ISIS Report 26/01/09
Safe, Less Costly Nuclear Reactor Decommissioning and More
How weak interaction LENRs can take us out of the nuclear safety and economic
black hole Lewis Larsen
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LENR ULM neutrons for cleaning up current nuclear and ultimately replacing
fossil fuel power generation
Low Energy Nuclear Reactions (LENRs) based on weak interactions
and their ultra low momentum (ULM) neutrons not only have the
potential to be used for an entirely new source of
green, clean energy (see  Low Energy Nuclear Reactions for Green
Energy and  Widom-Larsen Theory Explains Low
Energy Nuclear Reactions & Why They Are Safe and Green in SiS 41), they may also solve many serious public safety and environmental problems
associated with current nuclear fission and fossil-fuel power generation technologies,
and at the same time, dramatically reduce the risks
of nuclear weapons proliferation and significantly improve long-term profitability for the global power generation industry.
LENRs have the potential to offer revolutionary business and environmental
opportunities such as green low-cost, distributed power generation systems and/or
large grid-connected power plants based solely on weak interactions and gamma-shielded
neutron captures (see  Portable
and Distributed Power Generation from LENRs SiS 41), as well as substantial
savings on nuclear waste cleanup costs (see  LENRs for Nuclear
Waste Disposal SiS 41). In this article we shall explore how LENRs
could reduce costs and the time it takes for decommissioning old reactors; and
the potential for retrofitting certain types of nuclear reactors with safer,
cheaper LENR-based subcritical fission heat sources that can replace existing
reactor cores. In the next and final article in this series, we shall discuss
retrofitting existing coal-fired power generation plants with green LENR-based
boilers, an attractive economic option for commercial power plant operators.
ULM neutrons are efficient ‘triggers’ for nuclear fission and neutron capture
As discussed previously , compared with neutrons
at thermal and higher energies, ULM neutrons generated by LENRs could be extraordinarily
effective in triggering nuclear fission in fissile isotopes, and 3 – 4 orders of magnitude
more efficient at releasing nuclear binding energy via neutron capture on
various 1/v target fuels/isotopes. That is
one way in which LENRs could help improve existing fission power technologies.
Strong interaction fission reactions produce extremely energetic products
that are much more hazardous than ‘simple’ alpha
decays or weak interaction beta decays. Nevertheless, LENR
ULM neutron-triggered fission reactions do produce substantially
larger total energy releases than the most energetic weak interactions. When 1/v fissile heavy elements
 such as uranium and/or plutonium serve as target fuels for LENR ULM neutrons,
asymmetric heavy element fission releases ~190 – 200 MeV per reaction.
Nuclear binding energy released from fissile
target fuels is ~243 to 512 times breakeven energy cost for producing ULM
neutrons, depending on whether protons or deuterons are the base fuel for
making ULM neutrons. U-235 fission produces a much larger multiple of
breakeven than the ~16 MeV released by the green LENR lithium-8 beta decay reaction . Fission
releases much more energy than energetic beta and/or alpha decays that occur
in LENR systems; also more than ULM neutron captures that typically occur
on various isotopes of ‘green’ target fuels such as nickel, titanium, calcium,
or even dysprosium (such captures typically release binding energies of ~7–8
MeV ; any energetic gammas produced are converted directly into heat by
nearby heavy electrons).
Onsite cleanup of nuclear wastes from spent fuels with LENRs and ULM neutrons
Spent fuel now stored in cooling ponds located at nuclear power stations is generally
acknowledged to be a source of major hazards  Close-up on Nuclear
Safety (SiS 40). Developing a technology
for the cleanup of high-level nuclear wastes using LENR-based transmutation
reactors  would remove the hazard of storing them locally and/or shipping
them cross-country to secure storage sites such as Yucca Mountain in the US . Nuclear
weapons proliferation and environmental risks would be sharply reduced because fissile and/or highly radioactive isotopes
would never have to leave commercial reactor sites.
Nuclear power finance: cost structures of PWRs and BWRs are heavily front-loaded
Most existing commercial nuclear power plants are light-water
reactors (LWRs), with pressurized-water (PWRs) [8, 9] or boiling-water (BWRs)
[10, 11]. In PWRs and BWRs, a nuclear reactor core containing fuel rods and
related assemblies is enclosed within a thick, solid steel-alloy reactor vessel
inside a thick steel-reinforced concrete containment building. These massive
structures contain the radiation and protect the physical integrity of the
Of 439 nuclear power plants currently operating worldwide, 264 of them
are uranium-fueled PWRs, now the most common type in service; and 94 are uranium-fueled
BWRs, the second most common type. Light water PWRs and BWRs comprise 82 percent
of operating reactors and provide 88 percent of global nuclear power generation
Nuclear power plants cost much more to build than to operate over their
entire 20 – 60 year lifetimes. Some 60 percent of total, fully-burdened power
generation costs are actually initial capital investment costs ,
exclusive of upstream mining and enrichment or downstream decommissioning
and cleanup. In other words, the greater part of the economic costs is required
to design, construct, license all of the necessary physical facilities, load
the first round of fuel assemblies, and connect to the electrical grid. A
financier would say that nuclear power plant facilities have very front-loaded
cost structures. By comparison, ongoing variable costs of operation
(staff, nuclear fuel, maintenance, regulatory compliance, etc.) are modest.
If the costs of upstream mining and enrichment processes are included, the
reactor vessel itself and its contents only averages about 18 percent of the
total capital cost or roughly 11 percent of the total fully-burdened power
generation cost .
LENR technology for reducing the cost of decommissioning nuclear reactors
When present-day commercial nuclear fission reactors are
finally retired from decades of service, they must be decommissioned in approved
ways to minimize health and environmental hazards  (see
 The Nuclear Black Hole,
SiS 40). Worldwide, primarily three
strategies are utilized for decommissioning nuclear plant facilities .
Immediate dismantling and cleanup (in the US, this option
is called ‘Early Site Release/Decon’).
Safe enclosure of the facility for 40 –
60 years (in the US, this is called “Safestor”). The entire facility is placed in long-term
‘safe storage configuration’ awaiting deconstruction and nuclear waste cleanup
at some future date.
drastic alternative). The facility is placed
in a safer physical condition such that radioactive materials can remain sequestered
onsite without ever having to be totally removed. This last-ditch technique
was used to isolate the ruins of the Chernobyl power reactor [16, 17].
In decommissioning after permanent reactor shutdown
~99 percent of the radioactivity that is of greatest concern to human health
and the environment is associated with fuel rods and fuel assemblies .
The remaining 1 percent of post-shutdown radioactivity comprises the following:
water that may be contaminated with radioisotopes; ‘activation products’
mainly found in steel-alloy structural components that were heavily irradiated
with neutrons during a reactor’s operating life, including iron-55, cobalt-60,
nickel-63, and carbon-14; and trace amounts of radioactive gases that may
still be present. Spent fuel removal and disposal is thus a major part of
the cost in decommissioning reactors.
Reactor decommissioning costs can be very tricky to forecast. In the USA, many utilities now
estimate average costs of US$325 million per reactor (1998 $). In France,
decommissioning of the Brennilis Nuclear Power Plant, a fairly small 70 MW
power plant, cost 480 millions euros so far (20x initially estimated costs),
and cleanup is still ongoing after 20 years. Despite huge investments in ensuring
safe dismantlement of the reactor, radioactive elements such as plutonium,
cesium-137 and cobalt-60 accidentally leaked out into a surrounding lake,
further increasing costs and time. In the UK,
decommissioning of the Windscale Advanced Cooled Reactor (WAGR), a 32 MW power
plant, cost 117 million euros. In Germany, decommissioning of Niederaichbach nuclear power plant, a 100MW power
plant, cost about 90 million euros .
I have already mentioned that radioactive nuclear waste in spent reactor
fuel rods and assemblies could potentially be processed onsite with
LENR technology to transmute waste into complex arrays of non-radioactive
stable elements and isotopes . Exactly the same approach could be used
to get rid of fuel remaining in nuclear reactors after permanent shutdown.
In such cases, using LENRs for cleanup might significantly lower costs and
time for decommissioning, and avoid using the ‘safe enclosure’ and entombment
Potential for retrofitting LENR fission technology to existing nuclear power
Nuclear power’s unusually front-loaded cost structure opens
up a potential future business opportunity for plant operators to retrofit
and improve existing PW and BW reactors for substantially safer, much less costly
subcritical LENR fission power generation that, furthermore, would not produce
large quantities of highly radioactive waste. This could be done by replacing
current reactor cores with new heat sources based on LENR ULM neutron-triggered
In a capital-conserving strategy, the majority of the global power
generation industry’s enormous financial investment in infrastructure for
commercial fission reactors (land, licensing, containment buildings, reactor
vessels, steam generators, electrical generators, monitoring and control systems,
etc.) could be protected and redeployed with limited economic and technological
disruption. Plant operators that took advantage of retrofitting existing reactors
with LENR technology would be rewarded with more profitable businesses that
have intrinsically lower liability risks; the public and the environment would
be rewarded with much safer, less hazardous LENR-based fission power plants
that could continue to supply low-cost electricity to regional grids that
supply billions of people worldwide.
LENR-based sub-critical fission reactors safer, cheaper and cleaner for the
The production rates of ULM
neutrons from LENR reactions, to be used for triggering nuclear fission, range
from 1011 up to 1016/cm2/s
. Amazingly, these large fluxes were obtained
from small, poorly optimized laboratory systems. Yet they are comparable to
neutron fluxes that occur in commercial fission reactor cores, which typically
range from 1012 to 1014/cm2/s .
A ‘subcritical’ fission process  is one in which the total flux
of fission neutrons during reactor operation is deliberately controlled so
as to be insufficient to maintain ‘criticality.’ Put another way, in the absence
of another external source of neutrons, there simply aren’t enough fission
neutrons produced locally to achieve and maintain self-sustaining fission
chain reactions  inside the reactor. Importantly, a fission reactor that
is running below ‘critical’ will automatically fizzle out within a relatively
short period of time.
As ULM neutrons can
be used to trigger fission, we have developed proprietary concepts for LENR-based
subcritical fission reactors. If successfully developed, potentially
retrofitable LENR-based ‘cores’ might provide safety and environmental advantages
over existing types of uranium-based fission reactors, or even some concepts
for advanced thorium-based reactors , all of which depend on criticality
to sustain nuclear reactions.
As large fluxes of ULM neutron-triggered high-energy fission neutrons and significant fluxes
of energetic gammas would be released during reactor operation, subcritical
ULM neutron-triggered fission
reactors would still require the same types of radiation shielding
and related containment structures needed in today’s reactors. In relying on fission to produce heat, LENR-based subcritical
reactors could never be as environmentally green and safe as ‘pure’ weak interaction
LENR-based systems that create their heat using substantially less energetic, non-fissile/fertile target
fuels that produce heat via a combination of beta/alpha decays and gamma-shielded
neutron captures. Nonetheless, LENRs could still improve on existing fission
technologies as well as leverage the power generation industry’s existing
capital investments in plant infrastructure.
Safer subcritical fission reactors have been discussed since 1994, but none
The idea of developing safer subcritical fission reactors
for producing power and transmuting nuclear waste is not new; it has
been theoretically discussed by physicists for years. Perhaps the first well-publicized
subcritical concept was invented by Italian Nobel
laureate Carlo Rubbia in 1994. It was called an “energy amplifier”
[23, 24] and consisted of a proton cyclotron accelerator combined with a thorium-based
nuclear reactor cooled with liquid lead.
Conceptually, subcritical fission reactors depend on a very tightly
controlled external neutron source to provide additional neutrons that are
absolutely required to keep fission reactions going continuously in reactor
fuel. Similar to Rubbia’s earlier energy amplifier, current subcritical concepts
[25-31] typically integrate fission reactors with some sort of external particle
accelerator to speed up protons. Those protons are then directed at a special
target that produces a flux of energetic neutrons via spallation reactions.
The neutron flux created by the accelerator beam is then allowed to come into
contact with the reactor fuel, adding to neutron fluxes produced by local
fission reactions in the fuel. These subcritical reactor designs are called
Accelerator-Driven Systems (ADS). No large scale ADS has ever been built,
possibly because of the additional expense
and complexity of developing and integrating a large, external high-current
particle beam accelerator.
The overall rate of fission in an ADS subcritical reactor is controlled
by simply altering the accelerator beam current, which in turn controls the
required external supply of neutrons. Power generation in the reactor’s fuel
goes up or down in tandem with changes in total neutron fluxes (which are
the sum of locally produced fission neutrons and moderated neutrons derived
from energetic spallation neutrons produced by the accelerator).
A key advantage of subcritical fission reactors is their inherent controllability
and safety: if an accelerator producing spallation neutrons is simply turned-off,
the rate of fission in reactor fuel slows down and stops reasonably quickly.
Uncontrollable ‘runaway’ criticality accidents like the Chernobyl Reactor
#4 in the Ukraine (1986) 
or the Three Mile Island TMI-2 reactor in the US (1979)  are all but impossible with
subcritical reactors. Importantly, extremely complex, expensive real-time
monitoring, control systems, and operating procedures that are necessary for
current nuclear reactors to help prevent criticality accidents, would be unnecessary
with LENR-based subcritical reactors. This should reduce initial construction
costs and ongoing operating and maintenance costs.
Subcritical fission reactors by themselves
will not necessarily solve radioactive waste problems. However, LENR-based
fission technologies that combine subcriticality with complete waste burnup
could potentially solve both problems at once. Given dramatically improved
safety and tremendously reduced quantities of ‘hot’ radioactive waste, LENR-based
systems might have much lower intrinsic liability risks, reducing insurance costs.
LENR-based subcritical fission reactors incorporate novel design concepts
Our proprietary concepts for LENR ULM-based subcritical
fission reactors eliminate the cost and complexity of a large external, integrated
particle accelerator, replacing it with a lower-cost, better method of ‘in-core’
neutron generation that produces large, highly controllable fluxes of ULM
neutrons created in close proximity to target fuels and subsequent nuclear
reaction products. This LENR-based approach also handles the post-shutdown
residual ‘decay heat’ issue as an integral part of the subcritical reactor
While using mainly LENR ULM neutrons to trigger fission would not suppress
emissions of high-energy MeV neutrons that normally occur during fission processes
(massive radiation shielding and containment structures would still be needed),
the approach could still help solve many of today’s nuclear waste remediation
and proliferation problems.
Fluxes of LENR ULM neutrons, working together with concurrent fluxes
of fission neutrons, would be used to essentially burn up every isotope in
fissionable nuclear fuel that is capable of capturing neutrons, including
fissile/fertile isotopes, radiologically ‘hot’ fission fragments, and transuranic
elements. By carefully controlling and dynamically adjusting the ratio of
ULM neutron fluxes to concurrent fluxes of much higher-energy neutrons generated
by fission processes, as well as to the isotopic composition and current numbers
of available target nuclei, there would be essentially no radioactive waste
remaining after fuel burnup; nuclear waste remediation would then cease to
be a costly problem for plant operators.
Achieving effectively 100 percent burnup down to stable isotopes could
also solve most reactor decommissioning radioactivity issues, because storage
and disposal of radiologically ‘cold’ spent fuel remaining in an LENR-based
fission reactor after permanent plant shutdown would not pose any serious
safety or environmental hazards.
In LENR-based fission reactors, time needed to burn new,
nanoparticulate fuels down to stable isotopes would vary, depending
on the target fuel, operational and design details of a given reactor, and
anticipated power demand over some time interval. It would likely require
less than a few weeks for complete fuel burnup; not months or years.
Nanoparticulate nuclear fuels enable LENR-based reactors with new capabilities
Another important distinction between our LENR-based fission
concepts and present reactor technologies is the physical form of nuclear
fuel. Instead of being fabricated in the form of macroscopically large,
cylindrical fuel rods  or ‘pebbles’  (see  Safe New
Generation Nuclear Power?, SiS 29), LENR target fuels would be
in the form of specially designed and fabricated nanoparticulates (dispersed
in gases or liquids) that have extremely high surface-to-volume ratios. By
employing nanotechnology, this new type of nuclear fuel could be mass-produced
inexpensively and would enable very rapid, complete burnup of target fuels
down to ‘cold’ spent fuel comprised of stable isotopes.
Nanoparticulate target fuels utilized in commercial versions
of LENR-based subcritical fission reactors would be loaded into and stored
in separate nearby, deeply buried, secure underground fuel repositories. Although
nanoparticulate fuels and hydrogen isotopes stored in such repositories would
be densely packed, their composition and placement would be designed such
that even densely packed masses of fresh fuel would remain very far from criticality
under any conceivable scenario.
Compared to macroscopically large fuel rods or ‘pebbles’, high surface-area
nanoparticulate fuels and LENR ULM neutrons should be able to produce much
more complete energy release from target fuel before being ‘spent.’ This would
substantially increase heat production from a given quantity of fissile material
(e.g., uranium-235), thus improving plant profitability. Essentially 100 percent
burnup of fissiles in LENR-based reactors would also eliminate any need to
reprocess spent fuel to recover and burn valuable fissile isotopes. That should
ease nuclear proliferation risks, as significant quantities of weapons-usable
fissile isotopes would not be present in LENR-based reactors’ spent fuel.
At any given time, today’s commercial fission reactors may contain
anywhere from 1 to 3 years worth of unburned uranium-235 fuel, as well as
substantial quantities of other fissile isotopes (e.g., plutonium-239) and
dangerous nuclear wastes. By contrast, use of nanoparticulate fuels in LENR-based
subcritical fission reactors could eliminate the need to have large quantities
of unburned fissile fuel and ‘hot’ wastes present inside LENR fission reactors
during normal operation; nanoparticulates create this new capability because
they enable dynamic injection of fuel into reactors.
Dynamic on-demand ‘fuel injection’ in LENR-based subcritical fission reactors
The ‘heart’ of an LENR-based fission reactor could be conceptualized
as a ‘nuclear combustion chamber’ in which: large concurrent fluxes
of LENR ULM, moderated, and ‘fast’ fission neutrons are produced; neutron
captures occur, triggering nuclear fission and a broad array of different
transmutation reactions; and raw heat is generated for transfer and conversion
into electricity by a system’s integrated thermal generators.
Akin to a combustion chamber in an IC engine, LENR-based
subcritical fission reactors would be able to dynamically inject intentionally
limited quantities of nanoparticulate target fuels and hydrogen isotopes into
the ‘working region’ of a reactor. Such periodic injections would deliver
only the minimum amount of fuel necessary to meet anticipated power demand
during a period of a few days to perhaps a week or two.
When additional nuclear fuel is required to continue to
generate power, necessary quantities of target fuel would be very quickly
and securely conveyed from undergoing repositories and injected into an LENR-based
reactor’s ‘combustion chamber.’
Unlike today’s nuclear plants, long-term refueling of LENR
reactors would not involve a significant plant shutdown; it could be accomplished
simply by unloading nanoparticulate target fuels and hydrogen isotopes directly
from transport containers into secure underground repositories located at
Current PWRs/BWRs and most future ‘Gen-4’ nuclear reactor
concepts (likely deployment would be circa 2030) typically have years’ worth
of unburned fuel and waste products present in a reactor at any given time.
By contrast, LENR subcritical reactors’ separate secure underground storage
of fresh nuclear fuel, dynamic 'on-demand' injection of just enough fuel into
reactors to satisfy relatively ‘near-term’ power demands, and complete fuel
burnup, are revolutionary features unattainable in today’s reactors.
LENR-based subcritical fission reactors could be ‘omnivorous’ consumers of
Unlike comparatively inflexible fuel requirements of today’s
nuclear reactors, commercial LENR-based power plants could be extraordinarily
‘fuel-flexible.’ They could be designed to be able to utilize and switch between
nanoparticulate fissile and/or fertile target fuels comprised of uranium,
uranium-plutonium mixtures (MOX), and/or thorium isotopes. Uranium at any
level of enrichment could be burned. Using integrated mass spectrometers,
real-time computer modeling of fuel burnup, and digital sensor systems to
dynamically monitor and control fuel burnup processes, LENR-based power plants
could safely burn a variety of target fuels and reaction products down to
a complex array of stable isotopes .
Use of nanoparticulate target fuels and LENR ULM neutrons could provide
nuclear fuel suppliers and plant operators with unprecedented economic flexibility
to dynamically vary and blend least-cost fuel mixtures in response
to energy-equivalent market prices of alternative fissile and even non-fissile
‘target fuels.’ Unlike today’s nuclear plants, LENR-based reactors could
switch among a variety of competing fissile or non-fissile target fuels
or reasonable combinations thereof. When burning non-fissile, non-fertile
target fuels, large fluxes of energetic neutrons and hard gammas would
not be produced in LENR-based nuclear reactors; in that situation, massive
shielding and containment structures are superfluous. In that case, the plants’
operating safety margins would be even higher.
As world uranium supplies decrease over time, there may come a day
when the energy-equivalent economic price of fissile uranium or MOX becomes
substantially higher than the price of alternative, less energetic non-fissile
target fuels. In that event, LENR-based subcritical fission reactors could
switch to burning less expensive fuel to reduce costs; today, certain non-nuclear
‘multi-fuel’ power plants  can readily burn a variety of fossil fuels.
Reprocessing of spent nuclear fuel as it exists today could eventually cease
If LENR-based subcritical fission reactors were successfully
developed and deployed, fissile and/or fertile nanoparticulate target fuels
(uranium, thorium, or MOX mixtures) would be transported under guard in thick
bomb-proof casks from limited numbers of secure, government-licensed nuclear
fuel production facilities to commercial power plants. Target fuels would
then be ‘burned’ down to ‘cold’ stable isotopes in plants’ reactors.
As recoverable fissile isotopes and high-level radioactive waste would
not be present in spent fuel from LENR-based reactors, further transport of
spent fuel to physically distant sites for subsequent reprocessing to recover
fissile or fertile isotopes would be unnecessary.
Spent fuel waste products comprising almost entirely stable elements
could be readily stored or buried locally in other types of secure repositories
that prevent contamination of groundwater. Alternatively, ‘cold’ spent fuel
could be shipped from commercial reactors out to other locations for processing
and recovery of valuable transmutation products such as palladium, platinum,
gold, silver, etc. or simply buried in government-certified landfills.
LENR-based subcritical fission reactors would be much more terrorist-resistant
Terrorists could do little to compromise integrity of underground
fuel repositories short of using gigantic explosions to open them up. Assuming
that such an objective was even achievable, such acts would create little
additional mayhem, as releases of unburned nanoparticulate reactor fuel from
repositories would be comparatively benign events.
Today’s criticality-based fission reactors are potential
terrorist targets because large quantities of ‘hot’ radioactive waste
are almost always present in fissioning fuel rods during reactor operation
and/or in spent fuel assemblies stored in onsite cooling ponds. In contrast, future LENR-based subcritical fission reactors
would contain only comparatively limited quantities of unburned fuel and very
little hazardous waste in their ‘combustion chambers’ or stored onsite (cooling
ponds are unnecessary as final LENR-based fission waste is ‘cold’).
This characteristic would drastically reduce health and environmental risks
associated with successful acts of terrorism on LENR reactors.
In a worst case terrorist attack scenario (e.g., crashing a very large aircraft into
key containment buildings or striking them from the air with a small tactical
nuclear weapon or large conventional 'bunker buster' bomb), this unique characteristic
of LENR subcritical fission reactors means that a well-designed system could
be totally destroyed during operation, yet would still release only minuscule
amounts of hard radiation and ‘hot,’ long-lived isotopes into the environment.
Compared with today’s systems, LENR-based reactors could greatly reduce the
likelihood and consequences of nuclear terrorism.
Subcritical LENR-based fission vs. Gen-2 uranium and a Gen-4 thorium reactor
A number of different concepts for ‘Gen-4’ fission reactors have been promoted
by advocates of nuclear power. Two popular Gen-4 reactor concepts are the Integral
Fast Reactor (IFR)  developed at the US Department of Energy’s Idaho National
Laboratory and the Liquid-Fluoride Thorium Reactor (LFTR) , which was explored
in the US from the 1950s to 1970s.
Table 1 is adapted from a chart presented in a talk on LFTRs
given by Dr. Joe Bonomettis at Google.org on 18 November
2008 . The modified chart compares selected characteristics
of a typical Gen-2 LWR with a Gen-4 thorium LFTR as well as our concept for
a subcritical LENR-based fission reactor. Assuming that Lattice’s concepts
can be successfully developed as envisioned, Table
1 reveals that LENR-based fission reactors could be very attractive:
Significantly safer and more terrorist-resistant
than today’s uranium Gen-2 PWRs/BWRs or even Gen-4 thorium LFTRs;
Producing much smaller quantities (close to
zero) of ‘hot’ nuclear waste than a thorium Gen-4 reactor, let alone today’s
Producing ‘cold’ waste of almost entirely stable
isotopes (least costs for waste storage and remediation);
Limiting risks of nuclear weapons proliferation
(also true for LFTRs) because they do not produce large quantities of fissile
Much more efficient at burning nuclear fuel,
like LFTRs, and would have almost twice the heat-to-electricity thermal efficiencies
of Gen-2 LWRs;
Costing less to build, operate, and insure,
with vastly greater fuel choices, and much lower cradle-to-grave cost structures
than either Gen-2s or Gen-4 LFTRs.
Table 1. Comparing
(LFT), and LENR Fission Power Reactors
Reactors utilize criticality to burn fuel
Gen-2 U-235 LWR
Gen-4 Thorium LFTR
Need massive shielding/containment?
Overall plant safety
Better Than Gen-1
>> Better than Gen-2
Burn existing nuclear waste?
Radioactive waste volume (relative)
1/30th of Gen-2
Waste storage requirements
10 000+ years
~200 - 300 years
Produce large amounts of fissile isotopes?
High value nuclear by-products?
Even more extensive
Operating pressures / op. temperatures
High / Lowest
Low / Higher
Low / Highest.
Nanoparticulate solids dispersed in
gases or liquids
Fuel burning efficiency
~98 -100% est.
Can reactor burn non-fissile/fertile fuels?
Fuel mining waste volume (relative)
Fuel reserves - global (relative)
> 1 000
> 1 000 000 est.
Can reactor have dynamic fuel injection?
1 (high pressure)
<1 (low pressure)
<<1 (many reasons)
Plant thermal efficiency
~35% (low temp.)
~50% (higher temp.)
>60% (highest temp.)
Water or Air
Water or Air
Retrofit to existing nuclear power plants?
Yes – can design for it
Terrorists totally destroy reactor
Lot Less Disastrous
Limited Local Effects
Adapted from chart in ; other data estimated or compiled
by Lattice Energy LLC
The author declares his commercial interest as President and CEO of Lattice