Nuclear Energy – Explained

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Nuclear Energy – Explained

Ben St. John, Journalist, online editor

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The word radiation strikes fear into many people, and it’s justified. They don’t want another Chernobyl or another Nagasaki. But, in reality, we can’t live without radiation. It fuels the sun, it’s used to transmit information from cellphone to cellphone. But most importantly, it powers our homes. But how does it do that? Well, let me explain!

 

The first, most common type of nuclear reactor is the Pressurized Water Reactor. This reactor is primarily used by the United States to generate domestic power. The way this reactor works is simple: the nuclear fuel super heats pressurized water in the primary coolant loop. This water is put through a condenser, where the heat is transferred to a non-pressurized loop called the secondary loop. The water in the secondary loop, since it isn’t pressurized, boils and turns into steam. The steam is used to rotate turbines and crank a massive dynamo to generate electricity. The second loop’s water is pumped through a coolant pool after going through the turbines. The 1st loop is located inside the containment building and the second is partially in the containment building. To this day, this is one of the safest nuclear power generation methods.

 

The next form is the infamous RBMK reactor. The RBMK reactor type is the same type that blew up in 1986 spreading radioactive fallout all over Europe. Chernobyl. There are many flaws in the RBMK reactor design. The major problem is that it doesn’t have a containment building. Another problem that assisted in the making of the tragic event was the graphite tipped control rods. The operators, seeing the power surge immediately SCRAMed the reactor (safety control rod activation mechanism), and all the control rods were inserted. The catch was the rods had graphite tips. Graphite is a notoriously good neutron moderator, so when the rods were inserted, the graphite made the reaction even more vigorous, and caused a steam explosion (from the heat). The explosion blew the top of the reactor building clean off, scattering bits of fission products all across Europe in a massive radioactive cloud containing Cesium 137 and Strontium 90 (very potent, very radioactive isotopes). That’s not all. The fuel got so hot, hot enough to melt through the floor and get deposited in the basement. The mass was made out of pure Corium, a hodgepodge of Uranium, Plutonium, Cesium 137, Strontium 90, Cobalt 60, Polonium 210, and other various radioactive elements. The mass was so radioactive, spending 1 minute next to it would render the person dead within the next week. The mass has become less radioactive over time, and now, after 5 minutes next to it, the person would be dead at some point in the near future. After the accident, almost all RMBK reactors have been decommissioned. This human error catastrophe was put to rest in the 21st century when the new safe confinement was constructed and slid onto the old ‘sarcophagus’.

 

The next type of reactor is exclusively Canadian. It’s called the CANDU reactor: Canadian Deuterium reactor. It works like a PWR but the few differences are:

  • The reactor is NOT pressurized
  • Instead of water the reactor uses Deuterium Oxide instead of water as coolant

The reason the reactor is like this is because Deuterium has a higher boiling point than water and has better heat conductivity. Another reason the reactor uses D2O is it is an excellent neutron moderator. For those of you who don’t know, neutron moderators slow down fast neutrons to thermal neutrons. The neutrons, being slower, are captured easily by the fissile Uranium 235, splitting the nucleus, and creating more neutrons, further enhancing the chain reaction.

 

The final type of reactor is the MSR – the Molten Salt Reactor. This is the most unique form of nuclear reactor and it works by circulating molten Uranium Tetrafluoride nuclear fuel. The liquid fuel splits into a bunch of tubes, passes through a graphite block, then is sent to a heat exchanger and heats up salt in the secondary loop, which passes heat to the water in the turbine loop, which spins the turbines. If the reaction goes out of control, and gets too hot, a heat plug melts, and the liquid salt spreads out in the cooling room until it becomes solid. After that, the fuel can be reinjected into the first loop, and its business as usual! But, none of those facts are the most revolutionary. The most revolutionary fact is……the reactor rans on spent nuclear fuel! Crazy, right? Now, the deadliest waste on earth can be actually useful! It just needs to be turned into a fluoride salt, and it can go through the loop and generate power.

 

I hope than now after reading this article, you, reader, have a little more insight on how nuclear energy works. And that wraps up this article! Hope you enjoyed.