Which controls are part of the positive measures for nuclear safety?

The correct answer focuses on accident prevention measures and physical security as critical components of nuclear safety. These controls are essential for maintaining a safe nuclear environment by reducing the likelihood of accidents and ensuring that nuclear materials are adequately protected from unauthorized access or tampering.

Accident prevention measures involve systematic approaches to identify, analyze, and mitigate potential hazards that could lead to nuclear incidents. These could include engineering controls, maintenance procedures, and safety protocols designed to prevent equipment failure or human error. Physical security refers to measures taken to protect nuclear facilities and materials from sabotage, theft, or other malicious acts. This includes surveillance systems, access controls, and security personnel trained to respond to threats.

While design features and operational strategies, training programs for personnel, and administrative procedures are important for nuclear safety, the core emphasis of positive safety measures is on preventing accidents and securing facilities, which aligns directly with the answer choice that mentions both accident prevention and physical security. These elements represent fundamental safeguards vital to the overall safety framework for nuclear operations.