About this Article
Written by: Hannah Cyr
Written on: April 30th, 2014
Tags: energy & sustainability, power
Thumbnail by: Popular Mechanic
About the Author
Hannah Cyr is a sophomore currently studying chemical engineering with an emphasis in nanotechnology. She has spent the last two years conducting undergraduate research with Professor Dr. Najmedin Meshkati, studying the impact of Fukushima on nuclear plants and nuclear policy in the United States.
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Volume XVI Issue II > Big Things in Small Packages: The Development of Portable Nuclear Reactors
This paper discusses the development of portable reactor technologies and the history behind the science and engineering of portable reactors, focusing on describing the LENR or low energy nuclear reactions associated with the development of small modular reactors. In addition, it will elaborate on the companies and governments researching small reactors, and the current status of these reactors. The paper also examines whether or not these reactors have a foreseeable future in industry and personal use and the public reactions to them thus far.
The traditional nuclear power plant requires large everything: capital, employees, security, land, and resources. What if the energy from these plants could be harnessed in a new way, a method involving a much smaller reactor? In the last 30 years, the nuclear industry has made leaps and bounds in figuring out the technology and the potential designs of portable nuclear reactors, transforming this idea from a far thought into a near reality. Compact nuclear reactors have the potential to change the way we approach nuclear energy, presenting the idea of owning and operating your own backyard reactor.

The history of portable reactors

The first attempt by the US government to create a portable reactor was the ML-1, the first gas turbine that operated with a closed cycle (Fig. 1). It was initially tested in 1961, but the reactor proved to have many unforeseen issues, like poor internal insulation and compressor malfunctions, and was eventually shut down in 1965 [1].
Atomic Engines
Figure 1: The ML-1 Reactor tied to the back of a trailer, Source: [1]
After the failure of the ML-1, the US government ceased its funding and focused on developing other types of nuclear energy [2]. It was not until the 1980s that the idea of portable nuclear energy emerged into the forefront again. Two scientists, Stanley Pons and Martin Fleischmann, began investigating the technology behind portable nuclear energy and rediscovered Low Energy Nuclear Reactions, or LENR. Research with LENR had first began in the 1920s and 30s, but had subsided because of the failure of the ML-1. In 1989, Pons and Fleischmann announced their findings to the scientific community, reawakening research into LENR and the idea of creating a portable reactor [3].

How does LENR work?

LENR refers to nuclear reactions that take place at standard pressure and temperature, requiring low energy to catalyze these reactions. The process of LENR reactions is separate from that of fission and fusion, where high temperature or pressures are required. LENR harnesses the energy from a weak nuclear force, like slow-moving neutrons, whereas fission and fusion employ strong nuclear forces [4]. According to the Widom-Larsen theory, LENR energy is generated in four steps [5]. First, a heavy surface electron is created by electromagnetic radiation in the LENR cells. Next, this heavy electron binds with a proton to form “an ultra-low momentum (ULM) neutron and neutrino” [5]. The ULM neutron then latches onto a free-floating nucleus, causing a chain event in which a surrounding neutron undergoes beta decay. This beta decay causes the lone neutron to disintegrate into its component parts—a proton, electron, and neutrino—and effectively turns its electron into a proton. Since every different element has its own unique number of protons, the increase in the number of protons changes the original element into another one.
NASA’s best method of creating the Widon-Larsen process involves interacting hydrogen ions with a nickel lattice (Fig. 2) [4]. In Figure 2, the metal hydride represents the nickel lattice. This lattice attracts the hydrogen gas ions while oscillating at a high frequency. These oscillations excite the electrons from the nickel and form slow moving neutrons with the hydrogen ions. The nickel absorbs these slow moving neutrons and becomes unstable, regaining stability after a neutron is removed from an electron—changing the neutron into a proton and turning the nickel into copper. This process is difficult to achieve because the lattice must oscillate at a very high frequency, generating a large amount of energy during the transformation.
Extreme tech
Figure 2: Hydrogen ions interacting with nickel lattice. Source: [4].