Advanced isn’t Always Better


Below is a summary of key findings from the research titled “Advanced isn’t Always Better” by Edwin Lyman from the Union of Concerned Scientists. The study considered non light-water reactors (NLWR) aka Advanced nuclear or Generation IV reactors. It concludes that NLWRs are a long way from commercialisation and in their current form do not reduce safety or weapons risks and in many cases these risks are increased.

Former US Nuclear Regulatory Chairperson – Allison Macfarlane has recently made similar findings “But when it comes to averting the imminent effects of climate change, even the cutting edge of nuclear technology will prove to be too little, too late. Put simply, given the economic trends in existing plants and those under construction, nuclear power cannot positively impact climate change in the next ten years or more. Given the long lead times to develop engineered, full-scale prototypes of new advanced designs and the time required to build a manufacturing base and a customer base to make nuclear power more economically competitive, it is unlikely that nuclear power will begin to significantly reduce our carbon energy footprint even in 20 years—in the United States and globally. No country has developed this technology to a point where it can and will be widely and successfully deployed.”

Lyman, Edwin. 2021. “Advanced” Isn’t Always Better: Assessing the Safety, Security, and Environmental Impacts of Non-Light-Water Nuclear Reactors. Cambridge, MA: Union of Concerned Scientists. https://doi.org/10.47923/2021.14000. Pg 6.

Little evidence supports claims that NLWRs will be significantly safer than today’s LWRs. While some NLWR designs offer some safety advantages, all have novel characteristics that could render them less safe.

The claim that any nuclear reactor system can “burn” or “consume” nuclear waste is a misleading oversimplification. Reactors can actually use only a fraction of spent nuclear fuel as new fuel, and separating that fraction increases the risks of nuclear proliferation and terrorism. 

“Most NLWR designs under consideration do not offer obvious improvements over LWRs significant enough to justify their many risks. “

Once-through, breed-and-burn reactors have the potential to use uranium more efficiently without reprocessing, but many technical challenges remain.

High-assay low enriched uranium (HALEU) fuel, which is needed for many NLWR designs, poses higher nuclear proliferation and nuclear terrorism risks than the lower-assay LEU used by the operating LWR fleet. 

The significant time and resources needed to safely commercialize any NLWR design should not be underestimated.

Lyman, Edwin. 2021. “Advanced” Isn’t Always Better: Assessing the Safety, Security, and Environmental Impacts of Non-Light-Water Nuclear Reactors. Cambridge, MA: Union of Concerned Scientists. https://doi.org/10.47923/2021.14000. Pg’s 9 – 11.