Diverse safety systems are defined as systems that

• A. Use the same principles to perform the same function
• B. Use different principles to perform the same function
• C. Are always the primary path to safety
• D. Are never used in redundant configurations

Answer: (B)

Diverse safety systems are designed to achieve the same safety function but through different physical principles. The aim is to avoid common mode failures: if one type of failure affects one approach, the other system—using a different principle—can still perform the required safety action.

In practice, you might see one train that actuates a shutdown or safety injection via a hydraulic or pneumatic path, and another train that accomplishes the same outcome through an electrical or mechanical means, or a passive mechanism. Both are meant to respond to the same hazard and deliver the same protective result, but they don’t rely on the same technology or the same failure modes. This diversity strengthens overall reliability because it reduces the chance that a single fault could disable all protective measures.

Diversity is often used in redundancy to reinforce safety design, rather than serving as the sole path to safety. It complements redundancy by ensuring that multiple, independent ways exist to achieve the same end, so a common cause won’t knock out every route to safety.