ML20140H987
| ML20140H987 | |
| Person / Time | |
|---|---|
| Site: | 05200003 |
| Issue date: | 05/09/1997 |
| From: | Diane Jackson NRC (Affiliation Not Assigned) |
| To: | Liparulo N WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP. |
| References | |
| NUDOCS 9705130349 | |
| Download: ML20140H987 (3) | |
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UNITED STATES
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,j NUCLEAR REGULATORY COMMISSION o
'f WASHINGTON. D.C. 20665-0001 l
%,..... #o May 9, 1997 Mr. Nicholas J. Liparulo, Manager Nuclear Safety and Regulatory Analysis Nuclear and Advanced Technology Division 1
Westinghouse Electric Corporation P.O. Box 355 Pittsburgh, PA 15230 SUF 'ECT: REQUEST FOR REVISED DESIGN DRAWINGS, 3-D FINITE ELEMENT MODEL OF SHIELD BUILDING ROOF STRUCTURE AND OVERALL SEISMIC MODEL OF NUCLEAR ISLAND FOR THE AP600 DESIGN
Dear Mr. Liparulo:
In response to the Nuclear Regulatory Commission (NRC) requirements for post-72 hour actions, Westinghouse has proposed a number of design changes on 1
the shield building.
These design changes include a reduction of the passive containment cooling system (PCS) tank wall and roof slab thickness, increase of the height of the roof structure, and increase of the water inventory in 1
the tank.
i In a March 14, 1997, letter, (in respcnse to the staff's February 18, 1997, letter) Westinghouse proposed to perform a local (shield building roof) evaluation to demonstrate that the design changes are insignificant.
If the demonstration based on the local evaluation is not convincing, Westinghouse proposes to repeat the hard rock fixed-base analysis of the nuclear island stick model.
The staff has expressed concern regarding the completeness of i
the proposed evaluation because it is based on local structural elements and, therefore, does not capture the global effects due to the increase in mass at each nodal point and the reduction in stiffness on the seismic responses.
In addition, the staff believes that making a comparison between the results from j
a hard rock fixed-base seismic analysis against the existing analysis results is insufficient. The basis for the staff's conclusion is that the effect of increasing mass properties to the structural responses may not be significant for the hard rock site condition, but it could be pronounced for the soil site condition, especially for a soft soil site and if the mass properties of live load are included.
t From discussions with Westinghouse daring the April 14 through 18, 1997, y
meeting, it is the staff's understanding that Westinghouse is revising its
)
analysis models and continuing to perform the evaluation using the proposed approach. The staff has determined that it will conduct a new confirmatory soil-structure interaction analysis of the nuclear island based on the soft-to-medium-stiff site properties, and a finite element confirmatory analysis of the shield building roof structures under combined load conditions to reach its safety conclusion on the AP600 design.
For this purpose, Westinghouse needs to provide revised design drawings and analysis models (revised design drawing of shield building roof structures, 3-D finite element model of roof structures and revised 3-D lumped-mass stick model of the 9705130349 970509 e
ao" la NPiC FILE CENTER COPY l
l Mr. Nicholas J. Liparulo May 9, 1997 nuclear island structures). As stated the staff's letter, dated May 1, 1997, the revised 3-D lumped-mass stick model should:
(1) include the mass effec +s (including mass moment of inertia) due to the live loads and the increase of water inventory in the PCS tank at each mass degree of freedom, and (2) incorporate the changes of the PCS tank structure design and modify the stiffness properties of the shield building roof structure stick model.
Westinghouse is requested to provide revised the design drawings, the 3-D finite element model of the shield building roof structures, and the revised 3-D lumped-mass stick model of the nuclear island structures to perform our confirmatory analyses by the end of May to support the review schedule. This request for additional information (RAI) is identified as RAI# 220.111.
Sincerely, original signed by-Diane T. Jackson, Project Manager j
Standardization Project Directorate Division of Reactor Program Management Office of Nuclear Reactor Regulation i
Docket No.52-003 l
cc:
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0FFICIAL RECORD COPY
.l Mr. Nicholas J. Liparulo Docket No.52-003 Westinghouse Electric Corporation AP600
.cc: Mr. B. A. McIntyre Mr. Ronald Simard, Director Advanced Plant Safety & Licensing Advanced Reactor Programs Westinghouse Electric Corporation Nuclear Energy Institute 1
Energy Systems Business Unit 1776 Eye Street, N.W.
P.O. Box 355 Suite 300 Pittsburgh, PA 15230 Washington, DC 20006-3706 Ms. Cindy L. Haag Ms. Lynn Connor Advanced Plant Safety & Licensing Doc-Search Associates Westinghouse Electric Corporation Post Office Box 34 Energy Systems Business Unit Cabin John, MD 2083 Box 355 Pittsburgh, PA 15230 Mr. James E. Quinn, Projects Manager LMR and SBWR Programs Mr. M. D. Beaumont GE Nuclear Energy Nuclear and Advanced Technology Division 175 Curtner Avenue, M/C 165 Westinghouse Electric Corporation San Jose, CA 95125 One Montrose Metro 11921 Rockville Pike Mr. Robert H. Buchholz Suite 350 GE Nuclear Energy Rockville, MD 20852 175 Curtner Avenue, MC-781 i
San Jose, CA 95125 l
Mr. Sterling Franks I
U.S. Department of Energy Barton Z. Cowan, Esq.
NE-50 Eckert Seamans Cherin & Mellott
-19901 Germantown Road 600 Grant Street 42nd Floor Germantown, MD 20874 Pittsburgh, PA 15219 Mr. S. M. Modro Mr. Ed Rodwell, Manager i
Nuclear Systems Analysis' Technologies PWR Design Certification Lockheed Idaho Technologies Company Electric Power Research Institute Post Office Box 1625 3412 Hillview Avenue Idaho Falls, ID 83415 Palo Alto, CA 94303 Mr. Frank A. Ross Mr. Charles Thompson, !!uclear Engineer U.S. Department of Energy, NE-42 AP600 Certification Office of LWR Safety and Technology NE-50 19901 Germantown Road 19901 Germantown Road Germantown, MD 20874 Germantown, MD 20874
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