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.
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 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. Plutonium-240 exhibits a high rate of spontaneous fission, raising the neutron flux of any sample containing it. Plutonium
Atomic Insights Blog
Very-high-temperature reactor scheme. The very-high-temperature reactor (VHTR), or high-temperature gas-cooled reactor (HTGR), is a Generation IV reactor concept that uses a graphite-moderated nuclear reactor with a once-through uranium fuel cycle. The VHTR is a type of high-temperature reactor (HTR) that can conceptually have an outlet temperature of 1000 °C. Very high temperature reactor
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 . A summary of the benefits, from a recent announcement of the start of construction for a new prototype reactor: There is no danger of a melt-down like the Chernobyl reactor.
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. Uranium Is So Last Century — Enter Thorium, the New Green Nuke | Magazine
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.
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”.
Energy from Thorium
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. Named after Thor, the warlike Norse god of thunder, thorium could ironically prove a potent instrument of peace as well as a tool to soothe the world’s changing climate. New age nuclear
(Updated 16 November 2013) 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. Thorium
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. Interactive: A Visual Guide Inside Japan's Reactors
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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
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. Short Sharp Science: Nuclear crisis: 'Chain reaction could restart'
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. Japan's nuclear crisis: The story so far - environment - 15 March 2011
GCSE Bitesize: Nuclear fission
Learning Zone Class Clips - An introduction to nuclear fission - Science Video