Research Programs

 

Advanced Gas Cooled Modular Pebble Bed Reactors

The modular pebble bed reactor is one of the reactor concepts that is being considered for the Next Generation Nuclear Plant to be built at the Idaho National Laboratory. Emphasis continues on resolving key technical and economic questions on the viability of this and other high temperature gas reactors. The two key technical areas that CANES is addressing are the development of an advanced computer model for the microsphere fuel used in both the pebble and block reactors. Professor Ballinger and his students have included a new chemistry model to assess the affects of high temperature fission products on the pyrolytic carbon and silicon carbide. In addition Professor Ballinger is about to begin a study of the effect of transients on the coated particles to determine the probability of failures given reactor type transients. Professor Kadak is working with fuel manufacturers to begin to assess the viability of introducing advanced fuel designed particles into an integrated design and manufacturing process that will provide a mechanism for verifying the quality of the trillions of microspheres that will be needed for a typical pebble or block reactors.

The second major work area deals with the safety of high temperature gas reactors. One of the most significant challenges for graphite moderated high temperature gas reactors is associated with a postulated air ingress event due to a break in piping connected to the reactor vessel. In the past CANES had developed a benchmarked capability to analyze the complicated chemical processes involved using a computational fluid dynamics code. At present, Professor Kadak is working to do a blind modeling of a recent air ingress test completed in Germany’s Jeulich Research Center at the NACOK facility. This work is supported by Westinghouse as part of their interest in the Pebble Bed Modular Reactor being built in South Africa.

The last area of focus is on advanced modularity techniques that have been considered for the MIT version of the pebble bed reactor design. The “lego” style assembly of this reactor provides an opportunity to reduce cost by manufacturing productivity and reduced field construction time.

MIT continues to be active on the Chinese pebble bed project sponsored by the Institute of Nuclear Engineering Technology of Tsinghua University. Professors Kadak and Ballinger attended a major high temperature reactor conference in Beijing in September to further MIT/Tsinghua University collaborations. China has plans to build a full scale prototype pebble bed reactor by 2011 at a site already selected.

MIT is also continuing its collaboration with Brayton Energy on the development and testing of a lightweight compact plate fin heat exchanger to be used for MIT’s design of its electric plant and for application to hydrogen production being considered for INL.