Exploring Tomorrow’s Energy Options: Nuclear Fission and Fusion

Electricity is one of those things we take for granted until it's gone. When we walk into a dark room, we expect light to come on when we flip the light switch. In fact, I often find myself automatically flipping the light switch as I walk into a dark room even when I know I'm in a power outage. Have you ever stopped to think about where all this electricity comes from?

As you are likely aware, electricity is generated at power plants and then transferred to houses, businesses, universities, and elsewhere on electric power lines. So, how is this electricity generated at the power plants? The U.S. Energy Information Administration reported in August of last year that coal power plants generated the most energy (43.6 percent), followed by natural gas (21.7 percent), nuclear (19.4 percent), and hydroelectric (9 percent), with other energy sources comprising the remaining six-point-three percent. Are these methods of power generation sufficient for the long term? Concerns continue to rise over the long-term feasibility of our current power generation methods. Two major concerns are safety and future repercussions. For instance, coal burning power generation produces a CO₂ gas. CO₂ is a greenhouse gas responsible for keeping the earth warm by trapping the sun's heat in the atmosphere. Excessive coal burning may be contributing significantly to global warming. Other power generation methods have other risks, as we have recently seen in the aftermath of the Japan earthquake and tsunami.

If current power generation offers issues, what are our options for future? One energy generation method that is particularly exciting is nuclear fusion. Our current method of nuclear power generation is nuclear fission. Fusion and fission are opposite reactions. Nuclear fusion occurs when two or more atoms are fused into one. Fission occurs when an atom is split into two smaller atoms. Fission does not naturally occur, but fusion is found in the heart of every star, including our own sun. When atoms are split during fission, many highly radioactive particles (dangerous to humans) are released at very high energy levels. When two atoms are joined in fusion, no radioactive particles are released.

Nuclear fission as a power generator has some downsides. Most notable is the possibility of overheating and causing a fire that could spread radioactivity into the air, such as occurred in Japan in March 2011. Despite the possibility of this occurrence, nuclear fission plants are highly regulated with many effective safety precautions. Nuclear fission is also the most effective power generation currently available (using about 0.0025% of the amount of fuel that coal burning power plants use).

Inside the ITER. Photo credit: http://homepages.spa.umn.edu/~llrw/a1001/tokamak.html

Nuclear fusion has only one downside: we have not yet refined fusion to an effective power source. Fusion produces no radioactive particles, no possibility of overheating is present, and the power generated by nuclear fusion is three or four times that of fission. I stress the fact that we have not yet reached a viable source of nuclear power generation because we are well on the way. The National Ignition Facility (NIF) in California is attempting to reach ignition, a process in which the power output power is greater than the input. The NIF is using 192 lasers focused on an extremely small tube (about 5.75 mm in diameter and about 9.43 mm long) to create the same conditions that occur within a star. This and other projects, such as the International Thermonuclear Experimental Reactor (ITER, pronounced ee-ter) are hopeful to make nuclear fusion a reality. The NIF has set the goal of achieving ignition by the end of 2012, and commercialization of fusion technology by 2030.

Nuclear fusion power generation is a very attractive source of energy. It is more productive, safe, sustainable, and environmentally friendly then current energy sources. Projects such as ITER and NIF expect to reach ignition very soon. So be on the lookout for nuclear fusion, a possible answer for the energy crisis of today.