EXPERIMENTAL AND NUMERICAL DETERMINATION OF THE DYNAMIC PROPERTIES OF THE REACTOR BUILDING OF ATUCHA II N.P.P.

CEBALLOS, MARCELO A.; CAR, EDUARDO J.; PRATO, TOMÁS A.; PRATO, CARLOS A.; ALVAREZ, LUIS M.

NUCLEAR ENGINEERING AND DESIGN

ELSEVIER SCIENCE SA

Lugar: Amsterdam; Año: 1998 vol. 182 p. 93 - 106

0029-5493

Determination of the dynamic properties of the reactor building of Atucha II NPP is carried out in order to: (i) obtain valuable information for seismic qualification of the plant and (ii) access some procedures for testing and analysis that are used in the process of seismic evaluation of existing nuclear facilities founded on Quaternary soil deposits. Both steady state and impulsive dynamic tests were performed but attention is centered here in the techniques used to determine natural frequencies and modal damping ratios with impulsive tests. Numerical analyses were performed by means of a 3-D model of the superstructure together with foundation stiffness coefficients derived in a separate paper from steady state vibration tests, and also from analysis with a 2-D FE model of the soil layers capable of approximating the 3-D features of the problem. The computed foundation stiffness coefficients are compared both with those obtained from the tests and from an axisymmetric FE model: results indicate that foundation stiffness coefficients calculated with FE models with soil parameters given by laboratory tests performed on cored samples are significantly lower than those given by the steady state vibration tests.