The TerraPower "wave reactor" concept is backed by Microsoft's Bill Gates, is endorsed by Republican presidential hopeful Jon Huntsman Jr. and has gotten a receptive ear from President Obama's Energy Department.

But it's headed overseas for its next crucial step, if ongoing negotiations with a foreign sponsor are successfully completed, says Roger Reynolds, TerraPower's technical adviser.

The Bellevue, Wash., startup says it has verified the theory behind its slow-burning reactor through supercomputer simulations and now needs to build a pilot version of the reactor, to evaluate how the metal fuel casings in the core will withstand decades of radioactive bombardment.

The reactor is designed to run for 40 years or more without refueling as it steadily consumes most of its original fuel supply. Thus it remains intact, disarming concerns about long-term spent fuel storage or the theft of nuclear material during refueling or fuel reprocessing, the company said.

Reynolds said the plant won't be built in the United States.

"We've had conversations with the Chinese, the Russians, the Indians, the French," Reynolds said in an interview. "We have an aggressive schedule where we think it is important to get something built and accumulate data so that we can eventually build them in the U.S. Breaking ground in 2015, with a startup in 2020, is more aggressive than our current [U.S.] regulatory structure can support."

In addition to its unique fuel cycle, the TerraPower design employs a high-temperature, liquid metal core cooling technology suited to a breeder reactor with "fast" neutron activity, rather than today's predominant reactors whose water cooling systems slow neutrons. TerraPower wants to partner with countries that are actively pursuing fast, breeder reactor technology. "That isn't here right now," he said, referring to the United States.

'Breed and burn' process
TerraPower's design and other once-through reactor designs use a "breed" and "burn" process. The company's CEO, John Gilleland, originally likened his reactor to a smoldering cigarette or cigar, with a slow-moving fission phase moving wave-like through the fuel core, generating neutrons to maintain a gradually advancing chain reaction while it consumes most of the fuel.

TerraPower's scheme has changed as the research program has evolved. In the new version, the wave does not move, but remains stationary, and the fuel material is shuffled in and out of the breed and burn zones within the reactor, TerraPower officials say. Under this new approach, the reactor can still be sealed and run without being reopened for 40 to 60 years, Reynolds says.

Reynolds, who was chief technology officer in the United States for France's nuclear developer Areva, said the greatest engineering challenge is durability of the metal alloy used to encase the fuel. The pilot plant will enable TerraPower to assess the impact of radiation damage on the specialized stainless steel alloy, to document its survival capabilities.

"We believe the material will tolerate [the high radiation impacts], but there is no data to prove it," Reynolds said. "So one of the missions of the engineering demo is to accumulate that demo.

"And that is THE challenge. Everything else we know how to do." Reynolds added that TerraPower didn't start out with the goal of proving that fast breeder reactors could outgrow their troubled past.

"We're not building a fast reactor just to build it," Reynolds said. He said the approach was a response to the larger goals set down by Gates and Microsoft's former chief technology officer, Nathan Myhrvold, whose organization Intellectual Ventures developed the TerraPower concept.

Concept grew out of battle against poverty
"They were asking, what are some of the world's largest problems" that could be addressed by new technologies. "The problem they settled on was poverty," Reynolds said.

"You can't really deal with poverty unless you have a sufficient amount of energy," Reynolds said. "You can't grow your family; you can't build schools or hospitals; you can't mitigate all the problems that are associated with poverty without energy. So how do you generate a lot of energy without contributing to global warming?" was the question, he said. "They looked at all the alternatives and settled on nuclear power."

Reynolds said TerraPower hopes to secure a government partner for the pilot plant this year or next.

While he was still U.S. ambassador to China, Huntsman referred to TerraPower's approach to China with a sense of frustration. "Right now, the regulatory environment here in the U.S. means that it would take decades just to certify the design," he said at a U.S.-China energy summit last year. "By partnering with the Chinese, they can move ahead and commercialize the technology around the world when it is proven," Huntsman said.

Responding to increasing interest from members of Congress, the Nuclear Regulatory Commission has laid out a licensing path for small modular nuclear reactors of the size that TerraPower has proposed. The NRC has begun discussions with Babcock & Wilcox Co. about its proposed mPower modular reactor design that is currently under consideration by the Tennessee Valley Authority for construction at TVA's Clinch River site in Tennessee.

NRC officials expect that the mPower design will be the first to seek licensing approval, and that the commission could complete a review of an mPower project at Clinch River by 2020. Unlike the TerraPower concept, the mPower reactor relies on an advanced light water reactor cooling technology that NRC staff have deeply examined for decades.

Peter Lyons, who heads the Energy Department's nuclear energy program, told a House Appropriations subcommittee in March that DOE is seeking funding for two modular reactor programs in fiscal 2012: $67 million for a licensing demonstration project and $30 million for a review of advanced modular reactor concepts.

Heading for a home in China?
TerraPower could qualify for support under the latter program. "I'm trying to distinguish between reactors that we think can be deployed quite soon of the small modular reactor type ... as opposed to the more advanced, and the ideas proposed by Mr. Gates certainly are in the more advanced. Extremely interesting, but definitely the more advanced and longer-term," Lyons said.

Reynolds said TerraPower can't wait at the back of that line. "We've got to get something built so we can understand how these work and what is necessary to optimize them in terms of costs," he said. TerraPower has not issued an estimate of the cost of its reactor, but says its goal is to produce electricity at the same cost as the Westinghouse AP1000 reactor, or lower. That's the reactor chosen for the proposed expansion of the Vogtle nuclear plant in Georgia and for other U.S. reactor projects on utilities' long-range plans.

The demonstration reactor TerraPower hopes to build is outside DOE's budget. Reynolds said the cost is "less than $7 billion and more than $1 billion."

It would take a government entity -- perhaps in China -- to do a project of that scope. Such support inevitably comes with strings attached, typically a sharing of critical technology, U.S. technology experts note. Reynolds said TerraPower isn't anticipating losing exclusive control of its process. "I believe there is a desire there [in China] to use fast reactor technology to extend their energy base and enhance their energy security position. But that doesn't preclude the U.S. from doing the same thing," he said.

"We intend to build these in the U.S., but not the first one," he said. The best way to win regulatory approval in this country, he said, is to build a reactor. "They you get the data that says, 'This is what you can do, and here is the proof that it works.'"

Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC., 202-628-6500