What is the New Face of Safe Nuclear?

by rohit
(Washington)

Energy in different forms- coal, natural gas, nuclear, other renewables and petroleum is consumed for the generation of electricity. Fossil fuels are the topmost sources of electricity production, which are gradually depleting. Throughout the world, electricity is required for light, heat and air-conditioning. Energy is considered necessary for various other activities- growing, storing and distribution of food materials, transportation purposes, processing of waste products and domestic usage- heating and purification of water, cooling/ refrigeration, washing and drying, cooking and other miscellaneous activities -TV, Microwave, computers etc.

Considering the incessant growth of energy needs, and the over-exhaustion of fossil fuels, generation of unconventional energy forms is extremely important. Nuclear energy is a good source of energy, but along with its various advantages, certain disadvantages are also observed.

Water acts as one of the major elements for nuclear energy. Electricity can be produced by nuclear energy only at high pressure, and to create this pressure, water needs to be heated to the highest degree. The real challenge is that the water cool reactors have to run at high pressures of about 70 to 150 atmospheres of pressure than the normal pressure of 100 degree. The reactors work as pressure vessels and have to be constructed with steel walls over 20 meters, which can be cumbersome.
Sometimes the pressures are not maintained and when the reactor collapses, the water doesn’t stay liquid, as it is converted into steam. In order to hold the steam, water cool reactors are built inside big thick concrete buildings, called containers, which are larger than reactors. In spite of this arrangement, pressures at times exceed, resulting into overheating and melting down of reactors.
The reactors use uranium oxide as fuel, which is made of ceramic material –coffee cups, cookware are mostly made from this material. Ceramic is chemically stable but not good at transferring heat. The fuel is stored in the form of pellets. During a reactor's operation there is a large temperature difference between the center of the pellets and their surface, causing the center of the fuel pellets to become very hot. The heat must be constantly removed by a reactor cooling system because overheating could cause the fuel rods to melt, which could in turn lead to a catastrophic nuclear accident and release of radiations.

So what other options do we have?

Liquid fluoride thorium is emerging as the best alternative. It is a thorium reactor concept that uses a chemically stable fluoride salt for the medium in which nuclear reactions take place. This fuel form yields flexibility of operation and eliminates the need to fabricate fuel elements. It is chemically stable and does not react with air, water and other atmospheric elements. Liquid fluoride thorium does not need to operate at high pressure and therefore is not entrapped in heavy steel pressure container vessels. Unlike solid fuels, which need to be melted down while cooling, liquid fluoride fuels are already melted at lower temperatures in normal operations. During emergencies, in water-cool reactors, power has to be provided to the plant, to keep the water circulating and prevent the meltdown, whereas in reactors supported by liquid fluoride thorium, if there is a power breakdown, the reactor shuts down itself without human intervention and has a very safe and controlled configuration.

Thorium is a naturally occurring fuel, 4 times more common in earth’s surface than uranium and 200 times more efficient than uranium. Thorium produces less radioactive waste and cannot sustain a nuclear chain reaction without priming, so fission stops by default. Thorium ends the need of large high-pressure nuclear reactors, built in container buildings and they enable compact gas turbines instead of low efficiency steam turbines, it also makes power transmissions flexible as thorium can locate itself near the existing power-plant sites or near the demanded centers.

Considering these benefits from Thorium, will this clean, safe and sustainable energy lead the future?

Read more on : http://www.bridgingnations.org