Final answer:
The segregation distance for incompatible materials is important for safety and depends on local guidelines and substance risks, with 20 feet being a common practice for highly reactive materials.
Step-by-step explanation:
The question is related to the safe storage practices for incompatible materials in a laboratory or industrial setting. The recommendation for segregation of these materials typically depends on local regulations and specific risks associated with the substances involved. When dealing with the storage of fissile materials or other hazardous chemicals, it's crucial to keep them apart to prevent unwanted reactions. While the question does not provide a definite answer, a distance of not less than 20 feet is often considered a prudent practice for segregating highly reactive or incompatible chemicals, but this distance can vary. It's important to always refer to local guidelines and materials safety data sheets (MSDS) for specific segregation distances.