Scientists Turn Nuclear Waste Into Diamond Batteries (newatlas.com)

Scientists at the University of Bristol have found a way to convert thousands of tons of nuclear waste into man-made diamond batteries that can generate a small electric current for thousands of years. New Atlas reports: How to dispose of nuclear waste is one of the great technical challenges of the 21st century. The trouble is, it usually turns out not to be so much a question of disposal as long-term storage. Disposal, therefore is more often a matter of keeping waste safe, but being able to get at it later when needed. One unexpected example of this is the Bristol team's work on a major source of nuclear waste from Britain's aging Magnox reactors, which are now being decommissioned after over half a century of service. These first generation reactors used graphite blocks as moderators to slow down neutrons to keep the nuclear fission process running, but decades of exposure have left the UK with 104,720 tons of graphite blocks that are now classed as nuclear waste because the radiation in the reactors changes some of the inert carbon in the blocks into radioactive carbon-14. Carbon-14 is a low-yield beta particle emitter that can't penetrate even a few centimeters of air, but it's still too dangerous to allow into the environment. Instead of burying it, the Bristol team's solution is to remove most of the c-14 from the graphite blocks and turn it into electricity-generating diamonds. The nuclear diamond battery is based on the fact that when a man-made diamond is exposed to radiation, it produces a small electric current. According to the researchers, this makes it possible to build a battery that has no moving parts, gives off no emissions, and is maintenance-free. The Bristol researchers found that the carbon-14 wasn't uniformly distributed in the Magnox blocks, but is concentrated in the side closest to the uranium fuel rods. To produce the batteries, the blocks are heated to drive out the carbon-14 from the radioactive end, leaving the blocks much less radioactive than before. c-14 gas is then collected and using low pressures and high temperatures is turned into man-made diamonds. Once formed, the beta particles emitted by the c-14 interact with the diamond's crystal lattice, throwing off electrons and generating electricity. The diamonds themselves are radioactive, so they are given a second non-radioactive diamond coating to act as a radiation shield.

Comments

Long range space probes?

[Sasayaki]

Seems like this kind of technology would be very useful for long duration space probes.

Re:Long range space probes?

[AmiMoJo]

1g of carbon apparently produces 15 Joules per day, which if you work it out is only going to deliver tens of microamperes. Enough for timekeeping and maybe running a simple LCD, perhaps even the odd very short very low power very low range radio broadcast for a sensor.

I suppose if they includes a fairly large amount of the stuff it might generate enough energy to be useful in a space probe, but I don't think the power/weight ratio is there. You would want to use something a bit more potent if you were spending that much money, as they did with various nuclear powered probes.

Where it will shine is for sensors. There was a plan to install sensors on water pipes before they were buried using nuclear batteries, for example. Stress sensors in buildings and on bridges. All sorts of areas where replacing the sensor is difficult and expensive so you want decades of battery life and the basic sensor isn't going to change much in that time.

De Beers Marketing

[0100010001010011]

Don't get a radioactive man made diamond. Buy one of our questionably sourced ones.

We'll even train you how to spot the difference.

[My Mohs scale doesn't care. Minecraft has made me want a diamond everything hand tool.]

Energy input.

[Anonymous Coward]

What is the energy input required to create this vs the energy it will output?

Re:Energy input.

[wierd_w]

CVD is a low pressure ionized gas crystallization process. It produces gemstone class diamonds.

The researchers would likely benefit more from using the Russian hydraulic form compression method of producing said diamonds, because it is much cheaper. It does not produce single, large crystal diamonds without defects the way CVD does, but we aren't trying to make jewelry here. We are interested in trapping the emitted beta particles (high energy electrons emitted from the nucleus) in the lattice and using the high bandgap semi conductive properties of the diamond to transport those electrons as a reliable source of current.

Without exact figures for how many tons of irradiated graphite there is, how energy intense CVD us compared to compressive forming, and how efficient the two end products are, I cannot even begin to answer your question though.

Even if there is a big deficit, it might still be worthwhile, due to the immense savings on sequestration costs, and maintenance costs of these batteries.

Re:Energy input.

[Anonymous Coward]

The half life of Carbon-14 is 5730 years; a battery fabricated from it will produce a small current for thousands of years. Surely that has value beyond the energy input?

Re:Energy input.

[quanminoan]

The first hydraulic presses (tetrahedral presses) were made by an american engineer Tracy Hall. The "diamond makers" is a great book that discusses these early efforts and the long history of trying to create artificial diamond. Also not sure about efficiency, but high pressure formed artificial diamonds tend to be way more defective - a problem if you're trying to create semiconductor properties of a beta voltaic. CVD actually produces diamonds with less flaws than nature.

Not that simple ...

[perpenso]

What is the energy input required to create this vs the energy it will output?

Its not that simple. Basically the true comparisons are the alternative nuclear waste storage and energy storage (battery) options?

Brilliant research

[quax]

This could be a real game changer if it manages to change some minds. We need nuclear tech to cope with the nuclear waste, and this can be done in an inherently safe and responsible way that turns the waste into energy.

I very much hope this example in doing this on the small scale, as with these diamond batteries, will translate into support for bigger inherently safe designs that allow to transmute nuclear waste into lesser problems.

Re:Brilliant research

[Applehu Akbar]

"This could be a real game changer if it manages to change some minds. We need nuclear tech to cope with the nuclear waste, and this can be done in an inherently safe and responsible way that turns the waste into energy."

But take a closer look at the article. This iech only applies to reactors using graphite blocks as a moderator, a type not used in the US or Asia. The 14C is separated out from the stable 12C and formed into the energy-producing diamonds.

Our own spent fuel, because it still contains 95% of the original energy potential, is better off being fed to a new generation of full-burnup reactors that will extract all the energy and leave behind only short-lived waste.

Re:Fine, power your bitcoin asic ...

[jcochran]

You gotta remember that you're dealing with idiots who tremble at even a hint of an idea that radiation is near them. In fact, there's a little device in your car (assuming it's powered by gasoline) where it's name was determined due to the fear of radiation. The "catalytic converter" has that name because of idiots who fear the concept of radiation. The correct proper name for that device is "catalytic reactor". But the word reactor is used in nuclear reactors so "obviously" a "catalytic reactor" is dangerously radioactive and should never ever be placed in a car because it might spread radiation all over the place and don't even think about what would happen in an accident. Because of that fear, engineers call that little device a "catalytic converter" because that doesn't have the dangerous radiation inducing effects that the word "reactor" has.

Remember your audience and compensate for their ignorance and/or stupidity.

Energy density

[lorinc]

What's the recoverable energy density of this? I mean, how many watts of electricity can I get out of on of these, for how long, per cm^3?