It’s been nearly eight years since the Department of Energy (DOE) submitted to the Nuclear Regulatory Commission (NRC) an application for a license to construct the proposed Yucca Mountain high-level radioactive waste repository and six years since the Secretary of Energy unilaterally declared the project unworkable and attempted to withdraw the license application. Despite the lack of cooperation from DOE, the NRC has been quietly but steadily continuing its reviews of the application (to the extent of available appropriations) as required by the Nuclear Waste Policy Act and the D.C. Circuit Court of Appeals in the Aiken County case.

In October 2014, the NRC staff issued its completed Safety Evaluation Report (SER) addressing key aspects of the repository design and performance. On all counts, the NRC staff concluded that the repository satisfies NRC requirements. In that SER, the NRC staff found DOE’s performance assessment evaluations to be in compliance with the regulatory requirements and that in all areas the regulatory performance objectives are satisfied, including regulatory limits for individual protection, human intrusion, and separate standards for groundwater protection.

Now, on May 5, 2016, the NRC staff has issued a Final Supplement to the Yucca Mountain Environmental Impact Statement (FSEIS). This supplement describes the effected environment and assesses the potential environmental impacts with respect to potential contaminant releases from the repository into groundwater over a one-million-year period. The FSEIS evaluates the potential radiological and non-radiological impacts on groundwater, soils, ecology, and public health. The FSEIS assesses the potential for cumulative impacts associated with other past, present, or reasonably foreseeable future actions. The NRC staff concludes that each of the potential direct, indirect, and cumulative impacts from groundwater and surface groundwater discharges would be SMALL.

But, what does this mean for the future of Yucca Mountain? The NRC cannot issue a license for Yucca Mountain without completing the suspended contested hearing process in which the State of Nevada opposes the license. And, those processes cannot be completed without adequate funding from Congress and would likely require some support from DOE. But, despite the political and budgetary obstacles to completing the licensing process, the FSEIS demonstrates—as did the earlier SER—that the Yucca Mountain project is licensable. While project opponents have argued that Yucca Mountain is “not safe” or would have long-term environmental impacts, the fact that the expert independent agency charged with ensuring radiological health and safety at licensed facilities has found that the project meets regulatory requirements and has minimal environmental impact would seem to count for something.

The NRC reports are a small return on a very large investment at Yucca Mountain. Nonetheless, as the reasons for opposing Yucca Mountain get weaker in the face of the evidence, U.S. policy makers may be getting closer to a tipping point—where the political support for removing spent fuel from reactor sites around the U.S. and the cost of DOE’s continued recalcitrance overwhelms opposition by Nevada and others. Congress currently has before it two House bills (H.R. 3643 and H.R. 4745) and one Senate bill (S. 854) that would allow DOE to proceed with interim consolidated waste storage facilities. And an elusive permanent disposal facility at Yucca Mountain or some other site is not dead yet.