How does a Betavoltaic Laptop Fuel Cell work?

[Andronicus1717]

http://www.nextenergynews.com/news1/next-energy-news-betavoltaic-10.1.html

I cam across this article. It is horribly written from a scientific standpoint and lacks some necessary information on how the device works. But the basics are... Tritium is the beta source, porous silicon matrix channels the electrons to produce a usable current, and it has lifetime of 30 years.

Issues I can see:
1) Containment of the Tritium.
2) How can you effectively convert betas to usable power.
3) How does the silicon produce a usable current with a great enough magnitude.
4) How much Tritium is necessary for the device to produce usable power for 30 years.

If this thing pans out I see it being used in satellites far before you give people Tritium to walk around with. Another industrial issue would be the production of the Tritium as far as I know, Watts Bar is the only place in the US producing Tritium at scale (correct me if I'm wrong).

After some discussion, this thread might have to go into the debunking repository as these claims seem rather far fetched to me.

 

[vanesch]

When one knows the security issues with tritium, I would be highly surprised to see this hit the market any time soon !

I've recently visited a tritium laboratory in Karlsruhe, and they have a work permit for some tens of grams of tritium, and one has to see the security measures involved (confined laboratory with double gastight gates and so on).

 

[Morbius]

When one knows the security issues with tritium, I would be highly surprised to see this hit the market any time soon !

vanesch,

There are LOTS of products in use that contain tritium. For example, self-illuminating "Exit" signs.

The only real concern is accidental breakage and proper ultimate disposal:

http://www.epa.gov/radtown/exit-signs.htm

Dr. Gregory Greenman
Physicist

 

[daveb]

There are other concerns with tritium in the regulations. The activity exempt from licensing requirements (and most other regulatory) is 1 millicuire. The exit signs allow up to 10 Curies of tritium, but those who own or possesses such items are still required to report theft or incidents that fall under 10 CFR 20.2201 and .2202, so I have to wonder if the NRC would generally license these items to the general public if they contain that much tritium.

 

[Morbius]

The exit signs allow up to 10 Curies of tritium, but those who own or possesses such items are still required to report theft or incidents that fall under 10 CFR 20.2201 and .2202, so I have to wonder if the NRC would generally license these items to the general public if they contain that much tritium.

daveb,

I don't think we're talking about *individuals* having these Tritium-powered devices with large
quantities of Tritium.

However, as with the "Exit Signs" - it's not uncommon for industrial concerns and businesses
to be licensed to have such devices.

Dr. Gregory Greenman
Physicist

 

[vanesch]

vanesch,

There are LOTS of products in use that contain tritium. For example, self-illuminating "Exit" signs.

The only real concern is accidental breakage and proper ultimate disposal:

http://www.epa.gov/radtown/exit-signs.htm

I can only say

 

[mgb_phys]

Is tritium that dangerous? It's a fairly low energy beta emitter.
Or is the concern nuclear proliferation?

 

[theCandyman]

It is low energy, but consider how short the half life is. A lot of it won't be good for you.

 

[vanesch]

The main problem is that it gets integrated very quickly into the human body, but in fact, after checking, the radiotoxicity of 2-4 10^(-11) Sv/Bq, which is very low. I always heard that tritium (or better, tritiated water ; the gas itself is not really an issue, but exchanges quickly in contact with water) was a serious hazard, but visibly, this is a very low radiotoxicity. (actinides have toxicities which are about 10000 times larger)

http://ehs.ucmerced.edu/docs/App%20C%20Common%20Isotopes.pdf

So now I wonder indeed what's all the fuzz with tritium...

 

[Andronicus1717]

http://www.physics.isu.edu/radinf/tritium.htm

Here is a rather concise discussion on the dangers of Tritium with dosimetry examples.