Beta particle. Alpha radiation consists of helium nuclei and is readily stopped by a sheet of paper.
Beta radiation, consisting of electrons or positrons, is halted by an aluminum plate. Gamma radiation is dampened by lead. Beta particles are high-energy, high-speed electrons or positrons emitted by certain types of radioactive nuclei such as potassium-40. The beta particles emitted are a form of ionizing radiation also known as beta rays. The production of beta particles is termed beta decay. Β− decay (electron emission) Beta decay. An unstable atomic nucleus with an excess of neutrons may undergo β− decay, where a neutron is converted into a proton, an electron and an electron-type antineutrino (the antiparticle of the neutrino): n → p + e− + ν e This process is mediated by the weak interaction. Alpha particle. Alpha particles consist of two protons and two neutrons bound together into a particle identical to a helium nucleus.
They are generally produced in the process of alpha decay, but may also be produced in other ways. Alpha particles are named after the first letter in the Greek alphabet, α. The symbol for the alpha particle is α or α2+. Because they are identical to helium nuclei, they are also sometimes written as He2+ or 4 2He2+ indicating a Helium ion with a +2 charge (missing its two electrons). Plutonium. Plutonium is the heaviest primordial element by virtue of its most stable isotope, plutonium-244, whose half-life of about 80 million years is just long enough for the element to be found in trace quantities in nature. Plutonium is mostly a byproduct of nuclear reactions in reactors where some of the neutrons released by the fission process convert uranium-238 nuclei into plutonium. Both plutonium-239 and plutonium-241 are fissile, meaning that they can sustain a nuclear chain reaction, leading to applications in nuclear weapons and nuclear reactors.
Atomic Insights Blog. Very high temperature reactor. Very-high-temperature reactor scheme.
Accelerating Future » A Nuclear Reactor in Every Home. Sometime between 2020 and 2040, we will invent a practically unlimited energy source that will solve the global energy crisis.
This unlimited source of energy will come from thorium . Uranium Is So Last Century — Enter Thorium, the New Green Nuke. Photo: Thomas Hannich The thick hardbound volume was sitting on a shelf in a colleague’s office when Kirk Sorensen spotted it.
A rookie NASA engineer at the Marshall Space Flight Center, Sorensen was researching nuclear-powered propulsion, and the book’s title — Fluid Fuel Reactors — jumped out at him. He picked it up and thumbed through it. Hours later, he was still reading, enchanted by the ideas but struggling with the arcane writing. “I took it home that night, but I didn’t understand all the nuclear terminology,” Sorensen says. Published in 1958 under the auspices of the Atomic Energy Commission as part of its Atoms for Peace program, Fluid Fuel Reactors is a book only an engineer could love: a dense, 978-page account of research conducted at Oak Ridge National Lab, most of it under former director Alvin Weinberg. At the time, in 2000, Sorensen was just 25, engaged to be married and thrilled to be employed at his first serious job as a real aerospace engineer.
Thorium fuel cycle. The thorium fuel cycle is a nuclear fuel cycle that uses the naturally abundant isotope of thorium, 232Th, as the fertile material.
In the reactor, 232Th is transmuted into the fissile artificial uranium isotope 233U which is the nuclear fuel. Unlike natural uranium, natural thorium contains only trace amounts of fissile material (such as 231Th), which are insufficient to initiate a nuclear chain reaction. Additional fissile material or another neutron source are necessary to initiate the fuel cycle.
In a thorium-fueled reactor, 232Th absorbs neutrons eventually to produce 233U. This parallels the process in uranium breeder reactors whereby fertile 238U absorbs neutrons to form fissile 239Pu. The thorium fuel cycle claims several potential advantages over a uranium fuel cycle, including thorium's greater abundance, superior physical and nuclear properties, better resistance to nuclear weapons proliferation and reduced plutonium and actinide production. History  The Liquid Fluoride Thorium Reactor: What Fusion Wanted To Be. Reactor. Thorium reactors would be cheap.
The primary cost in nuclear reactors traditionally is the huge safety requirements. Regarding meltdown in a thorium reactor, Rubbia writes, “Both the EA and MF can be effectively protected against military diversions and exhibit an extreme robustness against any conceivable accident, always with benign consequences. In particular the [beta]-decay heat is comparable in both cases and such that it can be passively dissipated in the environment, thus eliminating the risks of “melt-down”. Thorium reactors can breed uranium-233, which can theoretically be used for nuclear weapons. However, denaturing thorium with its isotope, ionium, eliminates the proliferation threat. Like any nuclear reactor, thorium reactors will be hot and radioactive, necessitating shielding. Because thorium reactors will make nuclear reactors more decentralized. Even smaller reactors might be built.
Energy from Thorium. New age nuclear. Credit: Justin Randall What if we could build a nuclear reactor that offered no possibility of a meltdown, generated its power inexpensively, created no weapons-grade by-products, and burnt up existing high-level waste as well as old nuclear weapon stockpiles?
And what if the waste produced by such a reactor was radioactive for a mere few hundred years rather than tens of thousands? It may sound too good to be true, but such a reactor is indeed possible, and a number of teams around the world are now working to make it a reality. What makes this incredible reactor so different is its fuel source: thorium. Thorium. (Updated March 2014) Thorium is more abundant in nature than uranium.It is fertile rather than fissile, and can only be used as a fuel in conjunction with a fissile material such as recycled plutonium.Thorium fuels can breed fissile uranium-233 to be used in various kinds of nuclear reactors.Molten salt reactors are well suited to thorium fuel, as normal fuel fabrication is avoided.
The use of thorium as a new primary energy source has been a tantalizing prospect for many years. Extracting its latent energy value in a cost-effective manner remains a challenge, and will require considerable R&D investment. This is occurring preeminently in China, with modest US support. Nature and sources of thorium. Interactive: A Visual Guide Inside Japan's Reactors. Workers at Fukushima Daiichi nuclear power plant in the northeastern coast of Japan have been struggling to keep reactors there from overheating.
The troubles began March 11, when a massive earthquake and tsunami knocked out power at the facility, disabling cooling systems. Workers are now scrambling to cool the nuclear cores of three reactors, and there are new concerns about overheating in pools where spent nuclear fuel rods cool. Here's a visual guide to what's going inside the reactors. A is for Atom (1952) - Educational Animated Film - Part 1/2. Our Friend the Atom 1 of 5 - The Fisherman and the Genie. Our Friend the Atom 5 of 5 - Harnessing the Atom. Our Friend the Atom 4 of 5 - Nuclear Reactions. Our Friend the Atom 2 of 5 - Atoms and Molecules. Our Friend the Atom 3 of 5 - What's in an Atom. Nuclear crisis: 'Chain reaction could restart'
1800 GMT, 18 March 2011 Zena Iovino, reporter Japan has raised the accident level at the Fukushima Daiichi nuclear power plant to 5 on an international scale of 7, according to the Kyodo news agency and NHK. The partial meltdown at Three Mile Island in 1979 also ranked as a level 5. But there was some good news. The International Atomic Energy Agency (IAEA) said on Friday that the situation at reactors 1, 2 and 3 appears to remain fairly stable. Japan's nuclear crisis: The story so far - environment - 15 March 2011. Read full article Continue reading page |1|2 With muddled media reports of the ongoing crisis, we spell out exactly what has happened up to 15 March, and what might happen next Which reactors have been hit hardest by the quake, and where are they? Two major nuclear power plants are at the heart of the crisis, both of which were hit by the quake and the tsunami.
They are on the coast halfway between Sendai, the city which bore the brunt of the tsunami, and Tokyo. The first, called Fukushima Daiichi – literally, Fukushima Number 1 – has six units, each housing its own nuclear reactor. The second power plant involved, Fukushima Daini – Fukushima Number 2 – has four units, and all were working at the time of the quake. Did everything work as planned initially? GCSE Bitesize: Nuclear fission. Learning Zone Class Clips - An introduction to nuclear fission - Science Video.