Van Snyder's Web about Nuclear Power
Why Nuclear Power?
- Nothing else can provide all the energy we currently use. See the papers
linked below in Why Renewable Sources Aren't Enough.
- Even if the problems noted by Heard et al in the link
below can be overcome, providing firm power from dispersed and variable sources
will be extremely expensive. See the papers by Jenkins and
Thernstrom, Mearns, Shaner et al,
and Rogers 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 below.
- Nuclear power is the safest-ever way to make electricity, by an extremely
wide margin. Here's a graphic from the Paul Scherer Institut:
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,
- 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 significant expense to separate isotopes 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.
See the links to reports of used LWR fuel contents
For a completely closed system that produces no long-lived transuranics, a
fast-neutron reactor with fuel reprocessing, such as described by Till and Chang, is necessary.
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-chlorine thermochemical process at an energy cost of 532 kJ/mol (about
0.079 MWh/T), and the Fischer-Tropsch process to combine them. PARC estimates
this can be done for $3.00/gallon. 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.
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
- Sufficient storage is impossible
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 [renewable energy] 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
- Matthew R. Shaner, Steven J. Davis, Nathan S. Lewis, and Ken Caldeira
Geophysical constraints on the reliability of solar and wind power in the
United States Energy & Environmental Science (Issue 4, 2018)
that the storage requirement for the United States might be twice as large as
Mearns calculated, if current standards for reliability (99.97%) are desired.
- Norman Rogers reached a similar conclusion in
Is 100 Percent Renewable Energy Possible?. Using data from Texas,
he calculated that storage capacity of 400 watt hours 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.