ML20211B709
| ML20211B709 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 05/30/1986 |
| From: | Butler W Office of Nuclear Reactor Regulation |
| To: | Bauer E PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| References | |
| NUDOCS 8606110867 | |
| Download: ML20211B709 (5) | |
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UNITED STATES o
NUCLEAR REGULATORY COMMISSION 3
- j WASHINGTON, D. C. 20555 AIAY 3 01986 Docket No.:
50-353 Mr. Edward G. Bauer, Jr.
Vice President and General Counsel Philadelphia Electric Company 2301 Market Street Philadelphia, Pennsylvania 19101
Dear Mr. Bauer:
SUBJECT:
USE OF ASME CODE CASES N-411 AND N-397 FOR LIMERICK GENERATING STATION, UNIT 2 The staff has completed its review of the Philadelphia Electric Company's (PECo) request, dated March 27, 1986 for authorization to use the damping values of ASME Code Case N-411, " Alternative Damping Values for Seismic Analysis of Classes 1, 2, and 3 Piping Sections,Section III, Division 1,"
and the spectral shifting criteria of ASME Code Case N-397, " Alternative Rules to the Spectral Broadening Procedures of N-1226.3 for Classes 1, 2, and 3 Piping,Section III, Division 1," as alternatives to methods currently described in the FSAR.
Volume 5 of NUREG-1061, " Report of the U.S. Nuclear Regulatory Comission Piping Review Comittee," was published in April,1985.
In that report, the Comittee recomends that ASME Code Cases N-411 and N-397, as developed by the Pressure Vessel Research Council (PVRC) piping committee and cited in Welding Research Council (WRC) Bulletin 300, be expeditiously imple-mented.
Code Case N-411 is a conditionally acceptable Code Case.
Its use has been approved by the staff for specific plant applications, pending a revision of Regulatory Guides 1.61 and 1.84, when the following information and commitments have been provided.
l i
1)
The application of the Code Case shall be limited to piping systems analyzed by the response spectrum method only.
2)
The alternate damping criteria of the Code Case shall be used in their entirety in any given analysis. The mixed application of the Code Case l
and Regulatory Guide 1.61 is not permitted.
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Due to the increased flexibility of the system, the user shall check all recalculated displacements to verify that there is adequate clearance between the piping system and adjacent structures, components, and equipment, and to verify the ability of mounted equipment to withstand the increased motion.
4)
The user shall clearly indicate whether the Code Case will be used for new analyses, for reconciliation work, or for support optimization.
By letter dated March 27, 1986, PEC0 made the commitments, identified above, regarding the application of Code Case N-411.
PECO also stated that the Code Case will be used for new dynamic analyses of piping and pipe mounted equipment, reanalysis for snubber reduction and reconciliation.
4 Because the damping values identified in the Code Case are applicable only to piping, the damping values specified in Regulatory Guide 1.61 should be used for equipment.
If equipment is modeled with piping using the Code Case damping, the analysis results must show that the equipment have no responses t
below 20 hertz.
Furthermore, the Code Case damping values are applicable only l
to piping for which current seismic spectra and analysis methods are used.
This includes modal and direction combination, of all three earthquake directions (the FSAR specifies that only two directions are combined for B0P piping) in accordance with Regulatory Guide 1.92, use of enveloped response spectra, and consideration of a sufficient number of modes such that inclusion of additional modes does not result in more than a 10% increase in response, l
1.e., do not omit consideration of the load contribution of piping dynamic modes with natural frequencies above 33 hertz.
For Limerick Unit 2, the site specific spectra approved for the plant can be used with the damping values specified in the Code Case.
Code Case N-397 is a conditionally acceptable Code Case.
It has been accepted by Regulatory Guide 1.84 for application to all piping analyses using the response spectrum method.
Based on the above, the staff concludes that it is acceptable to use ASME Code Cases N-411 and N-397 for Limerick Unit 2 in the manner, and within the limit-ations, described above. Although PECo has made no such request, the staff notes that this approval to use the Code Case damping values does not include l
application to piping analyses when energy absorbers are included in the stress analysis model.
Walter R. Butler, Director BWR Project Directorate No. 4 l
Division of BWR Licensing cc:
See next page j
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~~
Mr. Edward G. Bauer, Jr
~
Limerick Generating Station Philadelphia Electric Company Units 1 & 2 cc:
Troy B. Conner, Jr., Esquire Chairman Board of Supervisors of Conner and Wetterhahn Limerick Township 1747 Pennsylvania Ave, N.W.
646 West Ridge Pike Washington, D. C.
20006 Limerick, Pennsylvania 19468 Barry M. Hartman Frank R. Romano, Chairman Office of General Counsel Air & Water Pollution Patrol Post Office Box 11775 61 Forest Avenue Harrisburg, Pennsylvania 17108 Ambler, Pennsylvania 19002 Federic M. Wentz Dept. of Environmental Resources County Solicitor ATTN: Director, Office Radiologic County of Montgomery Health Courthouse P. O. Box 2063 Norristown, Pennsylvania 19404 Harrisburg, Pennsylvania 17105 Mr. John Franz, Plant Manager Ms. M. Mulligan Limerick Generating Station Limerick Ecology Action Post Office Box A 762 Queen St.
Saratoga, Pennsylvania 19464 Pottstown, Pennsylvania 19464 Mr. Karl Abraham Thomas Gerusky, Director Public Affairs Officer Bureau of Radiation Protection Region I Dept. of Enviromental Resources U.S. Nuclear Regulatory Commission 5th Floor, Fulton Bank Bldg.
631 Park Avenue Third and Locust Streets King of Prussia, PA 19806 Harrisburg, Pennsylvania 17120 Mr. Gene Kelly Senior Resident Inspector U.S. Nuclear Regulatory Commission P. O. Box 47 Sanatoga, Pennsylvania 19464 Governor's Office of State Planning and Development ATTN: Coordinator, Pennsylvania State Clearinghouse P. O. Box 1323 HLrrisburg, Pennsylvania 17102
Philadelphia Electric Company Limerick Generating Station 1/2 cc:
Director, Pennsylvania Emergency Angus Love, Esq.
Management Agency 107 East Main Street Basement, Transportation &
Norristown, Pennsylvania 19402 Safety Building Harrisburg, Pennsylvania 17120 Helen F. Hoyt, Chairman Administrative Judge Robert L. Anthony Atomic Safety & Licensing Board Friends of the Earth U.S. Nuclear Regulatory Commission of the Delaware Valley Washington, D. C.
20555 103 Vernon Lane, Box 186 Moylan, Pennsylvania 19065 Dr. Jerry Harbour Administrative Judge Atomic Safety & Licensing Board Kathryn S. Lewis, Esq.
U.S. Nuclear Regulatory Commission Municipal Services Bldg.
Washington, D. C.
20555 15th and JFK Blvd.
Philadelphia, Pennsylvania 19102 Dr. Richard F. Cole Administrative Judge David Wersan, Esq.
Atomic Safety &' Licensing Board Assistant Consumer Advocate U.S. Nuclear Regulatory Commission Office of Consumer Advocate Washington, D. C.
20555 1425 Strawberry Square Harrisburg, Pennsylvania 17120 Mr. Spence W. Perry, Esq.
Associate General Counsel Federal Emergency Management Agency Room 840 500 C Street, S.W.
Washington, D. C.
20472 Mr. J. T. Robb, NS-1 Philadelphia Electric Company 2301 Market Street Philadelphia, Pennylsvania 19101 Timothy R. S. Campbell, Director Department of Emergency Services 14 East Biddle Street West Chester, Pennsylvania 19380
e
@ 30 3)
Due to the increased flexibility of the system, the user shall check all recalculated displacements to verify that there is adequate clearance between the piping system and adjacent structures, components, and equipment, and to verify the ability of mounted equipment to withstand the increased motion.
4)
The user shall clearly indicate whether the Code Case will be used for new analyses, for reconciliation work, or for support optimization.
By letter dated March 27, 1986, PEC0 made the commitments, identified above, regarding the application of Code Case N-411.
PEC0 also stated that the Code Case will be used for new dynamic analyses of piping and pipe mounted equipment, reanalysis for snubber reduction and reconciliation.
Because the damping values identified in the Code Case are applicable only to piping, the damping values specified in Regulatory Guide 1.61 should be used for equipment.
If equipment is modeled with piping using the Code Case damping, the analysis results must show that the equipment have no responses below 20 hertz. Furthermore, the Code Case damping values are applicable only to piping for which current seismic spectra and analysis methods are used.
This includes modal and direction combination, of all three earthquake directions (the FSAR specifies that only two directions are combined for B0P piping) in accordance with Regulatory Guide 1.92, use of enveloped response spectra, and consideration of a sufficient number of modes such that inclusion of additional modes does not result in more than a 10% increase in response, i.e., do not omit consideration of the load contribution of piping dynamic modes with natural frequencies above 33 hertz.
For Limerick Unit 2, the site specific spectra approved for the plant can be used with the damping values specified in the Code Case.
Code Case N-397 is a conditionally acceptable Code Case.
It has been accepted by Regulatory Guide 1.84 for application to all piping analyses using the l
response spectrum method.
Based on the above, the staff concludes that it is acceptable to use ASME Code i
Cases N-411 and N-397 for Limerick Unit 2 in the manner, and within the limit-ations, described above. Although PECo has made no such request, the staff i
notes that this approval to use the Code Case damping values does not include application to piping analyses when energy absorbers are included in the stress
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analysis model, unginal signed by Walter R. Butler, Director BWR Project Directorate No. 4 Division of BWR Licensing cc: See next page DISTRIBUTION Docket File NRC PDR
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