Making Nuclear Power Safer And More Efficient
Researchers at MIT have unveiled a new fuel fabrication process for uranium fuel in Pressurized Water Reactors (PWR). The new process will make the fuel about 50% more efficient while actually greatly reducing the operating temperature of the fuel. This is actually very, very slick.
Researchers say their new technology should be ready for commercial use in existing reactors in about 10 years.
In a nuclear reactor, the fission of uranium atoms provides heat used to produce steam for generating electricity.
Already, one pickup truck full of uranium fuel in a nuclear reactor can supply a city with enough electricity for a year. The MIT scientists believe they have found a way to make the fuel go even further, boosting output by about 50 percent.
Uranium fuel typically is formed into cylindrical ceramic pellets about half-inch in diameter. The pellets look like a smooth, black version of food pellets for small animals.
Pavel Hejzlar and Mujid Kazimi of MIT recently completed a three-year project for the U.S. Department of Energy, along with scientists from Westinghouse and other companies. The researchers looked at how to make fuel for pressurized water reactors more efficient while maintaining safety margins.
About two-thirds of the 103 reactors operating in the United States are pressurized, using high pressure to prevent the water from boiling.
The scientists changed the shape of the fuel from solid cylinders to hollow tubes, adding surface area that allowed water to flow inside and outside the pellets, increasing heat transfer.
The new fuel design also is much safer because it reaches an operating temperature of about 700 degrees Celsius, much lower than 1,800 degrees for conventional fuel and further from the 2,840 degrees melting point for uranium fuel.
Amazing. Something that simple and elegant will provide better efficiency and make it safer at the same time. These guys are good.
By American Crusader, Friday, 29 September , 2006 @ 12:50 pm
I hope the American public is ready to accept new nuclear power plants. We need to do everything possible to gain energy independence. What I didn’t see mentioned was anything about the spent fuel rods or other forms of nuclear waste.
Until the public is satisfied about the safety of storing nuclear waste, I think it will be hard to gain acceptance of new plants. Not many people are happy with Yucca Mountain..particularly the people of Nevada.
By Gaius, Friday, 29 September , 2006 @ 1:08 pm
The safest thing to do is to reprocess, then glassify the remaining high level waste.
By ajacksonian, Saturday, 30 September , 2006 @ 7:07 am
And then there is the pebblebed design that operates under *lower* than air pressure to allow neutrons to move between the pebbles. Each pebble is low radioactivity, easily reprocessed and generally spent by the time it reaches the bottom of the pile for removal. A few get added in at the top every day and a few get removed from the bottom. Reprocess to get any remaining radionuclei and add into the next gen of pebbles, the rest is high pressure glass or ceramic that is *also* re-used with fresh material. Environmentally low impact, low level waste comes pre-vitrified and even *that* gets re-used. Radioactive glass and ceramics are easily dealt with and any that get intensely radioactive get considered as such for the fresh mix. Call it continual recycling with fresh material expanding the resource pool. The spent pebbles are not hot enough to melt no matter *how* you pile them together and the only way to make them react *faster* is to put them in a vacuum. Safe, clean, efficient, easy to manage… the US looks to be skipping at least one if not two generations of improved reactor design… and we will *all* benefit from that.
By Gaius, Saturday, 30 September , 2006 @ 7:10 am
Yeah - I did a post on that as well. Lots of links to information on the reactor.