ML20097F422
| ML20097F422 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 02/12/1996 |
| From: | Mccollum W DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| GL-90-09, GL-90-9, NUDOCS 9602160061 | |
| Download: ML20097F422 (5) | |
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Dukehe Company WILuw R. MtOutM, Je 4
Catantoa Nudear Gemiation [kpartment.
Ike hesident 4800 Concordkd (803)o31JX10 Office
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' DUKE POWER February 12,1996 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555
Subject:
Catawba Nuclear Station, Unit 2 Docket No. 50-414
~ Request for Relief Serial Number 96-01 j
. Snubber Inspection Intervals for Unit 2 Gentlemen:
Pursuant to 10CFR50.55a(g)(5)(iii), Catawba is submitting the attached relief request for NRC review and approval. Per NRC Generic Letter (GL) 90-09, " Alternative Requirements for Snubber Visual Inspection Intervals and Corrective Actions":
"... the staff has developed an alternate schedule for visual inspections that maintains the same confidence level as the existing schedule and generally will allow the licensee to perform visual i_ spections and corrective actions during n
plant outages. Because this line item TS improvement will reduce future occupational radiation exposure and is highly cost effective, the alternate inspection schedule is consistent with tlie Commission's policy statement on TS improvements."
The attached relief request seeks relief from imp,ractical snubber inspection frequencies
' and will invoke the snubber testing frequency as reflected in the current Catawba Nuclear Station Technical Specification 3/4.7.8, which is the same as that reflected in the referenced GL 90-09.
Catawba is requesting NRC approval of this relief request by August 1,1996. Approval of this relief request will coincide with the start of Catawba Unit 2, second interval on August 19,1996. This will allow Catawba to continue to utilize the existing Technical Specification requirements governing. snubber inspection.
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Document Control Desk Page 2 February 6,1996 Should there be any questions regarding this matter, please contact Devereux Tower at (803) 831-3419.
Very truly yours, W.R. McCollum DT/s Attachment xc (with attachment):
S.D. Ebneter, Regional Administrator Region II R..I. Freudenberger, Senior Resident Inspector R.E. Martin, Senior Project Manager ONRR l
4 Document Control Desk Page 3 February 5,19% -
bxc (with attachment):
Z.L. Taylor L.J. Rudy M.D. Shutt.
R.C. Giles NCMPA-1 NCEMC PMPA SREC Document Control File 801.01 Group File 801.01 ELL-EC050 o
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DUKE POWER COMPANY i
REQUEST FOR RELIEF FROM INSERVICE INSPECTION REQUIREMENT i
Station:
Catawba Unit:
2 Requesting Department:
Nuclear Generation Department Reference Code:
ASME Boiler and Pressure Vessel Code,Section XI 1989 Edition i
I.
Component for which reliefis requested:
4
- a. Name of component:
Snubbers on component supports
- b. Function:
Snubbers act as dynamic restraints which limit acceleration and/or velocity of the supported components while allowing for movements due to thermal expansion.
I c.
ASME Section XI Code Class:
Class 1,2, and 3
- d. Construction Code and Class:
ASME Section III,1974 Edition through Summer 1976 Addenda, Class 1, 2, and 3 e.
Valve Category (If Applicable):
NA II.
Reference Code requirement that has been determined to be impractical:
ASME Section XI, Article IWF-5000, Subsection IWF-5300, Inservice Inspection Requirements For Snubbers - requirement that snubber examinations and tests be performed in accordance with the first Addenda to ASME/ ANSI OM-1987, Part 4 (published in 1988).
III.
Basis for requesting relief:
ASME Section XI, Subsection IWF-5300 specifies that snubber examinations and tests be performed in accordance with the first Addenda to ASME/ ANSI OM-1987, Part 4 (published in 1988). Snubber examinations and tests are currently performed under Technical Specification Section 3/4.7.8 as amended
per NRC Generic Letter 90-09, " Alternative Requirements for Snubber Visual
-Inspection Intervals and Corrective Actions". The stated purpose of the generic letter was to provide alternative guidance to snubber inspection schedules which were excessively restrictive. The alternate schedule was -
provided to alleviate the expenditure of unnecessary resources and prevent radiological exposure associated with the over restrictive examination schedule. The implementation of ASME/ ANSI OM-1987 would return the snubber examination and testing program to the state which existed prior to the issuance of Generic Letter 90-09, effectively cancelling the benefits intended through the generic letter.
The current inspection program as defined by the Technical Specification provides for a level of quality and safety equal to or greater than that of the i
proposed OM Standard. The OM Standard provides for Failure Mode Grouping of snubbers which fail visual examination, meaning only those snubbers identified as being in that group would require shortened intervals.
Under the existing Technical Specification program all snubbers in the population would be placed in a shortened inspection interval. On this basis the existing program is more conservative in corrective action than the OM Standard requirements.
The functional test plan required by the OM Standard also includes Failure Mode Groups. The use of failure mode grouping is required even for a single failure, and in some cases allows for the failed snubber to be reclassified as acceptable with no further testing. This is unconservative for the large snubber population which exists at Catawba (over 1000 per unit) as compared to the existing Technical Specification program. The current program at Catawba requires supplemental testing for all failures until the desired confidence level is assured, with no allowances to reclassify failed snubbers.
IV.
Alternative examination:
In lieu ofimplementing ASME BPVC,1989 Edition, Subsection IWF-5300, it is proposed that snubber inspections and testing continue to be performed under the existing program as defined in the Catawba Nuclear Station Technical Specification Section 3/4.7.8.
V.
Implementation schedule:
Snubber inspections and testing will continue to be scheduled and performed in accordance with the mandated Technical Specification requirements.
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