Online risk monitoring becomes increasingly a standard component of the risk-aware operation control. The underlying risk model of the facility in question is updated each time the state of the facility changes, including a new operation mode, external factors, and the availability of equipment. Then the relevant risk measures are evaluated and can serve as an input for operational decisions improving the facility performance. On one hand, the risk of an accident must be kept within acceptable bound. On the other hand, all activities affecting the risk level, such as maintenance or inspections, should be performed so that whenever possible they do not decrease the production and thereby the revenues. The model for utility risks and the evaluation methods differ depending on the definition of risks of interests and the nature of operation. We introduce general concepts of risk monitoring and its benefits. We describe implementations of a risk monitor for various types of risks: nuclear reactor core damage in a nuclear power plant, a reactor trip also in nuclear power plants, and an interruption in a drilling operation on an offshore oil rig. We also discuss other possible application domains for online risk monitoring.