California is making a fresh push to reopen the door to nuclear energy. AB 305, introduced in the State Assembly in January 2025 by Assemblymember Juaquin Arambula, seeks to exempt small modular reactors from the civil nuclear moratorium that has been in force in the state since 1976. If passed, the bill would allow the construction and operation of reactors with a capacity of up to 300 megawatts per unit — projects currently barred by law from even entering the permitting process.
California’s moratorium is rooted in the Nuclear Safeguards Act of 1976, which prohibits the certification of new nuclear fission plants until a demonstrated technology for the permanent disposal of high-level radioactive waste exists. Five decades later, that law continues to block next-generation projects as well, including the SMRs that the industry and several U.S. state governments are already actively considering. AB 305 proposes to carve this category of plants out of the general ban, creating a specific regulatory pathway for small-scale reactors.
This is not the first attempt. A previous measure, Assembly Bill 65, had already sought to establish a similar exemption for SMRs, but failed to advance through the legislative process. Before that, comparable proposals were killed in committee. The same pattern played out with AB 305: the bill made it to committee, but was scaled back to a feasibility study, deferring any real decision. Nuclear advocates have been blunt in describing this approach as “analysis paralysis.”
The requested study would examine the impact of admitting SMRs into California’s energy system, with a focus on grid reliability, consumer costs, and decarbonization benefits. The California Public Utilities Commission would be required to deliver its findings to the legislature by January 1, 2027. In the meantime, the political debate remains live. Governor Gavin Newsom’s office has stated that he maintains an interest in emerging nuclear technologies, provided they meet specific criteria on safety, cost, and environmental impact. State Senator Josh Becker, chair of the Senate Energy Committee, has indicated that no low-emission solution can be categorically ruled out from the climate discussion.
