Pebble bed modular reactor

Pebble Bed Modular Reactor (Pty) Ltd
	File:PBMRLogo.JPG
Company type	Engineering
Industry	Nuclear
Founded	1994
Headquarters	Centurion, Gauteng, South Africa
Area served	South Africa, International
Key people	CEO: Jaco Kriek
Services	Design, Project Management and Related Services
Number of employees	Est. 900
Website	http://www.pbmr.com

The Pebble Bed Modular Reactor (PBMR)is a particular design of pebble bed reactor under development by South African company PBMR (Pty) Ltd since 1994. The project entails the construction of a demonstration power plant at Koeberg near Cape Town and a pilot fuel plant at Pelindaba near Pretoria.

The PBMR is fueled and moderated by fuel spheres each containing TRISO coated oxide fuel particles. There are 15000 fuel particles per fuel sphere.

Although it is not the only gas-cooled high-temperature reactor currently being developed in the world, the South African project is internationally regarded as the leader in the global power generation field. The PBMR is characterised by inherently safe features, which mean that no human error or equipment failure can cause an accident that would harm the public.

Since its establishment in 1999, Pebble Bed Modular Reactor (Pty) Ltd has grown into one of the largest nuclear reactor design teams in the world. In addition to the core team of some seven hundred people at the PBMR head-office in Centurion near Pretoria, more than a thousand people at universities, private companies and research institutes are involved with the project.

Heat from the PBMR can be used for a variety of industrial process applications, including process steam for cogeneration applications, in-situ oil sands recovery, ethanol applications, refinery and petrochemical applications. The high temperature heat can also be used to reform methane to produce syngas (where the syngas can be used as feedstock to produce hydrogen, ammonia and methanol); and to produce hydrogen and oxygen by decomposing water thermochemically.

In 2006, the US Department of Energy awarded the PBMR consortium the primary contract for the first phase of its New Generation Nuclear Plant (NGNP) project. The scope for the first phase of this contract, which has now been completed, was for the pre-conceptual engineering of a nuclear co-generation plant for the production of electricity and hydrogen. Requests for proposals for the second phase of the NGNP project will soon be issued, to which the PBMR consortium will be responding within the next few months of 2009.

PBMR’s current investors are Eskom, the Industrial Development Corporation of South Africa and Westinghouse Electric Company in the United States. The PBMR project also enjoys solid support from the South African government, who regards it as one of the most important capital investment and development projects yet undertaken in the country.

The PBMR is modular in that only small to mid-sized units will be designed; Larger power stations will be built by combining many of these modules. As of 2008, 400MWt was emerging as an optimum module size, considerably larger than the original concept size.

The concept is based on THTR in Germany, but modified to drive a Brayton cycle turbine. The core is annular with a centre column as a neutron reflector. Operating fuel temperature is to be kept below 1130°C, to minimise fission product release from the fuel during operation. The control rods operate outside the fuel cavity, rather than in the spaces between the spheres, to simplify the geometry and management of the sphere lattice.

The core is designed so that passive cooling is adequate to keep the fuel within its safe temperature range during shutdown. No secondary containment is considered necessary.