The Institute of Electrical and Electronics Engineers (IEEE) 603-1991, “IEEE Standard Criteria for Safety Systems for Nuclear Power Generating Stations,” a technology neutral standard incorporated by reference in 10 CFR 50.55a(h), serves as the key regulatory requirement for instrumentation and control (I&C) safety systems in nuclear power plants in the U.S. Although the use of this standard and other IEEE standards have proven to be an effective method for the review and acceptance of I&C systems in the U.S., the NRC staff and a number of their stakeholders have indicated that relying on only conformance this standard to demonstrate safety may not provide the flexibility that many licensees and applicants desire. Although the U.S. has used IEEE standards since the beginning of the commercial nuclear industry as the primary reference for the development and licensing of I&C systems in nuclear power plants, other standards, such as the International Electrotechnical Commission (IEC) standards are widely used by vendors that provide components to the nuclear industry. There is an interest in using IEC standards to provide effective methods for the review of digital systems as part of the NRC review process. This paper will discuss possible alternatives for updating the regulatory infrastructure to accomplish this objective.