Lead-bismuth eutectic

Lead-bismuth eutectic

:"LBE redirects here. For the U.S. airport, see Arnold Palmer Regional Airport."

Lead-Bismuth Eutectic or LBE is a eutectic alloy of lead (44.5%) and bismuth (55.5%) used as a coolant in some nuclear reactors, and is a proposed coolant for the lead-cooled fast reactor, part of the Generation IV reactor initiative. It has a melting point of 123.5°C (pure lead melts at 327°C) and a boiling point of 1670°C.


The Soviet Alfa-class submarines used LBE as a coolant for their nuclear reactors throughout the Cold War.


As compared to sodium-based liquid metal coolants such as liquid sodium or NaK, lead-based coolants have significantly higher boiling points, meaning a reactor can be operated without risk of coolant boiling at much higher temperatures. This improves thermal efficiency and could potentially allow hydrogen production through thermochemical processes.

Lead and LBE also do not react readily with water or air, in contrast to sodium and NaK which ignite spontaneously in air and react explosively with water. This means that lead- or LBE-cooled reactors, unlike sodium-cooled designs, would not need an intermediate coolant loop, which reduces the capital investment required for a plant.

Lead is also an excellent radiation shield, blocking gamma radiation while simultaneously being virtually transparent to neutrons. In contrast, sodium will form potent gamma emitters following intense neutron radiation, requiring a large radiation shield for the primary cooling loop.

As heavy nuclei, lead and bismuth can be used as spallation targets for non-fission neutron production, as in Accelerator Transmutation of Waste (see energy amplifier).

Both lead-based and sodium-based coolants have the advantage of relatively high boiling points as compared to water, meaning it is not necessary to pressurise the reactor even at high temperatures. This improves safety as it reduces the probability of a loss of coolant accident dramatically, and allows for passively safe designs.


Lead and LBE coolant are more corrosive to steel than sodium, and this puts an upper limit on the velocity of coolant flow through the reactor due to safety considerations. Furthermore, the higher melting points of lead and LBE (327 °C and 123.5 °C respectively) may mean that solidification of the coolant may be a greater problem when the reactor is operated at lower temperatures. Finally, upon neutron radiation the bismuth in LBE coolant will undergo neutron capture and subsequent beta decay, forming polonium, a potent alpha emitter. The presence of radioactive polonium in the coolant would require special precautions during refueling of the reactor.


* [http://aaa.nevada.edu/pdffiles/LI.pdf ATW group, Los Alamos]

Wikimedia Foundation. 2010.

Игры ⚽ Нужно сделать НИР?

Look at other dictionaries:

  • Lead cooled fast reactor — The lead cooled fast reactor is a nuclear power Generation IV reactor that features a fast neutron spectrum, molten lead or lead bismuth eutectic coolant, and a closed fuel cycle. Options include a range of plant ratings, including a number of 50 …   Wikipedia

  • Nuclear reactor — Core of CROCUS, a small nuclear reactor used for research at the EPFL in Switzerland This article is a subarticle of Nuclear power. A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Most commonly they are… …   Wikipedia

  • Nuclear reactor technology — This article is a subarticle of Nuclear power .A nuclear reactor is a device in which nuclear chain reactions are initiated, controlled, and sustained at a steady rate, as opposed to a nuclear bomb, in which the chain reaction occurs in a… …   Wikipedia

  • Alfa class submarine — The Soviet Union/Russian Navy Project 705 ( Лира / Lyra ) was a submarine class of hunter/killer nuclear powered vessels (abbreviated PLA: Podvodnaya lodka atomnaya , nuclear hunter/killer submarine). The class is also known by the NATO reporting …   Wikipedia

  • Nuclear reactor coolant — Nuclear reactor coolants Coolant Melting point Boiling point Light water at 155 bar 345 °C Mercury 38.83 °C 356.73 °C NaK eutectic 11 °C 785 °C Sodium 97.72 °C 883 °C …   Wikipedia

  • Generation IV reactor — Generation IV reactors (Gen IV) are a set of theoretical nuclear reactor designs currently being researched. Most of these designs are generally not expected to be available for commercial construction before 2030, with the exception of a version …   Wikipedia

  • ESS European spallation source — L ESS (pour European Spallation Source en anglais, soit en français source européenne de spallation) est le nom d une future installation de recherche scientifique sur la matière utilisant des techniques de dispersion des neutrons. L installation …   Wikipédia en Français

  • Neutron reflector — A neutron reflector is any material that reflects neutrons. This refers to elastic scattering rather than to a specular reflection. The material may be graphite, beryllium, steel, and tungsten carbide, or other materials. A neutron reflector can… …   Wikipedia

  • LBE — ist die Abkürzung für: Lübeck Büchener Eisenbahn lead bismuth eutectic, eine Wismutlegierung, die als Kühlmedium für Kernreaktoren in U Booten diente Diese Seite ist eine Begriffsklärung zur Unterscheidung mehrerer mit demselbe …   Deutsch Wikipedia

  • Wismutlegierung — Wismut (Bismut in der chem. Fachsprache wegen des Symbols Bi) wird neben Cadmium, Gallium und Indium für niedrig schmelzende Legierungen verwendet. Die angegebenen Legierungen weisen ggf. einen Schmelzbereich auf, da sie nicht immer das… …   Deutsch Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”