Forgot your password?
typodupeerror
Power Science Technology

Nuclear Battery That Runs 10 Years 689

Posted by Zonk
from the never-have-to-recharge-your-ipod dept.
Jenny writes "A battery with a lifespan measured in decades is in development at the University of Rochester, as scientists demonstrate a new fabrication method that in its roughest form is already 10 times more efficient than current nuclear batteries -- and has the potential to be nearly 200 times more efficient. Similar to the way solar panels work by catching photons from the sun and turning them into current, the science of betavoltaics uses silicon to capture electrons emitted from a radioactive gas, such as tritium, to form a current. As the electrons strike a special pair of layers called a 'p-n junction,' a current results. I can imagine lots of applications for this new battery including my own laptop."
This discussion has been archived. No new comments can be posted.

Nuclear Battery That Runs 10 Years

Comments Filter:
  • Great... (Score:5, Funny)

    by Jace of Fuse! (72042) on Friday May 13, 2005 @12:28PM (#12520788) Homepage
    So now instead of just overheating... my laptop can have a total meltdown?
    • Re:Great... (Score:3, Funny)

      by Dan667 (564390)
      And if it was in your lap at the time, your nuts would glow.
    • Re:Great... (Score:5, Interesting)

      by AKAImBatman (238306) * <<akaimbatman> <at> <gmail.com>> on Friday May 13, 2005 @12:40PM (#12520970) Homepage Journal
      I realize you're joking, but just for the record these *can't* go into a "meltdown" state (what is technically termed a prompt critical reaction). Unlike nucelar reactors which function via nuclear fission, these batteries function by capturing the rays from radioactive materials and converting them into energy. The side effect of this is that these batteries tend to be inherently safe because they can't explode and they produce almost no extra radiation (because they're using the radioactivity directly as a power source).

      The biggest concern with batteries such as this is actually cost. Radioactive materials are controlled by the government (although anyone with a license can obtain some through various online webstores) and thus have experienced little competition overall. As a result, prices have stayed high.

      As I've said before, one solution to this problem is to lease the battery instead of selling it outright. Given its ten year lifespan, the costs can be spread out over that time. When the battery is exhausted, the manufacturer can then reuse the remaining materials in a new battery, thus slowly driving down the prices.
      • Re:Great... (Score:5, Interesting)

        by Walt Dismal (534799) on Friday May 13, 2005 @12:46PM (#12521051)
        Given the paranoid yet incompetent state of security in this country, every single radioactive battery is probably going to get the bearer stopped by the police at some point. Take a radioactive laptop on a plane? -- Stripsearch. Just wait and see. If Homeland Security's detectors currently false-alarm over the natural radioactive potassium isotopes in bananas - yes, bananas! - then these batteries might get the fisheye from these morons.
        • Re:Great... (Score:5, Informative)

          by Walt Dismal (534799) on Friday May 13, 2005 @01:09PM (#12521335)
          I'm just curious. How is relevant concern about national security and these batteries rated as a troll? Obviously the moderator has never heard that the NY City police carry radiation detectors now, and that people who have had medical exams involving isotope injection for scanning have actually been pulled off public transit. Radioactive batteries *will* get law enforcement response.
          • Re:Great... (Score:5, Informative)

            by toomanyhandles (809578) * on Friday May 13, 2005 @01:44PM (#12521792)
            Well, troll is a little strong I think, the concern is valid but should be alleviated with some background knowledge :) These batteries won't be detected by radiation detectors, anyway. No pulling you off public transport for that. Not only will the weak beta radiation not get out of the battery, even if the battery does leak, you can pour millicuries of tritium all over detectors, be it badges or geigers or whatever. The weak beta radiation won't even develop film. Now, medicinal doses of I131 or wahtever- those show up loud and clear. I had a friend who had to have his thyroid zapped- he pegged out lab geiger from 5 feet away. Weak beta emitters like tritium that are really almost no concern- I'd like it if they were more dangerous as then you can monitor them more easily (they show up on things like a geiger). The onyl way to "detect" weak betas like tritium is to mix it with some other substance that glows just a tiny bit when hit with low energy beta particles, and then load it into a special very sensitive machine to look for that emitted light. All that said, I'd like to know if they are loading their battery with millicurie quantities or what- if it leaked, that could be an ingestion hazard. I've not RTFA to see though :) HTH. HTH.
            • Re:Great... (Score:3, Informative)

              by -Harlequin- (169395)
              you can pour millicuries of tritium all over detectors, be it badges or geigers or whatever.

              No, only if you're using a gamma-only geiger tube. Any alpha-capable geiger tube detects tritium fine. My pancake geiger (as well as my beta-gamma scintillation probes) goes nuts from the tritium of those glow capsule (used in compasses and keyrings) though the glass capsule it's sealed in. You're right in that you need to get the sensor so close that it's not going to be an issue on public transport, but it defin
              • Re:Great... (Score:3, Interesting)

                by deglr6328 (150198)
                I wish I had one of those keychains do test this out myself! I have a pancake ludlum too!! :) It's not that I doubt your claim, it's just that it is IMPOSSIBLE for the 18KeV (max) betas from H-3 to escape the glass capsule. Either you are detecting radiation from the glass itself (not an uncommon phenomenon) or you are detecting the X-rays (bremstrahllung) from the deceleration of the betas as they slam into the glass.... OR...could the phosphor be a rare earth (Eu?) variety with some leftover contaminatio
        • Re:Great... (Score:3, Informative)

          The beta radiation from tritium won't even penetrate the outler layer of dead skin cells on your body. It's that weak. Nothing would get out of the battery to trip any detectors.
          You have to eat huge amounts of it to get any harmful doses.
          See : http://www.physics.isu.edu/radinf/tritium.htm [isu.edu]
        • Re:Great... (Score:4, Informative)

          by mikael (484) on Friday May 13, 2005 @02:58PM (#12522677)
          The Register [theregister.co.uk] has an article about how radioactive tritium "glowring" keyrings cannot be imported into the US since the authorities have placed an embargo on the civilian use of radioactive material.

          More details [epa.gov] on Tritium.

          Given these restrictions, we probably won't have nuclear powered laptops, but it will help make space probes lighter.

      • Re:Great... (Score:5, Interesting)

        by Erioll (229536) on Friday May 13, 2005 @12:49PM (#12521099)
        Buy a smoke detector. Those have radioactive materials in them. Wasn't it on /. a few years ago that there was a story about a kid making a mini-reactor in his backyard shed out of tritium from gun sights, and whatever the material is in old smoke detectors?
      • Re:Great... (Score:3, Insightful)

        by metlin (258108)
        The biggest concern with batteries such as this is actually cost. Radioactive materials are controlled by the government (although anyone with a license can obtain some through various online webstores) and thus have experienced little competition overall. As a result, prices have stayed high.

        Well, yeah. Except that as always, some countries would give a damn about regulations and these are the ones who will take advantage of the new technology and get ahead.

        You think I'm kidding? Wait a few more years a
      • Re:Great... (Score:5, Funny)

        by xkenny13 (309849) on Friday May 13, 2005 @01:22PM (#12521491) Homepage
        Unlike nucelar reactors which function via nuclear fission, these batteries function by capturing the rays from radioactive materials and converting them into energy.

        Ummmm ... didn't Chekov do this in Star Trek IV!?
      • Re:Great... (Score:5, Funny)

        by MarkGriz (520778) on Friday May 13, 2005 @01:33PM (#12521637)
        "...these batteries tend to be inherently safe because they can't explode..."

        Maybe not, but lets keep that Australian kid [slashdot.org] away from them, just to be safe.
    • And if the heat from your laptop isn't already doing enough to harm your sperm count, now you can irradiate your groin to kill off whatever remains! :-)
    • Re:Great... (Score:5, Funny)

      by DrStrange66 (654036) on Friday May 13, 2005 @12:55PM (#12521181)
      Now the Energizer bunny will be replaced with the Radiation bunny!

      It keeps glowing and glowing...
    • by j!mmy v. (613784) on Friday May 13, 2005 @12:56PM (#12521198)
      This will be awesome in iPods.

      Until your mother launders it.

      And you take a screwdriver to it.

      And it flips you into orbit.

    • by sterno (16320) on Friday May 13, 2005 @01:10PM (#12521345) Homepage
      This is going to be an interesting thing to see develop over the next few decades. Nuclear power went from this supposed clean and perfect energy source to becoming the demon of nuclear war, chernobyl and three mile island. When you say nuclear power to people, they get images of three-eyed fish, cancer, etc.

      Having said that, safe nuclear power, which is entirely feasible right now, is really our best option for dealing with energy shortages in the near future. The pebble bed nuclear reactor technology doesn't melt down, provides copious energy, and doesn't emit a gram of CO2. Plus, if I'm not mistaken, the disposal of the pebbles is less troublesome than the leftovers from the more traditional reactors.

      A nuclear battery that could last 10 years would be way better, not only for the users of the batteries, but also for the environment. Think about how much energy you have to use to charge a laptop. All of that energy is primarily coming from fossil fuels. Then when you are done with the battery, you throw it in a dump (at least most people do), and the heavy metals that go into most of those batteries leak into the environment.

      Of course, in order for any of this progress to happen, you're going to have to get people comfy with having a radioactive source a few inches away from their crotch. It might have all the shielding in the world, but it's still going to make a lot of people nervous.
      • by drew (2081) on Friday May 13, 2005 @04:34PM (#12523817) Homepage
        Of course, in order for any of this progress to happen, you're going to have to get people comfy with having a radioactive source a few inches away from their crotch. It might have all the shielding in the world, but it's still going to make a lot of people nervous.

        Then don't call it a nuclear power source. When most people think nuclear, they are thinking nuclear fission, a la chernobyl and three mile island. Just call it a "betavoltaic power source". Tell people it's similar to solar cell technology, just skip the 'N' word. If they still ask where the power is from, tell them it comes from natural decay of hydrogen atoms, the same thing that makes the hands on their watch glow.

        Besides, if I remember corrctly, beta particles can be stopped by a sheet of aluminum foil. When most people think of radiation shielding, they are thinking af gamma rays, which require much more effort to stop.
  • Careful... (Score:3, Funny)

    by daveschroeder (516195) * on Friday May 13, 2005 @12:28PM (#12520790)
    If you ever have an iPod with one of these things, don't send it through the washing machine, and then start stabbing it with a screwdriver...
    • Re:Careful... (Score:5, Informative)

      by AKAImBatman (238306) * <<akaimbatman> <at> <gmail.com>> on Friday May 13, 2005 @12:47PM (#12521075) Homepage Journal
      They're probably pretty close to indestructable, so I wouldn't worry too much about idiots. Even if they do manage to penetrate the outer shell, the materials will probably be of a "safer" radioactive type such as an Alpha Emitter. Alpha rays are generally not dangerous as they easily bounce off the outer skin.

      The primary safety hazard is actually the inhalation of an Alpha Emitter. Once inside the soft tissues of the lungs, the emitter increases the risk of broken DNA strands, thus leading to cancer. Note that this is a worst case scenario. Most Alpha Emitters are far too heavy to float in the air, and far too strong to be easily pulverized into pieces small enough to float.

      Note that evidence suggests that the other concern, indigestion, is a non-issue. In all documented cases where Plutonium (a common alpha emitter) was accidently ingested, it was found to pass through the digestive tract without issue. Radiation was not an issue due to the general thickness of the digestive system.

      Compare this to the safety hazards of Alkaline and other battery technologies. These technologies can easily poison water wells, are quite dangerous if ingested, have the potential to explode, and can cause serious burns when in contact with the skin.
  • next time (Score:4, Interesting)

    by mmkkbb (816035) on Friday May 13, 2005 @12:28PM (#12520791) Homepage Journal
    Next time your laptop battery runs out, you get to replace the entire laptop.
    • by tomcode (261182) on Friday May 13, 2005 @01:00PM (#12521245)
      Actually, you'd keep the battery and buy a new laptop for it every few years.
  • Non-lethal exposure (Score:5, Interesting)

    by suso (153703) * on Friday May 13, 2005 @12:28PM (#12520792) Homepage Journal
    Before going off and thinking that a radioactive battery would be bad because
    of toxic exposure through its mere presense, please read this Wikipedia article about Tritium [wikipedia.org], which explains
    that " The low-energy beta radiation from tritium cannot penetrate human skin, so tritium is only dangerous if inhaled or ingested."

    So it might make a good candidate for a household battery.
    • " The low-energy beta radiation from tritium cannot penetrate human skin, so tritium is only dangerous if inhaled or ingested."

      Still, I'm not sure that I'd like to have one of these in my laptop, unless it was as a form of permanent contraception.

    • by Cyclotron_Boy (708254) on Friday May 13, 2005 @12:38PM (#12520945) Homepage
      This is a really exciting breakthrough, but the idea is far from new. The parallel-place electrometer [wikipedia.org] was used in the early days to detect ionizing radiation by knocking off stored charge with the incoming flux of charged particles. This is in a way harnessing the current created by radioactive decay. Modern radiation dosimeters [wikipedia.org] use a similar principle. It was always discussed that if you could simply harness the current of the emitted betas, you would have a useable battery. Until now this wasn't feasible due to the efficiency of capturing those betas and using them as a current source. I can't wait till this is made available to the public.
  • by drizst 'n drat (725458) on Friday May 13, 2005 @12:30PM (#12520810)
    Naw ... just kidding but think of the added benefits ...
  • by American AC in Paris (230456) * on Friday May 13, 2005 @12:30PM (#12520816) Homepage
    To help answer some of the imminent "nukular batteries? Isn't that going to kill us all?" questions, here's a sampling from the EPA's webpage on tritium [epa.gov]:

    How does tritium affect people's health?

    As with all ionizing radiation, exposure to tritium increases the risk of developing cancer. However, tritium is one of the least dangerous radionuclides because it emits very weak radiation and leaves the body relatively quickly. Since tritium is almost always found as water, it goes directly into soft tissues and organs. The associated dose to these tissues are generally uniform and dependent on the tissues' water content.

    How does tritium change in the environment?

    Tritium readily forms water when exposed to oxygen. As it undergoes radioactive decay, tritium emits a very weak beta particle and transforms to stable, nonradioactive helium. Tritium has a half-life of 12.3 years.

    How do people come in contact with tritium?

    People are exposed to small amounts of tritium every day, since it is widely dispersed in the environment and in the food chain. People who live near or work in federal weapons facilities or nuclear fuel cycle facilities may have increased exposure. People working in research laboratories may also come in contact with tritium.

    How does tritium get into the body?

    Tritium primarily enters the body when people swallow tritiated water. People may also inhale tritium as a gas in the air, and absorb it through their skin.

    What does tritium do once it gets into the body?

    Tritium is almost always found as water, or "tritiated" water. Once tritium enters the body, it disperses quickly and is uniformly distributed throughout the body. Tritium is excreted through the urine within a month or so after ingestion. Organically bound tritium (tritium that is incorporated in organic compounds) can remain in the body for a longer period.

  • by lawpoop (604919) on Friday May 13, 2005 @12:31PM (#12520822) Homepage Journal
    Betavoltaics? I'll wait until this radioactive battery is more... stable.
  • Will it sell? (Score:3, Insightful)

    by miyako (632510) <miyako&gmail,com> on Friday May 13, 2005 @12:31PM (#12520831) Homepage Journal
    I just wonder, no matter how efficient, safe, and cheap this thing can be, if it will ever sell. Nuclear tech seems to be kind of a boogeyman still. How long until Fox or the SciFi channel makes a Made for TV movie about someone's pace maker having a meltdown and taking out 2/3 of north america.
    • Re:Will it sell? (Score:4, Insightful)

      by American AC in Paris (230456) * on Friday May 13, 2005 @01:09PM (#12521339) Homepage
      I just wonder, no matter how efficient, safe, and cheap this thing can be, if it will ever sell.

      I dunno--the promise of never having to plug your computer/cell phone in to anything may sway a significant portion of the population.

      Seriously. 100% self-contained, self-sustaining portable systems. Elimination of the single most annoying part of modern gadgetry--the external power source.

  • I can imagine lots of applications for this new battery including my own laptop.

    Yeah. Just don't try to take it on a plane.

  • Nooooooo!!! (Score:4, Insightful)

    by LordKronos (470910) on Friday May 13, 2005 @12:31PM (#12520834) Homepage
    Have we learned nothing. Calling it a nuclear (or nucular) battery will only ensure it's complete and total failure.
    • Right! They should call it a Beta-Battery, like as indicated in the info, or something like that, so it sounds happy and friendly, and the hippies won't catch on.

      -Jesse
    • Have we learned nothing. Calling it a nuclear (or nucular) battery will only ensure it's [sic] complete and total failure.

      I was with you up to the equating of nucular with nuclear. Regardless of your feelings about Bush, pro or con, you have to admit he's managed to sway a lot of people by his [irony acknowledged] scientific choice of words. So since, as you seem to implicitly suggest, we seem a nation more susceptible to words than truths, maybe this is just the shift that's needed to get it over

  • AKA (Score:3, Informative)

    by ZagNuts (789429) on Friday May 13, 2005 @12:32PM (#12520848) Journal
    special pair of layers called a 'p-n junction'

    The p-n junction is sometimes called by its more technical name: the "diode".
    • Re:AKA (Score:5, Informative)

      by Avian visitor (257765) on Friday May 13, 2005 @12:47PM (#12521070) Homepage
      p-n junction can be so much more than a diode. A diode is in many cases composed of a single p-n junction, but diode != junction. I totally agree with the poster for calling it that way.

      You don't call two p-n junctions in the transistor a diode. You don't call the p-n junction in the solar cell a diode...

      The term "diode" can also be applied to a vacuum diode, Schotky diode, etc. neither of which is composed of a p-n junction.
      • Re:AKA (Score:5, Informative)

        You don't call two p-n junctions in the transistor a diode. You don't call the p-n junction in the solar cell a diode...
        Sure you do. Any electrical engineer would. Saying things like "don't forward bias the base-collector diode" or "the emitter-base diode has a low reverse breakdown voltage" is common.
        The term "diode" can also be applied to a vacuum diode, Schotky diode, etc. neither of which is composed of a p-n junction.
        You're correct on the vacuum tube diode. As for Schottky barrier diodes, it's been a while since my semiconductor physics class, but while it may be technically incorrect to classify it as p-n, it most certainly is a junction.
  • by grub (11606)

    I can imagine lots of applications for this new battery including my own laptop

    That a calculated risk: will you end up sterile and impotent or the proud wielder of a 14 inch hammer...
  • Nucular (Score:2, Funny)

    by kevin_conaway (585204)
    Its pronounced "nu-cu-lar"
  • by rokzy (687636) on Friday May 13, 2005 @12:33PM (#12520869)
    nuclear decay is a completely spontaneous process. the only way to get more beta particles is to have more radioactive material. long lasting does not mean lots of power.

    this reminds me of an essay I read by a second year physics student that nanotechnology would allow us to run 10GHz computers for 10 years off a watch battery. it's BS but you don't need to look at the technology to see that, it's just basic thermodynamics:

    law 1. you can't win
    law 2. you can't break even.
    law 3. you can't get out of the game.
    • by American AC in Paris (230456) * on Friday May 13, 2005 @12:48PM (#12521085) Homepage
      nuclear decay is a completely spontaneous process. the only way to get more beta particles is to have more radioactive material. long lasting does not mean lots of power.

      Consider the following:

      You could engineer your batteries to produce significantly more power than the system needs. As the isotope decays, you approach the system's minimum power needs. System alerts you six months before it needs a new battery.

      You could design a hybrid battery--part traditional power storage, part nuclear generation. As the traditional battery is drained, the nuclear battery charges it; best of all, when you're not using the laptop, it charges by default. You wouldn't need a nuclear battery big enough to run the whole laptop--just big enough to stretch that five hour standard battery to a ten-hour battery, with the added bonus of automatic, cordless recharging when the system isn't in use...

    • A 10GHz computer for 10 years. Let's see. Assume a single instruction demolishes 64 bits of data. That's 2x10^18 bits of data in total and hence you can place a lower bound of 2x10^18 bits of entropy being generated. Use E=kT*bits we find that at room temperature the lower bound on energy is 10^-2 Joules. I see no essential conflict with thermodynamics there. There may be some practical issues, but nothing that follows directly from the laws of thermodynamics.
  • by Linker3000 (626634) on Friday May 13, 2005 @12:33PM (#12520871) Journal
    "So ladies and gentlemen - here we have it; a high-tech battery that lasts many times longer than those made with current technology, a clean and efficient power source for the 21st century - ideal for all sorts of gadgets and items essential for the executive on the move! Just one small thing - how do we convince power laptop users to accept having a radioactive source approximately 2" away from their testicles? Anyone?"
  • I can imagine lots of applications for this new battery including my own laptop

    As if the existing laptops are not bad enough for putting on your lap! After Chernobyl there was a joke in Russia - "if you want to become a father, encase your ____ in lead".
  • by OverflowingBitBucket (464177) on Friday May 13, 2005 @12:37PM (#12520938) Homepage Journal
    Okay, I've made some adjustments to a previous story to cope with this new technology. Just a few words.

    Apple: iPod Dangerous When Wet

    Posted by CowboyNeal on Friday May 13, @05:43AM
    from the potential-hazards dept.

    somefutureslashdotter writes "What do you do when your mom washes your iPod? Fix it, of course. A teenager in Australia found out the hard way that messing with the insides of his iPod is dangerous and needed to be pieced together from basic components after it exploded, leveling several city blocks."
  • not much detail (Score:3, Informative)

    by warrior (15708) on Friday May 13, 2005 @12:44PM (#12521025) Homepage
    There's not much detail in TFA on how it works. FYI a pn junction is nothing new, it's aka a diode, and is the basis of other more complicated semiconductor structures (FETs, BJTs). Does anyone know how this works? I'd imagine it's similar to the way a BJT works. In a BJT, two pn junctions join to make pnp or npn bipolar transistors, the n or p in the middle is the base and it is a very thin layer. Injecting a small amount of charge in the base causes electrons to diffuse across one of the pn junctions (of of them is doped differently than the other). The base is thin enough that before the electrons can recombine they are swept across the other junction. In this manner you get very high current gains -- a small base current results in a much larger current in your bjt. Anyone know anymore about the battery tech in the article?
  • by Bryan Ischo (893) * on Friday May 13, 2005 @12:47PM (#12521068) Homepage
    If it generates electricity by catching electrons resulting from nuclear fission, then how do you turn it off? Is it always generating electricity? Do you have to have a constant connection to ground so that it can sink any current that's not being used?
    • If it generates electricity by catching electrons resulting from nuclear fission, then how do you turn it off?

      First off, its beta decay (a neutron in the nucleus in turn into a proton and ejects an electron), not fission. And you're correct, there no turning it off.

      Is it always generating electricity?

      Yes.

      Do you have to have a constant connection to ground so that it can sink any current that's not being used?

      You can just burn off extra power in a resistor (generating heat). Or you

  • Nuclear! (Score:3, Interesting)

    by pastpolls (585509) on Friday May 13, 2005 @12:48PM (#12521084)
    Don't these people know anything about marketing. I would NEVER use the word nuclear and tie it into a product. Can't they hire some marketing person to think of a new term? Joe public has know idea what nuclear really is, other than it can blow stuff up or give you cancer.
  • by Bun (34387) on Friday May 13, 2005 @12:49PM (#12521105)
    There is no mention of the power delivered by the battery - only its lifetime. It doesn't take much to run a pacemaker, but a laptop might require a battery the size of a loaf of bread, for all we know. Also, while tritium isn't all that dangerous, it IS radioactive, and carries all of the regulatory baggage that goes with that designation, so great care would have to be taken to prevent leakage during its lifetime, which wouldn't be easy.
  • by kravlor (597242) on Friday May 13, 2005 @12:50PM (#12521124) Homepage

    Disclaimer: I am a nuclear engineering graduate student.

    This seems like a rather nifty extention of the technology. However, note that the fuel source, tritium, is rather hard and expensive to come by. (The total world supply of the stuff is < 40 kg.) So I see this as a great boon for, say, space probes or other fancy applications where getting your hands on some tritium gas aren't the biggest of concerns on the budget. It'd be interesting to see how they compare to other nuclear batteries that rely on heat from alpha-decay of heavy isotopes like plutonium to generate electrical currents.

    As far as all the jokes about a nuclear laptop battery using this technology causing sterility, note that tritium decays via beta emission (i.e. an electron), with a range in solid materials of a few mm, so those energetic electrons will stay in the battery. Your primary concern would be if you somehow cracked the thing open and inhaled the tritium gas -- then those few mm of exposure in your lungs etc. aren't the best things to have around energetic particles. (And, as far as having to ingest nuclear sources, tritium is probably one of the better ones, since not only does it have a relatively short half-life of ~12 years, but it gets flushed out of the body rather rapidly as it diffuses into the bloodstream/water in tissues, leading to a much shorter effective biological half-life of 11 days.)

  • tritium on my lap (Score:3, Interesting)

    by fasta (301231) on Friday May 13, 2005 @01:02PM (#12521259)
    About 25 years ago, I bought a very inexpensive digital watch that was 'glow-in-the-dark'. On the back was a radioactivity symbol that indicated the watch contained 200 mCi of 3H. As a molecular biologist who became very very careful when working with 5 mCi of 32P (a much stronger emitter) or 3H-thymidine, the idea of wearing 200 mCi of 3H seemed quite exciting.

    Indeed, I believe there was a superfund site due to 3H contamination from watch manufacturing.
  • Recycling costs? (Score:3, Insightful)

    by Weaselmancer (533834) on Friday May 13, 2005 @01:02PM (#12521262)

    Company I'm working at right now just gave away a bunch of old Thinkpads. Reason being - it's cheaper to give them away than send the batteries off for a proper recycling.

    So I wonder what the cost would be to recycle a spent tritium battery?

  • by slashusrslashbin (641072) on Friday May 13, 2005 @01:03PM (#12521278)
    1) Use specific tritium charger only. Do not use a NiMH or NiCd charger - Failure to do so may a cause fire, which may result in personal injury and property damage, across a wide area.
    2) Never charge batteries unattended. When charging H-3 batteries you should always remain in constant observation to monitor the charging process and react to potential problems that may occur, by running away, fast.
    3) Some H-3 chargers on the market may have technical deficiencies that may cause it to charge the H-3 batteries incorrectly or at an improper rate. It is your responsibility solely to assure the charger you purchased works properly. Always monitor charging process to assure batteries are being charged properly. Failure to do so may result in meltdown.
    4) If at any time you witness a battery starting to balloon or swell up, discontinue charging process immediately, disconnect the battery and observe it in a safe place, several miles away, for approximately 500 years. This may cause the battery to leak, and the reaction with air may cause the isotopes to chain-react, resulting in mushroom cloud.
    5) Since delayed chain reaction can occur, it is best to observe the battery as a safety precaution. Battery observation should occur in a safe area outside of any building or vehicle and away from any fissile material.
    6) Wire lead shorts can cause fire! If you accidentally short the wires, the battery must be placed in a safe area for observation for approximately 800 years. Additionally, if a short occurs and contact is made with metal (such as rings on your hand), severe injuries may occur due to the conductibility of electric current.
    7) A battery can still fission even after 1000 years.
    8) In the event of a crash, you must remove battery for observation and place in a safe open area away from any combustible material, and major cities, for approximately 5000 years.
    9) If for any reason you need to cut the terminal wires, it will be necessary to cut each wire separately, ensuring the wires to not touch each other or a short may occur, potentially causing a chain-reaction.
    10) To solder a connector: Remove insulating 8-inch lead shielding of Red wire and solder to positive terminal of a connector, then remove insulating 8-inch lead shielding of Black wire and solder to the negative terminal of connector. Be careful not to short the wire lead. If you accidentally cause the battery to short, place it in a safe open space and observe the battery for approximately 100,000 years. A battery may swell or even possibly induce fission after a geologically insignificant time.
    11) Never store or charge battery pack inside your car in extreme temperatures, since extreme temperature could cause irreparable damage to you car, and blow away half the state.

    With apologies to thunderpower-batteries.com [66.102.9.104]
  • by just fiddling around (636818) on Friday May 13, 2005 @01:04PM (#12521286) Journal
    For those of you who were not awake in the semiconductor course, a P-N junction is what a diode is made of. It is a junction between an electron-rich zone (the N) and a hole-rich zone (the P) in a semiconducting material. When "something" happens to the junction, the passage to the hole-rich zone is facilitated, making the electrons jump in the holes and generating current. In photovoltaics, the "something" is a photon hitting the junction; in this case, "something" is a radioactive particle.

    There is another way to make a "nuclear battery", which was discussed in the september 2004 issue of IEEE's Spectrum magazine [ieee.org] (could not get a link...): by ionizing a bit of matter, it gets attracted to other matter (think static electricity). So you ionize a flat, piezoelectric part that's attached at one end over an unmovable base plate. The attraction makes the loose end of the part strain down to the base, and the piezoelectric nature of the part makes it generate electricity on the way.

  • by Animats (122034) on Friday May 13, 2005 @01:14PM (#12521394) Homepage
    This thing runs on tritium, which is made in nuclear reactors. Or used to be. The US no longer has a tritium production capability, and hasn't had one since 1988 when K reactor at Savannah River shut down. Tritium currently costs around $100,000/gram. Current production is around 1500g/year, mostly from old CANDU reactors in Canada.

    There's a modest demand for tritium. It's needed to recharge H-bombs. Fusion researchers need sizable quantities of it. It's used for night lights in exit signs, watches, and gunsights. Tritium has a half life of about 12 years, so you lose 5.5% every year as it decays to helium-3. So a new product that requires tritium faces a major supply problem.

    The hazards of tritium exposure aren't high, but some precautions are required. Cleanup procedures for a broken tritium exit sign are as follows:

    When an Exit Sign Containing Tritium (3H) Is Damaged (broken with the release of 3H): [hps.org]

    1. Evacuate the area immediately.
    2. Ventilate the area to the outside.
    3. Isolate the area; do not allow entry.
    4. Identify all individuals possibly exposed to the H-3.
    5. Individuals possibly exposed should immediately:
      • Shower with soap and water (or at least wash face and hands).
      • Change clothing (retain in plastic bag).
      • Drink plenty of fluids.
      • Collect a urine sample immediately and then 24-hour cumulative samples and follow Nuclear Regulatory Commission (NRC), state, or health physics consultant advice on where to send them for analysis.
    6. Call the NRC Regional Office.
    7. Call the State Radiation Protection Program.
    8. Call manufacturer of signs for technical information.
    9. Be prepared to hire a health physics consultant to deal with initial monitoring, decontamination, and disposal of the exit sign and contaminated materials.

      The protective clothing required for cleanup usually consists of gloves and booties. The broken sign should be placed in an air-tight container by a health physics consultant. If silica gel is available it should be placed in the container with the broken sign. The silica gel will collect tritiated water. At a minimum, the broken sign and any miscellaneous pieces should be double bagged and sealed in plastic. Disposal of the broken sign should be arranged through the manufacturer or a health physics consultant.

    And people screw up, even with ordinary exit signs. Here's a Nuclear Regulatory Commission report from 2004:

    • UNPLANNED CONTAMINATION [nrc.gov]

      USAF personnel in the Johnston Atoll in the Pacific were attempting to remove the "batteries" from an exit sign they believed to be battery powered. During the attempt to open the case, they destroyed the sign only to discover that it was a tritium sign. All tritium modules were broken.

      Five personnel were in the room at the time and all were potentially exposed to the tritium. The Radiation Safety Officer (RSO) isolated the room and the personnel clothing, etc. Pre-cleanup surveys indicated greater than 6 times the normal background survey readings in the room. The RSO double-bagged the sign and tritium module debris. The room and work areas were decontaminated. Post-cleanup surveys indicated normal background readings. Personnel uptake and dose evaluations are currently being assessed.

    So, like the nuclear batteries of the 1960s, this will be a specialized technology of very limited application.

  • waste? (Score:3, Interesting)

    by pr0nbot (313417) on Friday May 13, 2005 @01:15PM (#12521413)
    If we can turn radioactivity into electricity, can't we build generators around toxic nuclear waste?

    • Re:waste? (Score:3, Informative)

      yes, we can. the problem is that to do this you need to reprocess the material and the US doe snot reprocess it. even though reprocessing it reduces the radioactivity of the material to much safer levels, so you could simply reprocesses it and transport it if you do not want to recycle it for energy.
  • by photon317 (208409) on Friday May 13, 2005 @04:20PM (#12523619)

    At first I figured the output, while long lasting, would just be too low to be useful. I went to beta-batt's website, got the numbers and did the math. These batteries are surprisingly good.

    The first-gen tritium ones (and tritium ones is probably all we'll ever see in commercial applications) put out 400 microwatts per cubic centimeter of nuclear battery volume, half-lifing at 12 years of course.

    Based on various data I pulled from Energizer's website and Betabatt's website, it comes out like this:

    A regular AA-sized NiMH rechargeable battery (2,500mAh @ 1.2V) can be recharged by a nuke battery of identical volume (picture a companion Nuclear-AA battery next to it) from empty to full in roughly one month. Or five AA-sized nuked batteries could recharge a normal NiMH AA in a little under a week. In either case, that's for years (obviously, the charging rate gets slower as the years go on).

    Even in that form, it's quite useful. Assuming linear scalability in both regular and nuke batteries, that means if you have a device which can last up to two months on a rechargeable battery of some size, you can stick a nuke-charged of equivalent volume to your battery next to it, and between the two of them your device will stay continuously powered for at least 12.3 years.

    Imagine when the next generations come out and get more efficient. I can't wait. For useful largish devices you'll always need a chemical battery for bursty amperage, but have a nuke-batt as a recharger is so handy.

It is surely a great calamity for a human being to have no obsessions. - Robert Bly

Working...