Sunday, December 23, 2012

Rare Earth China Syndrome, Pt. 3

The Oak Ridge National Laboratory ran a Molten Salt Reactor for over 22,000 hours in the late 60's and early 70's.  It used molten thorium fluoride salts as fuel, which in its liquid state is a clear liquid. Thorium is fertile, not fissile, so the Oak Ridge reactor achieved criticality with the introduction of U-239 and later U-233 as a source of neutron radiation. A Liquid Fluoride Thorium Reactor (LFTR) operates at atmospheric pressure, maintaining a peak temperature of 1,300 degrees F.

A LFTR will not go kerpow like Fukushima Daiichi because you do not need power to cool fuel rods kept under multiples of atmospheric pressure. Barbarella's China Syndrome is not possible. With a loss of power in the Oak Ridge MSR, the liquid fuel in the hot tub melts a freeze plug. The fuel drains into a cooling tank where the nuclear reaction comes to a stop and the fuel becomes solid, containing radioactive materials. You can then put the frozen fuel back into the hot tub, starting the nuclear reaction anew.  If the reaction becomes too hot, the liquid expands and boils, taking away the geometry you need to sustain fission.  The reaction will stop if you do noting, because of spent fuel in the liquid. A LFTR is walk away safe.

A LFTR burns nearly all of the dissolved thorium rocks you put into it, rather than the best case scenario 5% of the solid fuel in a light water reactor like the mPower modular that helped win Pennsylvania for Obama.  Misshapen ceramic pellets with 95% of the fuel still remaining do not need to be trucked to Yucca Mountain with a LFTR, because the liquid fuel just keeps bubbling and burning burning until it is more than 90% consumed.  What can you do with a hot tub that maintains a 1,300 degree F temperature all by itself? Jiang Mianheng has a few ideas about that.

This year, Xu Hongjie spoke at the International Thorium Energy Organization in Shanghai. He described that his Chinese Academy of Sciences (CAS) presently employs over 300 scientists and engineers with a five year budget consisting of $500 million. 

The CAS research involves the Thorium Molten Salt Reactor (TMSR) – a high temperature, low pressure, clear liquid salt reactor, as Xu describes. Their research includes the development of reactor core design, neutron physics and thermal hydraulics. The disciplines include engineering design and the deployment of key technologies and construction techniques.

The CAS will additionally develop Molten Salt loop technology, for use in solid fuel pebble bed designs. Their work will include design and construction of molten salt loops, development of key components of molten salt loops and techniques for purification of fluoride salt such chemical separation of actinides from fuel.

The CAS has developed and tested their own formulations for Hasteloy-N, a high performance Nickel based alloy that the Oak Ridge National Laboratories very successfully employed to contain molten fluoride salts. The CAS will also develop and study the use of carbon fiber based materials for use in molten salt reactors.

It might seem puzzling why the Chinese published so much information about their work with thorium based fuel. We are used other governments acting in secret regarding nookyulur energy and only crowing about great achievements. The presentation of Xu Hongjie at the International Thorium Energy Organization meeting seemed positively mundane.

The heart of the establishment of intellectual property is a legal determination that and idea is patentable. An inventor gains the right to profit from an idea by establishing it is unique or novel. Once you have protection, you publish the idea. Once the idea is published, it is no longer unique enough to be patentable. If you have patented a good idea, people, business organizations and governments may want to use it. Then comes negotiation or litigation over whether or how much royalty the licensee must pay.

The words of Xu Hongjie is the sound of the decline of the United States.  When, and I do not believe if, the time comes to build a LFTR on American soil, we will ask Jiang Mianheng how much of a royalty we will need to pay. Because right now here in America, Thorium is bad.


ikaika said...

One problem : You mention "Salt" and Reactor, and the greenpeace nazis will refer back to the Sodium Reactor Experiment.

frithguild said...

The Santa Susana Field Laboratory Sodium Reactor Experiment reactor used seven stainless steel tubes six feet long, each filled with twelve uranium fuel slugs. Liquid salt circulated over the fuel providing cooling and the heat source for mechanical energy.

A LFTR uses thorium within the molten salt as the fuel. A meltdown does not happen because the fuel is already liquid.

With a LFTR you remove spent fuel while it is still molten salt through chemical reactions that do not effect the thorium, which is chemically very stable. With a solid fuel system, the fuel pellets crack, deform and hollow as the material decays. Spent solid fuel becomes difficult to contain, and you never burn it all. Then you need to truck it to Yucca Mountain.
A LFTR burns nearly all of the rock you put into it, because the fuel just keeps circulating.

The Santa Susana Field Laboratory Sodium Reactor Experiment is very similar to what the Chinese are doing with pebble bed reactors. Rather than slugs in tubes, a pebble bed uses spheres encased in graphite or ceramics that will contain the fuel even if the reaction chamber becomes uncontrolled.

A LFTR does not need people to control it to prevent a run away reaction. Physics is your friend.

ikaika said...

Otter: Point of parliamentary procedure!
Hoover: Don't screw around, they're serious this time!
Otter: Take it easy, I'm pre-law.
Boon: I thought you were pre-med.
Otter: What's the difference?

frithguild said...

Is that a LFTR in your briefcase or are you just happy to see me?