PBR

PBR (Pebble Bed Reactor)

The Pebble Bed Reactor is quite possibly one of the most promising designs in safe nuclear power. Not only is this reactor completely melt down proof, simply because of the laws of physics, waste is not radioactive, and the fuel cannot be easily transformed into harmful forms. The reactor works quite differently than the conventional, or even the CANDU reactor.

PBR Design

Fuel Pebble Design

The fuel instead of the conventional rods, are small spheres, each 6cm in diameter. The sphere itself is graphite, which acts as a moderator for the neutrons, and spurs on reaction. Inside this graphite sphere are many smaller spheres that are carbon coated fuel pellets. The fuel could be a number of radioactive materials, not only Uranium. These spheres are dumped into a core, and they create heat through fissions. Helium gas is circulated through, and then transfers it’s heat to water, which produces power. Due to the structure of the fuel sphere, the fuel can only heat up to a certain temperature, far below the melting point of Uranium. This makes the reactor melt down proof. It is also highly efficient, transferring almost 50% of the thermal energy produces into electrical energy. Also once the spheres are used up, they are not radioactive, and could be safely stored out in the open. They only emit a tiny amount of radiation after they are spent, and this has been judged to be safe. The reactors are small compared to other types of nuclear power, but they can increase the number to produce more power. The PBR has drawn much support from many people who were previously against nuclear power. It is still an experimental reactor, but China has begun to construct a few to meet their growing power demands. This is truly a perfectly safe form of nuclear power, and has much support my many parties that used to oppose nuclear power.

Fuel Pebble

Citations

1. http://www.geocities.com/nuclearpowernow/reactors.html

2. http://fr.wikipedia.org/wiki/R%C3%A9acteur_%C3%A0_lit_de_boulets

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