en.wikipedia.org/wiki/Nuclear_power#Water
The Susquehanna Steam Electric Station, a boiling water reactor. The nuclear reactors are located inside the rectangular containment buildings towards the front of the cooling towers.
Nations in dark green have reactors and are constructing new reactors, those in light green are constructing their first reactor, those in dark yellow are considering new reactors, those in light yellow are considering their first reactor, those in blue have reactors but are not constructing or decommissioning, those in light blue are considering decommissioning and those in red have decommissioned all their commercial reactors. Brown indicates that the country has declared itself free of nuclear power and weapons. Nations in dark green have reactors and are constructing new reactors, those in light green are constructing their first reactor, those in dark yellow are considering new reactors, those in light yellow are considering their first reactor, those in blue have reactors but are not constructing or decommissioning, those in light blue are considering decommissioning and those in red have decommissioned all their commercial reactors. Brown indicates that the country has declared itself free of nuclear power and weapons.
conducted experiments with the products of neutron-bombarded uranium. They determined that the relatively tiny neutron split the nucleus of the massive uranium atoms into two roughly equal pieces, which was a surprising result.
Leo Szilard who was one of the first, recognized that if fission reactions released additional neutrons, a self-sustaining nuclear chain reaction could result. This spurred scientists in many countries (including the United States, the United Kingdom, France, Germany, and the Soviet Union) to petition their government for support of nuclear fission research.
World War II, the fear that reactor research would encourage the rapid spread of nuclear weapons and technology, combined with what many scientists thought would be a long road of development, created a situation in which reactor research was kept under strict government control and classification. In addition, most reactor research centered on purely military purposes.
Actually, the consensus of government and business at the time was that nuclear (fission) power might eventually become merely economically competitive with conventional power sources.
These vessels were both lost due to malfunctions in systems not related to the reactor plants. Also, the sites are monitored and no known leakage has occurred from the onboard reactors.
History of the use of nuclear power (top) and the number of active nuclear power plants (bottom). History of the use of nuclear power (top) and the number of active nuclear power plants (bottom).
gigawatt (GW) in 1960 to 100 GW in the late 1970s, and 300 GW in the late 1980s. Since the late 1980s worldwide capacity has risen much more slowly, reaching 366 GW in 2005. Between around 1970 and 1990, more than 50 GW of capacity was under construction (peaking at over 150 GW in the late 70s and early 80s) -- in 2005, around 25 GW of new capacity was planned.
However, changes were made in both the reactors themselves (use of low enriched uranium) and in the control system (prevention of disabling safety systems) to prevent the possibility of a duplicate accident.
Pebble Bed Modular Reactor (PBMR) Several EU member states actively pursue nuclear programs, while some other member states continue to have a ban for the nuclear energy use. Japan has an active nuclear construction program with new units brought on-line in 2005.
energy policy of the United Kingdom it is recognized that there is a likely future energy supply shortfall, which may have to be filled by either new nuclear plant construction or maintaining existing plants beyond their programmed lifetime.
Japan Steel Works, the only factory in the world able to manufacture the central part of a nuclear reactor's containment vessel in a single piece, which reduces the risk of a radiation leak. The company can only make four per year of the steel forgings, which contain radioactivity in a nuclear reactor. It will double its capacity in the next two years, but still will not be able to meet current global demand promptly. Utilities across the world are submitting orders years in advance of any actual need. Other manufacturers are examining various options, including making the component themselves, or finding ways to make a similar item using alternate methods.
nuclear submarines and large naval surface ships, such as aircraft carriers, commonly use highly enriched uranium. Although highly enriched uranium is more expensive, it reduces the frequency of refueling, which is very useful for military vessels.
The chain reaction is controlled through the use of materials that absorb and moderate neutrons. In uranium-fueled reactors, neutrons must be moderated (slowed down) because slow neutrons are more likely to cause fission when colliding with a uranium-235 nucleus.
Light water reactors use ordinary water to moderate and cool the reactors. When at operating temperatures if the temperature of the water increases, its density drops, and fewer neutrons passing through it are slowed enough to trigger further reactions.
Generation IV reactors, are the subject of active research and may be used for practical power generation in the future. A number of the advanced nuclear reactor designs could also make critical fission reactors much cleaner, much safer and/or much less of a risk to the proliferation of nuclear weapons.
Fusion reactors, which may be viable in the future, have no risk of explosive radiation-releasing accidents, and even smaller risks than the already extremely small risks associated with nuclear fission. Whilst fusion power reactors will produce a very small amount of reasonably short lived, intermediate-level radioactive waste at decommissioning time, as a result of neutron activation of the reactor vessel, they will not produce any high-level, long-lived materials comparable to those produced in a fission reactor.
The Nuclear Fuel Cycle begins when uranium is mined, enriched, and manufactured into nuclear fuel, which is delivered to a nuclear power plant. After usage in the power plant, the spent fuel is delivered to a reprocessing plant or to a final repository for geological disposition. In reprocessing 95% of spent fuel can be recycled to be returned to usage in a power plant .
At this point, the enriched uranium, containing more than the natural 07% U-235, is used to make rods of the proper composition and geometry for the particular reactor that the fuel is destined for.
spent fuel pool where the short lived isotopes generated by fission can decay away. After about 5 years in a cooling pond, the spent fuel is radioactively and thermally cool enough to handle, and it can be moved to dry storage casks or reprocessed.
The Estimate of Available Uranium depends on what resources are included in the estimate. The squares represent relative sizes of different estimates, whereas the numbers at the lower edge show how long the given resource would last at present consumption.
FBFB Reserves in current mines FBFB Known economic reserves FBFB Conventional undiscovered resources FBFB Total ore resources at 2004 prices FBFB Unconventional resources (at least 4 billion tons, could last for millennia) The Estimate of Available Uranium depends on what resources are included in the estimate.
This represents a higher level of assured resources than is normal for most minerals. On the basis of analogies with other metallic minerals, a doubling of price from present levels could be expected to create about a tenfold increase in measured resources, over time. The fuel's contribution to the overall cost of the electricity produced is relatively small, so even a large fuel price escalation will have relatively little effect on final price. For instance, typically a doubling of the uranium market price would increase the fuel cost for a light water reactor by 26% and the electricity cost about 7%, whereas doubling the price of natural gas would typically add 70% to the price of electricity...
|
http://csua.com/feed/