Human reliability analysis (HRA) contributes to assessment and to reduction of the impact of human operators to the risk of technologies and processes. The objective of this paper is to integrate realistic deterministic safety analysis and probabilistic safety assessment to show how deterministic safety analysis impacts the HRA, which is integrated into the probabilistic safety assessment. The RELAP5/MOD3.3 computer code is used for realistic safety analysis. Parametric safety analysis studies give time parameters for human actions as an input for selected HRA. Calculated human error probabilities arc inserted into probabilistic safety assessment and the results are obtained, where the focus goes to the most important risk contributors. The method and the results are shown on selected HRA method through two selected representative human actions. Results show that realistic safety analysis represents an important standpoint for assessment of human error probabilities within HRA. (C) 2007 Elsevier Ltd. All rights reserved.