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Posted on Sustainabilitank.info on August 17th, 2014
by Pincas Jawetz (pj@sustainabilitank.info)

 

 Transatomic is a MIT spinoff and could save us with Molten Salt Nuclear Reactors that can use wastes from Water Cooled Reactors for useful purpose.

Transatomic Power’s advanced molten salt reactor consumes spent nuclear fuel cleanly and completely, unlocking vast amounts of cheap, carbon-free energy. It solves four of the most pressing problems facing the nuclear industry: ecological stewardship, public safety, non-proliferation, and cost-efficiency. Only an advanced reactor that meets all four goals at once can truly change the nuclear fission game and allow for broad adoption of nuclear power.

A technical white paper gives a more detailed description of the reactor design.

This reactor can be powered by nuclear waste because it uses radically different technology from conventional plants. Instead of using solid fuel pins, they dissolve the nuclear waste into a molten salt. Suspending the fuel in a liquid (the mo;ten salt) allows  it to be kept in the reactor longer, and therefore capture more of its energy. Conventional nuclear reactors can utilize only about 3% – 5% of the potential fission energy in a given amount of uranium before it has to be removed from the reactor. This design captures 96% of this remaining energy.

Why it’s different

Molten salt reactors are not a new technology – they were originally developed and tested at the Oak Ridge National Laboratory in the 1950s, 1960s, and 1970s. In many respects, Transatomic’s reactor is similar to these early designs. It uses similar safety mechanisms (such as freeze valves), chemical processing techniques (such as off-gas sparging), and corrosion tolerant alloys (such as modified Hastelloy-N). These similarities to previous designs allowed Transatomic to build on an established body of research and reduce the uncertainty associated with the design.

The main differences between Transatomic Power’s molten salt reactor and previous molten salt reactors are the metal hydride moderator and LiF-(Heavy metal)F4 fuel salt. These features allow  to make the reactor more compact and generate electricity at lower cost than other designs. Furthermore, previous molten salt reactors, such as the Oak Ridge Molten Salt Reactor Experiment, used uranium enriched to 33% U-235.

The newly proposed reactor can operate using fresh fuel enriched to just a minimum of 1.8% U-235, or light water reactor waste.

The above comes with  MIT  research and was brought to our attention in today’s CNN/GPS program by Fareed Zakaria (August 17, 2014) who had as guest recently graduated PHD student Dr.Dewan.

In effect – Transatomic, is a Massachusetts Institute of Technology (MIT) spinoff intent to commercialize a safer fission nuclear reactor designed to overcome major barriers to nuclear power.  For the anti-nuclear folks the design offers to burn up the existing spent fuel from the world’s fleet of nuclear reactors in a design that doesn’t offer a chance for a meltdown.  That should be nirvana for those alarmed about atomic energy and weapons proliferation.
Dr. Leslie Dewan and coleague Mr. Mark Massie seem to be the young folks who started this MIT offshoot.
Dr. Dewan was Fareed Zakaria’s guest on his program – August 17, 2014.

The US has 100 operating nuclear reactors and additional five in construction.
China has now 21 nuclear reactors and an additional 86 in construction.
Above means that the dangers of nuclear material contaminated water is immense, not just the danger of melt downs –  and that is why opponents to water cooled fission reactors are up in arms.
Imagine the potential for hope if a method is found to decontaminate that water and even find a positive use for the wastes?

We found an old article by Brian Westenhaus of  March 17, 2013 from which we picked:

Transatomic, founded by a pair of very smart and innovative young nuclear engineers, has updated the molten-salt reactor, a reactor type that’s highly resistant to meltdowns. Molten-salt reactors were demonstrated in the 1960s at Oak Ridge National Lab, where one test reactor ran for six years.  What remains is raising $5 million to run five experiments to help validate the new basic design.

Russ Wilcox, Transatomic’s new CEO estimates that it will take eight years to build a prototype reactor at a cost of $200 million.  The company has already raised $1 million in seed funding, including some from Ray Rothrock, a partner at the venture capital firm Venrock.

The cofounders, Mark Massie and Leslie Dewan, who we met here in April last year, are still PhD candidates at MIT. Yet the design has attracted some top advisors, including Regis Matzie, the former CTO of the major nuclear power plant supplier Westinghouse Electric, and Richard Lester, the head of the nuclear engineering department at MIT.

Ms Dewan Mr. Massie and Mr. Lester of Transatomic Power
Ms Dewan Mr. Massie and Mr. Lester of Transatomic Power.

The new reactor design called the Waste-Annihilating Molten Salt Reactor (WAMSR) so far exists only on paper.
Ray Rothrock says the company will face many challenges. “The technology doesn’t bother me in the least,” he said. “I have confidence in the people. I wish someone would build this thing, because I think it would work. It’s all the other factors that make it daunting.”  We’ll get to those daunting factors in a moment.

Related article: France Predict Cost of Nuclear Disaster to be Over Three Times their GDP

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Background – today’s conventional nuclear power plant is cooled by water, which boils at 100º C a temperature far below the 2,000° C at the core of a fuel pellet. Even after the reactor is shut down, it must be continuously cooled by pumping in water until the whole internal core apparatus is below 100º C.  The inability to do that properly is what has caused the problems at troubled plants.  Oddly, the nuclear industry and regulatory agencies haven’t come to realize the notion of mixing water and nuclear fuel is the dangerous matter.

The big problems can be solved by using molten salt, instead of water as the coolant, which is mixed in with the fuel. Molten salt has a boiling point higher than the operating temperature of the fuel. That way the reactor has a built-in thermostat – if it starts to heat up, the salt expands, spreading out the fuel and slowing the reactions cooling the thing off.

In the event of a power outage where cooling circulation would stop carrying away the heat, a plug at the bottom of the reactor melts and the fuel and salt mixture flows by gravity into a holding tank, where the fuel spreads out enough for the reactions to stop. The salt then cools and solidifies, encapsulating the radioactive materials.

Ms Dewan now the company’s chief science officer says, “It’s walk-away safe, if you lose electricity, even if there are no operators on site to pull levers, it will coast to a stop.”

She needs only $5 million to prove it, she said.

Technology – Transatomic’s design improves on the original molten-salt reactor by changing the internal geometry and using different materials. Transatomic is keeping many of the proprietary design details to itself, but one change involves eliminating the graphite that made up 90% of the volume of the Oak Ridge reactor. The company has also modified conditions in the reactor to produce faster neutrons, which makes it possible to burn most of the material that is ordinarily discarded as waste.

WAMSR Reactor Schematic Graphic Diagram.
WAMSR Reactor Schematic Graphic Diagram.

 

The design offers a couple other real strong incentives.  Because it runs at atmospheric pressure rather than the high pressures required in conventional reactors the amount of steel and concrete needed to guard against accidents is greatly reduced.  The technical approach will work for uranium or for the future thorium fuels as well.

Related article: Will Japan Embrace Geothermal Power to Move Away from Nuclear?

Here is the comparison that should light up the hearts of the antinuclear crowd.  A conventional 1,000-megawatt reactor produces about 20 metric tons (44,000 lbs.) of high-level waste a year, and that material needs to be safely stored for 100,000 years. The 500-megawatt Transatomic reactor will produce only four kilograms (8.8 lbs.) of such waste a year, along with 250 kilograms (550 lbs.) of waste that has to be stored for a few hundred years.

In the presentation the duo projects some warming numbers for both the low cost power and the anti nuclear folks.  Conventional nuclear reactors can utilize only about 3% of the potential fission energy in a given amount of uranium before it has to be removed from the reactor. The Transatomic design captures 98% of this remaining energy.  A fully deployed Transatomic reactor fleet could use existing stockpiles of nuclear waste to satisfy the world’s electricity needs for 70 years, now through 2083 when about 99.2% of today’s dangerous spent fuel – would be burned away.

Even though the basic idea of a molten-salt reactor has been demonstrated the Nuclear Regulatory Commission’s (NRC) certification process is set up around light-water reactors.  NRC spokesman Scott Burnell said for the next few years, the NRC will be focused on certifying the more conventional designs for SMNRs.  But he also said that the commission is aware of Transatomic’s concept but that designs haven’t been submitted for review yet.  The certification process for Transatomic will take at least five years once the company submits a detailed design, with additional review needed specifically for issues related to fuel and waste management.

The detailed design is years and $4 million more dollars away.  Wilcox estimated that it will take eight years to build a prototype reactor – at a cost of $200 million.  Low cost power customers and the antinuclear folks might want to coordinate getting the Congress to rewrite the NRC’s procedures to speed things up.

After all, China is reported to be investing $350 million over five years to develop molten-salt reactors of its own. It plans to build a two-megawatt test reactor by 2020.

It’d be a pity to miss out on a trillion dollar industrial market and trillions more in electricity savings.  Plus get rid of all that weapons ready, costly to store used fuel.

A hat tip goes to Brian Wand for spotting the latest update to Tranatomic’s progress.

By. Brian Westenhaus  —   Original source: The Nuke The Anti Nuke Crowd Should Love

 

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