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Stopping Global Warming's Advance
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Stopping Global Warming's Advance
Here is how we could begin:
There is no technical reason in the world we could not start on a "Coal Yard Nuke"
demonstration facility tomorrow.
Pebble bed reactors are a fact, not wishful thinking like "Clean Coal's"
The quickest and most efficient thing for us to do next is to have a German-speaking American nuclear expert present the idea of converting existing fossil-fuel power plants to pebble bed reactors to the German engineers who designed, built, and ran the superheated steam THTR-300 (there was little or no awareness of Global Warming back then) along with touching base with any additional engineers who may have worked on only the THTR-500. The THTR-300 home web site is: http://www.thtr.de/index.htm
At the same time, have a Chinese-speaking American nuclear expert do the same with the engineers working on China's 19 HTR-PM Pebble Bed reactor complex at Rongcheng, China, another superheated steam facility. Dr. Andrew Kadak of MIT may already be up to speed on Rongcheng. Worth a telephone call.
These exploratory trips should be the first government funding for the "Coal Yard Nukes" project.
"Between 1966 and 1988, the AVR experimental pebble bed reactor at Juelich, Germany, operated for over 750 weeks at 15 MWe, [megaWatt electric] most of the time with thorium-based fuel. The fuel consisted of about 100,000 billiard ball-sized fuel elements. The thorium was mixed with high-enriched uranium (HEU). Maximum burnups of 150 GWd/t were achieved. [90 GWd/t is typical for conventional reactors] It was used to demonstrate the inherent safety of the design due to negative temperature coefficient: the helium coolant flow was cut off and the reactor power fell rapidly.
The 300 MWe THTR reactor in Germany was developed from the AVR and operated between 1983 and 1989 with 674,000 pebbles, over half containing Th/HEU fuel (the rest graphite moderator and some neutron absorbers). These were continuously recycled and on average the fuel passed six times through the core. Fuel fabrication was on an industrial scale. Several design features made the AVR unsuccessful, though the basic concept was again proven. It drove a steam turbine.
An 80 MWe HTR-modul was then designed by Siemens as a modular unit to be constructed in pairs. It was licensed in 1989, but was not constructed. This design was part of the technology bought by Eskom in 1996 and is a direct antecedent of PBMR.
During 1970s and 1980s Nukem manufactured more than 250,000 fuel elements for the AVR and more than one million for the THTR. In 2007 Nukem reported that it had recovered the expertise for this and was making it available as industry support."
Notable Pebble Bed and Prismatic HTGR Reactors over the entire world
Project
Description
X-10
3.5 MWth US Oak Ridge - 1943
Dragon
20 MWth British - 1964 to 1977
Peach Bottom-1 110 MWth US - General Atomics - 1967 to 1974
http://en.wikipedia.org/wiki/Peach_Bottom_Nuclear_Generating_Station
AVR
15 MWe Experimental pebble bed reactor operated for 21 years in Germany
THTR
300 MWe German pebble bed reactor with steam turbine operated for 5 years
http://www.thtr.de/index.htm
Fort St Vrain 330 MWe US prism HTGR operated for
14 years - General Atomics
HTR-MODUL 80 MWe German modular
pebble bed reactor design by Siemens, 1989
HTR-100
100 MWe German modular pebble bed reactor design by HRB/BBC
HTTR
30 MWth Japanese prism HTGR reached criticality in 1998 - Lab unit for hydrogen
production
HTR-10
10 MWth Chinese pebble HTGR reached criticality in 2000 - Lab unit for teaching,
steam generator design projects
HTR-10
HTR-PM
100 MWe Chinese pebble HTGR steam turbine power reactor design for 19-reactor Rongcheng
complex
PBMR
110 MWe South African direct cycle turbine pebble bed design -
Demonstration facility under construction
PBMR
GT-MHR
300 MWe US direct cycle turbine prism HTGR design -
General Atomics joint project with Russia - Electricity from warhead material
GT-MHR
ANTARES GT-MHR 600 MWth French - Russian - Japanese. Prismatic
indirect cycle. H2 + both Brayton and Rankine electric. AREVA, Russian
Institute, FUJI
I know the Russians have built several but I have no project names or specifications.
If you happen to know, please let me know.
A near-precedent for the reactor I'm proposing actually ran in the late 1980s as the German THTR-300 Thorium Reactor (Right). While it was a pebble bed reactor and produced exactly the superheated steam needed for converting large fossil fuel plants like Tampa's Big Bend to nuclear, it ran largely on thorium rather than uranium and had a dry cooling tower . It provided electricity to the German electrical grid for almost 2 years, most of that time at full power. Under political attack by the Greens, and being something of a prototype and not without its problems, it was shut down, decommissioned, and its planned follow-on, the THTR-500 was never built. http://en.wikipedia.org/wiki/THTR
We have a wonderful pebble bed reactor line-up already. Coal burning power plant units vary in size from less than 50 mWe to over 600 mWe. The "Coal Yard Nuke" system is a 'one-size-can-fit-all' approach using a NRC standardized Westinghouse-ESKOM PBMR 180 mWe pebble bed reactor. I believe no one knows more about how to make a commercially successful circulating pebble reactor than PBMR.
I know almost nothing about the newer design and perhaps more appropriate Chinese HTR-PM. In a 2004 paper, calculations indicated 190 megaWatts electrical of 1,000°F, 2,000 psi superheated steam with feedwater temperature of 400°F. External coolant flow layout resembles the GT-MHR reactor rather than the PBMR.
Other possibilies would be the 325 mWe General Atomics GT-MHR "Prismatic" reactor, and the never-built German THTR-500 mWe reactor. The Russians are in on the GT-MHR and are rumored to have at least one pebble bed in the works in another company. These reactors all combine to provide an initial spectrum of reactor sizes that would convert over 90% of all existing fossil fuel power plant units. The never-built German THTR-500 reactor is closest in size to what I think an ideal big 'Coal Yard Nuke' would be like.
Just grabbing any of these products and running with it would give us a very quick start. The advantage of using a large reactor is that the 5,000 worst CO2 producing power plants identified by the IPCC are the largest power plants in the world. Most remediation for the fewest number of conversions would result from using a THTR-500 size reactor. As it happens, a THTR-500 would be exactly the size needed for a 1 for 1 coal-to-nuclear change-out without loss of electricity at TECO's Big Bend plant.
Closer to our needs in size and temperature but not yet available is a pebble bed that's been under development by MIT's Andrew Kadak. It is a pebble bed that falls between the PBMR and the GT-MHR in size. There is also a Generation-IV Very High Temperature Reactor being developed at the Idaho National Laboratories but it won't be a prototype for several more years.
Demonstration facility: Both the existing Westinghouse-ESKOM PBMR and the General Atomics GT-MHR are already in the Nuclear Regulatory Commission's New Reactor Certifications process, have the sponsorship of United States companies, and have ample capacity for powering at least one of the J. R. Whiting's generators as an initial demonstration facility project.
http://www.iaea.org/inisnkm/nkm/aws/htgr/abstracts/abst_iwggcr15.html IWGGCR-15: Technology of steam generators for gas-cooled reactors.
The pebbles themselves are in very short supply at the moment. PBMR is licensing the German technology which, as I understand it, is a thorium pebble with a dash of uranium. This pebble has the best reputation. I don't know anything about the pebble the Chinese are using in their HTR-10 teaching reactor or their 19 Rongcheng reactors or even if the license PBMR has is exclusive. If the Germans also had a U.S. patent, its 17-year U.S. patent interval would have run out by now, diminishing the value of any multi-national patents on the pebble.
The Chinese pebble bed reactors being designed for China's 19-pebble bed reactor complex at Rongcheng, designated the HTR-PM, are steam producing designs that might ultimately prove to be very technically strong candidates for fossil fuel plant conversion use but, unfortunately, like the German THTR-500, do not currently have a sponsor at the United States Nuclear Regulatory Commission's Reactor Evaluation and Approval Committee - which charges about $250 per bureaucrat hour - adding up to many millions total for a new reactor - according to someone close to the process.
Smaller Pebble Bed High Temperature, Gas-Cooled Reactors:
A typical coal-burning electricity generating power plant produces between 100 and 400 megaWatts electrical - mWe. Holland's NEREUS and Rod Adam's Atomic Engine fall into the power category of a shipboard diesel engine, about 10 to 30 megaWatts electric, hot enough, but too small by a factor of 10 to power an existing 100+ megaWatt municipal power plant.
Nuclear "batteries"
The 10 to 50 mWe Toshiba's 4S is going to be used in 10 mWe form to power Galena, Alaska. Located on the Yukon River in a remote part of Alaska it will be buried in a silo and it's steam used to heat several main village buildings after passing through the electricity generating turbine.
The 27 mWe, 1,000°F, $25 million uranium hydride Hyperion "Triga" reactor is a bit too cool and quite a bit too small to be considered as possible replacements for coal's fire in a typical power plant. Several dozen Triga reactors are now operating around the world.
On August 12, 2008, Hyperion Power Generation issued a press release announcing the receipt of a letter of intent (LOI) from TES Group, an investment company that is developing energy projects in Central Eastern Europe. LES intends an initial purchase of 6 Hyperion Power Modules (HPM) at a cost of approximately $25 million per unit. That order might expand to as many as 50 units.
The 45 mWe/150 mWt Nu-Scale (a nascent start-up at this writing) reactor vision appears to be a smaller, more compact version of a conventional reactor. Again, the steam temperatures would be far too low for it to replace a coal burning boiler in an existing power plant.
Liquid Fluoride Thorium Reactors (LFTRs), can run as hot as 1,300°F but, incredibly, no one is interested in them. There is as much thorium as mankind would ever possibly want for the easy taking and it's just dumped into the reactor like ingredients into a soup. http://en.wikipedia.org/wiki/Molten_salt_reactor
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