A Betavoltaic cell is a device that uses a radioactive source of beta particles and a semiconductor p-n junction to generate electricity. Tritium, an isotope of hydrogen, is often used as the radioactive element. You may think that tritium is hard to obtain or even forbidden, however, recently you can find tritium in self-lightning key chains, and it is also used in watches and firearm night sights. The beta particles (electrons) from the tritium radioactive process causes phosphors in the device to glow, giving a light that can last for years.
[NurdRage] has just created a nuclear battery using tritium vials from key chains. After getting rid of the plastic containers, he sandwiches the vials between two small solar panels. That’s all! Instant power for the next 15 years. Of course, the amount of power you can get from this device is on the order of microwatts. The battery produces around 1.6 volts at 800 nano amps. He gets 1.23 microwatts, not much, but it is in fact more than the output of commercial units at 0.84 microwatts, for a ten percent of the cost. That minuscule amount of power is actually not easy to measure, and he does a great job explaining the circuit he used to measure the current.
In the 1950s and 1960s, the prospects for a future powered by nuclear energy were bright. There had been accidents at nuclear reactors, but they had not penetrated the public consciousness, or had conveniently happened far away. This was the age of “Too cheap to meter“, and The Jetsons, in which a future driven by technologies as yet undreamed of would free mankind from its problems. Names like Three Mile Island, Chernobyl, and Fukushima were unheard of, and it seemed that nuclear reactors would become the miracle power source for the second half of the twentieth century and beyond.
The first generation of nuclear power stations were thus accompanied by extremely optimistic public relations and news coverage. At the opening of the world’s first industrial-scale nuclear power station at Calder Hall, UK in 1956, the [Queen] gave a speech in which she praised it as for the common good of the community, and on the other side of the Atlantic the American nuclear industry commissioned slick public relations films to promote their work. Such a film is the subject of this piece, and though unlike the British they could not muster a monarch, had they but known it at the time they did employ the services of a President.
The Big Rock Point nuclear power plant was completed in 1962 on the shores of Lake Michigan. Its owners, Consumers Power Company, were proud of their new facility, and commissioned a short film about it. The reactor had been supplied by General Electric, and fronting the film was General Electric’s established spokesman and host of their General Electric Theater TV show, the Hollywood actor and future President [Ronald Reagan].
The film below the break starts by explaining nuclear power as a new heat source powering a conventional steam-driven generator, and stresses the safety aspect of reactor control rods. We are then treated to a fascinating view of the assembly of an early-1960s nuclear reactor, starting with the arrival of the pressure vessel and showing the assemblies within it that held the fuel and control rods. Fuel rods are shown at their factory in California, and being loaded onto a truck to be shipped across the continent, seemingly without the massive security that would nowadays accompany such an undertaking. The rods are loaded and the reactor is started, as [Reagan] puts it: “The atom has been put to work, on schedule”.
Random number generators come in all shapes and sizes. Some are software based while others, known as true random number generators, are hardware based. These can be created from thermal noise, the photoelectric effect and other methods. But none of these were good enough for [M.daSilva]. He would base his off of the radioactive decay of Uranium 238, and construct a working nuclear powered random number generator.
Because radioactive decay is unpredictable by nature, it makes for an excellent source for truly random data. The process is fairly simple. A piece of old fiestaware plate is used for the radioactive source. Put it in a lead enclosure along with a Geiger tube. Then wire in some pulse shaping circuitry and a microcontroller to count the alpha particles. And that’s about it. [M.daSilva] still has to do some statistical analysis to ensure the numbers are truly random, along with making a nice case for his project. But all in all, it seems to be working quite well.
This week’s film begins as abruptly as the Atomic Age itself, though it wasn’t produced by General Electric until 1952. No time is wasted in getting to the point of the thing, which is to explain the frightening force of nuclear physics clearly and simply through friendly animations.
[Dr. Atom] from the Bohr Modeling Agency describes what’s going on in his head—the elementary physics of protons, neutrons, and electrons. He explains that atoms can be categorized into families, with uranium weighing in as the heaviest element at the time. While most atoms are stable, some, like radium, are radioactive. This evidently means it stays up all night doing the Charleston and throwing off neutrons and protons in the process of jumping between atomic families. [Dr. Atom] calls this behavior natural transmutation.
Artificial transmutation became a thing in the 1930s after scientists converted nitrogen into oxygen. After a couple of celebratory beers, they decided to fire a neutron at a uranium nucleus just to see what happened. The result is known as nuclear fission. This experiment revealed more about the binding force present in nuclei and the chain reaction of atomic explosions that takes place. It seemed only natural to weaponize this technology. But under the right conditions, a reactor pile made from graphite blocks interspersed with U-235 and -238 rods is a powerful and effective source of energy. Furthermore, radioactive isotopes have advanced the fields of agriculture, industry, medicine, and biochemistry.