ML20236A303
| ML20236A303 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 03/08/1989 |
| From: | Musolf D NORTHERN STATES POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20236A305 | List: |
| References | |
| IEB-79-14, NUDOCS 8903170051 | |
| Download: ML20236A303 (4) | |
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l Nodhern Staters Power Company l
414 Nicollet Mall Minneapohs, Minnesota 55401
'l Telepnone (612) 330 5500 l
Director of Nuclear Reactor Regulation l
U S Nuclear Regulatory Commission l
Attn: Document Control Desk Washington, DC 20555 PRAIRIE ISLAND NUCLEAR CENERATING PLANT Docket Nos. 50-282 License Nos. DPR-42 50-306 DPR-60 Supplemental Information Related to NRC Bulletin 79-14 Torsional Moment Fnelusion When Using USAS B31.1-1967 Code The purpose of this letter is to provide additional information re-lated to piping analysis performed by the Prairie Island architect-engineer, Fluor Daniel, in response to NRC Bulletin 79-14.
This information supplements our letter of January 10, 1989.
We believe that the Fluor Daniel interpretation of the USAS B31.1-1967 Code is correct regarding the exclusion of torsional moments when calculating stresses due to occasional loads.
Refer to the attached letter and report prepared for NSP by Teledyne Engineering Services, TR-7049C, "A Discussion of Torsion Effects on Limit Moment Theory and Piping Code Criteria." Also attached is a report prepared for Fluor Daniel by S. Levy Incorporated, SLI-8904, " Documentation of Method-ology Used for Combination of Moments for Piping Constructed to the USAS B31.1-1967 Power Piping Code."
Both reports support the inter-pretation of the Code made by Fluor Daniel.
In addition, both reports discuss the technical adequacy of the USAS B31.1-1967 Code requirements which deal with occasional loads.
Both reports conclude that use of this code is technically sound.
Fluor Daniel has also completed a random sampling study to evaluate the effects of adding torsional moments to existing pipe analyses.
All analyses evaluated showed stressen were still within USAR allow-ables when torsional moment was included.
In our previous letter we stated that a preliminary evaluation of a selection of cases including torsion resulted in stresses that were within or would only marginally exceed USAR allowables (if torsional moment was required to be included). Only one case showed stresses that would exceed USAR allowables. However, this case was found to be well within our approved criteria for justifying continued oporction, gjd 8903170051 890308 PDR ADOCK 05000282 I/
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' Director of NRR March 8, 1989 Northom States Power Company Page 2 and the piping represented by this case and had already been scheduled for' modification at our April, 1989 refueling outage due to as built discrepancies.
In summary, we have concluded that our stress calculation methods are in compliance with our USAR commitments and are safe and technically
- sound.
Please contact us if you have any questions related to the information l
we have provided.
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David Musolf Manager Nuclear Support Services c: Regional Administrator, Region III, NRC J A Gavula, NRC Region III NRC Sr Resident Inspector NRC Sr Project Manager G Charnoff Attachments l
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.y DONALD F, LANDE Premdent TELEDYNE ENGINEERING SEPMCES 130 SECONO AVENUE WALTHAM, MA08ACHUBETT5 02264 0106 -
(017) 8043300 TWX (710) 324-7808 January 19, 1989 7049C-1 Mr. Greg Rolfson Prairie Island Nuclear Generating Plant
'1717 Wakonade Drive East Welch, Minnesota ~
55089 Sub.iect: TES Technical Report TR-7049C, A Discussion of Torsion Effects on Limit Moment Theory and Piping Code Criteria
Dear Mr.' Rolfson':
The. attached report 'is submitted in response to your request for a review of the subject item by TES..The report was prepared by me and reviewed and verified by-Dr. William E. Cooper of our staff.
I would be happy to discuss our conclusions and reasons for reaching them at your convenience.
If you have any questions, please do not hesitate to contact me.
Very truly yours, a,Y DFL/1h Attachments I
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@ Tr:nsmittol-Please Sign cnd Return Ackn:wledgement 1PT WNE Request for Informtti;n (RFI)
Wherr Requested Assign Control Number ENGNEERING SERVICES
' Receipt (TES 'Use Only)
Page._1.of 1 1
Change Request Confirmation i
Control No.
7049C/001 Originator
- n. F_ landern
__ Transmit To: Mr. nrog Rn1fenn Project No.
7049C Prairio Te Niylone Generating Plant D:tte 1.1Q_Ro 1717 Wakonado nriva Fact Client PO Welch. Minnesota 550R0 Transmitted Under Separate Cover To:
N Ib Date QAE,UQ Date M9/Af Approved : Pro,ect Mgr.
NOTE: Furnish complete identificati$n for items transmitted (below).
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QTY TYPE ITEM IDENT NO.
REV DESCRIPTION - Title and Nomber of Sheets /Panas cf 5
I:opies TR-7049C 0
A Discuss' inn of Torsion Fffecte nn Iimit Mnmant Theory and Pipina Code Criteria
/15 g [ RWA)
ACKNOWLEDGEMENT OF RECEIP.T BY M/d TITLE dc<#hA DATE / ~2 0 -E '7 DISPOSITION FOR PREVIOUS REVISIONS
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O Return to TES O Mark Void Destroy Uncontrolled NOTE TO ADDl3)SS_E_E: Uilless stated otherwise the listed items are furnished to you as Controlled Documents. Please sign and return the number 2 copy to:
l TELEDYNE ENGINEERING SERVICES I
130 Second Avenue Waltham, Massachusetts 02254 Attention: Document Control, Project 7049C
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