The discovery of nuclear fission in the 1930s brought with it first the threat of nuclear annihilation by nuclear weapons in the 1940s, followed by the promise of clean, plentiful power in the 1950s courtesy of nuclear power plants. These would replace other types of thermal plants with one that would produce no exhaust gases, no fly ash and require only occasional refueling using uranium and other fissile fuels that can be found practically everywhere.
As nuclear reactors popped up ever faster during the 1950s and 1960s, the worry about running out of uranium fuel became ever more present, which led to increased R&D in so-called fast reactors, which in the fast-breeder reactor (FBR) configuration can use uranium fuel significantly more efficiently by using fast neutrons to change (‘breed’) 238U into 239Pu, which can then be mixed with uranium fuel to create (MOX) fuel for slow-neutron reactors, allowing not 1% but up to 60% of the energy in uranium to be used in a once-through cycle.
The boom in uranium supplies discovered during the 1970s mostly put a stop to these R&D efforts, with some nations like France still going through its Rapsodie, Phénix and SuperPhénix designs until recently finally canceling the Generation IVASTRID demonstrator design after years of trying to get the project off the ground.
This is not the end of fast reactors, however. In this article we’ll look at how these marvels of engineering work and the various fast reactor types in use and under development by nations like Russia, China and India.
The Chicago Pile led to the Manhattan Project, which led to the atomic bomb. In Germany, there were similar efforts with less success, and now we have physical evidence from the first attempted nuclear reactor in Germany. In Physics Today, there’s a lovely historical retrospective of one of the ‘fuel cubes’ that went into one of Germany’s unsuccessful reactor experiments. This is a five-centimeter cube that recently showed up in the hands of a uranium collector. In the test reactor, six hundred of these cubes were strung along strings and suspended like a chandelier. This chandelier was then set inside a tub surrounded by graphite. This reactor never reached criticality — spectroscopy tells us the cube does not contain fission products — but it was the best attempt Germany made at a self-sustaining nuclear reaction.
The biggest failing of the Arduino is the pinout. Those header pins aren’t all on 0.1″ centers, and the board itself is too wide to fit on a single solderless breadboard. Here’s the solution to that problem. It’s the BreadShield, an Arduino Uno-to-Breadboard adapter. Plug an Uno on one end, and you get all the pins on the other.
There’s a new listing on AirBnB. this time from NASA. They’re planning on opening the space station up to tourism, starting at $35,000 USD per night. That’s a cool quarter mil per week, launch not included. The plan appears to allow other commercial companies (SpaceX and whoever buys a Boeing Starliner) to accept space tourists, the $35k/night is just for the stop at the ISS. Costs for launch and landing are expected to be somewhere between $20 and $60 Million per flight. Other space tourists have paid as much: [Dennis Tito], the first ‘fee-paying’ space tourist, paid $20M for a trip to the ISS in 2001. [Mark Shuttleworth] also paid $20M a year later. Earlier space ‘tourists’ paid a similar amount; Japanese journalist [Toyohiro Akiyama] flew to Mir at a cost of between $12M and $37M. Yes, the space station is now an AirBnB, but it’s going to cost twenty million dollars for the ride up there.
At any given moment, several of the US Navy’s Nimitz class aircraft carriers are sailing the world’s oceans. Weighing in at 90 thousand tons, these massive vessels need a lot of power to get moving. One would think this power requires a lot of fuel which would limit their range, but this is not the case. Their range is virtually unlimited, and they only need refueling every 25 years. What kind of technology allows for this? The answer is miniaturized nuclear power plants. Nimitz class carriers have two of them, and they are pretty much identical to the much larger power plants that make electricity. If we can make them small enough for ships, can we make them small enough for other things, like airplanes?
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.
The ship was built to clear shipping paths to the northern ports of Russia. Testing of both ice and models of the ship design point to the ability to break ice layers that are two meters thick. This requires a lot of power as ice-breakers generally use their hull shape and gravity to break the ice by driving up onto it to bend the ice to the breaking point. The Lenin achieved this power using its nuclear reactor to heat steam which drove electric generators. The energy produced drove three screws to power the vessel.
Of course this was back in the day when control panels were substantial, which you can get a peek at starting half-way through the twenty-minute film. This includes a demonstration of the ship’s network of radiation sensors which alert the control room, and sound a local alarm when they are triggered. During it’s 30-year operational life the vessel had a couple of accidents stemming from refueling operations. You can find more on that over at the Wikipedia page, but stick with us after the jump to see the vintage reel.