They have based much of their work on two propositions that are mutually exclusive:
The first assumption is that nuclear power can correct its economic problems via a large scale build-out of standardized reactor designs. For California alone they speak of one new reactor/year for 40 years.
The second is the claim that nuclear is a very low emissions technology with the assumption that it will continue in that state as it is scaled up.
There is significant evidence unaddressed in the CCST report which indicates that as nuclear ramps up, the grade of uranium fuel will decline, leading to significant increases in CO2e emissions. Switching to alternative fuel cycles that *might* keep emissions lower than that delivered by lower grades uranium ore would invalidate the economics and present a completely different set of serious external costs that would have to be evaluated.
There is also reason to believe the present day claims regarding the once through uranium fuel cycle GHGe emissions are suspect as valid data for a comparison of generating resource emissions.
Shrader-Frechette** examined claims usually encountered and found two common fallacies. The CCST paper is only guilty of one, but it is enough. Describing her own article, Shrader writes that those who argue for nuclear power based on the necessity to address climate change usually commit at least 2 errors. First they "trim" the GHGe data; and second they do not consider that the "climate-necessity argument" in relation to the merits of renewables which are better energy sources for avoiding GHG emissions.
Since in this paper CCST did do a comparison with renewables, we are concerned with the issue of data trimming. Quoting Shrader,
The nuclear-fuel cycle has 13 stages:
(1) uranium mining,
(2) milling,
(3) conversion to uranium hexafluoride (UF6),
(4) enriching UF6,
(5) fuel fabrication,
(6) reactor construction,
(7) reactor operation,
(8) waste-fuel processing,
(9) fuel conditioning,
(10) interim waste storage,
(11) waste transport,
(12) permanent storage, and
(13) reactor decommissioning and uranium-mine reclamation. When proponents of the climate-necessity argument claim nuclear energy is "carbon free," they err by trimming GHGE data. Even under optimum conditions, only one or two nuclear-fuel-cycle stages — often #(7) — is carbon free...
That paragraph continues with Shrader reviewing the studies available on the topic:
...If one excludes all fuel-lifecycle GHGE analyses that rely on secondary sources, are unpublished, or fail to explain GHGE estimation/calculation methods, 103 fuel-lifecycle, GHGE analyses remain. These calculate nuclear-fuel-cycle GHGE ranging from 1.4 to 288 g carbon-dioxide-equivalent emissions per kWh of electricity (gCO2/kWh). Nuclear-industry studies give total GHGE as 1.4 g but consider only one/two nuclear-fuel-cycle stages. Environmental groups give total GHGE as 288 g but appear to double-count some emissions. The mean total GHGE calculated by these 103 studies is 66 gCO2/kWh—roughly what independent university scientists (funded by neither industry nor environmentalists), at places like Columbia, Oxford, and Singapore, calculate <13–15>. These university analyses use current, refereed, published, empirical data on facilities’ lifetime, efficiency, enrichment methods, plant type, fuel grade, and so on. Their calculations (fairly consistent across universities), show the COAL:COMBINED-CYCLE NATURAL GAS:NUCLEAR:SOLAR PV:WIND ratio—for mean, fuel-lifecycle GHGE—is 1010:443:66:32:9—a ratio of 112 coal : 49 gas : 7 nuclear : 4 solar : 1 wind. If reasonably correct, these calculations show nuclear emits about 16 times fewer GHG than coal; about 2 times more than solar; and about 7 times more than wind <5>.
Shrader identifies the Kyoto Protocol language as a root source of trimmed data, and since the CCST uses the IPCC for emissions data, the argument used by CCST seems to be based on what Shrader identifies as a "fallacy of composistion" where the CO2e emissions in 1 or 2 stages are accepted as an accurate proxy for the entire, 13 stage fuel cycle;
Because climate-necessity proponents fail to count most nuclear emissions, they commit a fallacy of composition, making an invalid inference from GHGE in 1–2, to all 13, nuclear-fuel-cycle stages. Trimming these data however, may arise partly from Kyoto-Protocol conventions. These conventions assess carbon content in nuclear fuels at their consumption-point (electricity generation) and hence ignore fuel-cycle carbon content.
She identifies another are where data trimming occurs, which is the one I mention at the beginning of this response that is related to uranium ore quality.
Even when they consider GHGE from most nuclear-fuel-cycle stages, climate-necessity proponents typically trim nuclear-GHGE data through unrealistic assumptions, e.g., considering only nuclear-GHGE associated with higher-grade, not lower-grade, uranium ores. Yet cleaner, higher-grade ores are nearly gone <17>. Nuclear-fuel cycles using ten-times-less-concentrated ore (\0.01 percent yellow- cake) have total GHGE equal roughly to those for natural-gas-fuel cycles; all other things being equal, lower-grade-uranium-ore nuclear cycles release 12 times more GHGE than solar cycles, and 49 times more than wind cycles <18>. Some scientists even claim that low-grade-uranium-ore cycles could require more energy than they produce <14>, <19>.
Shrader's conclusion is
"Although there may be other, ethical, reasons to support nuclear tripling, reducing or avoiding GHG does not appear to be one of them."**Sci Eng Ethics (2009) 15:19–23 DOI 10.1007/s11948-008-9097-y
Data Trimming, Nuclear Emissions, and Climate ChangeKristin Sharon Shrader-Frechette