In a report released on August 2, 1999, the The President's Committee
Of Advisors On Science And Technology (PCAST
)
recommended that the U.S. consider participating in international research
on extracting uranium from seawater:
"One possibility for maintaining fission as a major option without
reprocessing is low-cost extraction of uranium from seawater. The
uranium concentration of sea water is low (approximately 3 ppb) but the
quantity of contained uranium is vast - some 4 billion tons
(about 700 times more than known terrestrial resources recoverable at a
price of up to $130 per kg). If half of this resource could ultimately
be recovered, it could support for 6,500 years 3,000 GW of nuclear
capacity (75 percent capacity factor) based on next-generation reactors
(e.g., high-temperature gas-cooled reactors) operated on once-through
fuel cycles. Research on a process being developed in Japan suggests
that it might be feasible to recover uranium from seawater at a cost of
$120 per lb of U3O8.40 Although this is
more than 10 times the current uranium price, it would contribute just
0.5¢ per kWh to the cost of electricity for a next-generation reactor
operated on a once-through fuel cycle-equivalent to the fuel cost for an
oil-fired power plant burning $3-a-barrel oil." [emphasis added]
40 Nobukawa 1994: H. Nobukawa "Development of
a Floating Type System for Uranium Extraction from Sea Water Using Sea
Current and Wave Power," in Proceedings of the 4th International
Offshore and Polar Engineering Conference (Osaka, Japan: 10-15 April
1994), pp. 294-300.
US Patent # 4,835,433
Apparatus for Direct
Conversion of Radioactive Decay Energy to Electrical Energy
(May 30, 1989)
Paul M. Brown
Abstract
~
A nuclear
battery in which the energy imparted to radioactive decay products
during the spontaneous disintegrations of radioactive material is
utilized to sustain and amplify the oscillations in a high-Q LC tank
circuit is provided. The circuit inductance comprises a coil wound on a
core composed of radioactive nuclides connected in series with the
primary winding of a power transformer. The core is fabricated from a
mixture of three radioactive materials which decay primarily by alpha
emission and provides a greater flux of radioactive decay products than
the equivalent amount of a single radioactive nuclide.
Inventors:
Brown; Paul M. (Boise, ID)
Assignee: Nucell, Inc. (Portland,
OR)
Appl. No.: 153070
Filed: February 8, 1988
Current U.S. Class: 310/305; 136/202;
376/320; 976/DIG412
Intern'l Class: G21H 001/00
Field of Search: 376/320,321
310/301,304,305 136/202
Seawater as source of the fuel
Getting the most out of that fuel
Broken Link to the Future: Suppression
Dr. Paul M. Brown
(Died April 7, 2001) ~ Obituary
www.nuclearsolutions.com
Company Literature:
Peripheral Systems
(1980s)
A radioisotope electric power
system developed by inventor Paul Brown is a scientific breakthrough
in nuclear power. The battery utilizes the energy given off by
decaying radioactive material, converting it directly into a
continuous AC electrical current. Unlike conventional nuclear
generating devices, the power cell does not rely on a nuclear reaction
or chemical process and does not produce radioactive waste products.
Brown's first prototype power
cell produced 100,000 times as much energy per gram of strontium-90
(the energy source) than the most powerful thermal nuclear battery yet
in existence. The Nucell battery yielded 7500 watts per gram of
strontium-90. Compare this to an advanced device recently developed by
the US Dept. of Energy Byproducts Utilization Program. Their
state-of-the-art thermal nuclear battery produced 0.063 watts per gram
of strontium-90…
The key to the Nucell battery is
Brown's discovery of a method to harness the magnetic energy given off
by the alpha and beta particles inherent in nuclear material. Alpha
and beta particles are produced by the radioactive decay of certain
naturally occurring and man-made nuclear material (radionuclides).
The electric charges of the
alpha and beta particles have been captured and converted to
electricity for existing nuclear batteries, but the amount of power
generated from such batteries has been very small. Alpha and beta
particles also possess kinetic energy by successive collisions of the
particles with air molecules or other molecules. The bulk of the R&D
of nuclear batteries in the past has been concerned with this heat
energy which is readily observable and measurable.
The magnetic energy given off by
alpha and beta particles is several orders of magnitude greater than
either the kinetic energy or the direct electric energy produced by
these same particles. However, the myriads of tiny magnetic fields
existing at any tie cannot be individually recognized or measured.
This energy is not captured locally in nature to produce heat or
mechanical effects, but instead the energy escapes undetected. Brown
has invented a way to "organize" these magnetic fields so the great
amounts of otherwise unobservable energy could be harnessed.
The weight of the strontium-90
used to generate 75 watts of power in the Nucell prototype is
approximately the same as the weight of 2 millimeters of wire cut off
the end of a small paper clip. Projected sizes of the Nucell battery
will range from the size of a soup can to the size of a small barrel
or waste can for a 50 kilowatt model.
The alpha and beta particles
utilized in the Nucell battery have a limited ability to penetrate
matter; alpha particles can be contained by a piece of paper; beta
particles require 0.03" of aluminum. The Nucell battery is housed in a
stainless steel, high-vacuum container, making it a safe, impermeable
source of power.
"Technical
Explanation of the Power Cell Invention" (Excerpt)
Useful Fuels ~
Any radioisotope in the form of
a solid that gives off alpha or beta particles can be utilized in the
new power cell. The first cell constructed (that melted the wire
components) employed the most powerful source known, radium-226, as
the energy source. However, radium 226 gives rise through decay to the
daughter product bismuth-214, which gives off strong gamma radiation
that requires shielding for safety. This adds a weight penalty in
mobile applications.
Radium-226 is a naturally
occurring isotope which is formed very slowly by the decay of
uranim-238. Radium-226 in equilibrium is present at about 1 gram per 3
million grams of uranium in the earth's crust. Uranium mill wastes are
a readily available source of radium-226 in very abundant quantities.
Uranium mill wastes contain far
more energy in the radium-226 than is represented by the fission
energy derived from the produced uranium.
Strontium-90 gives off no gamma
radiation so it does not necessitate the use of thick lead shielding
for safety. Strontium-90 does not exist in nature, but it is one of
the several radioactive waste products resulting from nuclear fission.
The utilizable energy from strontium-90 substantially exceeds the
energy derived from the nuclear fission which gave rise to this
isotope.
Once the present stores of
nuclear wastes have been mined, the future supplies of strontium-90
will depend on the amount of nuclear electricity generated. Hence
strontium-90 decay may ultimately become a premium fuel for such
special uses as for perpetually powered wheel chairs and portable
computers.
The most difficult problems in
managing nuclear wastes are handling the great amount of heat
generated by alpha and beta emitters and isolating the alpha and beta
emmitters' biosphere. Virtually all other alpha and beta emitters in
nuclear fission wastes can be employed in the new power cells. Hence
these no longer constitute wastes but have become valuable energy
assets.
