An initiative by former Microsoft CEO Bill Gates offers the
possibility of adapting evolving nuclear technology to future commercial
maritime propulsion. His research team seeks to combine an improved version of
thermal storage technology pioneered by the solar thermal power industry with a
345MW liquid sodium cooled reactor. That combination offers future propulsive
possibility to the maritime sector.
Over the past 10 years, a small number of companies have
developed small-scale nuclear reactors with output comparable to large
commercial ships. Toshiba has developed an installation of 10MW output,
Hyperion focused on developing an installation of 25MW and NuScale has
developed an installation of 60MW. While nuclear fuel is costly, the group
supported by Gates has focused on developing a nuclear reactor capable of using
spent nuclear fuel rods as the main energy source. The sheer amount of spent
nuclear fuel rods internationally enhances the commercial and social
attractiveness of re-using spent fuel rods.
The development of thermal storage technology enhances the
operation and cost-effectiveness of nuclear power stations. During off-peak
periods and during rare emergency shut-downs, a large portion of heat produced
by a nuclear reactor may be transferred into heat-of-fusion thermal storage at
constant temperature. There may be scope to develop thermal storage technology
for mobile operation aboard a vessel and to source thermal energy from a large
shore or offshore-based stationary large-scale thermal storage installation
built adjacent to a nuclear power station. Mobile thermal storage may also
allow for development of commercial nuclear ship propulsion.
Evidence from the natural world indicates that thermal storage
material has incredible useable life expectancy. Water has solidified and
melted billions of times over the earth’s history. High temperature thermal
storage material capable of producing steam can also offer thousands to
millions of repeated cycles solidifying during cooling and melting during
reheating. Nuclear reactors operate optimally with highest reliability when
maintained at constant temperature, which access to thermal energy storage
would encourage. Access to thermal storage would enhance the operation of even
a small nuclear reactor adapted to mobile operation in maritime propulsion.
Onboard heat-of-fusion technology that produces steam to
drive an engine can offer ships a few hundred miles of operational range. The
technology could be installed into a tug that would push and navigate a barge.
Alternatively, the heat-of-fusion vessel could be a power generator to be towed
by a large ship to which it provides electrical power to activate ship-mounted
electric motors that drive propellers (azipods). The towed vessel could also
include a small nuclear generator that would provide propulsive electric power
to the main ship and offer trans-ocean sailing range.
While a stationary nuclear power station would provide
recharge energy to a large-scale stationary thermal storage installation, there
would likely be scope to modify the technology to include thermal recharging
from mobile nuclear reactors installed in a towed vessel that provides
propulsive electrical power to a large ship. Onboard stored battery electric
power could provide short-distance low-speed sailing to the large ship, with
the option of the ship towing a local battery-electric or thermal-electric
vessel able to provide propulsive electric power to the ship’s propellers. Such
ships would sail between ports that have nearby coastal thermal storage
technology.
Future nuclear power would include the Gates-inspired 345MW
reactor designed to operate on spent nuclear fuel rods as well as
radiation-free fusion thermal power currently being researched. Access to
thermal storage technology would enhance the economics of nuclear fission and
radiation-free fusion technologies, as well as mobile nuclear technologies that
include the 60MW NuScale reactor, the 25MW Hyperion reactor and 10MW Toshiba
reactor that could all be adapted to civilian commercial maritime propulsion.
Research in underway involving thorium based reactor technology with potential
to reprocess thorium for repeated use to maintain reactor thermal energy
production.
The combination of coastal nuclear power with grid-scale
thermal storage would allow thermal rechargeable tugs and vessels to operate
comparatively short-sea shipping service, between ports where thermal energy
storage is also available. Coastal short-sea shipping is cost-competitive in
terms of moving bulk cargo and includes both domestic shipping and
international ship transportation. Most short-sea shipping operations involving
thermal energy storage would combine a large tug pushing and navigating a large
barge. International trans-oceanic shipping involving the operation of a
nuclear reactor would be restricted to routes where navies could assure ships
security from piracy.
Security reasons would prevent sailing nuclear powered
commercial vessels via the southern region of the Red Sea, leaving trans-North
Atlantic routes between Europe and North America, trans-Pacific routes between
the Americas and Australia as well as between the America’s and East Asia.
Future nuclear-powered trans-Pacific commercial shipping would likely involve
transshipment operations at any of the Philippines, Taiwan or Chinese ports
located east of Hong Kong. With big ships requiring over 80MW of main engine
power, a ships carrying a 345MW nuclear reactor could sail in a convoy of 4 to
5-ships to which it supplies propulsive electrical power.
Several companies internationally are involved in the
research and development of small-scale nuclear power capable of providing
propulsive power to a single ship or a small convoy of ships. The development
of thermal energy storage technology that is compatible to nuclear power
enhances the long-term operation and long-term cost competitiveness of small
–scale nuclear power. The initiative of former Microsoft CEO Bill Gates
involves both the development of suitable thermal storage technology as well as
methods by which to generate electric power from energy contained in the
abundance of spent nuclear fuel rods.
While nuclear power is controversial, small-scale nuclear
power combined with thermal storage technology offers a future propulsion
option to the maritime industry.