May
6
Nuclear Power Growth Without New Plants?
May 6, 2008 | 3 Comments
Brian Wang of NextBigFuture posted about improvements to atomic fission processes with four new concepts that are making their way forward. With atomic fission provided the U.S. with about 20% of the electrical power generation even minor improvements are significant. Any new fission plant is faced with difficult, time consuming and expensive barriers to get over before a watt sees its way to a consumer, with each watt priced to consumers for the excess trouble.
That makes improvements to an existing plant highly interesting. Brian offers this graphic that shows the shares of power generation with the caption in part “Boosting nuclear power by 50% would be like doubling hydroelectric and all renewable power.” We’re big supporters of renewable here, but the amounts of power needed to avoid summer brownouts and load shedding without even adding the advantages to driving down the cost of power require much larger proportions than currently in planning.
The MIT fuel rod, which simply put, isn’t a rod any more, but has become a tube with the inner hole also moving coolant, is another design that achieves much better efficiency. This new design cuts the operating temperature to less than half, making the distance to meltdown 2140 degrees C, a near doubling of the temperature spread, which forms a much saver operating design. While more complex in manufacturing, Westinghouse has already runs trials at 95% yields, making it possible to calculate the costs for the new fuel design. Use scenarios for refueling include both solid and the new annular designs in existing reactors. Tests are planned to bring this idea to commercial use. There may be up to 50% more power available from reactors using this innovation.
The idea to “spike the coolant” has gained traction too. In this concept, the water has added particles in nano sizes that add thermal carrying and thermal exchange rates. The coolant water takes heat away from the hot fuel and then releases it outside where the heat can be used. Water is the limiter in thermal exchanges holding efficiencies to about 33%. Increase the limit and you can move more heat, perhaps double the amount of efficiency. But the problem to be worked out is the “spiked” additives bunch up and settle out. Work is underway, as this idea offers a huge opportunity if the problems can be worked out.
Another take on the shape of fuels coming from MIT is a cross shaped pellet. With 40% more surface area, more heat can be taken away thus more efficiently operated. The current art, based on a Russian idea, is a 4-lobe design twisted to enhance turbulence. The gains in early tests show a 30% power density uprate with a 30% lower pressure drop.
A new type of outer surface for fuel rods is being considered using Silicon Carbide over the current zirconium alloy. The motivator is the higher strength, resistance to radiation damage, and other internal operating advantages.
The important words in this are “efficiency” and “uprates.” Efficiency offers improved economics and performance. Uprates can mean an existing plant might be adding generators, which from a rate paying consumers point of view is a very good thing, no new plant site, fighting about it, and waiting years for construction and bringing it on line.
Let’s just go look at Brian Wang’s post. He has complete graphics and links for further investigation. We get the importance that uprates can offer. Now if we could get the politicians to wake up to the problems and push a little on these matters something good might get done without crushing the consumer over rates.
Comments
3 Comments so far
These methods will decrease fuel consumption at existing plants, but sadly will not increase total generation, since the steam generation, turbine-generator and cooling systems will each have the same size and power capacity as before.
Warren, sorry but your missing the point. When the reactor core upgrade project is undertaken, new coolant lines, cooling towers and turbines will be added to take advantage of the increased available btu output/flow rate. This in turn causes the increased plant output. Additionally, annular fuel has a considerably higher burnup rate, so less spent fuel waste is generated overall.
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