Van Snyder's Web about Nuclear Power
Why Nuclear Power?
- Nothing else can provide all the energy we currently use. See the paper by
Heard et al linked below.
- If the problems Heard et al note below can be overcome, providing firm power
from dispersed and variable sources will be extremely expensive. See the papers
by Jenkins and Thernstrom, Mearns, and Shaner et al linked below.
- Decommissioning nuclear reactors undercuts carbon emission reductions. The
next doubling of solar capacity will not make up for carbon emission reductions
foregone by the recent closure of five reactors. See the papers by Roth and Jaramillo and Roberts, linked
- Nuclear power is the safest-ever way to make electricity, by an extremely
wide margin. See the papers by Hannum, Marsh, and Stanford
and Baurac linked below. See the references in my long paper about energy and nuclear power. Read the
UNSCEAR reports on Chernobyl and Fukushima linked below.
- The right kind of nuclear reactor, with the right kind of used-fuel
reprocessing, can effectively destroy the substance we currently call "nuclear
waste," and nothing else can (see link to Plentiful
Energy below). Nuclear "waste" is actually valuable 95%-unused fuel. The
unused fuel part needs custody for 300,000 years, but a better idea is to turn
it into energy and fission products. Fission products are produced at the rate
of one tonne per gigawatt-electric year (8,766,000,000 kWh). In spent fuel that
has "cooled off" for ten years,
See the links to reports of used LWR fuel contents
- 3.93% (39.3 kg/GWe-yr) of fission product isotopes produce 99.3% of
radiotoxicity and need custody for 300 years. These are mixed with 52.7
kg/GWe-yr of nonradioactive isotopes of the same elements, making 9.2%, or 92
kg/GWe-yr, if the trouble to separate them is not taken.
- 43.6% of fission product elements produce the remaining 0.7% of
radiotoxicity and are less radiotoxic than uranium in nature before 30 years.
- 47.1% of fission product elements are not radioactive or have such low
activity that ICRP Publication 119 does not list a dose factor.
We will need liquid hydrocarbon fuels indefinitely for airplanes, probably for
ships, heavy construction equipment, farm equipment, and heavy freight too large
for trains, and maybe for long-distance auto travel. In
CO2 extraction from seawater using bipolar membrane electrodialysis
(Energy & Environmental Science 2012, DOI 10.1039/c2ee03393c), Eisamen et
al described the PARC BPMED process to extract 52% of dissolved CO2 from
seawater at an energy cost of 242 kJ/mol (about 1.5 MWh/T). Hydrocarbon fuels
can be made using CO2, hydrogen extracted from seawater using the copper-chloride
process, and the Fischer-Tropsch process to combine them. The energy density of
automotive gasoline is about 12.5 MWh/T. Burning hydrocarbon fuels made from
seawater would be a net negative CO2 transfer to the atmosphere and oceans. CO2
that results from burning the fuels will go into the atmosphere, and eventually
back into the oceans, but surely some will be trapped in plants and soils.
Uranium can be extracted from seawater, but this will not be necessary for a
very long time. The United States has 80,000 tonnes of spent fuel and 900,000
tonnes of depleted uranium. This is enough to fuel an all-nuclear all-electric
American energy economy for 575 years -- longer than that to the extent solar
and wind contribute. The long term attraction is that it is essentially
limitless. Uranium salts are water soluble, and are continuously entering the
oceans from the bottom and in rivers. The concentration of uranium in seawater
and ocean-bottom rocks is in equilibrium. As uranium is taken from seawater,
more enters from rocks. There is enough uranium already in the oceans to
provide all the energy humanity currently uses for a million years.
Why Renewable Sources Aren't Enough
Comments? Questions? Spot any mistakes?
- 100% Renewable can't work
B.P. Heard, B.W. Brook, T.M.L. Wigley, C.J.A. Bradshaw, Burden of proof: A comprehensive review of the
feasibility of 100% renewable-electricity systems, Renewable and
Sustainable Energy Reviews 76, Elsevier (2017), 1122-1133.
"While many modelled scenarios have been published claiming to show that a 100%
renewable electricity system [that excludes nuclear power] is achievable, there
is no empirical or historical evidence that demonstrates that such systems are
in fact feasible."
Free link: http://www.thesciencecouncil.com/images/pdfs/Burden%20of%20Proof.pdf
- Deep decarbonization is expensive
Jesse D. Jenkins and Samuel Thernstrom,
Deep Decarbonization of the Electric Power Sector: Insights from Recent
Literature (March 2017).
Deep decarbonization without nuclear power will be extremely expensive (and
Heard et al say it's impossible).
- Shutting down reactors is stupid
- Storage can't work
Grid-Scale Storage of Renewable Energy: The Impossible Dream,
Energy Matters (November 20, 2017).
UK had about 26 GWe installed peak label capacity of wind and solar in 2016,
which produced 4.6 GWe-yr in 2016 -- a capacity factor of 17.7%. From the
abstract of the article:
"The utopian ambition for variable renewable energy is to convert it into uniform
firm capacity using energy storage. Here we present an analysis of actual UK
wind and solar generation for the whole of 2016 at 30 minute resolution and
calculate the grid-scale storage requirement. In order to deliver 4.6 GW uniform
and firm RE supply throughout the year, from 26 GW of installed capacity,
requires 1.8 TWh of storage. We show that this is both thermodynamically and
economically implausible to implement with current technology."
Geophysical constraints on the reliability of solar and wind power in the
United States, Shaner et al calculated that the storage requirement for
the United States might be twice as large, if current standards for reliability
(99.97%) are desired.
Is 100 Percent Renewable Energy Possible?, Norman Rogers reached a
similar conclusion. Using data from Texas, he calculated that 400 watt hours
of storage is needed per average watt of wind and solar capacity.
My back-of-the-envelope calculation concluded that a
1,700 GWe all-renewable American energy system would require spending 2.8 to 5.5
times US 2016 GDP per year for batteries alone. This is not economically
viable, even if storage costs decrease by a factor of ten.
- South Australian blackout
I waited to comment on the SA blackout: reflections on preliminary findings,
Ben Heard explains that the entire grid in the State of South Australia failed
after a windstorm because of a lack of inertia (i.e., frequency stability).
There was insufficient frequency stability, so more and more providers had to
shed load to prevent damage to their systems. What provides inertia on an
electricity distribution grid? Heavy synchronous rotating generators -- coal,
gas, nuclear, hydro. The relatively clean, modern, 485 MWe combined-cycle gas
generator in Adelaide was offline because its economics had been subsidized away
to pay for wind from the public purse.
van dot snyder at sbcglobal dot net.