nuclear reactor — Physics. reactor (def. 4). Also called nuclear pile. [1940 45] * * * Device that can initiate and control a self sustaining series of nuclear fission reactions. Neutrons released in one fission reaction may strike other heavy nuclei, causing them … Universalium
Void coefficient — In nuclear engineering, the void coefficient (more properly called void coefficient of reactivity ) is a number that can be used to estimate how much the reactivity of a nuclear reactor changes as voids (steam bubbles) form in the reactor… … Wikipedia
Noble gas — Group 18 Period 1 2 He 2 … Wikipedia
Pressurized water reactor — (PWRs) (also VVER if of Russian design) are generation II nuclear power reactors that use ordinary water under high pressure (superheated water) as coolant and neutron moderator. The primary coolant loop is kept under high pressure to prevent the … Wikipedia
Neutron poison — For information on biological effects of excessive ionizing radiation, see radiation poisoning. A neutron poison (also called a neutron absorber or a nuclear poison ) is a substance with a large neutron absorption cross section in applications,… … Wikipedia
Critical mass — This article is about nuclear fission reactions. For other uses, see Critical mass (disambiguation). As part of a re creation of a 1945 criticality accident, a plutonium pit is surrounded by blocks of neutron reflective tungsten carbide. The… … Wikipedia
Nuclear poison — A nuclear poison, also called a neutron poison is a substance with a large neutron absorption cross section in applications, such as nuclear reactors, when absorbing neutrons is an undesirable effect. However neutron absorbing materials, also… … Wikipedia
Selective chemistry of SWNT — Single walled nano tubes (SWNT) Structure and Reactivity Reactivity of the fullerene molecules with respect to addition chemistries is strongly dependent on the curvature of the carbon framework. Their outer surface (exohedral) reactivity… … Wikipedia
chemical compound — Introduction any substance composed of identical molecules consisting of atoms (atom) of two or more chemical elements (chemical element). All the matter in the universe is composed of the atoms of more than 100 different chemical elements … Universalium
Negative temperature coefficient — A negative temperature coefficient (NTC) occurs when the thermal conductivity of a material rises with increasing temperature, typically in a defined temperature range. For most materials, the thermal conductivity will decrease with increasing… … Wikipedia
Nuclear meltdown — Three of the reactors at Fukushima I overheated, causing core meltdowns. This was compounded by hydrogen gas explosions and the venting of contaminated steam which released large amounts of radioactive material into the air.[1] … Wikipedia