ML20140J286
| ML20140J286 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 03/27/1986 |
| From: | Capstick R VERMONT YANKEE NUCLEAR POWER CORP. |
| To: | Muller D Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20140J290 | List: |
| References | |
| FVY-86-26, NUDOCS 8604040296 | |
| Download: ML20140J286 (2) | |
Text
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f VERMONT YANKEE NUCLEAR POWER CORPORATION RD 5 Box 169. Ferry Road, Brattleboro, VT 05301
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ENGINEERING OFFICE 1671 WORCESTER ROAD March 27, 1986 FR AMINGHAM, M ASSACHUSETTS 01701 T ELEPHONE 617-872-8100 FVY 86/26 United States Nuclear Regulatory Commission Washington, DC 20555 Attention:
Office of Nuclear Reactor Regulation Mr. Daniel R. Muller, Dircetor BWR Project Directorate No. 2 Division of BWR Licensing
References:
(a) License No. DPR-28 (Docket No. 50-271)
(b) Letter, VYNPC to USNRC, FVY 85-43, dated May 14, 1985 (c) Letter, VYNPC to USNRC, FVY 85-64, dated July 10, 1985 (d) Letter, USNRC to VYNPC, NVY 85-150, dated July.22, 1985 (e) Letter, USNRC to VYNPC, NVY 85-168, dated August 12, 1985
Subject:
Request for Approval of PVRC Damping Analysis Method
Dear Sir:
Vermont Yankee herein requests approval of the use of Pressure Vessel Research Committee (PVRC) recommended damping. values for response spectrum seismic piping analysis at Vermont Yankee. We are requesting the use of these values per ASME Code Care N-411'as promulgated by the Main Committee on June 28, 1984. These values were previously approved for use at Vermont Yankee for analysis of the Replacement Recirculation System (References (d) and (c)).
It is our intention to apply these values for the analysis of any Seismic Class 1 Lines at Vermont Yankee. PVRC damping will be used as follows:
1.
Support optimizatiat - We intend to use the PVRC damping values to eliainate the need for seismic restraints, where appropriate.
2.
Verification of as-built piping / support configurations - We intend to use PVRC damping values to preclude the need for costly and/or difficult support modifications, where necessary.
Please be advised that the requested approval will neither impact any Vermont Yankee commitments regarding the Seismic Reanalysis Program, nor result in the elimination of deadweight suppurt modifications.
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United States Nuclear Regulatory Commission March 27, 1986 Attention:
Mr. Daniel R. Muller Page 2 PVRC damping values will be applied to amplified response spectra developed from a synthetic Regulatory Cuide 1.60 time history, normalized to a 0.14g acceleration for SSE.
Piping analysis will use the B31.1 Power Piping Code. Reanalysis of any piping using PVRC damping will be limited to complete systems / structural boundaries (for example, if a 12"0 header is analyzed using PVRC damping, then a 4"O branch line will also be analyzed using PVRC damping) and no mixing of analysis methodology will be permitted.
Piping analysis models will use either large equipment such as pumps, heat exchangers, tanks, etc., or structural attachments as anchors for defining the model boundary. Evaluation of piping loads (from the pipe stress analysis) imposed on nozzles of anchored equipment is to be performed using appropriate criteria (i.e., equipment manufacturers' allowable loads / stresses). This treatment of large equipment is consistent with the methodology in the Seismic Reanalysis Program.
Furthermore, the acceptance criteria to ensure that adequate clearance exists to allow for all piping displacement includes a walkdown review to ensure that mounted equipment can withstand any increased motion resulting from increased flexibility of the system. A copy of these walkdown procedures is included as Attachment 1 to this letter. A final walkdown of all piping in the Seismic Reanalysis Program is already planned, prior to startup. This walkdown will now include inspection for any increased piping deflections resulting from use of PVRC damping.
In accordance with the provisions of 10CFR170.12, an application fee of
$150.00 is. enclosed.
Because your review and approval of this request could potentially impact the scope of work associated with our current outage, your expedited review would be appreciated.
We believe the above information and attachments to this letter provide the documentation necessary for your expedited review and approval of PVRC damping for all Seismic Class I lines at Vermont Yankee. Should you have any questions or require additional information, please do not hesitate to contact me.
Very truly yours, VERMONT YANKEE NUCLEAR POWER CORPORATION l
R. W. Capstick l
Licensing Engineer RWC/pmv Enclosures l
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