Why the Versatile Test Reactor is Key to Attaining Our Carbon-Free Energy Future

Thanks Laura.

The study finds each kilowatt hour of electricity generated over the lifetime of a nuclear plant has an emissions footprint of 4 grammes of CO2 equivalent (gCO2e/kWh). The footprint of solar comes in at 6gCO2e/kWh and wind is also 4gCO2e/kWh.

I think the figures you quoted for carbon emissions are a bit misleading, especially when considering the data from the source publication.

Most studies give a range of carbon emissions per kwh generated.  The ranges are broad,  making it very difficult to pin down any comparison.  In addition,  the source of the numbers cited are somewhat speculative, at best, as described in the Carbon Brief article:

«...this chart shows figures for a 2C world in 2050, when global electricity supplies have been largely decarbonised. This shift cuts the impact of indirect emissions due to electricity use, for example at a solar cell factory or nuclear fuel site.»

Also, as explained in the article, variation depends to quite a large degree on location:

«Note that the global average figures in the chart, above, hide wide geographical variation for some power sources, particularly hydro and solar.

The best solar technology in the sunniest location has a footprint of 3gCO2/kWh, some seven times lower than the worst solar technology in the worst location (21gCO2/kWh). Even at this top end, however, solar’s footprint is very low compared to other sources.»

Even the World Nuclear Association, never shy to tout nuclear, however nonsensically, as it describes nuclear waste, lists ranges for different power technologies:

No discussion of CO2 emissions with various forms of electricity generation would be complete without reference to the highly detailed Stanford studies:

Here, nuclear clearly takes a back seat, especially to solar and offshore wind.

It is tempting to simply say that nuclear and renewables are all far lower than fossil fuels, including coal with CCS (“…the study assumes that CCS only captures 90% of power plant CO2”), and leave it at that. But because of the large ranges for the carbon intensities for different power sources,  I suggest that the choice of power generation in a particular place and time needs to take into account where on the range of emissions a particular project might be.  Hydro especially, may turn out to be in the upper range and result in higher emissions than might be expected.  Hydro that does not require a dam or much storage of water may be on the lower range of emissions.  Therein may be the niches for nuclear.

I would add that the emissions from disposal of nuclear waste are not included in any of these approximations, since there is, so far, no such thing as final disposal of nuclear waste.  I can only guess that it won´t be trivial. Nor is any estimate inclusive of small nuclear power plants, SMRs, as they do not yet exist either.  I have seen no estimate of life cycle GHG emissions from those.  Presumably, they would result in higher emissions per kwh as they are smaller and more of them would be necessary.

I fear that at least part of the objective of the versatile test reactor program may be similar to the approach for the defense department´s F-35 multi-role fighter plane. Once enough money is spent, it becomes “too big to fail”. Heaven help us if that mentality takes over.

Has been my experience that industrial process heat employs saturated steam at relatively modest pressures. Also, need low-cost steam and that pretty much rules out using a nuclear reactor. Hydrogen production needs low cost electricity and/or steam, again pretty much ruling out using a nuclear reactor.

Seems to me the nuclear industry is engaging in a lot of marketing hype  to try and convince folks to go along with nuclear power. The main driver should be economics and not climate change conjecture. I would use the same admonition with green energy. The point ultimately being use the right energy source in the right place. That mix is highly dependent on location and available resources. One size does not fit all, which kind of echos Marks observations.