Science in Society Archive

Low Energy Nuclear Reactions for Green Energy

How weak interactions can provide sustainable nuclear energy and revolutionize the energy industry Lewis Larsen

Existing nuclear power generation depends on ‘strong interaction' that splits atoms. The technologies were directly derived from nuclear physicist Enrico Fermi's experimental work in Chicago , USA , in the 1940s [1]. Thanks to the unfortunate legacy of the US Manhattan Project to secretly build the atom bomb and World War II, today's commercial nuclear power generation and fuel cycles [2] have always been intimately interwoven with nuclear weapons .

In contrast, Low Energy Nuclear Reactions (LENRs), which emerged from ‘cold fusion' [3] ( From Cold Fusion to Condensed Matter Nuclear Science and other articles in the series, SiS 36) are a revolutionary new primary energy source. If successfully commercialized, LENRs could potentially herald in a new age of affordable and clean energy. Unlike power generation by current nuclear fission technologies, LENRs are safe and green.

Being nuclear, LENRs could potentially improve by many orders of magnitude the density and longevity of energy storage compared with existing technologies such as chemical batteries and electrostatic capacitors, and provide a vast array of cost effective, scalable, portable, and distributed power generation systems that could be deployed throughout in the world.

Research and development on LENRs is quietly being pursued by companies as well as a small scientific community in the US , Russia , China , Japan , Italy , France , and Israel . Very recently, there have been indications that India may restart its basic R&D efforts in this area [4]. To date, funding has been very limited. In the US, the government and major venture capita) firms have largely ignored LENRs (due to the controversy over ‘cold fusion'), preferring to invest in incremental improvements to better-known existing energy technologie s, or worse, in conventional nuclear power stations with all the attendant problems of safety, serious health hazards, terrorist sabotage and nuclear proliferation [5] ( Nuclear Renaissance Runs Aground and other articles in the series, SiS 40). .

LENRs are not ‘cold fusion'

In a hastily scheduled, now infamous television news conference held in March 1989 [6], two University of Utah chemistry professors, Pons and Fleischmann (P&F) reported experiments with ordinary electrochemical cells filled with deuterium (D) in which they claimed to have observed rates of excess heat production so very high that they could only have been the result of some sort of nuclear process [3]. Amazingly, the experiments all took place at roughly room temperatures and pressures. P&F proposed some sort of ‘cold' D-D fusion reaction [7].

Thus began a heated running battle between P&F and their supporters and advocates of ‘cold fusion' on one side, and mainstream science on the other, that has continued to the present day. In the 19 years since the ill-fated 1989 news conference, the controversy surrounding LENRs has continued. Although much improved from the early days, experimental results have never matched-up with anything that is known about nuclear fusion reactions. Until very recently, no one had been able to develop a theory of LENRs that could explain all of the experimental data and survive peer review by mainstream physicists. Prior fusion-based theories of LENRs were unable to explain or guide experimental work in the right direction.

In retrospect, it is clear that P&F's speculative conclusion about fusion being responsible for the unusual amounts of excess heat was wrong. Their critics were right on that point; the observed effect was not due to strong interaction D-D fusion. P&F were also right about the excess heat being the result of a nuclear process, but it came from weak interactions [8], unbeknownst to them or anyone else at the time.

LENRs comprise a complex, interrelated family of nuclear phenomena that fundamentally differ from fission (violent splitting of heavy atoms) and fusion (fusing together of light atoms, such as in stars), which are what most people are familiar with in connection with nuclear reactors and military weapons.

Collective weak interaction LENRs can occur at the interface between the chemical and nuclear energy realms. In condensed matter systems, nanoscale many-particle collective effects enable certain nuclear reactions to take place at ordinary temperatures and pressures. You don't need a fission reactor or a star to make neutrons, transmute elements, and, if the circumstances are right, release large amounts of energy.

Beginning in May 2005, Allan Widom at Northeastern University and I at Lattice Energy LLC have made a series of theoretical breakthroughs that, for the first time, explain the physics underlying a large body of experimental anomalies observed by scientists for 100 years. This body of work has become known as the Widom-Larsen theory of LENRs [9 – 15].

Unlike the somewhat ad hoc theoretical ideas advocated by cold fusion theorists for many years, our work is anchored in the ‘bedrock' of electroweak theory within the framework of Standard Model. It weaves together all the previously disparate threads of experimental evidence into a coherent whole using rigorous, established, well-accepted physics and collective effects. As a result, we have gained unique insights and understanding that will enable us to overcome the major technological roadblocks to commercialization of LENRs [see various comments made in 11, 15].

Weak interaction LENRs enable development of a clean, green nuclear technology

A key difference between LENRs and fission or fusion technologies lies in the fact that LENRs involve very large emissions of neutrinos [16], a ghostly, massless type of photon (i.e., light) that can carry substantial energy but barely interacts with ordinary matter (which is why you can't see them like visible light). An energetic neutrino can pass through a billion miles of lead with very little chance of being absorbed. Generally speaking, a nuclear reaction in which neutrinos are either emitted or absorbed involves what physicists call the “weak interaction”. Importantly, there is a type of weak interaction nuclear transmutation process called “beta decay” [17] wherein an unstable atom emits a light energetic electron called a “beta particle” and a neutrino photon, which merely flies off into space at the speed of light.

In beta decay, a neutron (with no net electric charge) located inside an unstable atomic nucleus spontaneously decays into a positively charged proton (which remains inside the nucleus), an energetic negatively charged electron (that escapes the nucleus entirely, being emitted from the atom as a beta particle), and a neutrino photon that flies off into space. As the nucleus of the atom undergoing beta decay suddenly contains one more new proton, its atomic number increases by +1 which means that the atom is now a different element. This transformation of one element into another different element or isotope is called a transmutation.

Mediated by one or more intermediate beta decays, transmutation reactions eventually produce stable, non-radioactive isotopes of different elements. A sequence of beta decays immediately followed by successive rounds of neutron absorption produces progressively heavier elements; astrophysicists believe that most elements found in the periodic table were originally created by that process in stars [18].

Collective weak interaction transmutation reactions can be used to deliberately transmute one element into another; this can be commercially valuable for producing certain rare elements/isotopes from more common ones. However, what is potentially vastly more valuable to society is that ‘ultracold' (low energy) neutrons uniquely produced in certain LENR weak interactions can be used to trigger the release of stored nuclear energy from target fuel atoms on-demand. This capability creates an opportunity to develop an entirely new nuclear power technology that is extremely ‘green' compared to the old (see below).

Why weak interaction LENRs are truly green compared to fission and fusion

In weak interaction LENRs, excessive releases of nuclear binding energy are to a degree ‘bled-off' in the form of emitted neutrino photons, which carry-off substantial amounts of energy in a completely benign form, the neutrino itself, which just flies off into space without interacting with local matter. The remaining weak nuclear reaction products, the negatively charged beta particles and non-radioactive stable or weakly-radioactive unstable beta-decay isotopes, do not create dangerous, deeply penetrating radiation. In other words, LENRs can be used to develop a safe nuclear energy technology that does not create dangerous hard radiation and/or long-lived radioactive and toxic wastes.

In contrast, fission and fusion processes involve ‘strong interaction' in which all of the nuclear binding energy released is channelled directly into various non-neutrino highly energetic products: charged electrons and alpha particles; uncharged neutrons; ;hard' (very energetic) gamma/X-ray photons [19]; and ‘hot' (highly radioactive), comparatively long-lived isotopes. Unlike weak interaction neutrinos, all of these strong interaction fission and fusion products can readily interact with matter, including living organisms. Energetic neutrons and gammas/X-rays are one reason why radiation containment structures for commercial fission reactors often have walls consisting of 1 metre thick reinforced concrete and 25 cm thick special steel plates [20] ( Close-up on Nuclear Safety , SiS 40). .

Energetic neutrons, which are ~1839 times heavier than beta particles, are very hazardous nu clear reaction products. Being heavy, uncharged, and energetic, they can deeply penetrate solid objects, potentially creating induced radioactivity when they are finally ‘stopped' and absorbed by atoms. Such neutrons are extremely dangerous for living organisms because, unlike neutrinos, they can be directly absorbed by hydrogen and other elements found in living tissue, causing great damage.

Energetic ‘hard radiation' photons (X- and gamma-rays commonly produced in fission and fusion reactions) are also quite dangerous. Unlike photons of visible light, which are readily stopped' and absorbed by metals and optically opaque solid materials, they can penetrate deep into solid structures, including metals. When they are finally ‘stopped', they can knock electrons out of atoms, causing local ionization. Modern electronics can be damaged or destroyed by such ionization events. In living organisms, absorption of energetic ‘hard' photons creates ionization, breaks chemical bonds, damages DNA, and generally wreaks havoc with biochemical reaction networks.

LENRs could have a revolutionary impact on energy markets

Commercial LENR-based power generation systems could be developed that have unprecedented levels of energy density, longevity, and scalability. Such systems might eventually allow a car or an airplane to travel around the world without refuelling. They would create true energy independence, breaking oil's stranglehold on the global economy. LENRs could also be used to radically improve existing nuclear fission technology and nuclear waste remediatio n (see other articles in this series).

The author declares his commercial interest as President and CEO of Lattice Energy LLC.

Article first published 13/11/08


  1. Chicago Pile-1, Wikipedia, 24 October 2008 ,
  2. Nuclear fuel cycle, Wikipedia, 24 October 2008 ,
  3. Ho MW. From cold fusion to condensed matter nuclear science. Science in Society 36 , 32-35, 2007
  4. Jayaraman KS . Cold fusion hot again. Nature – India , online 17 January 2008
  5. Ho MW. Nuclear renaissance runs aground. Science in Society 40 (in press).
  6. “Cold Fusion” Press Conference at the University of Utah , 23 March 1989 (Google video posting courtesy of New Energy Times – 39 minutes)
  7. Nuclear fusion, Wikipedia, 24 October 2008 ,
  8. Weak interaction, Wikipedia, 24 October 2008 ,
  9. Widom A and Larsen L. Ultra low momentum neutron catalyzed nuclear reactions on metallic hydride surfaces, European Physical Journal C Particles and Fields 46 107 2006(arXiv version released 2 May 2005 )
  10. Widom A and Larsen L. Absorption of nuclear gamma radiation by heavy electrons on metallic hydride surfaces (September 2005),
  11. Widom A and Larsen L. Nuclear abundances in metallic hydride electrodes of electrolytic chemical cells (February 2006),
  12. Widom A and Larsen L. Theoretical standard model rates of proton to neutron conversions near metallic hydride surfaces (September 2007),
  13. Widom A, Srivastava YN, and Larsen L. Energetic electrons and nuclear transmutations in exploding wires (September 2007),
  14. Widom A, Srivastava YN, and Larsen L. High energy particles in the solar corona (April 2008),
  15. Widom A, Srivastava YN, and Larsen L. A primer for electro-weak induced low energy nuclear reactions ( October 2008),
  16. Neutrino, Wikipedia, 24 October 2008 ,
  17. Beta decay, Wikipedia, 24 October 2008 ,
  18. Nucleosynthesis, Wikipedia, 24 October 2008 ,
  19. Ionizing radiation, Wikipedia, 24 October 2008 ,
  20. Ho MW. Close-up on nuclear safety. Science in Society 40 (in press).

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