Photonuclear energy sources, could we build a nuclear "battery"?

I don't think there are any on the market yet, but there's been talk of this for some time:

http://www.rexresearch.com/nucell/nucell.htm

http://blog.tmcnet.com/blog/tom-keating/technology-and-science/nuclear-battery.asp

So, you are not JUST AN ENGINEER, you are dreamer also.

Good, such dreams only guides us to new progress.

No wonder in just less than 300 posts, you have 31 GAs

Hi,

Your idea is quite good and among the emerging nuclear reactor types.

It will need a steerable influx of neutrons and provide ordinary nuclear fission with all the existing and known problems.

But as you dream there is no need for a critical mass.

Direct conversion to electricity does not seem possible.

This is not pushing electrons to a few eV but GeV level and particles and fission products.

Details have been discussed at the 2007 ICENES conference.

RHABE

Any nuclear radiation (gamma rays) striking a semi conductor junction will generate electricity by the same mechanism as the photoelectric effect.

In addition, charged particles distort the crystal lattice and can also generate electricity.

In the 60's, when transistors were becoming known, there was talk of using this effect for power generation, but the efficiency turned out to be abysmal and, as far as I know, virtually no research work has been done on this since.

Nuclear batteries are made, usually using the heat of decomposition and thermoelectric generation, or sometimes a version of the rankine cycle. One of the plutonium isotopes is most commonly used, but there seems no reason why any intense source couldn't be used.

This could be a way to dispose of our high level waste.

I don't have the reference readily available, but beta emitters in a plasma can be stimulated to decay up to a billion times faster by application of a strong electrostatic field. The resultant liberation of energy should also be able to be used to generate power.

Who knows, one day we may even regard high level waste as a useful asset!

You could put a layer of phosphor between the source and the photocell to up the efficiency. The efficiency is a function of the bandgap of the semiconductor used. most silicon semiconductors are sensitive the the red to near infrared region, Gallium Arsenide and Gallium Indium Arsenides are more sensitive to the yellow/green range if memory serves. Silicon Carbide is sensitive to the blue range I believe. So if you chose the phosphor wavelength to coincide with the preferred wavelength of the semiconductor you should be able to maximize efficiency.

One issue I think you'll run into is that Gamma and X-rays damage the crystalline structure of semiconductors by knocking the electrons out of their orbits and re-arranging the crystalline structure so you will have a limited lieftime due to cumulative gamma ray damage. That would argue against using a gamma source and argue for perhaps a beta or alpha source that the phosphor layer would be able to stop or attenuate.

I just reread that and I realize I was not clear in what I was trying to say. The efficiency at a given wavelength of incoming light, is a function of the semiconductor's bandgap.

Dreams are a key to knowing...John Galt may be the heroic industrialist/architect in Aynn Rands interesting novel "Atlas Shrugged"..Using available free-er energy seemsa good way to go...The EM spectra is to say the least vast in opportunity..Not being well versed in nuclear decay,gap junctions etc i can only add that practice tends to make if not perfect at least better..Large sources of decaying spent fuel rods already litter the planet and in general there is great fear surrounding them..I heard at a small gathering saturday past about a find in a South African mine of a uranium source that was so rich that it was in essence an ongoing fission reactor of substance..We jump shifted during the conversation to the notion that if there is one known source then in all likelyhood the planets nether depths is littered with many more making nuclear fission a naturally occuring event..WE,the human species,utilize naturally occuring events more and more as time passess because of our inate desire to understand/play with them..Power needs for a burgeoning population are apparent..MAny forms are already available at a cost...Changeing streams of energy input is allways difficult but does continually happen...Looking forward via dreamers such as the initiator of this thread is hopeful..Thanks for sharing..

Regards,Marty Wolf

That may be a working approach but how much energy is waisted?

Also with beta or alpha particles there is crystal damage if particles hit material - too much energy!

So if the phosphor is amorphous it may work but it has to be self healing as the particle bombardment will decompose any molecule - may be heated SiC is a possible candidate.

RHABE

I'm thinking P22R phosphor like that used in CRT's.

http://en.wikipedia.org/wiki/Phosphor

Another article, similar to Bricktop's link in post 1...

"Your next laptop battery..."...

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

...this was linked-to within a previous CR4 thread.

Don't know WHY all-the-fuss about a laptop battery lasting 30 years...

Your OS will be obsolete in less than 1/4th that time-period, and in order to UPgrade to the new OS will mandate new HARDware, which, itself, will mandate purchasing the all-new / sleeker / built-in battery that accompanies same...

?...A 30-year laptop battery...? HA! ... It'll never catch on! {Ooops; never-mind, I caught myself. They'll simply adapt it to a product that really DOES need it; like the camcorders for "Girls Gone Wild" tours...}...(sigh).

Or perhaps pacemakers which currently have to be replaced every 3-5 years or so.

Or permenantly installed downhole oil tools that must power instrumentation such as pressure and temperature sensors.

Or active prosthetic devices like the C-leg.

Here is a better description of the device AFRL is working on.

http://www.newscientist.com/blog/invention/2007/07/betavoltiac-batteries.html

as to the "3d photodiodes" described in the article, it sounds a lot like this:

http://www.hno.harvard.edu/gazette/1999/12.09/silicon.html

Check out http://www.hyperionpowergeneration.com for another approach to nuclear power generation...

yep thorium breeders. we luv them breeders.....

Hi,

I searched for their principle(s) - nothing

I searched for the patents under companys and CEOs name: nothing

I searched the links: nothing but advertising and commonplace,

so what?

Anybody knows what they do or intend to do?

RHABE

A friend of mine is a science reporter for the local fishwrap and he has been working on a story about them. He has told me bits and pieces. From what I have gathered from his hints (he won't tell me the whole thing, I talk to dang much.), the reactors are thorium breeder reactors. The idea is to have a sealed self contained unit that you bury in your back yard like a large septic tank. I THINK they use thermoelectrics to generate power. They don't use any coolant so they must use the Seeback effect. When the pile gets too cold to continue to generate power, you have a crew come out and dig it up, swap in a new one and they cart the old one away for refuelling at the factory. Adams Atomic Engines has a similarly sealed and self contained truck mounted/skid mounted concept using a pebble bed reactor design. Both designs are inherently self limiting and cannot go supercritical.

Hi,

look to www.aecl.ca

they are really working with reactors that can burn thorium (or uranium) and have a lot of positive features. But well known size and enrgy production and cost.

It is not thinkable that privates or small companies will get permission to store large quantities of highly radioactive material in order to use the wasted heat.

Adams and Hyperion seem to have this in their minds.?

With the size reactor they are talking about, I think they will probably have to use well enriched fuel.

A smaller version of this may be feasible for locomotive or even large aircraft use. Of course the naysayers will immediately freak out at the possibility of serious repercussions after a crash, but suitable sealing could be found

Could open interesting possibilities with respect to transport costs.

Waste from such reactors could be turned into nuclear batteries for RAPS use.

I think they are using neutron generators (an electron gun with a beryllium target) to overcome the neutron flux issue so that high levels of enrichment are not required. the beauty of that approach is that if you turn the neutron generators off, the reaction stops.

"I think they are using neutron generators (an electron gun with a beryllium target) to overcome the neutron flux issue so that high levels of enrichment are not required. the beauty of that approach is that if you turn the neutron generators off, the reaction stops."

Neat.

I wonder what % of the power is chewed up by the electron gun?

Toshiba is working on a 20' x 6' 200kW micro reactor as well.

forgot the link:

Hi,

All these mini-nuclear reactors rely on safe handling of extremely dangerous stuff,

if heat is produced by radioactive decay, nobody will get permission to operate this as a power generator: any failure would have catastrophic consequences,

if heat is produced by fission the original uranium or thorium is converted into nasty radioactive elements: what is on debate about deposits for burnt fuel?,

if plutonium is involved this is worse than the other elements as uranium mining workers are allowed 1mg per year intake, but Pu is a factor of 10⁸ more poisonous!

So I would forget about these and I would ban any of these activities and put considerable effort into further development of the CANDU-type reactors, details at www.aecl.ca/, and similar designs.

RHABE

RHABE, I think the driving concept is twofold. One is distributed power generation. placing small generating stations near the end users so to limit line losses and to take a load off of the long distance power grid. The other is power generation in remote parts of the world. Africa, South America, Antarctica, Siberia, northern Canada, and offshore oil rigs, locomotives, and marine propulsion, that sort of thing.

And these reactors such as Hyperion's and Adams' are what is known as intrinsically safe. They cannot melt down. if the PBR one loses coolant (the hyperion one doesn't even USE coolant.), the reaction stops. If the Hyperion one starts to runaway, all you have to do is turn off the neutron guns and it shuts down. Individuals won't own these, but private companies might. And no, they do not rely on safe handling, at least not by the end users. They come from the factory pre-fuelled and sealed for the life of the reactor.

But we were originally talking about nuclear batteries which are an entirely different beast and far safer.

I'm surprised that no one has expressed concern about radioactive materials becoming more available to terrorists for use in dirty bombs (maybe someone commented and I missed it?). This would seem to be a valid concern if nuclear batteries become commonplace.

"If plutonium is involved this is worse than the other elements as uranium mining workers are allowed 1mg per year intake, but Pu is a factor of 10⁸ more poisonous!"

Respired Pu is extremely toxic, but the oxide is unbelievably insoluble, making it difficult to ingest enough to cause problems.

I'm not sure about the solubility of the carbide but I think it is also insoluble.

The claim about Pu toxicity is frequently made, but no one ever seems to check whether it is true or not.

Pu metal is toxic as it is absorbed fairly easily and displaces Fe, distributing a powerful alpha emitter throughout the body via the blood stream.

Note that Pu metal oxidizes easily, so it is difficult for anything to become exposed to the metal itself.

To summarise, the toxicity of Pu is very much over rated.

Hi,

And these reactors such as Hyperion's and Adams' are what is known as intrinsically safe.

This is true if you think about nuclear fission - chain reaction.

But if you have insufficient cooling this pile of waste will heat up until either melting some surrounding material will melt or some nearby water will be explosively converted to steam. (No cooling is in reality free convection cooling that can fail too.)

This happened to a nuclear waste facility in the Soviet-Union.

And if you think about intended or unintended cracking of the container and leaching of the radioactive material to the groundwater or recovery by criminals - you will not really want this to happen.

Respired Pu is extremely toxic, but the oxide is unbelievably insoluble, making it difficult to ingest enough to cause problems.

Pu is radio-toxic by accumulation in the sheaths that separate the bones from other tissue, this accumulation enhances radio-toxicity as any nearby structure will be damaged by the radiation until the repair or self-kill mechanisms of the damaged cells are no longer working and cancer starts.

So the carbide does not have to be soluble but inhalable material will first stick to nasal to lung surface, then there being dissolved (yes this is working in our body) transported by blood to the bones, some excreted by urine (damaging the kidneys) and the rest doing further damage.

Nobody would ever use metallic Pu except in reprocessing and nuclear weapons.

To summarise, the toxicity of Pu is very much over rated.

How much the factor of 10⁸ do you think is to be corrected?

In the radioactive waste use the proponents of these energy machines want to make money with there are a lot of other ugly elements. As long as there is no clear indication what is planned by them I do not believe in any success nor feasibility.

The only possible exception may be the lithium reactor.

The way to come to real solutions for the waste problem of nuclear technology is along the CANDU type reactors that are capable of much better usage of slightly enriched uranium and thorium, thus reburning a considerable part of the waste by longterm use of the fuel-rods. If the international community will ackknowledge this principle and enter a joint development, progress will be faster. Today progress is delayed by competition between US, Europe and Russia.

(See AECL and ICENES for details).

RHABE

Hi RHABE,

I've done a little research on the toxicity and solubility of Pu.

It appears that the danger from it is similar to that of Uranium, so I would replace your factor of 100 million with 1.

When Ralph Nader made the claim that Pu was the most toxic material on earth, a physicist who had been studying the subject challenged him by offering to eat as much Pu as Nader drank caffiene. (Nader ignored the challenge, so the claim of the extreme toxicity of Pu has persisted). While this illustrated that Pu toxicity was very much over rated, it was also a have as the physicist was well aware that the amount of Pu absorbed from the digestive system is virtually nil.

Like any alpha emitter, Pu is dangerous, but not significantly more so than U and substantially less so than Ra. Rn is also dangerous and anyone who has a house in granite country will have detectable levels in his house if he insulates and seals it to the degree recommended.

Radiation scares people because they cannot see or feel it, yet it can damage them.

Provided the benefits are sufficient to make it worthwhile, the risks involved can be handled without too much difficulty.

The potential benefits of small nuclear plants and atomic batteries seem worth the risks involved and should be pursued.

http://www.atsdr.cdc.gov/toxprofiles/tp143.pdf

Hi Sceptic,

if you compare on alpha-decays per second then damage may be similar, except for the enhancement of Pu at bone-skins.

From the above compilation of existing data for Pu I made a rough estimate that the factor of toxicity of natural uranium (with likely radiating byproducts) (1mg/year allowed) to plutonium (which mixture of isotopes to be defined) is more likely near 3000 and not as claimed near 10⁸. (Pu: one intake and 50 years of mixed excretion and persistence). I do not know the allowed level of one time natural U intake level (this is on mining so contaminants are there).

Very pronounced premature death of dogs is caused by Pu levels of around 1KBq (to be converted to mass).

RHABE

From much of what has gone before, it looks as though a nuclear battery is feasible and may even be economic.

It could use up our present high level nuclear waste, allow good supplies to remote areas, allow local area base load power generation, thereby reducing line losses and improving reliability of supply.

A new industry could be spawned servicing and recharging run down batteries and extracting the decomposition end products, most of which have commercial value.

If the solid state type generators proved too inefficient or unreliable or short lived, submerging high level wastes in Na/K eutectic and boiling the K into a thermionic generator, with the condensed K returning to the bath and the cooling of the generator raising steam for conventional generation would require no particularly new technology to generate significant amounts of power.

Either way, this could remove the problem of high level wastes which dogs the nuclear industry.

Of course the problem of medium and low level waste disposal would still be with us.

As a Nuke engineer friend of mine explained to me, the fuel for these don't over heat. They use an inverse thermal expanding metal to separate the fuel pellets so as the reaction heats up the fuel moves apart. Some SNAP reactors work similar to this. As for dirty bombs a Depleted uranium round could fall into that category

Brad

This is exactly what is used in deep space probes isn't it? Out there in space where solar panels no-longer work, it is small nuclear devices that produce the power needed to run the various devices needed to orient the craft and to send and receive communications.

Uh, actually no. They use nuclear thermoelectric generators. essentially they are a subcritical mass of a radioactive isotope (usually weapons grade plutonium 239) surrounded by thermocouples covering ever square inch of surface area. the heat generated by nuclear decay provides the hot side of a thermocouple and the cold of space provides the cold side. what we are discussing here is a device to use the nuclear decay particles directly. in our case it would probably be a beta decay particle from the decay of tritium (third isotope of Hydrogen) combined with oxygen to form tritrated water. when the tritium decays it becomes helium, disassociates with the oxygen, releasing helium and oxygen. beta decay is essentially the same as an electron beam like that created in a CRT or X-ray tube. It is not terribly penetrating and can be stopped by a thin layer of metal unlike Gamma rays which are released by Uranium and Plutonium.

So in theory this ball of energy with a skin of bimetallic material can generate power of sufficient quantity to send signals to the earth stations tuned to the appropriate frequency and is also capable of receiving signals back from the pinpoint of earth which at the vast distances to the planets is no inconsequential feat...No only that there is sufficient energy available to run complex manuvers etc..Outside of the fear of everything that could go wrong if all humanity were benevolent creatures this would be an excellent way to generate electricity locally..Or am i stretching it with the hope that people could be good ?

Regards...Marty W.

R....Thanks for the insight..There is another blog discussing the possibilities of fusion as a means to generate electricity on a massive scale...I take it fast breeders would be a simpler way at this point in technological acumen and an excellent way to use spent fuel bundles/pellets currently generating decay energetics in tombs of sorts...Could the lack of will to proceed be a function of vested interests(coal/oil)stymying efforts to get funding etc...Then again some demand generators would be required but i suppose storing heads of water or other fluid to flow over generators/transformers could be done on a grand scale with any nuclear systems..Design of closed or closer loops makes sense...Again thanks for the quick lesson..Marty W.

"I come into this world with my fists closed expecting all the world to be mine..I leave with hands open leaving it all behind" a bit of a Hebrew Madrash i read this morning but couldn't relocate the exacy saying..sorrry this is all i could remember so the wording is not precise but it was poignant in context..

I suppose that the NG, Fuel oil, and coal industries have a lot of money at stake and it would not surprise me if they didn't have lobbyists working to prevent that, but as you said, some peak generation will be needed regardless so there is room for fossil fuel plants in the mix, just not as much as currently.

Go on eBay and buy a tritium powered exit sign. Tear it apart and remove the tritium glass rods. Place the rods next to each other to form a square. Buy some common small solar cells with a total area slightly smaller than twice that of the square. Wire them for whatever voltage you prefer. 13.5-volts output recommended for 12-volt battery recharging. Cover the square on both sides with the wired solar cells and glue-gun it all together. Now you have a nuclear battery!