When you here nuclear anything you instantly think its dangerous/harmful/splodey. More so when I say nuclear power plant you think of the disaster in Japan. But not all nuke plants are dangerous, new ones are less dangerous (that one in Japan is from the 70’s) and a specific type called the PBR is possibly meltdown proof. See nuclear power plant rely on both passive and active (just the later for our Japanese friend, that’s why it failed) safety systems to prevent a meltdown from occurring…..you know what just read these excerpts:
The word “meltdown” defines our worst fears about nuclear reactors, and with good reason: without complex and redundant cooling systems, reactors can run out of control, generating so much heat that they melt their own fuel, releasing massive amounts of radioactivity in the process.
Generally, nuclear power plants rely on redundant safety systems, both active and passive, to prevent a meltdown in case of an accident like an earthquake or tsunami. Japan’s stricken Fukushima Daiichi nuclear plant is what’s called a light water reactor, or specifically a boiling water reactor, because the heat generated in the core of the reactor is used to boil water into steam, powering a turbine to generate electricity.
Immediately after the earthquake, the reactor successfully shut down, meaning that control rods were inserted into the core to disrupt the nuclear reactions directly. However, there’s still a lot of heat contained in the core, which is still boiling water and making steam, which raises pressure in the reactor and makes things dangerous. To keep itself cool, the reactor depends on a continuous supply of water, and the problem is that the pumps to supply this water haven’t been functioning. This means that the reactor gets hotter, more water turns into steam, and the pressure inside increases (making it more difficult to pump water in), and eventually enough water gets turned into steam that the fuel rods themselves get exposed to air, which can cause them to melt.
So the safety systems are a huge deal to prevent overheating at all times. There is a golden outlook so to speak when it comes to nuclear safety, the PBR(pebble bed reactor) is a newish type reactor that has a different function that the usual rod reactor setups, one that is just about completely meltdown proof. The reactor uses “pellets” of graphite of various sizes (from marble to tennis ball) with scattered sand grain size bits of uranium (up to 9 grams), to creat a reaction all you have to do is pile them together till the reach critical mass and start burning up baby! once the reaction starts all you have to do is cycle out the pebbles one ball at a time, there’s about 380,000 of them so it takes a while. helium is then blown thru the space between the pebbles to carry out the heat to spin a turbine which generates the electricity. Okay best part here, The PBR pretty much cant meltdown,ever.
Let’s just skip directly to the worst-case scenario, like in Japan, where failure of the coolant system caused the reactor to overheat uncontrollably. In terms of what would happen to a pebble bed reactor, this means that there’d no more helium coolant. So, okay, as you might expect, the reactor would start to get really, really hot. As nuclear fuel heats up, the uranium atoms start to move faster, making it harder for them to absorb extra neutrons and split, reducing the reactor’s power. This is what’s called negative feedback, and while it takes place in all reactors, the low fuel density of the pebbles magnifies it in a PBR. As the PBR continues to heat up, the negative feedback gets stronger and stronger until at about 1600 degrees Celsius, the core stabilizes at an “idle” temperature. This temperature is a solid 400 degrees short of what it would take to cause any damage to the fuel spheres or reactor vessel, which are made of a special kind of super strong graphite.
See if the coolant system ever shut down the temperature would reach it’s glass ceiling 400 degrees shy of meltdown temp, so it would just sit there all hot and shit, but never ba-booming. There is a catch tho and is probably the reason we dont see many PBR’s today, aside from the obvious inherent dangers of radiation and waste the plant only produces about 1/30 the power of a standard nuclear power plant. But honestly I think thats a good thing, as needing more plants would require more workers and there’s nothing wrong with getting more workers in power plants. Oh well, I strongly recommend you read the linked article as it was extremely informative and really opened your eyes to an alternate nuclear future (one not based after Fallout), it’s also important to show any anti-nuke plant persons…just so they know there are safer possibilities. One last thing the only thing better than uranium is myanium