ML20215M113
| ML20215M113 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 10/15/1986 |
| From: | Knighton G Office of Nuclear Reactor Regulation |
| To: | Tison Campbell ARKANSAS POWER & LIGHT CO. |
| References | |
| RTR-REGGD-01.084, RTR-REGGD-1.084 NUDOCS 8610300037 | |
| Download: ML20215M113 (4) | |
Text
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OCT 15 WH Docket No.:
50-368 Mr. T. Gene Campbell Vice President Nuclear Operations Arkansas Power and Light Company Post Office Box 551 Little Rock, Arkansas 72203 Dear Mr. Campbell
SUBJECT:
ASME CODE CASE N-411 By letter dated March 28, 1986, Arkansas Power and Light Company submitted a request in accordance with 10 CFR 50.55a(a)(3) for approval to use the damping values stated in ASME Code N-411, " Alternative Damping Values for Seismic Analysis of Classes 1, 2, and 3 Piping Sections,Section III, Division 1," as an alternative to the damping values currently specified in the FSAR. Require-ments and conditions for the applicability of this Code Case are stated in Regulatory Guide 1.84, Rev. 24, June 1986 and summarized in Enclosure 1.
The staff has reviewed your request and has determined that if the applicability requirements of Enclosure 1 are met and you fulfill the commitments described in your March 28, 1986 letter, that use of the proposed alternative methodology provides an acceptable level of quality and safety and is, therefore, acceptable.
The staff, therefore, approves your request for use of ASME Code Case N-411 for application in Arkansas Nuclear One, Unit 2 piping analyses.
The use of the Code Case should be documented in a future amendment to your FSAR.
If you have any questions in this regard, contact the Project Manager, R. Lee at(301)492-8555.
1 Sincerely,
/3/
4 8610300037 g h000 68 George W. Knighton, Director PDR ADOCK PDR PWR Project Directorate No. 7 P
Division of PWR Licensing-B l
Enclosure:
As stated cc: See next page Distribution:
RLee Attorney Docket File NSIC EJordan ACRS (10)
NRC PDR PD7 Reading JPartlow MHartzman LPDR JLee BGrimes FMiraglia DCrutchfield
- Previously concurred on by:
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@ ton 10/ 9/86 10/ 9/86 10/14/86 10 /86
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Mr. T. Gene Campbell Arkansas Nuclear One Arkansas Power & Light Company Unit No. 2 cc:
Mr. J. Ted Enos, Manager Mr. Charlie B. Brinkman, Manager Nuclear Engineering and Licensing Washington Nuclear Operations Arkansas Power and Light Company C-E Power Systems P. O. Box 551 7910 Woodmont Avenue Little Rock, Arkansas 72203 Suite 1310 Bethesda, Maryland 20814 Mr. James M. Levine, Director Site Nuclear Operations Arkansas Nuclear One P. O. Box 608 Russellville, Arkansas 72801 Nicholas 55 Reynolds, Esq.
Bishop, Liberman, Cook, Purcell & Reynolds 1200 Seventeenth Street, N.W.
Suite 700 Washington, D.C.
20036 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission Office of Executive Director for Operations 611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76011 Senior Resident Inspector U.S. huclear Regulatory Commission P. O. Box 2090 Russellville, Arkansas 72801 Nr. Frank Kilson, Director Division of Environmental Health Protection Arkansas Department of llealth 4815 West Markam Street Little Rock, Arkansas 72201 Mr. Robert B. Borsum Babcock & Wilcox huclear Power Generation Division Suite 22C 7910 Woodmont Avenue Bethesda, Maryland 20814
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APPL.ICABILITY OF ASME CODE CASE N-411 1.
ASME Code Case N-411 is acceptable for application to piping system
[
analysis under the following conditions:
A.
For analyses in new and operating plants which currently use or connit to use all the following criteria:
(1) Current seismic spectra (Regulatory Guide 1.60 or properly justified site spectra), with amplified spectra broadened per Regulatory Guide 1.122.
(2) The envelope response spectrum analysis method with Regulatory Guide 1.92 modal and directional combinations, including load contributions fra piping system modes with natural frequencies above 33 Hz such that their inclusion does not result in more than a 10% incremental increase in response.
(3) Damping values lower than, or equal to, those from Regulatory Guide 1.61.
B.
For the piping segments of a pipin values or.demping values from A(3)g system either N-411 damping may be used. The mixture of both is not acceptable.
C.
For equipment only, damping values from A(3) or experimentally deter-mined damping values may be used. Conversely, if the equipment is modelled with the piping using N-411 damping, the analysis results must show that the equipment have no responses below 20 Hz. For piping systems with different damping values for piping segments, equipment and supports, the modal damping values should be determined using composite dam,ning techniques (ASME Code,Section III, Appendix N).
l 2.
The user shall indicate whether the Code Case will be used for new analyses, for reconciliation work, or for support optimization. Due to the increased system flexibility of the system, the following shall be checked and verified for reconciliation or snubber / support optimization work:
a.
Adequate clearance with adjacent structures, components and equipment at all locations of maximum predicated displacements.
b.
The capability of mounted equipment to withstand the increased motion.
3.
Analyses involving the peak shifting technique per ASME Code Case N-397 and N-411 damping are acceptable.
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4.
ASME Code Case N-411 is not acceptable for application to piping system analysis under the following conditions:
a.
Analysis of piping in which stress corrosion cracking has occurred, unless a case-specific evaluation is made and is reviewed by the a
staff.
i b.
Use of the time-history method of dynamic analysis c.
Analysis of piping systems which include energy absorbers designed according to ASME Code Case N-420.
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Reference:
Regulatory Guide 1.84, Revision 24 i
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