Nuclear energy

Researchers at Purdue University have new evidence supporting earlier findings by other scientists who designed an inexpensive "tabletop" device that uses sound waves to produce nuclear fusion reactions.

The technology, in theory, could lead to a new source of clean energy and a host of portable detectors and other applications.

The new findings were detailed in a peer-reviewed paper appearing in the May issue of the journal Nuclear Engineering and Design. The paper was written by Yiban Xu, a post-doctoral research associate in the School of Nuclear Engineering, and Adam Butt, a graduate research assistant in both nuclear engineering and the School of Aeronautics and Astronautics.

Claims of cold fusion are intriguing, but not convincing. That is the conclusion of an 18-member scientific panel tasked with reviewing research in the area.

The findings, which were released on 1 December by the US Department of Energy, rekindle a 15-year-old debate over whether nuclear fusion can occur at room temperature.

According to the report, the panel was "split approximately evenly" on the question of whether cold experiments were actually producing power in the form of heat. But members agreed that there is not enough evidence to prove that cold fusion has occurred, and they complained that much of the published work was poorly documented.

Later this month, the U.S. Department of Energy will receive a report from a panel of experts on the prospects for cold fusion—the supposed generation of thermonuclear energy using tabletop apparatus. It's an extraordinary reversal of fortune: more than a few heads turned earlier this year when James Decker, the deputy director of the DOE's Office of Science, announced that he was initiating the review of cold fusion science. Back in November 1989, it had been the department's own investigation that determined the evidence behind cold fusion was unconvincing. Clearly, something important has changed to grab the department's attention now.

Amidst a prolonged stalemate over where to build the world's largest nuclear fusion facility, the US is halting work on a homegrown fusion project. The decision caused concern among researchers at a fusion meeting earlier this week.

The US is pinning its hopes on ITER (International Thermonuclear Experimental Reactor), which aims to lay the groundwork for using nuclear fusion as an inexhaustible and clean energy source.

But the project has been stalled since December 2003 because its six members - the US, the European Union, China, Japan, South Korea, and Russia – cannot agree on where to build the facility. The EU, China, and Russia favour the French city of Cadarache, while the US, South Korea, and Japan back the Japanese town of Rokkashomura.

The deadlock has persisted even after both the EU and Japan sweetened their offers in June, each agreeing to pay half of ITER's estimated $5 billion construction costs to host the reactor. And rumours have spread that some parties might splinter off to build the reactor on their own.

Now, the standoff has lasted so long that the US has reached a deadline on another fusion project. The deadline was set in 2002 by a committee advising the US Department of Energy (DOE) to proceed with a smaller project called FIRE (Fusion Ignition Research Experiment) if ITER negotiations had stalled by July 2004.

What: A 10,000-year storage facility for radioactive nuclear waste
Where: yucca mountain, nevada
Cost: $58 billion
Crux: Approximately 60 miles of access and emplacement tunnels to house stainless-steel waste casks. A robotic transport system of gantries, cranes and railcars.

Whether outraged or supportive about DOE's planned reevaluation of cold fusion, most scientists remain deeply skeptical that it's real.

The cold fusion claims made in 1989 by B. Stanley Pons and Martin Fleischmann didn't hold up. But they did spawn a small and devoted coterie of researchers who continue to investigate the alleged effect. Cold fusion die-hards say their data from the intervening 15 years merit a reevaluation-- and a place at the table with mainstream science. Now they have the ear of the US Department of Energy.

Physical Review E has announced the publication of an article by a team of researchers from Rensselaer Polytechnic Institute (RPI), Purdue University, Oak Ridge National Laboratory (ORNL), and the Russian Academy of Science (RAS) stating that they have replicated and extended previous experimental results that indicated the occurrence of nuclear fusion using a novel approach for plasma confinement.

This approach, called bubble fusion, and the new experimental results are being published in an extensively peer-reviewed article titled “Additional Evidence of Nuclear Emissions During Acoustic Cavitation,” which is scheduled to be posted on Physical Review E’s Web site and published in its journal this month.