The deployment of nuclear energy systems across diverse industrial and grid applications is constrained by mismatches between reactor capabilities, application requirements, and integration architectures. Existing approaches evaluate projects on a case resulting in inconsistent comparisons and non This paper introduces the Nuclear Engineering Interface Architecture (NEIA) based framework that organizes nuclear energy integration into structured classes representing demand characteristics, reactor capabilities, integration architectures, and resulting system configurations. The NEIA framework provides a consistent vocabulary for describing applications and enables identification of feasible deployment pathways, compatible reactor classes, and integration complexity. The framework is conceptual and classification supporting early-stage planning, technology screening, and nuclear energy applications.