Japan, Nuclear Power, Real Challenges
The earthquake in Japan brings us face to face with another challenge to the engineering community. The earthquake is certainly a disaster, and we hope and pray that the loss of life in Japan will be small. But the emerging crisis of radiation leaking from nuclear powerplants that have been damaged by the quake and tsunami waves are pause for serious reflection about the future of energy.
The damage is the result of natural forces that are beyond the ability of designers to engineer against. And how we take heed of these events, or even if we take heed, may be the real measure of progress in western civilization. The future of nuclear power plants is going to have include choices and alternative technology.
A nuclear power plant is a complex system, mostly controlled by technology from the process industry because it creates steam to drive a turbine which turns a generator. The generator is a classic electric motor run in reverse to create electricity from torque. So there is mechatronic technology involved in the process itself.
Even more mechatronics content is involved in the creation of the fuel and the operation of the control rods in water cooled reactors. Robots are also frequently used in the processing of the fuel into the final shape for use in a reactor.
But the bigger question is what are the technology choices for nuclear power generated electricity that can survive the forces of natural disasters? Interestingly, there are a number of mini reactor technologies that because of their small size, are much more likely to withstand the forces of nature. Just Google mini nuclear reactors and you will find pages of information. And discussions of numerous technologies that are competing for use in the power industry.
Large water cooled reactor have been producing electricity for 40 years or more. But these designs are massive and susceptible to failure when the water flow is interrupted. Which is what we have going on in Japan.
There are wave reactors, Thorium reactors, small water cooled designs and pebble bed reactors. Each technology working its way through the torturous process of qualification for use by federal regulators.
Some of the technology is unproven and controversial. But since I have seen the pebble bed reactor demonstrated, for me this is a leading edge technology. The pebble fuel is a small .5mm diameter pebble of uranium contained in layers of graphite and ceramic. By spacing the fuel apart in small bits, it cannot reach thermal runaway, and in fact, using helium coolant, the system can reach thermal equilibrium at 800 degrees. Since the ceramic insulator is designed to withstand temperatures of 3000 degrees, there is little chance of the fuel melting the insulator and creating a runaway chain reaction. Safe, small. The American Nuclear Regulatory Commission attended a demonstration of this technology years ago. I saw the video.
So the question is, when are we going to see some progress? At the rate our government chooses to do things, it will take years. At the risk of being redundant, providing electricity shouldn’t be about politics, it should be about free markets, and doing things right. If the electric power industry is going to be regulated by politicians, then politicians need to be doing the people’s business and getting it done.