Kauczor and W. Lenzi and R. Napoli, G.
Maggioni, S. Carturan, M. Gelain, J. Eberth, G. Della Mea, D. De Salvador, G. Mariotto, A. De Lorenzi, G.
Recommended for you
Valotto, M. Grimaldi, S. Tati, M. Loriggiola, D. Rosso and P. Arellano, J. Delaroche and A. Valente and J.
- Advances in Nuclear Science and Technology - 1st Edition.
- Electrically Assisted Forming: Modeling and Control.
- IN ADDITION TO READING ONLINE, THIS TITLE IS AVAILABLE IN THESE FORMATS:?
Favela, E. Andrade, O. Sarmiento, D. Rudolph, U. Forsberg, P.
Next Generation Nuclear Power
Golubev and L. Flechas, L. Sarmiento, F. Cristancho and E. Scoccola and P.
Progress in Nuclear Science and Technology Vol.2
Santos and B. Molina, A. Tain, D. Jordan and L. Molina, P. Aguilera, J.
- Expertise. Insights. Illumination..
- Navigation menu!
- No Greater Love: A 90-Day Devotional to Strengthen Your Marriage?
- Australian Nuclear Science and Technology Organisation - Wikipedia.
Morales, M. Zambra, D. Calderon, S. Bustamante, R. Crispieri, J. Daie, C. Henriquez, H. Hidalgo, L. By recycling the fuel from fast reactors, they can deliver much more energy from uranium while reducing the amount of waste that must be disposed of for the long term. These breeder-reactor designs are one of the keys to increasing the sustainability of future nuclear energy systems, especially if the use of nuclear energy is to grow significantly. Beyond supporting the use of a fast-neutron spectrum, metal coolants have several attractive qualities.
First, they possess exceptional heat-transfer properties, which allows metal-cooled reactors to withstand accidents like the ones that happened at Three Mile Island and Chernobyl. Second, some but not all liquid metals are considerably less corrosive to components than water is, thereby extending the operating life of reactor vessels and other critical subsystems. Third, these high-temperature systems can operate near atmospheric pressure, greatly simplifying system design and reducing potential industrial hazards in the plant.
More than a dozen sodium-cooled reactors have been operated around the world. This experience has called attention to two principal difficulties that must be overcome. Sodium reacts with water to generate high heat, a possible accident source. This characteristic has led sodium-cooled reactor designers to include a secondary sodium system to isolate the primary coolant in the reactor core from the water in the electricity- producing steam system.
10th Latin American Symposium on Nuclear Physics and Applications
Some new designs focus on novel heat-exchanger technologies that guard against leaks. The second challenge concerns economics. Because sodium-cooled reactors require two heat-transfer steps between the core and the turbine, capital costs are increased and thermal efficiencies are lower than those of the most advanced gas- and water-cooled concepts about 38 percent in an advanced sodium-cooled reactor compared with 45 percent in a supercritical water reactor. Moreover, liquid metals are opaque, making inspection and maintenance of components more difficult. Next-generation fast-spectrum reactor designs attempt to capitalize on the advantages of earlier configurations while addressing their shortcomings.
The technology has advanced to the point at which it is possible to envision fast-spectrum reactors that engineers believe will pose little chance of a meltdown. Nuclear energy has arrived at a crucial stage in its development. The economic success of the current generation of plants in the U. Novel reactor designs can dramatically improve the safety, sustainability and economics of nuclear energy systems in the long term, opening the way to their widespread deployment.
Nuclear Power Primer Most of the world's nuclear power plants are pressurized water reactors. In these systems, water placed under high pressure atmospheres to suppress boiling serves as both the coolant and the working fluid. Initially developed in the U. The reactor core of a pressurized water reactor is made up of arrays of zirconium alloy—clad fuel rods composed of small cylinders pellets of mildly enriched uranium oxide with the diameter of a dime. A typical bysquare array of fuel rods constitutes a fuel assembly, and about fuel assemblies are arranged to form a reactor core. Cores, which are typically approximately 3.
The nuclear fission reactions produce heat that is removed by circulating water. The coolant is pumped into the core at about degrees Celsius and exits the core at about degrees C. To control the power level, control rods are inserted into the fuel arrays. Control rods are made of materials that moderate the fission reaction by absorbing the slow thermal neutrons emitted during fission. They are raised out of or lowered into the core to control the rate of the nuclear reaction. To change the fuel or in the case of an accident, the rods are lowered all the way into the core to shut down the reaction.
In the primary reactor coolant loop, the hot water exits the reactor core and flows through a heat exchanger called a steam generator , where it gives up its heat to a secondary steam loop that operates at a lower pressure level. The steam produced in the heat exchanger is then expanded through a steam turbine, which in turn spins a generator to produce electricity typically to 1, megawatts.
The steam is then condensed and pumped back into the heat exchanger to complete the loop.
Aside from the source of heat, nuclear power plants are generally similar to coal- or fuel-fired electrical generating facilities. There are several variants of the light-water-cooled reactor, most notably boiling-water reactors, which operate at lower pressure usually 70 atmospheres and generate steam directly in the reactor core, thus eliminating the need for the intermediate heat exchanger. In a smaller number of nuclear power plants, the reactor coolant fluid is heavy water containing the hydrogen isotope deuterium , carbon dioxide gas or a liquid metal such as sodium.
The reactor pressure vessel is commonly housed inside a concrete citadel that acts as a radiation shield.