Thursday, 16 May 2013

Small Modular Reactors: Remaining Challenges

Small modular reactors (SMRs) are the subject of increasing interest in recognition of their potential to offer a cheaper, safer and simpler alternative to the large-scale nuclear power plants currently used. The concept of SMRs is based on small reactors that are assembled from factory-fabricated parts or "modules". Each module represents a portion of the finished plant and, in comparison to current large nuclear power plants, SMRs require much less site work to assemble the components into an operational power plant. 

The interest in SMR's technology arises from the fact that SMRs are not only cheaper to construct, run and maintain but can also be built faster than the conventional large nuclear reactors because of their simple design and modular nature. These features make SMRs very attractive to a wide range countries especially those with limited financial capabilities and small (below 10 GW) electricity grids.

Despite these clear advantages, SMRs must overcome a number of challenges before being accepted as a deployable technology in the near future. The main challenge is an institutional one. Current nuclear regulatory bodies lack the human and technical capacities to licenses SMRs, especially the designs that have no performance history or track record such as  the high temperature gas-cooled reactor concept. In addition, the industry lacks a SMR initial project that would prove the point with regards to cost, flexibility and adaptability claims. Such a project would definitely provide many answers and inspire confidence in SMRs. 

While nuclear waste is considered the main problem of the nuclear industry as a whole. SMRs could add an extra complication by being spread out in remote places, as it has been suggested as one of their potential uses. This will make the management of the waste more difficult. A given amount of highly radioactive nuclear waste is easier to manage from one site rather than multiple.  It should be  noted, however,  that fast SMRs have the potential of being able to recycle the waste to breed new fuel while generating power. This will require more R&D in fast SMRs which are less favourable, so far, than thermal (water) SMRs.  Fast SMRs should be given more funding to demonstrate their superior features particularly with regards to recycling actinides (the long-lived part of the nuclear waste) in the fuel as well as incorporating thorium which could prove to be more sustainable than the current uranium- and plutonium-based fuels.