The analysis uses the seismic response curves (OBE, SSE) for SINKORI 3/4 that were reflected the revision to the seismic requirement of nuclear power plant. New curves contain higher amplitude than those of previous nuclear power plants in Korea. The structure was modeled using finite element techniques. Calculated stresses from finite element model are evaluated in accordance with design criteria of KEPIC MCN, 2000.
The Refueling Machine (RM) consists of two structural parts of bridge and trolley. The bridge structure is approximately 8.5 m long and 5 m wide and is primarily composed of two 700 mm deep wide flange sections spanning the reactor area at the operating level. A trolley structure is mounted on wheels that roll on the rails of the bridge structure.
The trolley supports a tubular mast which extends approximately 8.5 m below the trolley. This tube houses a movable hoist assembly which can extend an additional 5 m during operation.
The model drawing which is included as part of this report shows the finite model in detail. Geometry, element numbers and symbols are described on the model drawings. The base structures of RM are the shell for bridge, trolley, mast and hoist and the beam for hoist frame and grapple. A trolley assembly is mounted on wheels and assumed positioned at two locations of side and center on the rails of the bridge structure.
The seismic analysis utilizes the response spectrum analysis. The mode shapes and spatial components for the X, Y and Z directions were combined using the square root if the sum of the squares (SRSS) method. Closely spaced modes are combined in accordance with NRC Reg. Guide 1.92.
The natural frequencies are used by the first fifty modes in the seismic analysis of the ANSYS. It can be seen that the higher modes do not have a significant effect on the results.
The stresses in all element due to the static and seismic loads were combined and evaluated with respect to the allowable stress. The stresses of welds and bolts also are checked based on KEPIC SWS and MCN 2314.