3.2　Content and Depth of Investigation

3.2.1　For the seismic investigation and evaluation of a nuclear power plant，the content and depth of investigation shall be determined according to the evaluation requirements in the preliminary feasibility study phase，feasibility study phase and preliminary siting.

3.2.2　The investigation and evaluation in the preliminary feasibility study phase shall mainly include collecting existing geological，seismic and geophysical data，and an appropriate amount of field investigation and exploration for preliminary evaluation of key issues in the region，near region and site vicinity scopes.The investigation shall cover the following:

1　Evaluation of the seismic and geological conditions affecting the site qualification，including seismogenic structure，maximum potential earthquake and capable faults.

2　Estimation of the upper value of SL-2 ground motion peak acceleration of the site.

3　Evaluation of earthquake-induced geological disasters.

4　Evaluation of regional crustal stability.

3.2.3　The investigation and evaluation in the feasibility study phase shall be conducted on the basis of the preliminary feasibility study.Additional geological，seismic and geophysical data shall be collected，and field investigation and exploration shall be conducted to complete the seismic safety evaluation.The investigation shall cover the following:

1　Evaluation of seismic activities，geodynamic and seismotectonic characteristics in the site region，and establishment of a regional seismotectonic model.

2　Definite evaluation of the capable faults in the site vicinity scope.

3　Determination of the design basis ground motion parameters of the site.

4　Evaluation of earthquake-induced geological disasters.

3.2.4　In general siting，the distribution，activity and capable faults in site vicinity scope shall be preliminarily described on the basis of the existing geological and seismic data collected，the upper value of the SL-2 ground motion peak acceleration shall be estimated and the design basis seismic acceleration of the site and the corresponding basic seismic intensity shall be presented.