Project risk management is one of the ten PMI knowledge areas.
Risk management includes the following processes:
- plan risk management
- identify risks
- perform qualitative risk analysis
- perform quantitative risk analysis
- plan risk responses
- control risks
PMI's ten knowledge areas: Integration management, Scope management, Schedule management, Cost management, Quality management, Resource management, Communications management, Risk management, Procurement management, Stakeholder management
Risk management is described in chapter 11 of the PMBOK, 5th edition.