ML17059B244

Non Proprietary Version of Suppl 1 NMP-1 Seismic Analysis, Core Shroud Repair Mod.

ML17059B244
Person / Time
Site:	Nine Mile Point
Issue date:	08/13/1996
From:	Gleason T, Mahadevan A, Ranganath S GENERAL ELECTRIC CO.
To:
Shared Package
ML17059B240	List: ML17059B239 ML17059B241 ML17059B242 ML17059B243 ML17059B244 ML18040A180
References
GENE-B13-01739, GENE-B13-01739-03, GENE-B13-1739, GENE-B13-1739-3, NUDOCS 9608210143
Download: ML17059B244 (22)

Text

ENCLOS 4 SUPPLEMENT 1 MILKPOINT 1 SEISMIC ANALYSIS, CORE SHROUD REPAIR MODIFICATION NON-PROPRIETARY VERSION 9b082iOi43 9b08i4 PDR ADOCK 05000220 ',

P PDR

a CE Nuclear'nergy GENE Bf3417XRV Supplement 1 Classlll August f8%

~EPruprieta~nformation Supplement f Nine Nile Point f Seismic Analysis, Core Shroud Repair Modification Prepared for.

Niagara Mohawk Power CorporatIon Nine Mile Point Unit 1 Prepared by:

GENuclear Energy Reactor Nodjfication Services 175 Curtner Avenue, N/C 511 San Jose, California 951ZS

0 GE Nuclear Energy GENE B13-01739-03 Supplement 1 Class III August 1998 Supplement 1 Nine Nile Point 1 Seismic Analysis, Core Shroud Repair Modification Prepared by:

A. Mnhndevnn, Seninr Engineer er/B t n Modification Services 0'eactor Reviewed by: 8'- $ '-p t TE. Gleason, Principal Engineer Reactor Modification Services Approved by:

3 <sag S. Ranganath, Engineering Fellow GE Nuclear Engineering

GENEB1341 RHU Supplement 1 Cisss ill August, 1998 81ON S Revision Approval Date Description 0 P. Walier Dec. 1994 Initial issue.

Suppl. 1 S. Ranganath August, Evaluate revised lower spring spacing.

1996 . /

GENE B1$ 4D3943 Supplamant 1 Class III August fS98

.ROPRIET Y..INFORMATIO .NOTICE This document contains prop infomiation of the Gen lectric Company (GE) and is furnished to the Niagara Mohawk Power purposes stated in the transmittal letter. No o information it contains is authorized. N the information it contains to oth thout oration s

the (N

written e,

l not pu 'r consent in direct or o

confidence indirect, solely for the purpose or of the document or the otherwise disclose this document or and shall return the document at the request of GE.

The propri mformation contained in this report is designated by "bars" located in the ri and I

~mar i IMPORTANT- NOTIC G CO S OF THIS REPORT Please read carefully 1

This report was prepared by Gcncral Electric solely for the use of thc Niagara Mohawk Power Corporation. The information contained in this report is believed by General Electric to be an accurate and true representation of the facts known, obtained or provided to General Electric at the time this report was prepared.

The only undertakings of the General Electric Company respecting the information in this document are contained in thc contract governing this work, and nothing contained in this document shall bc construed as changing said contract. The use of this information except as defined by said contract, or for any purpose other than that for which it is intended, is not authorized; and with respect to any such unauthorized use, neither General Electric Company not any of the contributors to this document makes any representation or warranty (express or implied) as to the completeness, accuracy, or usefulness of the information contained in this document or that such use of such information may not infringe upon privately owned rights; nor do they assume any responsibility for liability or damage of any kind which may result &om such use of such information.

~Nmprietasylokanstian GElIlEB13403943 Supplement 1 Cliss III August,'1998 CONT&MTS INTRODUCTIONooooooooooooooooooooooooe ooooooo ooo oioooooooooooooooooooo~oooooooooo~oooo oooooooo ~ oooooooooooooooool

SUMMARY

AND CONCLUSIONS ANALYSIS RESULTS~oo~~~

REFERENCES

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..4

8ENE81341 3947 SuplJlement1 Classlll August,;1Hf

1. INTRODUCTION Thc purpose of this supplement to the seismic analysis is to address the change in the spacing between lower spring on the shroud repair hardware. Lower springs located at 90'ntervals have the .

same equivalent spring constant in any direction of thc applied load. Spacing greater than two adjacent springs tends to decrease the equivalent spring constant for loads applied 90'etween between thc two. Spring spacing less than 90'ends to increase thc equivalent spring constant for loads applied between the two. Relocating the 270'ower spring to the opposite side of the tic rod, along with changes made prcvioulsy, result in the maximum spring spacing increasing to108'nd the minimum spacing between springs decreasing to 76'.

2.

SUMMARY

AND CONCLUSIONS

I q GENE B13417%49 Supplement 1 Cless///

August, 1896'.

ANALYSIS The as-built locations of the tie rods are at azimuths.90',-1 66'-,.270', and 350'.. The lower stabilizer is attached to one side of the tie rod assembly (consistcnt side) at all four tie rod locations. The lower stabilizer at the 270'ie rod location, however, was found to be contacting the RPV at the'bend radius of the rcciculation pipe nozzle, resulting in partial bearing against the RPV. In order to remedy this, the lower stabilizer spring at this tie rod location is proposed to be removed and re-attached to the

'other'ide of the tie rod assembly. This would result in the lower stabilizers being apart as follows:

350'0' Stabil. Locn.

100'odif. 40 166'66' 90'6O 274'74' 350'50'

=

=

108'6O 904 270'rig. / WQ~

Stabil. Locn. A I

Lower Stabilizer Minimum Angle Spread =

Angle Spread = 108' 76'aximum Tic Rod The nominal lower stabilizer stiffhess used in seismic analysis is based on 90'pread. The minimum angle spread of 76 (Load direction B) results in upper bound net stabilizer stiffness and the maximum angle spread of 108'Load direction A) results in lower bound nct stabilizer stiffness.

Analysis was performed to assess the impact of the variation of the lower stabilizer stiffness (bounded by these upper and lower bound stabilizer stiffnesses) on the hardware seismic loads and displace ments.

GENEBf341ÃRRU Supp/ament 1 Class Ill August', t998 3.1 Lower StablHzer Stiffness

4. RESULTS The resulting hardware loads, displacements, loads in key internal components, and shroud frequencies are surninarized in Table l.

The displacements are within the allowables specified in the design specification (Reference 2). The hardware loads will be reconciled separately by comparing against the design loadslmargins. The loads on key internal components are also suinmarized and are less than or equal to the loads based on uncracked, unmodified shroud. The shroud frequency shifts due to the stiffness changes are very small and moreover, they are in the frequency range where the spectral amplitudes are almost flat or mildly ramping, thus resulting in the above insignificant effects.

CENEB134f AMB Supplement 1 Cljkslll Augu+ 1998 (ii)

5. REFERENCES 5.1. Nine Mile Point 1: Seismic Analysis -Core Shroud Repair Modification, Report Number:

GENE-B13-0173943, Revision 0.

5.2. Design Specification - Shroud Repair, GE Document No. 25A5583.

GE Nuclear Energy GENE-B13-01739-03 Supplement 1 Table 1 NMP 1 Shroud Repatr: Selemlc Analysis - Lower StabNzer StNnesa Parametrfc Study August, 1996