The Glade 4.0

In reality, the DoE in large doesn't oversee commercial or research nuclear facilities (and the licensing therein) nor processing, reclamation, storage or disposal entities (and their licensing). Those were under the purview of the Atomic Energy Act which became the current NRC more or less. Interestingly enough, DoT/NTSA actually has some regulatory influence for the latter functions because they involved transportation of materials . And in reality, the NRC itself farms many of its regulatory functions out to de-facto czar organization such as INPO and EPRI. This is especially true when it comes to industry best practices type items.

The reality is, most of NRC's function is performed (from a design perspective) at a microscopic level by de-facto regulatory professional type societies such as ANSI, ASME, IEEE, ASTM, NIST, AISC, AISI etc. Much as legislative derived code gives way to administrative regulation in terms of which law actually ultimately defines what you can and cannot do, NRC's regulatory guidelines are much the same way to INPO/WANO/EPRI and the sundry list of professional societies I provided (as well as ones I can't think of). The NRC may identify specific commonalities within plants for design vulnerabilities but they do not define specifically if and how you are vulnerable or have designed a robust barrier between yourself and such a vulnerability. Those issues and their myriad of aspects ultimately fall at the feet of those secondary entities which are oftentimes forced to develop specific design criteria. The problem is, the NRC doesn't have the ability to judge if the guidance provided will satisfy the intent of their regulation. It's more or less reactive to do so.[/spoiler]
The truth is, the industry would follow these professional societies with or without the regulatory "guidance" of the NRC to do so because the large bulk of technical knowledge is invested in these types of organizations and in the general common engineering "library" of knowledge at large.

Even more disturbing is the somewhat racket like situation involving commercial power reactor licensing and commercial industry giants such as GE and Westinghouse. There is a 0% chance of a Hitatchi reactor ever coming online in the United States although GE Hitatchi has sold a few ABWR's already licensed in the US. Many of the Gen III+ type reactors have been denied license due the the complicated paperwork involved in licensing the plants and the fact that GE and Westinghouse basically hold the magic rubber stamp in the United States for commercial reactors. My personal opinion is the NRC at best, has severely retarded development of the industry in the United States (look to India and France to see the gap) and at worse made the US less safe in general. Post TMI and Chernobyl, when all pending combined construction/operation licenses were suspended and subsequently denied (or at least suspended indefinitely) many companies were forced to adopt long term strategies to keep plants in operation since new plants couldn't be brought online and seek license extensions (called renewals) pushing many plant components past their intended design life or into ages where evidence invalidates their original design life. Now, these of course can be replaced, but almost at a cost which almost makes the plant unprofitable.

In your example Hopwin, I'd combine those functions into the Department of Interior and Defense, which absolutely should exist. Defending the nation's power supplies is a function of our military and infrastructure should be handled by Interior. Transportation should be rolled into Interior as well and limited greatly. The EPA, FDA, and other regulatory agencies should be cut back a lot.