ML20056D435
| ML20056D435 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 08/09/1993 |
| From: | Rhodes F WOLF CREEK NUCLEAR OPERATING CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| ET-93-0092, ET-93-92, GL-89-08, GL-89-8, NUDOCS 9308160197 | |
| Download: ML20056D435 (3) | |
Text
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LFCREEK W@ NUCLEAR OPERATING Forrest T. Rhodes August 9, 1993 Wce Presdent Engirenng ET 93-0092 U. S.
Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station F1-137 Washington, D.
C.
20555
Reference:
Letter ET 89-0055, dated July 21, 1989, from F.
T.
Rhodes, WCNOC, to NRC
Subject:
Docket No. 50-482: Updated Response to Generic Letter 89-08 Gentlemen:
The purpose of this letter is to update information which was provided in the reference.
The reference provided Nolf Creek Nuclear Operating Corporation's (WCNOC) response to NRC Generic Letter 89-08,
" Erosion / Corrosion-Induced Pipe Wall Thinning,"
in accordance with 10 CFR 50.54 (f)
This letter is being submitted in response to an NRC inspection of the erosion / corrosion monitoring program conducted June 7-11 and 21-25, 1993 (NRC Inspection Report 50-482/93-18).
The NRC inspector suggested that WCNOC submit a supplemental response to address the upgraded long-term erosion / corrosion monitoring program.
Generic Letter 89-08 required all licensees to respond with information on whether or not a long term erosion / corrosion monitoring program had been implemented or would be implemented that would provide assurance that procedures or administrative controls are in place to assure that the Nuclear Utility Management and Resource Council (NUMARC) program or another equally effective program is implemented and the structural integrity of all high-energy carbon steel systems is maintained.
It was stated in the reference that procedure ADM 08-212,
" Erosion / Corrosion Monitoring Program,"
provided WCNOC a long term erosion / corrosion monitoring program that would provide assurance that erosion / corrosion would not affect the structural integrity of high energy carbon steel systems.
Procedure KGP-1264, " Component Wall Thinning Monitoring Programs," was issued on February 3,
- 1993, to supersede procedure ADM 08-212.
Procedure KGP-1264 describes the programs and responsibilities established to detect, monitor, and mitigate compenent wall thinning.
The scope ct the Component Wall Thinning Monitoring Programs include large and small bore piping and components susceptible to internally initiated wall thinning.
This includes components affected by Flow Accelerated Corrosion (FAC), Microbiologically Induced Corrosion (MIC),
general and localized corrosion, and cavitation erosion. These pronrams continue to provide assurance, as required by Generic Letter 89-08, that erosion / corrosion will not affect the structural integrity of high energy carbon steel systems.
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s ET 93-0092 Page 2 of 3 i
There are two major subtier procedures that support the Component Wall Thinning Monitoring Programs.
These. procedures are WCNOC-84,
" Guidelines for Technical Support-Flow Accelerated Corrosion Monitoring Program," and QCI 12.1-503, " Ultrasonic Examination for Component Wall Thinning."
Procedure WCNOC-84 documents pertinent methods and
)
information regarding WCNOC's Flow Accelerated Corrosion Monitoring Program.
Procedure WCNOC-84 also provides guidance - on program scope, responsibilities, component selection, evaluation of inspection data, and a schedule for full implenientation of the program.
Procedure QCI 12.1-503 prescribes the requirements for Ultrasonic Thickness Examinations to detect Component Wall Thinning.
Additional Information Self-assessments of the FAC Monitoring Program, as described by KGP-1264, are regularly conducted by WCNOC.
In 1992, a self-assessment was conducted to determine the effectiveness of the program as it' related to NRC Inspection Procedure
- 49001,
" Inspection of
-l Erosion / Corrosion Monitoring Program."
.Also, an independent audit was conducted by WCNOC's Quality Assurance Department during January 1993,.
with technical support from outside sources. Continued self-assessments of the FAC Monitoring Program are required to be conducted at - least every two years by procedure KGP-1264.
i WCNOC has evaluated instances of piping failures and significant wall thinning that have occurred at other nuclear plants as a result of FAC.
Methodology for these evaluations of plant experiences is proceduralized
-l in WCNOC-84 to determine applicability to Wolf Creek Generating Station and subsequent inspections.
Various sources for plant experiences include NRC Information Notices and Generic Letters, INPO network messages, Electric Power Research Institute-CHECMATE Users Group reports.
and meetings.
WCNOC utilizes ultrasonic (UT),
radiographic (RT),
and visual (VT) inspections to assess wall thinning as a result of FAC.
UT inspections are primarliy conducted on large-bore piping during refueling outages, whereas RT inspections are primarily conducted on small-bore piping during power operation.
VT inspections are primarily conducted on large components such as vessels and cross-around piping via manway entry and a
on smaller components upon accersibility during disassembly.
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ET 93-0092 Page 3_of 3 i
If you have any questions concerning this matter, please contact me at (316) 364-8831, extension 4002, or Mr. Kevin J. Moles at extension 4565.
s Very truly yours,
,/.
Forrest T. Rhodes Vice President Engineering-i PTR/jra cc:
W.
D. Johnson (NRC)
J. L. Milhoan (NRC)
G. A. Pick (NRC)
W. D. Reckley (NRC) l
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