Engineering firm Babcock & Wilcox has designed a scalable nuclear reactor that it says has the potential to change the face of the global clean energy market.

B&W says that its new 125MW reactor, known as mPower, will be cheaper and more flexible than the larger designs currently on offer and will appeal to a broad spectrum of users, including regional and municipal utilities with limited electricity requirements, or developing countries which have transmission & distribution systems that cannot handle large reactors.

B&W has not pubicly put a price tag on the reactor. However John Fees, CEO of McDermott International, B&W’s parent company, said he believes it can be delivered for less than $5000/MW, the price typically quoted for the larger reactors on the market.

The steam system for the new reactor will be manufactured in existing B&W facilities in the USA and can be shipped by rail to construction sites. Fees said this would lead to greater cost certainty, which is a key factor for companies investing in nuclear power. The fact that modules can be added sequentially will also improve project financing. Capital cost can be staggered and modules can be earning revenue as soon as they are completed, regardless of the progress of other units on the site.

Described by B&W as ‘true Generation III++ nuclear technology’ mPower is a passively safe advanced light water reactor with a below-ground containment structure. The design will include a fuel pond with sufficient capacity to store all the spent fuel arising over the unit’s planned 60-year lifetime.

The reactor will need to be refuelled once every five years and will use conventional 17×17 PWR fuel, although the assemblies will be slightly shorter than usual. A decision has not yet been made about who will manufacture the fuel although B&W has said its plans are to use the existing supply chain.

In June chief executive officer of B&W Brandon Bethards said that in April the company had notified the Nuclear Regulatory Commission of its intent to seek design certification for the new reactor. He said pre-licensing activities could begin in July. The submission of a design certification application is scheduled for 2011. Potentially the first combined operating licence application (COLA) could be submitted to the NRC in 2012, construction could start as early as 2015, with the first reactor online by 2018. This is an ambitious timetable but Bethards says that the market community and the regulatory environment suggest that it is a realistic one.

B&W has formed a new business unit, B&W Modular Nuclear Energy, LLC, to lead the development, licensing and delivery of mPower reactor projects.

•Tennessee Valley Authority will soon begin evaluating a potential lead site for the mPower reactor, its favourite at present being Clinch River. It is essentially a greenfield site except that it includes the early earthworks for the foundations of an earlier nuclear reactor project, later abandoned. TVA’s evaluation will be similar to the one needed for an NRC early site permit application but no firm decision has yet been made to go ahead with the plant. However, B&W says it has signed a Memorandum of Understanding with TVA and a consortium of regional municipal and co-operative utilities to explore the possibility of constructing a fleet of mPower reactors.

US utility Exelon is also working with B&W and TVA in an advisory capacity on the design and licensing of the reactor.