ML19350E048

Forwards Response to Structural Engineering Branch Concern Addressed in Draft SER Section 3.8.2 Re Evaluation of Local Stresses in Steel Containment Shell

ML19350E048
Person / Time
Site:	Waterford
Issue date:	06/12/1981
From:	Maurin L LOUISIANA POWER & LIGHT CO.
To:	Tedesco R Office of Nuclear Reactor Regulation
References
W3P81-1450, NUDOCS 8106160344
Download: ML19350E048 (3)

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l LOUISIANA 242 cainance swa P O W E H ' & L i G H T! P 0 BOX 6008

• NEW ORLIANS. 70174(OUISIANA

+ (504) 368-2345 deess June 12, 1981 W3P81-1450 Q-3-A29.03 3-A1.01.04

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Mr. R. L. Tedesco ,

- N Assistant Director for Licensing 4 g\ . l,,,

U. S. Nuclear Regulatory Commission

\ N9gN# 7 Washington, D. C. 20555 k

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SUBJECT:

Waterford 3 SES \$ d N Docket Nc. 50-382 Structural Engineering Branch (SE3)

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Outstanding Draft SER Concern Yrd~~ 7/ *,g, ,y-d/

Dear dr. Tedesco:

Please find enclost4 material requested by the SEB needed to address a concern contained in Draft SER Section 3.8.2 regarding the evaluation of local stresses in the steel containment shell.

It you have any additional questions on this information, please do not hesitats eo call.

Yours very truly,

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f L. V. Maurin Assistant Vice. President Nuclear Operations LVM/MPF/dde Enclosure cc: E. L. Slake, W. M. Stevenson TPOI 1 S

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/Il l5 819616e344 l

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't I SEB AUDIT /SER OPEN ITEM NRC CUNCERN: "The applicant identified the use of the ' Welding Research i Council Bulletin No.107' for the evaluation of local l stresses of the cylindrical steel shcIl due to external j loads. - It was found that a substantial extrapolation of the data provided by the above reference was done without

.providing justification. The applicant has agreed to investigate this design procedure and provide required justification. This remains as an open item."

Response

The justification for the extrapolation of WRC-107 curves for cylindrical shells is provided wish two approaches, analytical and experimental. SHELLTECH Report 80-2,

" Evaluation of Reinforced Openings in Large Steel Pressure vessels", uddresses the principle of extending the curves and sF Ns the comparison from both analytical and experi-mental yproachen.

1) Analytical Approach ,

Bijlaard's work was plotted in WRC-107 with 2 geometric parameters, shell parameter gamma ( Y ) and attachment

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parameter beta ( # ) . Both parameters are in terms of Rm (mean radius of cylindrical shell) s T (wall thick- ,

ness of cylindrical shell) and r (outside radius of cylindrical attachment) .

Bijlaard's work was replotted in the SHELLTECH with a new parameter lambda ( h ) . The new parameter is in terms of d (outside diameter of nozzle), D (outside diameter of cylindrical vessel) and T (thickness of cylindrical vessel).

However, the parameters used in WRC-107 and SHELLTECH are comparable.

SHELLTECH Figure 2 shows that WRC-107 curves for all T values collapse into one common curve with new parameter ) . CB&I program #1634 (a thin shell re-volution program) farther supports the correctness of the WRC-107 curve by 5 plottings for (D/T = 1200),

which is approximately equivalent to ( Y = Rm/T-600) .

2) Experimental Approach The SHELLTECH Report includes the experimental results shown in CB&I's Report #74-9453 (1979).

" Experimental Testing Program for Nozzle Connec-tions in Cylindrical Shells", they are shown in Tables 1 thru 3, and Figures 14 thru 26.

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For example SHELLTECH Figure 14 shows a series of curves in comparison with the experimental data. For both CB&I programs #1634 (a thin shell revolution program) and #1682 (a finite element plate program), a general agreement with the experimental strain gage results is satis-

• factory. The experiments covered 2 nozzles with the shell parameter ( ( ) of 525 approximately.

The research program for evaluation of rein-forced openings in large steel pressure vessels is sponsored by the Pressure Vessel Research Connaittee (PVRC). The SHELLTECH woric was sub-mitted to the PVRC Sub-connaittee on reinforced openings and external loadings, the principal investigator is Professor Charles R Steelo of

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Stanford University.

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