Wednesday, June 9, 2010

Mixed outlook for gas reactors

Progress planned in Europe, but a fire sale looms in South Africa

HTGR imageThe future of high temperature gas-cooled reactors is taking different directions depending on where you look. In Europe a multi-national collaboration is working on plans for a site to build the Allegro Reactor. However, in South Africa the proposed “rescue plan” for the Pebble Bed Modular Reactor involves selling off the now unfunded project by auction.

In Europe the Czech Republic, Hungary, and Slovakia have agreed to a joint program to select a site and host the construction of the first-of-a-kind project. Nuclear R&D organizations from all three countries signed a memorandum of agreement in late May. Funding support comes in part from the French Atomic Energy Commission.

In South Africa PBMR officials, at least those who remain following massive layoffs, did not attend a key energy conference May 21 where the future of the Pebble Bed Reactor was hashed over by a panel.

According to wire service reports, the lead speaker, Leon Louw, head of an economic think tank, said that “rescue” of the PBMR project should involve selling it off to the highest bidder.

flounderHe said it was an mistake for the company to have relied so heavily on government funding which has been withdrawn due to the global economic crisis.

He added that losing the project result in South Africa failing to develop a leadership role for the next generation of nuclear reactors.

“Somebody is going to pick this up and run with it. We will be like fishermen who talk about the one that got away.”

Reactor design profiles

The Allegro Reactor design targets 50-80 MW thermal power as a prototype plant for future applications at full scale for generation of electricity and process heat transfer. Several fuel types are being investigated with high temperature (850C) and lower temperature (560C) outputs.

The R&D objective is to demonstrate an alternative to sodium-cooled reactor designs as part of the Generation IV International Forum. Key topical areas include helium as a coolant, fuel qualification, core physics, safety of MOX fuel, and computer codes for safety analysis of fast reactors.

The Pebble Bed Modular Reactor design targets 165 MW output for electricity generation and process heat using spherical fuel elements at about 10% enrichment cooled by helium. The R&D objectives have been to develop a commercial product.

In the U.S. the Department of Energy is providing $40 million for completion of conceptual design work later this year. Like the other two reactors, the Next Generation Nuclear Plant (NGNP) is proposed to be a high-temperature gas cooled reactor. However, it is expected to have electricity output of 300 MW or 600 MW thermal for process heat applications especially in the petro-chemical industry.

PBMR is a member of a consortium fielded by Westinghouse which owns an equity stake in the company. The other participant is a consortium led by General Atomics which has its own technology.

Prior coverage on this blog

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Jason Ribeiro said...

Dan, given what I've read about the engineering challenges with helium as a coolant gas from our friend Rod Adams, could that aspect of the design be a major obstacle toward a reliable workhorse model of pebble bed reactor?

Given the safety features of the design and elimination of many parts compared to the LWR, the pebble bed would seem to be the one Gen4 design to be banked on, so why not go for a more practical coolant gas to speed things along. The design of the pebble bed works, I just hope they figure out which design works best and sooner than 10 years from now.

kellermfk said...

Helium is not the primary problem; rather reactor vessel fabrication is. The temperatures/pressures involved require materials that have not been sanctioned by the ASME and vessel thicknesses are well outside current fabrication capabilities.

However, there is another NGNP concept under development (outside the confines of the DOE) that marries the gas reactor with the combined-cycle power plant, with the strategic objective of using coal and nuclear power. The technology is vastly more versatile than either DOE concepts, being readily able to produce power, liquid transportation fuel, substitute natural gas and all manner of process chemicals as well as process heat.

A recent article in an ASME publication (see summarizes the hybrid-nuclear technology.

The hybrid overcomes the material and fabrication problems that plague the current NGNP concepts. Also, see