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Number of reactors operating in the
world:
~ 436 Commercial Nuclear Reactors ~ 250 Research Reactors ~ 220 Reactors power ships and submarines This amounts for a total of ~ 14,000 years of operation TERM 2
The only major accidents to have occurred
are
DEFINITION 2 Three Mile Island and Chernobyl. One was contained without direct harm to anyone while the other was much more severe and caused direct loss of lives TERM 3
Since the 50s there have been a series of
DEFINITION 3 minor accidents with apparently no direct loss of human lives: 22 TERM 4
International Nuclear Event Scale
DEFINITION 4 CERNOBYL 7 TM Island 5 TERM 5
Regulations
DEFINITION 5 Independent Government Agency that controls the sector [US Nuclear Regulatory Commission (NRC)] Formulates policies, develops regulations governing nuclear reactor and nuclear material safety, issues orders to licensees, and adjudicates legal matters
The Agency must have the
power to inspect the nuclear power plant and enforce regulations. This includes the authority to shut down the plant if needed TERM 7
Formal process required to obtain
DEFINITION 7 a license to build and operate a Nuclear Power Plant TERM 8
Defense in Depth Approach
DEFINITION 8 Containment System for the Nuclear Power Plant, to limit the co nsequences of system failures Conservative design for the Nuclear Power Plant TERM 9
Single failure criterion:
DEFINITION 9 A Nuclear Power Plant has to be able to sustain failure of any single component without conseguences for the nuclear fuel TERM 10
Radioactive waste is a
DEFINITION 10 waste product containing radioactive material. It is usually the product of a nuclear process such as nuclear fission. However industries not directly connected to the nuclear industry may also produce quantities of radioactive waste.
This waste is produced by
nuclear power plants, hospitals, research labs, and Dept of Energy facilities TERM 17
The waste can be contained in
DEFINITION 17 secure landfills, above ground facilities, or earth bound bunkers and Hundreds of nuclear facilities across the country produce LLRW, but only a very few disposal sites are currently willing to store it. TERM 18
Disposal facilities at Clive (Utah), Barnwell
(South Carolina), and Richland, (Washington),
accepted over
DEFINITION 18 2,000,000 cubic feet of LLRW in 2008, (1,419,000 cubic feet in 1998). Sources include nuclear reactors, industrial users, government sources (other than nuclear weapons sites), and academic TERM 19
Transuranic waste is composed
of
DEFINITION 19 radioactive elements heavier than uranium TERM 20
Transuranic waste (also called TRU waste) is
a
DEFINITION 20 regulatory classification of waste that applies only in the U.S. This type of waste is called "transuranic", because it contains more than 3700 Bq per gram of elements heavier than uranium (the elements with atomic number higher than 92)
Waste is
low level with respect to radioactivity, but some of the waste (e.g. plutonium) has long half life, so waste must be isolated for a very long time (i.e. 250,000 years) TERM 22
TRU waste is comprised of
DEFINITION 22 certain wastes from reprocessing and waste from nuclear weapons production. The Department of Energy has considerable TRU in storage and in 1999 started sending it to the Waste Isolation Pilot Plant in New Mexico (WIPP), where it is stored in Salt Domes TERM 23
Since the U.S. does not reprocess its spent
fuel
DEFINITION 23 the commercial nuclear science and technology industry currently produces no transuranic waste TERM 24
Bq (becquerel) =
DEFINITION 24 is a unit of radioactivity. One Bq is defined as the activity of a quantity of radioactive material in which one nucleus decays per second TERM 25
High level waste, including spent fuel rods,
are radioactive up to
DEFINITION 25 100s of thousands of years
Currently, spent fuel is being stored
temporarily at nuclear power plants in pools of water TERM 32
Many sites have
DEFINITION 32 reached or exceeded their storage capacity TERM 33
A number of nuclear power plants in the
United States now store waste
DEFINITION 33 on-site indefinitely in dry casks made of steel and concrete TERM 34
Dry cask storage is a
DEFINITION 34 method of storing high-level radioactive waste, such as spent nuclear fuel that has already been cooled in the spent fuel pool for at least one year. The fuel is surrounded by inert gas inside a large container. These casks are typically steel cylinders that are either welded or bolted closed. Ideally, the steel cylinder provides leak- tight containment of the spent fuel. Each cylinder is surrounded by additional steel, concrete, or other material to provide radiation shielding to workers and members of the public. Some of the cask designs can be used for both storage and transportation. TERM 35
A Repository must provide safe storage of the
waste for 10,000 years. So what do we do
now? In May 2009, Energy Secretary Steven
Chu stated
DEFINITION 35 "Yucca Mountain as a repository is off the table. What we're going to be doing is saying, let's step back. We realize that we know a lot more today than we did 25 or 30 years ago. The NRC is saying that the dry cask storage at current sites would be safe for many decades, so that gives us time to figure out what we should do for a long-term strategy. We will be assembling a blue-ribbon panel to look at the issue. We're looking at reactors that have a high-energy neutron spectrum that can actually allow you to burn down the long-lived actinide waste. These are fast-neutron reactors. There's others: a resurgence of hybrid solutions of fusion fission where the fusion would impart not only energy, but again creates high-energy neutrons that can burn down the long-lived actinides. ...
"Some of the waste is already vitrified. There
is, in my mind, no economical reason why you
would ever think
of pulling it back into a potential fuel cycle. So one could well imagine again, it depends on what the blue-ribbon panel says one could well imagine that for a certain classification for a certain type of waste, you don't want to have access to it anymore, so that means you could use different sites than Yucca Mountain, such as salt domes. Once you put it in there, the salt oozes around it. TERM 37
These are geologically stable for a
DEFINITION 37 50 to 100 million year time scale. The trouble with those type of places for repositories is you don't have access to it anymore. But say for certain types of waste you don't want to have access to it anymore that's good. It's a very natural containment. ...whereas there would be other waste where you say it has some inherent value, let's keep it around for a hundred years, two hundred years, because there's a high likelihood we'll come back to it and want to recover that. TERM 38
"So the real thing is,
DEFINITION 38 let's get some really wise heads together and figure out how you want to deal with the interim and long-term storage. Yucca was supposed to be everything to everybody, and I think, knowing what we know today, there's going to have to be several regional areas." TERM 39
Renewable energy sources provide how much
of US energy
DEFINITION 39 8% of US energy TERM 40
Most Renewable Energy in the U.S. Goes to
DEFINITION 40 Producing Electricity
Hydroelectricity is generated by the use of
the
gravitational force of falling or flowing water. It is the most widely used form of renewable energy. TERM 47
Hydroelectric power comes
from
DEFINITION 47 the potential energy of dammed water driving a water turbine and a generator. TERM 48
energy extracted from the water depends on
the
DEFINITION 48 volume and on the difference in height between the source and the water's outflow. TERM 49
This height difference is
called
DEFINITION 49 the head. TERM 50
the amount of potential energy in water is
DEFINITION 50 proportional to the head. To deliver water to a turbine while maintaining pressure arising from the head, a large pipe called a penstock is used.
The northwestern states
produce
the most hydroelectric power in the U.S. TERM 52
Idaho produces
DEFINITION 52 100% of its electricity from hydroelectric dams TERM 53
Hydroelectricity is the
DEFINITION 53 cheapest form of electricity -- electricity rates in the northwest U.S. are low! TERM 54
the National Inventory of Dams defines a
major dam as being
DEFINITION 54 50 feet tall with a storage capacity of at least 6.17 million m3, or of any height with a storage capacity of at least 30. million m3. TERM 55
The nearly 8100 major
DEFINITION 55 dams in the United States in 2005.
The Chinese state regards the project as an
historic engineering,
social and economic success, and a move toward the reduction of greenhouse gas emissions. TERM 62
However, the dam has
DEFINITION 62 also flooded archaeological and cultural sites, displaced some 1.3 million people, and is causing significant ecological changes, including an increased risk of landslides. TERM 63
Plate boundaries are the
DEFINITION 63 best locations to look for geothermal energy TERM 64
Iceland is almost entirely run on
DEFINITION 64 geothermal energy! TERM 65
The Earth's internal heat ;These power rates
are
DEFINITION 65 naturally flows to the surface by conduction at a rate of 44. terawatts (TW) and is replenished by radioactive decay of minerals at a rate of 30 TW. These power rates are more than double humanitys current energy consumption from all primary sources, but most of it is not recoverable.
Solar energy is
radiant light and heat from the sun TERM 67
Earth receives
DEFINITION 67 174 petawatts (PW = 1015 Watt) of incoming solar radiation. ~ 30% is reflected back to space while the rest is absorbed by clouds, oceans and land masses. TERM 68
The total solar energy absorbed by Earth's
atmosphere, oceans and land masses is
approximately
DEFINITION 68 3,850,000 exajoules (EJ = 1018 Joule) per year. In 2002, this was more energy in one hour than the world used in one year. TERM 69
The amount of solar energy reaching the
surface of the planet
DEFINITION 69 is so vast that in one year it is about twice as much as will ever be obtained from all of the Earth's non-renewable resources of coal, oil, natural gas, and mined uranium combined. TERM 70
Renewable energy sources are
DEFINITION 70 derivatives of the Suns energy.
When light energy strikes the solar
cell,
electrons are knocked loose from the atoms in the semiconductor material. If electrical conductors are attached to the positive and negative sides, forming an electrical circuit, the electrons can be captured in the form of an electric current. TERM 77
The best area for using solar energy for
generating electricity
DEFINITION 77 on a large-scale is the Southwest... TERM 78
Wind strength is important for
DEFINITION 78 electricity generation TERM 79
The strength of wind
DEFINITION 79 varies, and an average value for a given location alone does not indicate the amount of energy a wind turbine could produce there. Different locations will have different wind speed distributions. TERM 80
Making wind power more consistent
requires
DEFINITION 80 that various existing technologies and methods be extended, in particular the use of stronger inter-regional transmission lines to link widely distributed wind farms.
Before installing a wind turbine or wind farm,
we need to know
if the wind resource in the location is adequate and its dynamics. TERM 82
Energy obtainable from wind
DEFINITION 82 is proportional to the cube of the wind speed, so wind speed is critical TERM 83
High speed, steady winds are needed to
DEFINITION 83 generate electricy on a large scale. TERM 84
Since so much power is generated by higher
wind speed
DEFINITION 84 , much of the energy comes in short bursts. TERM 85
In the case of the Lee Ranch sample ;
consequence:
DEFINITION 85 half of the energy available arrived in just 15% of the operating time. The consequence is that wind energy from a particular turbine or wind farm does not have as consistent an output as a fuel-fired power plants.
Cellulolys is processes (biological
approach):
hydrolysis on pretreated materials, using enzymes to break complex cellulose into simple sugars such as glucose and followed by fermentation and distillation; TERM 92
Energy is yielded during
DEFINITION 92 fusion because matter is converted into energy according to: E=MC TERM 93
During fusion
reaction,
DEFINITION 93 small amount of mass is lost, 38 parts per 10,000 Matter has not been destroyed, but is converted to energy according to Einsteins equation: E = mc TERM 94
Even a very small mass can
DEFINITION 94 yield a great amount of energy TERM 95
If 1 gram of material were completely
converted to energy
DEFINITION 95 , it would equal about 10,000 tons of TNT
Biomass is
organic material used to generate energy TERM 97
Biomass is biological material
derived
DEFINITION 97 from living, or recently living organisms, such as wood, waste, and alcohol fuels. TERM 98
Biomass is plant matter
DEFINITION 98 grown to generate electricity, to produce heat or to make fuels. Forest residues (dead trees, branches and tree stumps), yard clippings, wood chips and garbage may be used as biomass. TERM 99
Biomass also includes
DEFINITION 99 plant or animal matter used for production of fibers or chemicals. Biomass may also include biodegradable wastes that can be burnt as fuel. TERM 100
Biofuels are a wide range of
DEFINITION 100 fuels which are in some way derived from biomass. They are gaining increased public and scientific attention, due to oil price spikes and the need for increased energy security.
