011 1 3006881 Korea - Yonggwang J 45307431 1 1 November 2011 Note (1): These are the four subcovers returned by Perry that are the subject of this evaluation.
CORRECTIVE ACTIONS:
Customers may elect to justify use of a shorter bolt to facilitate installation of in-stock covers.
Otherwise it is ESI's recommendation that customers return the subcovers for replacement.
The root cause analysis determined that the cause of this issue was that the pattern for the casting is missing the portions that would ultimately form this upper mounting pad. In addition, the machining drawing was unclear in showing these locations. As a result, ESI's inspections did not specifically check for these locations and the non-conforming subcovers were shipped to the customer.
The pattern is now being corrected to ensure the presence of the upper mounting pads. Also, ESI's dedication report is being revised to add specific checks to inspect for the presence of these pads. This will be completed prior to any future shipments of this item.