[en] 1 - Description of program or function: An integrated fault-event tree software package PSAPACK (Probabilistic Safety Analysis Package) was developed for level-1 PSA using personal computers (PC). IT is a menu driven interactive modular system which permits different choices, depending on the user's purposes and needs. The event tree development module is capable of developing the logic accident sequences based on the user's specified relations between event tree headings. Identification of success sequences and core damage sequences is done automatically by the code based on the success function input by the user. It links minimum cut sets (MCS) from system fault trees and performs the Boolean reduction. It can also retrieve data from the reliability data base to perform the quantification of accident sequences. 2 - Restrictions on the complexity of the problem: The fault tree module contains full screen graphics and text editors. It is possible to transfer the tree structure from graphics to text format and vice-versa. Fault tree reduction and minimum cut set determination is performed by well known codes like ALLCUTS, MOCUS of FTAP. Convenient interfaces have been developed for input data preparation and for storage of the results in the MCS library. The MCS module can be used for the MCS screening and quantification. PC version of SAMPLE code is used in this module for uncertainty analysis