That was the case when Rothrock was still a working nuclear engineer back when Three Mile Island occurred. At the Cleantech Forum in San Francisco on Wednesday, Rothrock said that in the wake of Three Mile Island, the U.S. Nuclear Regulatory Commission (NRC) immediately began a review process of U.S. nuclear plants that took half a year to get through. For a startup like NuScale, which is making a modular nuclear reactor design and is planning on submitting its application to the NRC for review within 18 months, a very busy and cautious NRC could mean a significantly longer time to pass regulatory hurdles and get to market.

Venrock has backed stealthy nuclear company Tri-Alpha Energy, which has been working on technology out of the University of California at Irvine that involves a mixture of hydrogen and boron that “chase” one another in a plasma electric generator, according to a U.C. Irvine report.

CMEA Principal Rachel Sheinbein, who also spoke on the panel at the event, said, “Three Mile Island set us back 30 years, and we lost the opportunity to be a world leader in nuclear.” CMEA has invested in NuScale.

It is generally believed that the ongoing situation at the nuclear plants run by Tokyo Electric Power Co. looks to have surpassed the severity of Three Mile Island. Department of Energy Secretary Steven Chu made that assessment in a hearing before the House Energy and Commerce committee this morning.

However, beyond the immediate knee-jerk reaction that could come from the NRC in the U.S., Rothrock thinks next-generation nuclear technology development will ultimately be able to learn from any design issues with the GE mark-1 reactors that were used in Japan and are undergoing a partial meltdown right now. Ultimately, when problems happen with reactors, it’s all the more reason why new nuclear technology needs to be developed, said Rothrock.

Both Rothrock and Sheinbein pointed out the aging design and technology that was being used in the GE mark-1 reactors in Japan. They worked as designed, said Rothrock, but the design was just an older system.

The CTO of NuScale, Jose Reyes, who was the third speaker on the panel, pointed out some of the innovations that his company has developed that he thinks could make nuclear technology safer and more economical. NuScale has built a modular system that has a passive safety design that is built underground, suspended in water and uses a much smaller amount of fuel per module. A NuScale module has 5 percent of the fuel that a large nuclear plant has, said Reyes.

The NuScale design does not require an external power source or an external supply of water, delivered by pumps or generators, said Reyes. Instead the fuel is suspended in a 30-day supply of water, and because it’s housed in water, it has a better ability to withstand earthquakes. Reyes said one second after a NuScale reactor is shut down, it’s producing only 10 MW of thermal energy. One hour after shutting down, a NuScale reactor is producing 2.5 MW of thermal energy.

The modular simplified design will be lower cost, too, says Reyes. That’s partly because the reactor can be built and assembled offsite, then brought to the site to be completed, reducing the time to produce electricity from 6 years to 3 years. The smaller reactors are also a lot less daunting for utilities to put up the initial capital, compared to a $10 billion large nuclear reactor.

Of course, NuScale isn’t a commercialized technology yet, and now could face even more time to commercialization now that nuclear safety is front and center.

Related research and analysis from GigaOM Pro:
Subscriber content. Sign up for a free trial.

• Ups and downs for cleantech in Q1
• After Solyndra: analyzing the solar industry
• Financing the next generation of great cleantech ideas

Helion Energy

That engine, which the company currently has a prototype of at one-third scale, works by forming hot, ionized hydrogen gas. The gas is then electromagnetically accelerated to greater than 1 million mph and collided in a burn chamber to generate enormous amounts of heat energy.

The company’s plan is to sell its technology to new and existing power generation sites. Helion’s engines, once commercially ready, could be used to produce heat in power plants that currently rely on burning coal or natural gas, Wallace said. The heat runs steam turbines that drive generators to produce electricity. “We are very confident that we can out perform all carbon-based energy sources. If we can implement the technology, the economics follow,” he said.

But any venture capitalist that invests with Helion better have patience. Wallace said the full-scale prototype should be ready by 2011 or 2012 and a commercial engine available within a “decade.” Meanwhile, other companies are pushing to develop technology based on nuclear fusion. They include Burnaby, British Columbia-based General Fusion and the super-stealthy Tri-Alpha Energy, which reportedly raised $40 million in venture funding in 2007. Still, Helion’s Wallace believes his company can commercialize more quickly and cheaply than its competitors.

Nuclear fusion is often confused with its more politicized cousin, nuclear fission, but the two are distinct. In fusion, two light atomic nuclei are fused together to form a heavier nucleus and in the process release a large amount of heat energy. Unlike with fission, which produces radioactive waste, the by-product of fusion is environmentally safe. Wallace said that’s one reason why generating electricity from fusion will be cheaper than current nuclear power, which is based on fission—companies using it wouldn’t have the safety and regulatory hurdles to overcome.

As exciting as Helion’s technology is, it’s going to take a lot of money before its fusion engines start replacing coal. The company predicts it will need $100 million on top of the $20 million it currently seeks to go from full-scale prototype to commercial production.

Related research and analysis from GigaOM Pro:
Subscriber content. Sign up for a free trial.

• Flash analysis: the Fisker debacle and its implications on investing, innovation, and government incentives
• Building energy management systems: overview and forecast
• Cleantech first-quarter 2013 analysis and outlook