In the face of evolving threats, nuclear security frameworks must adapt to new risk factors and challenges, both internal and external. In examining what factors are the most likely to indicate an insider threat from nuclear facility personnel, the systems and methods to identify indicators – both for new hires and existing personnel are based off of problematic and antiquated conceptualizations of who or what constitutes a threat. For nuclear facilities to more effectively screen their personnel for insider threats, a more diverse, equitable, and inclusive (DE&I) security culture must be the norm. By creating a DE&I security culture, nuclear facilities can more effectively incorporate these elements into their broader nuclear security architecture from the ground up. This paper will examine cases studies of insider threat incidents through a DE&I lens to highlight where gaps in nuclear security insider threat assessments exist. It will then go on to argue that by implementing DE&I into personnel reliability programs and nuclear security culture, nuclear facilities can improve insider threat assessments to screen for domestic violent extremists, protect against foreign threats, and more effectively identify risks to nuclear facilities.