The company is working with the city of Galena on its application to the NRC, and while the small Yukon River community could become one of the first sites for the new reactor, Toshiba also plans an aggressive worldwide marketing program to sell the units for power generation at remote mines, desalinization plants and the making of hydrogen as an alternate fuel.
Approval by the NRC is important to Toshiba because the U.S. regulatory agency's stamp of approval on the design will enable the company to get approvals for the reactor in many countries.
The company hopes to sell four times the number of units for hydrogen production than would be sold for conventional power generation, as in Galena, according to Marvin Yoder, a consultant to Galena on the project.
“The central concept of the reactor design is that the 4-S is safe and simple to operate,” he said.
Yoder told the Resource Development Council in Anchorage April 17 that Toshiba has made two presentations to NRC staff in Washington on the reactor design, with a third briefing session planned for May 23. One more staff briefing will be held and then the Japanese company, which has also acquired U.S. nuclear manufacturer Westinghouse, will prepare its formal applications to the NRC seeking approvals. Yoder said Toshiba hopes to make the application in 2009.
If the commission approves the design in 2010 or 2011, the 4-S unit could be installed in Galena and generating power by 2012 or 2013, Yoder said.
The 4-S reactor is a small unit that would generate 10 megawatts of power and operates with passive systems, meaning there are no mechanical parts in the reactor itself, Yoder said. A larger 50-megawatt unit is also under development.
The reactor unit would be about 8 feet by 3 feet in dimension and will be encased and buried 40 feet below the surface. The nuclear reaction will heat liquid sodium that will be moved through heat exchanges with electro-magnetic pumps. Power is generated in a steam turbine at the surface.
Unlike large conventional nuclear reactors, Toshiba's 4-S design involves passive systems, meaning there are no mechanical parts that can break down. The safety systems are not dependent on emergency power to function. It will also not need refueling at the site.
The fuel loaded in the reactor will be sufficient for 30 years. Toshiba's plan is to refuel the reactor after 30 years, with the entire unit being extracted from the site and shipped elsewhere for refueling and maintenance.
The NRC may decide to have the reactor checked before 30 years, particularly if the Galena reactor is the first commercial installation, Yoder said. An important security consideration is that the grade of nuclear fuel to be used is well below weapons grade. This is a security concern with some reactor designs used elsewhere.
Very little on-site maintenance of operations staff would be needed, except with the power generation turbine on the surface. Modular construction, with the unit moved to its final location by barge, will save costs and construction time.
Galena officials hope the nuclear plant, if it is installed, can reduce local electricity costs to 17 cents per kilowatt hour or less, Yoder said. While Galena now uses much less power than the 10 megawatts the 4-S unit could produce, the local power requirement will very likely grow over time, particularly if local residents switch from heating with fuel oil to heating with electricity.
(Source: Alaska Journal of Commerce)