Exploring Feasibility of Home/Neighborhood Nuclear Generators

In summary, the conversation discusses the possibility of using a small amount of radioactive material to heat water for a central heating system instead of relying on gas. However, the use of nuclear fuels is expensive and highly regulated, making it impractical for home use. Additionally, there are safety concerns and challenges in managing the heat produced by a mini-reactor.
  • #1
lavalamp
279
1
Recently I got a whole new central heating system. Apparently it's all very efficient (over 90%). The boiler is used to produce hot water that's piped round the house to radiators, and also to provide instantaneous hot water for the taps.

However, since it is gas fired, it throws out rather a lot of CO2, which depending on your point of view is either bad or irrelevant. For the sake of this thread, let's assume that it's bad.

So I was thinking, a boiler doesn't have to be particularly powerful, I believe mine has a peak power output of 28 KW, so what would be the feesability of using a small amount of radioactive material to heat the water, rather than requiring a constant supply of gas?

I understand that such a device would require shielding, however since only a small amount of power is required, only a small amount of fuel would be required, therefore hopefully the shielding wouldn't need to be excessive. There are questions that I don't have answers to though, such as what's the smallest amount of fuel that could be used? If there's too little it simply won't chain react, if there's too much it would be wasteful and possibly dangerous.

What the fuel might be is another question, I gather that Plutonium trumps Uranium when it comes to chain reactions, however the government might get a bit antsy about handing out Plutonium. Thallium springs to mind as it is abundant in the crust and fairly useless as a nuclear bomb, though of course any radioactive fuel could find an application as a dirty bomb.

Just to be clear I was thinking that such a device would provide energy only in the form of heat, which would simplify it over a whole electrical power plant design. Similar in design to perhaps a nuclear powered aircraft which would in theory just heat the air for thrust as a sort of ramjet without combustion.

Also, about the fuel, would it be possible to include enough fuel for the device to run until way past when it is obsolete and needs to be replaced? This would side-step the issue of having the home owner getting their hands dirty/irradiated. If we assume an average power output of 1KW, then that's 3.16 TJ of energy over 100 years (far more than should be needed to ensure it never needs to be refueled).

But I'm not done yet, when I get thinking I tend to think in several directions at once, so I also thought, what if it did include an electrical generator? How small could a nuclear powered generator be made? If it's not possible to make a home generator small enough, perhaps it would be possible to build neighbourhood generators which would generate electricity and steam to be delivered to homes. The steam would be mixed with cold water to provide the hot water for central heating and the taps.

It seems that huge power plants throw away most of their energy as heat, whereas a home or neighbourhood plant could put this "wasted" energy to good use.

I'm curious as to what anyone has to say in terms of problems associated with such systems (other than public opinion) and ways in which they might be solved. For example, nuclear power plants are monitored by engineers with lots of letters after their names, but could a mini reactor be monitored by software to a sufficient extent that it could run autonomously with only routine maintenance?
 
Engineering news on Phys.org
  • #2
Nuclear fuels are some of the more poisonous and expensive substances on the face of the earth, so no, you're not getting your hands on any.

As for waste heat, a lot of power plants these days are cogen plants, producing both electricity and hot water or steam.
 
  • #3
Would a small amount of some nuclear fuel be more expensive than years and years worth of gas though? And yes, I understand that nuclear fuels can be dangerous, but so many things are, bleach for instance, at least this would be in a sealed unit.
 
  • #4
Wouldn't be worth it. Nuclear plants can do it because of the scale at which they work. They only need 1 massive reactor (or system of reactors, however it works), a bulk load of the material, and enough people to run the thing safely.

For home use, you'd need everybody to have their own reactor, which would automatically drive the cost way up, buy the material in small quantities, which would cost a lot more than buying in bulk, and also need to have someone install this for you, because letting a non-specialist do it is like releasing a pedophile in a kindergarden. Yes, it would be just as horrific.

Moreover, turning a nuclear reactor on and off isn't as simple as cutting off gas flow in the heater. So it's much easier to let the big reactor just keep producing it and then let you tap in whenever you want some juice, like we do it now.
 
  • #5
lavalamp said:
Would a small amount of some nuclear fuel be more expensive than years and years worth of gas though? And yes, I understand that nuclear fuels can be dangerous, but so many things are, bleach for instance, at least this would be in a sealed unit.

Nuclear stuff is EXTREMELY dangerous. We know also how to handle it, and if one does it right, one can master the dangerousity while getting the benefits. But that has a price: draconian safety rules, inspections, authorisations etc... which can only become cost-effective and effective all together when used on large scale. The safety problems would become unmanageable if everyone had his mini-reactor in his basement!

Because apart from the direct radiation (which is the least of the problems) and the sealing, the main problem is the heat management: what do you do when you can't get rid of the heat ? There's no plug to pull, or valve to close to stop the heat production: you have to have a good heat evacuation in all kinds of disaster scenario's which is BTW, the main challenge in the design of a good reactor.
 
  • #7
sas3 said:
I do not know how reliable this story is but take a look here.

http://www.engadget.com/2007/12/19/toshibas-building-a-micro-nuclear-reactor-for-your-garage/

Toshiba's Micro Nuclear reactors are designed to power a single apartment building or city block, and measure a mere 20-feet by 6-feet. The 200 kilowatt reactor is fully automatic and fail-safe, and is completely self-sustaining. It uses special liquid lithium-6 reservoirs instead of traditional control rods, and can last up to 40 years, making energy for about 5 cents per kilowatt hour.
The story is correct in these details, but this is not a system for one's home, unless one has many millions of dollars. A 20 ft by 6 ft is just the reactor - the containment and generator building is much larger.

The smaller the core, the greater the enrichment required, particular if the core is not to be refueled. Generation of nuclear energy by fission produces fission products, which themselves produce high levels of radioactivity, hence the need for shielding. For these reasons, small nuclear systems are very expensive - mainly due to high capital and backend costs.
 
  • #8
sas3 said:
I do not know how reliable this story is but take a look here.

http://www.engadget.com/2007/12/19/toshibas-building-a-micro-nuclear-reactor-for-your-garage/

Well, two things make we wary: first of all, Toshiba doesn't seem to know it itself (do a search on their press releases of their nuclear activities, you'll find lots of stuff, but no "micro nuclear reactor").

Next, a Wiki article on this subject was recently deleted, and the reason given is that it is a hoax.


That said, low power nuclear reactors do exist of course. But usually they have special purposes (such as research).
 
  • #9
It is certainly doubtful that a 200 kWe (~600-800 kWt) reactor would be feasible, but the Endgadget story seems to be based on the Toshiba 4S modular reactor, which was originally envisioned in the 10 MWe range.

The small modular reactor was proposed for Gelana, Alaksa.
http://www.iser.uaa.alaska.edu/Publications/Galena_power_draftfinal_15Dec2004.pdf

http://www.roe.com/pdfs/technical/Galena/Overview%20Whitepaper%20Rev02.pdf [Broken]

http://www.atomicinsights.com/AI_03-20-05.html

Toshiba has looked at smaller compact designs from the technical side, but economically it a whole different matter.
 
Last edited by a moderator:
  • #10
The problem with using radionuclides for home heating (or any other type of energy use) is that in order to do so, you need large activities (i.e., far exceeding the exempt from licensing quantity), meaning you are now regulated by either the NRC or an Agreement State. If you're going to possesses special or source material for a reactor, it's the NRC. In this case, the annual fee for your license is going to be prohibitively expensive unless you are a power company. Plus, in any case, you'll need shielding, proper training, etc., making it prohbitively expensive, again, unless you're a power company. Even using regular radionuclides instead of nuclear fuel wouldn't work. Remember, 1 Curie of activity at 1MeV/disintegration only produces about 6 milliwatts power - not a lot. the reason reactors can produce so much power is that 200 MeV per usion is released, and there are in excess of 10^12 neutrons for fission per cubic centimeter.
 
  • #11
Building a reactor for a home heating device is definitely a Rube-Goldberg sort of adventure. It's fun to talk about, but is wholly impractical and definitely dangerous. You'd be better off just piping your current heater exhaust into a CO2 scrubber.
 
  • #12
Astronuc said:
The smaller the core, the greater the enrichment required...
Duh, I forgot about that - while a big furnace and a little furnace are fundamentally the same (a little natural gas and a lot of natural gas act the same), reactors aren't as scaleable.
 

1. What is a nuclear generator?

A nuclear generator is a device that produces electricity through the process of nuclear fission, which involves splitting atoms of a radioactive material to release energy. This energy is then converted into electricity that can be used to power homes and other devices.

2. How does a home/neighborhood nuclear generator work?

A home/neighborhood nuclear generator works by using a small nuclear reactor to produce heat, which is then used to create steam. The steam then turns a turbine, which is connected to a generator, producing electricity. The electricity is then distributed through a power grid to homes and buildings in the neighborhood.

3. Is it safe to have a nuclear generator in a residential area?

The safety of a nuclear generator greatly depends on the design and maintenance of the generator. With proper safety measures in place, such as thick shielding and redundant safety systems, a nuclear generator can be safe for use in a residential area. However, it is important to note that any nuclear technology carries a certain level of risk and must be carefully regulated and monitored.

4. What are the benefits of using a nuclear generator in homes/neighborhoods?

One of the main benefits of using a nuclear generator is its efficiency. Nuclear energy is a highly concentrated source of energy, meaning it can produce large amounts of electricity using a relatively small amount of fuel. Additionally, nuclear energy does not emit greenhouse gases, making it a clean source of energy. It also provides a stable and reliable source of electricity, which can help reduce dependence on fossil fuels.

5. What are the potential challenges of implementing home/neighborhood nuclear generators?

One of the main challenges of implementing home/neighborhood nuclear generators is the cost. Building and maintaining a nuclear generator requires a significant investment, and the costs may be passed on to consumers through electricity bills. There are also concerns about nuclear waste management and the potential for accidents, which must be carefully addressed and regulated. Additionally, there may be public perception and acceptance issues that need to be addressed before widespread implementation can occur.

Similar threads

  • Nuclear Engineering
Replies
0
Views
504
Replies
10
Views
2K
Replies
9
Views
2K
Replies
2
Views
1K
Replies
10
Views
2K
Replies
32
Views
464
  • Nuclear Engineering
Replies
6
Views
2K
  • Nuclear Engineering
Replies
3
Views
3K
  • Nuclear Engineering
Replies
4
Views
2K
  • Nuclear Engineering
Replies
29
Views
4K
Back
Top