As long time Atomic Insights readers know, I have been following the developments of the South African Pebble Bed Modular Reactor (PBMR) project for many years – since before the company was formed, in fact. As a result of many factors, the government of South Africa has decided to stop funding the project. Though the details have not been released, the company’s efforts to find customers and additional investors have also failed, so the project team is being reduced from about 800 scientists, engineers and technicians to an interim head count of about 25 people.
As far as I can tell, none of the remaining members have “update the web site” as a task that is high on their priority list. The most recent press release posted is from March 8, 2010, announcing the resignation of Jaco Kriek from the position of CEO.
There was an article published on July 15, 2010 on timeslive.co.za titled Government pulls plug on PBMR that provides some additional information about the current status of the company, some key expenditures since project inception in 1999 that added up to 9 billion rand ($1.19 B), and the remaining assets.
The Pebble Bed Modular Reactor Company (PBMR), which was established in 1999 to build small nuclear power reactors, faces imminent closure.
In a letter dated July 5, Public Enterprises Minister Barbara Hogan told the National Union of Mineworkers (NUM): “The minister of finance has clearly stated that there will be no further funding for the company, and I would like to reiterate that this position has not changed.
“It is clear that the remainder of the cash on hand is to be utilised solely for the winding down of the company as well as the preservation of the intellectual property.”
Though there are many factors that led to the demise of this project, it is important to understand that the failure does not mean that pebble bed reactors using high temperature fuel made up of particles coated with several protective layers is an inherently bad idea. It most certainly does not mean that smaller reactors or reactors targeted for the process heat market are doomed to failure.
|HTR-10 Cross Section|
There is a 10 MWth research and test reactor operating in China today called the HTR-10 that is performing well enough in testing to encourage the construction of at least two additional larger units in Shidaowan, near Rongcheng in Weihai city. This commercial demonstration station will consist of two 250 MWth HTR-PM modules feeding a single 210 MWe steam turbine.
In contrast to the technical choices made at the beginning of the PBMR project to design and build both a pebble bed reactor heat source AND a unique, helium cooled direct cycle compressor-turbine unit “balance of plant”, the Chinese engineers decided to refine a physically proven system using helium circulated and heated by a graphite moderated nuclear reactor to produce steam for a conventional steam plant. That combination produced significant quantities of power in the past at the 330 MWe Ft. St. Vrain nuclear power station in Colorado and at the 300 MWe Thorium High Temperature Reactor (THTR) in Germany. Though neither one of those examples had operated for a full commercial lifetime, both were far more than “paper reactors” or test platforms.
The combination that the PBMR engineers chose had never before been constructed; in fact, the 165 MWe helium turbomachine envisioned for the project existed only on paper. Unfortunately, it took the project leaders many years to recognize the technical difficulty and cost challenge of designing and building a unique turbomachine using helium from scratch. After about ten years of various design changes and contractor shifts, the project leaders decided last year to abandon the direct cycle gas turbine part of the project and focus on using the pebble bed reactor as the heat source for industrial processes.
That decision apparently came at the wrong time to save the project. (Either it was too late and the funding decision makers within the South African government had lost patience, or it was not well received by potential process heat customers because they have other choices available that are cheap enough.) Probably because of the uncertain status of their PBMR partners, I recently learned that Westinghouse has declined to participate in the US NGNP detailed concept design, even though they were initially chosen to receive half of a $40 million DOE project award. At this point, the remaining option for NGNP is the prismatic core design that General Atomics prefers.
I hope, for the sake of the South African taxpayers, that the people left at PBMR Co. Pty. do a good job of obtaining some value for the intellectual property that they developed. There was a time when many people around the world were looking to South Africa to produce the first of a kind high temperature gas cooled direct cycle nuclear power plant, and the team took some important steps. From a very long distance away from the project, it appears now that the steps were not well considered or focused on moving in a fertile technical direction. There are some lessons to be learned here about the value of evolutionary vice revolutionary design and the importance of getting products to market before funders lose patience.
|Pebble Fuel Element|
For the record, I am still fascinated and enthusiastic about the potential applications of what an old friend and mentor used to call my “hot rocks” concept of reactors that are formed by filling a “bucket” full of a suitable number of balls containing a mixture of graphite moderator, heavy metal fuels, and adherent coatings that prevent fission product releases. Someday, I hope to have the opportunity and the resources needed to show the flexibility of this fuel/reactor concept using nitrogen, an inert gas that works well in conventional combustion turbomachinery.