Written by Max Michalec, ESLLC 2016-2017
There is exciting developments going on in the world of nuclear power and it could be here sooner than you think. The Generation IV International Forum (GIF) was initiated in 2000 as an international collective of 14 countries who see nuclear power as a reasonable option as part of our energy future. Generation IV plants are scheduled to be available for commercial production between 2020-2030.
There are many types of Generation IV plants that have been proposed but they can mainly be classified into two main categories, thermal reactors and fast reactors. Thermal reactors include a neutron moderator to slow the neutrons emitted by fission to make them more likely to be captured by the fuel. These reactors use molten salt or supercritical water as the primary coolant and fuel mixture allowing for nuclear fission to happen at much higher temperatures to increase the output of energy. A fast reactor directly uses the fast neutrons emitted by fission, without moderation. Unlike thermal neutron reactors, fast neutron reactors can be configured to “burn“, or fission, all actinides, and given enough time, therefore drastically reduce the actinides fraction in spent nuclear fuel produced by the present world fleet of thermal neutron light water reactors, thus closing the nuclear fuel cycle.
Some models such as the sodium-cooled fast reactor is cooled by liquid sodium and fueled by a metallic alloy of uranium and plutonium or spent nuclear fuel, the “nuclear waste” of light water reactors. The systems use of liquid metals instead of water as coolant allows for this type of reactor to operate at standard atmospheric pressure, therefore decreasing the possibility of leakage of radioactive materials.
Compared to previous nuclear reactors there are many advantages to generating power with these new plants. Nuclear waste that remains radioactive for a few centuries instead of millennia. There is 100–300 times more energy yield from the same amount of nuclear fuel. A broader range of fuels, and even unencapsulated raw fuels can be used in fusion. In some reactors, the ability to consume existing nuclear waste in the production of electricity, that is, a closed nuclear fuel cycle. This strengthens the argument to deem nuclear power as renewable energy! There would also be improved operating safety features, such as (depending on design) avoidance of pressurized operation, automatic passive (unpowered, uncommanded) reactor shutdown, avoidance of water cooling and the associated risks of loss of water (leaks or boiling) and hydrogen generation/explosion and contamination of coolant water. The potential is there for a major renovation of how we view nuclear power and how it is used.
When you hear nuclear power don’t just think Chernobyl or Fukushima, think of nuclear energy’s potential to become the next big thing in renewable energy.