Following obstacles make it difficult to prevail the actual application of risk assessment techniques in various industrial fields in spite of its excellent power on preventing troubles and accidents, i) Listing up the hazards and risks existing among job processes and environments is only to rely on personal experiences or memory; ii) Crucial risk information such as accident reports, near miss event reports and safety improvement proposals was not ready for use and each was locally distributed; iii) Risk assessment activities need much efforts and time. It is still important to overcome above obstacles for further application of this technique with enough validity. If it is possible to offer the effective tool for the risk assessment, proactive measures to reduce accidents could be avail, and more leading to ensuring safety culture. Considering how to remove above obstacles, CRIEPI has been developing a tool applicable to real working field based on the risk information data-base (DB) system, in which various kinds of risk data collected from actual environment and expert experience and also extended preliminary to implementing risk evaluation and taking suitable countermeasures. This tool has been developed with a close cooperation to one of the thermal power plant.