Tuesday, January 18, 2011

More on Small Modular Reactors


UxConsultants has recently published an extensive 500 page special report (description) on Small Modular Reactors, available for purchase at $10,000. You can get an idea of the nature of the report by reading this PDF excerpt, which includes table of contents and lists of figures, tables, and illustrations. Here is a newsrelease description of the report:
Some of the main findings of UxCs SMRA report include:

1) Up to 7 of the leading designs could see at least one plant built by 2020

2) SMRs are likely to be deployed in Russia, China, South Korea, United States, Kazakhstan, and elsewhere

3) Integral PWR designs have the highest likelihood for near-term deployment, but various HTR and LMR concepts are also experiencing positive advances

4) SMR economics can be competitive with larger LWR/HWR designs, if technical and supply chain issues are properly addressed

5) SMRs offer broad appeal for a great number of potential customers, especially due to their multiple applications from generation of both electricity and process heat

UxCs SMRA report aims to fill a clear information gap in the developing SMR marketplace and is believed to be the first ever global comparative analysis of the competing SMR designs. _EyeofDubai

Another promising advanced SMR design not listed in the report summary above, is the ARC-100 molten sodium cooled reactor from Advanced Reactor Concepts.
The new product now under development in the Virginia suburbs of Washington, D.C., is a 100 MW liquid-metal (sodium) cooled fast reactor (large image) that will require refueling once every 20 years. It is remarkable that the technology of EBR-II will live again in this small reactor design. One of the pioneers of that technology, Leon Walters, is now working on the project and is interviewed here.

He told the American Nuclear Society (PDF file) in 2004 that those who built and operated EBR-II have not given up the vision. Walters notes, the design “is proven, it is proliferation-resistant, it decreases waste disposal problems, it’s inherently safe, and perhaps most important of all, Fermi’s original idea—conserving fissionable material—is still sound.”

The ARC reactor system comprises a small uranium-zirconium-fueled nuclear core, submerged in a tank of ambient pressure liquid sodium. The liquid sodium passes through the core where it is heated to 950 degrees Fahrenheit (510 degrees Celsius), it then passes through a heat exchanger where it heats sodium in an intermediate loop, which in turn heats working fluid for energy conversion turbines.

The working fluid can be water that is heated to create steam. Alternatively, the fluid can be carbon dioxide heated to create supercritical (almost liquid) carbon dioxide. The steam, or supercritical carbon dioxide, then spins a turbine to make electricity and is recycled in a closed loop for reheating. According to the company, the supercritical carbon dioxide energy converter system, called the Brayton cycle, provides a thermal efficiency (percentage of heat energy converted to electricity) of 40% or more, significantly higher than the efficiency of conventional steam driven turbine systems. _IS
No doubt there are yet other SMR designs which are being developed around the world, which did not make it into the UxC report.

SMRs will first be built and operated in countries other than the US, because the Obama Nuclear Regulatory Commission policies discourage the licensing of new reactors. The NRC process is almost prohibitively expensive and unnecessarily hamstrung by bureaucratic makework. The NRC has in fact not licensed significantly new types of reactor designs in decades, and clearly has no intention of making it any easier to do so now -- regardless of the critical need to do so.



Post a Comment

Subscribe to Post Comments [Atom]

<< Home

Newer Posts Older Posts