ML20246L345
| ML20246L345 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 07/14/1989 |
| From: | Murphy W VERMONT YANKEE NUCLEAR POWER CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| BVY-89-66, GL-89-08, GL-89-8, NUDOCS 8907180403 | |
| Download: ML20246L345 (3) | |
Text
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a > l, VERMONT YANKEE
?NU LEAR POWER CORPORATION
- r Ferry Road, Brattleboro. VT 05301-7002 n m yto s
ENGINEERING OFFICE
'l 680 MAIN STREET DOLToN, MA 01740 '
(508)779-6711 l
July 14, 1989 i
U.S. Nuclear Regulatory Commission l
Washington, D.C.
20555 Attention:
Document Control Desk
References:
a)
License No. DPR-28 (Docket No. 50-271) b)
Letter, USNRC to All Holders of Operating Licenses l
or Construction Permits for Nuclear Power Plants, 1
NVY 89-106, " Erosion / Corrosion-Induced Pipe Wall Thinning (Generic Letter 89-08)," dated 5/2/89 c)
Letter,'VYNPC to USNRC, FVY 87-94, dated 9/11/81 d)
Letter, VYNPC to USNRC, FVY 87-121, dated 12/24/87
Dear Sir:
l
Subject:
Vermont Yankee Response to NRC Generic Letter 89-08:
.l Erosion / Corrosion-Induced Pipe Wall Thinning j
The purpose of this letter is to provide Verment Yankee's response to the subject Generic Letter request. Specifically, Generic Letter 89-08 requested licensees.to provide assurances that a program, consisting of
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systematic measures to ensure that erosion / corrosion does not lead to j
degradation of single-phase and two-phase high energy carbon steel systems, j
has been implemented. Further, the letter requested that the response
' include information on whether or not licensees have implemented, or intend to implement, a long-term erosion / corrosion monitoring program that provi-des' assurances that procedures or administrative controls are in place to assure that the NUMARC program or another equally effective program is implemented and the structural integrity of all high energy (two-phase as well as single-phase) carbon steel systems is maintained.
If such a program is not yet implemented, the letter requested that the scheduled implementation date be provided.
Pursuant to the subject Generic Letter j
request, Vermont Yankee herewith provides the following response.
l Vermont Yankee has performed facility-specific monitoring programs of steam and two-phase piping systems for pipe wall thinning since 1978. This plan hes been continuously upgraded to address industry events and past
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inspection results.
j l
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8907180403 890714 PDR ADOCK 05000271
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v VERMONT YANKEE NUCLEAR POWER CORPORATION-
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I' U.S. Nuclear Regulatory Commission July 14,,1989 Page 2 In response to the 1986 Surry incident, Vermont Yankee initiated an engineering evaluation to identify sections of the Condensate and Feedwater systems susceptible to single-phase erosion / corrosion.
Inspections of single-phase. piping systems performed during the 1987 refueling outage were
. based on this study [see. References c) and d) for additional detail].
For the 1989 refueling outage, the EPRI CHEC Code was used to augment the original single-phase study. The inspection scope for single-phase piping was based on a combination of the study results, the CHEC Code results,~and several piping components previously inspected during the 1987 outage. Steam and two-phase component selection was based on the sur-veillance plan,, previous inspection results, and other plant operating experience.
For both the 1987 and 1989 refueling outages, component selection cri-teria, inspection techniques, and acceptance criteria were modeled on the NUMARC guidelines. Results of these inspections indicated that single-phase erosion / corrosion is not significant in the Condensate and Feedwater Systems at Vermont Yankee. Steam and two-phase erosion has been identified and repair or replacement of the affected components has been performed on a case-by-case basis.
In the past, Vermont Yankee's Erosion / Corrosion Monitoring Program focused on identifying inspection locations for the next scheduled outage.
A long-term erosion / corrosion program i, currently being developed. The goal.of this program is to provide a set of criteria, systematic methods, and specific guidelines which will ensurt that the structural integrity of all high energy piping at Vermont' Yankee is maintained.
The program will be administered in a similar manner to the existing Inservice Inspection Program. Vermont Yankee plans to implement this erosion / corrosion program during the 1990 refueling outage.
Accordingly, the foregoing demonstrates that Vermont Yankee has pre-viously implemented a refueling outage inspection program consisting of systematic measures to ensure that erosion / corrosion does not lead to degradation of single-phase and two-phase high energy carbon steel systems.
Further, Vermont Yankee hereby commits to implement, during the 1990 refueling outage, a long-term erosion / corrosion monitoring program that assures that procedures or administrative controls are in place to ensure that the structural integrity of all high energy (two-phase and single-phase) carbon steel systems is maintained.
VERMONT YANKEE NUCLEAR POWER CORPORATION I
U..S. Nuclear Regulatory Commission July 14, 1989 Page 3 We trust this submittbl is responsive to your request; however, should you have any questions or. requite additional information regarding this-matter, please do not hesitate to cont 0ct us.
Very truly yours, VERMONT YANKEE NUCLEAR POWER CORPORATION fM Warren P.
urphy l
Vice Pres dent and-Manager of Operation
/dm cc: USNRC Project Manager, VYNPC USNRC Regional Administrator, Region I USNRC Resident Inspector, VYNPS STATE OF VERMONT)
)ss WINDHAM COUNTY )
Then personally appeared before me, Warren P. Murphy, who, being duly sworn, did state that he is Vice President and i'anager of Operations of Vermont Yankee Nuclear Power Corporation, that he is duly authorized to execute and file the foregoing document in the name and on the behalf of Vermont Yankee Nuclear Power Corporation and that the statements therein are true tc the best of his knowledge and belief, e
S Diane M. McCue
~[ Netary Public My Commission Expires F 1991 norm 1
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