Is there a micro nuclear reactor that can power up a house for entire life time – quora electricity facts label


Researchers in Israel (Dr. Yigal Ronen) designed a thermal aqueous homogeneous reactor [1] that weighed 4.95 kgs and had a radius of 9.6 cm (<4" radius) and a power output of a few kilowatts. The small Israeli reactor was spherical in shape and was powered by a solution of Am-242m(NO3)3 in water. When a fission reactor is very small in physical size (<10 cm radius sphere) it requires relatively little total lead shielding to fully enclose the reactor with 11" of lead to provide protection from penetrating gamma radiation. Really small fission reactors are easier to build in safer and well shielded configuration for that reason.

Los Alamos is currently using many off the shelf components to build their kilowatt power space fission reactor called KRUSTY (Kilowatt Reactor Using Stirling TechnologY)[3]. The LANL KRUSTY reactor uses heat pipes to transfer heat from the small reactor core into a commercial Stirling engine that converts nuclear heat into rotary motion. Rotary motion of a spinning shaft can then be used to turn a conventional electric generator producing electricity.

1) Fusion has no critical mass requirement, all that a fusion reaction requires is the right conditions be met (temperature, plasma density, and confinement time) to support fusion. As a result, very tiny fusion power plants can potentially be built.

4) Neutrons are much easier and more cost effective to shield. A layered combination of light weight and economical Borated HDPE poly plastic followed by a high-z absorber like lead is effective in stopping neutrons. HDPE can be easily cast into whatever form desired forming shielding with no gaps providing excellent operator safety.

While pure fusion experiments have so far not produced any net energy, impure fusion produced from fission-fusion assemblies works routinely and reliably (and has since 1952) producing fusion power on demand. Modern Small staged assemblies that use Fusion->Fission->Fusion have been designed[2] that use as little as 0.25 grams of fissile, 100 milligrams of Tritium, and less than 8 grams of cryo-Deuterium fluid to produce fusion bursts of 100 GJ (the approximate energy produced when burning 779 gallons of gasoline). Hybrid Fission-Fusion power plants in mobile applications like a house could produce periodic bursts of fusion energy to generate electricity through magneto-hydrodynamic power conversion (no moving parts – near 100% Carnot cycle energy conversion efficiency) when convenient and on demand a few times a day to recharge batteries used to continuously power a house.

Proton-Boron-11 fusion is a current interest for the fusion community. p-B11 fusion produces primarily alpha-particles which are easy to shield against and have attractive intrinsic safety features for human operators – all of which is vital for a home reactor application. While p-B11 is expected to produce a few neutrons through side reactors, this style of fusion is one of the better candidates among fusion reactions for safely powering a normal home.

It has been calculated that ion temperatures of DT ignited targets reach very high values, exceeding 200 keV. This is a temperature at which proton-boron 11 fusion reaction rates are at high enough levels to be relevant for energy production (and to practical high fusion energy gain). A small DT first stage explosion tends to generate electron temperatures of a lower typical value, usually below 100 keV, which is helpful in reducing radiation losses and conduction losses from the plasma. A scheme can be devised to exploit proton-boron 11 fusion by using a staged device design initiating the fusion wave with a DT spark.

Note: The isotope Am-242m is an interesting nuclide as it shows one of the highest known thermal neutron fission cross-sections of any fissile nuclear fuel. This could be useful in some special applications, like nuclear reactors for space propulsion and small-core nuclear reactors for unusual applications like powering a remote home or a larger transportation vehicle. Am-242m is rare synthetic nuclear fuel that can be manufactured in current Light Water Reactors or in future fusion reactors that should be abundant cheap sources of neutrons. Am242m is present in the waste of LWR nuclear reactors, at a level of some tenth percent of the total Americium. After 60 years of LWR operation, substantial amounts of Americium exist in accumulated waste.

This is a scaled down model of a Topaz reactor. The full-scale reactor weighs about 320 kg and produces 5 kW of electricity, enough to power a home. Other than the fact that it weighs a lot more than most appliances in your home, it could be manageable. Other than the cost, the potential harm from radiation, and the unavailability to the general public, it’s perfectly suited for any home dweller with the desire to get off the grid and attract major attention from whoever you stole it from. It could probably cut your heating bill significantly since most of the energy from the reactor is generated as heat. However, there is another downside: It will not last a lifetime. It has a projected lifetime of around 3-5 years, so you would need to replace it every once in a while.

However, development of small nuclear reactors is under way. Small plants are being designed and built as the desire of long-lasting energy in desolate places increases. Perhaps one day, your neighborhood could be powered by their own nuclear reactor sometime soon.