The main design features, services, and human-machine interface characteristics are described of the CERTA VITA on-line plant information system developed and installed by KFKI AEKI at the Nuclear Safety Directorate (NSD) of the Hungarian Atomic Energy Authority (HAEA) in cooperation with experts from the NSD. The Center for Emergency Response, Training, and Analysis (CERTA) located at the headquarters of NSD, Budapest, Hungary, was established in 1997. The center supports the NSD installation, radiological monitoring, and advisory team in case of nuclear emergencies, with appropriate hardware and software for communication, diagnosis, prognosis, and prediction. The vital information transfer and analysis (VITA) system represents an important part of the CERTA, as it provides for the continuous remote inspection of the four VVER-440/V213 units of the Hungarian Paks nuclear power plant (NPP). The on-line information system maintains a continuous data link with the NPP through a managed leased line that connects CERTA to a gateway computer located at the Paks NPP. The present scope of the system is a result of a 4-yr development project: In addition to the basic safety parameter display functions, the VITA system now includes an on-line break parameter estimation module, an extensive training package based on simulated transients, and on-line data transfer capabilities to feed accident diagnosis/analysis codes.