Nuclear Facts Flashcards
(35 cards)
What is a positron?
The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. The positron has an electric charge of +1 e, a spin of 1/2 (same as electron), and has the same mass as an electron.
What is a chemical bond?
A lasting attraction between atoms, ions or molecules that enables the formation of chemical compounds.
What is “exothermic?”
A reaction or process accompanied by the release of heat.
What is “nucleation?”
That point at which a physical phase change commences.
What are the ways that we know to produce nuclear energy?
Fission, fusion and Low-Energy Nuclear Reactions. Only fission has been utilized commercially to date.
What are the two types of fuel used for fission?
Solid or Liquid
What are the two traditional fuel cycle mechanisms?
Burner and breeder reactions, which achieve criticality.
Name some of the types of coolants utilized?
Light water, heavy water, sodium, fluoride salt, lead bismuth, and gas cooled.
Describe the new possibility in a fuel cycle
Accelerator-driven subcritical reactors
What is fission?
Fission occurs when one atom is split into two smaller fragments, creating an explosion of sorts and resulting in the release of heat energy.
What is fusion?
Fusion is the process by which a gas is heated up and separated into its ions and electrons. When the ions get hot enough, they can overcome their mutual repulsion and collide, fusing together. When this happens, they release a lot of energy – about one million times more powerful than a chemical reaction (and 3-4 times more powerful than a fission reaction?)
What are some of the challenges of fusion?
Fusion can only happen in 100 million degrees Celsius temperatures. Particles must also remain in close proximity with one another, and the plasma, which is ionized gas that’s created during the fusion process, must be contained or risk drifting away.
What are the approaches used in fusion development?
Tokamak, which employs magnets to keep plasma from escaping and cooling off (used by ITER). Others use lasers to rapidly compress hydrogen into frozen pellets that are 1000 times denser than ordinary matter and can achieve a momentary pulse of fusion.
What approach does General Fusion take?
General Fusion uses a hybrid of both, though it doesn’t use lasers. It injects plasma, which is surrounded by liquid metal, into a compression chamber where magnets help contain the gas. Then, pistons put pressure on the chamber to compress the plasma to fusion conditions. The now heated liquid metal gets turned into heat, which then gets turned into electricity.
Are we building any new nuclear reactors in the U.S.?
Georgia is building two new units, Vogtle Units 3 and 4, which are Westinghouse AP1000s, the first new builds in 3 decades.
The Vogtle plant is so uneconomic, it requires U.S. Department of Energy’s Loan guarantees of more than $12 billion to complete, why is this a good idea?
The projects will support 9,000 jobs during construction (and 800 during operation) and the funding is helping the project train a new class of workers and rebuild the nuclear work force, which was weakened during the period when we stopped building.
When will the Vogtle units come online?
2021 and 2022 and they’ll have advanced safety systems that automatically shut them down in the event of loss of power.
How much power will they provide?
Vogtle Units 3 & 4 are expected to generate more than 17 million megawatt-hours of clean and reliable electricity. That’s enough to power more than 1.6 million average American homes.
The reactors will also prevent up to 10 million metric tons of carbon dioxide annually—the equivalent of removing 1 million cars from the road each year.
How many nuclear power plants are there worldwide, how much energy do they provide, and what’s the percentage of world electricity?
Today there are about 450 nuclear power reactors operating in 30 countries plus Taiwan, with a combined capacity of about 400 GWe. In 2017 these provided 2506 billion kWh, over 10% of the world’s electricity. (World Nuclear Association)
The 1980s was the period with the most nuclear growth. What was that?
In the 1980s, 218 power reactors started up, an average of one every 17 days. These included 47 in the USA, 42 in France and 18 in Japan. These were fairly large – the average rated power was 923.5 MWe. (World Nuclear Association)
How many new nuclear power plants are being built today?
Over 100 power reactors with a total gross capacity of about 120,000 MWe are on order or planned, and over 300 more are proposed. Most reactors currently planned are in the Asian region, with fast-growing economies and rapidly-rising electricity demand. (World Nuclear Association)
How many countries have nuclear power plants already and now many are considering adding them?
30 countries plus Taiwan have plants today (total of about 450) and about 30 countries are considering, planning or starting nuclear power programmes, and the UAE, Belarus, Bangladesh and Turkey are all constructing their first nuclear power plants (see World Nuclear Association paper on Emerging Nuclear Energy Countries).
Why aren’t more countries building nuclear?
One major issue for many countries is the size of their grid system. Many nuclear power plants are larger than the fossil fuel plants they supplement or replace, and it does not make sense to have any generating unit more than about one-tenth of the capacity of the grid (maybe 15% if there is high reserve capacity). This is so that the plant can be taken offline for refuelling or maintenance, or due to unforeseen events.
Why else aren’t more countries building nuclear?
Another issue is that of licensing reactor designs. Emerging countries generally do not have the expertise for this, and must initially rely on design licensing by countries such as the UK, USA, France, Russia and China while they focus on building competence to license the actual operation of plants. State-owned nuclear companies in Russia and China have taken the lead in offering nuclear power plants to emerging countries, usually with finance and fuel services.
