Mondolithic Studios

China Rising – To celebrate Chinese New Year. This piece was done a little while back for the cover of New Scientist Magazine on the emergence of China as a global leader in Science and Technology.

The image shown here is a syndication for the Frankfurt Weekly in Germany. It is an editorial piece on the simplicity and safety of the Chinese designed Pebble Bed Nuclear Reactor. You can see the original full illustration originally done for Wired Magazine here.

The pebble bed reactor (PBR) is a graphite-moderated, gas-cooled, nuclear reactor. It is a type of Very high temperature reactor (VHTR) [formally known as the high temperature gas reactor (HTGR)], one of the six classes of nuclear reactors in the Generation IV initiative. Like other VHTR designs, the PBR uses TRISO fuel particles, which allows for high outlet temperatures and passive safety.

The base of the PBR’s unique design is the spherical fuel elements called “pebbles”. These tennis ball-sized pebbles are made of pyrolytic graphite (which acts as the moderator), and they contain thousands of micro fuel particles called TRISO particles. These TRISO fuel particles consist of a fissile material (such as ²³⁵U) surrounded by a coated ceramic layer of SiC for structural integrity. In the PBR, 360,000 pebbles are placed together to create a reactor, and is cooled by an inert or semi-inert gas such as helium, nitrogen or carbon dioxide.

This type of reactor is also unique because its passive safety removes the need for redundant, active safety systems. Because the reactor is designed to handle high temperatures, it can cool by natural circulation and still remain intact in accident scenarios, which may raise the temperature of the reactor to 1600 ^oC. Also because of its design, its high temperatures allow higher thermal efficiencies than possible in traditional nuclear power plants (up to 50%).

Also, the gases do not dissolve contaminants or absorb neutrons as water does, so the core has less in the way of radioactive fluids.

A number of prototypes have been built. Active development is ongoing in South Africa as the PBMR design, and in China whose HTR-10 is the only prototype currently operating.

The technology was first developed in Germany^[1] but political and economic decisions were made to abandon the technology.^[2] In various forms, it is currently under development by MIT, the South African company PBMR, General Atomics (U.S.), the Dutch company Romawa B.V., Adams Atomic Engines [1], Idaho National Laboratory, and the Chinese company Huaneng ^[3].

In June 2004, it was announced that a new PBMR would be built at Koeberg, South Africa by Eskom, the government-owned electrical utility.^[4] There is opposition to the PBMR from groups such as Koeberg Alert and Earthlife Africa, the latter of which has sued Eskom to stop development of the project.^[5]

The reactors are used in nuclear power plants to produce nuclear power from nuclear fuel. [thanx Wiki]