Power from Thorium Conference coming soon. FYI

[Helius]

Remember, the original molten salt reactor was designed with the intention of powering an aircraft. They can be COMPACT!!!

Shipboard reactors (50 to 150 MWth) are not very large. It is all the other stuff that takes up the space.

True they are not extremely large, but larger than an MSR. And all the otherstuff in an MSR can also be compact by comparison to a PWR.
The other thing I didn't mention last time is they tend to be very LIGHT in comparison too. No massive pressure containment vessle.

MSRs also seem to harken back to the Physics rather than dally in technological issues. I like the concept whereby we can build a "black box" whereby Fertile material goes in, and extremely high quality Process heat and fission product comes out. In a Sub reactor, ultimately more fuel comes out than fission product. It's still a "once through" fuel cycle.

Now given the great physical potentialities of MSRs, how close, technologically can we get?

There seems to be a lot of political force that trends toward intransigence. The perspective: "Gotta protect the cash flows generated by existing systems" seems to be a strengthening American philosophy as existing energy Industries are now long maturing. This intransigence will have strong effect on any new energy technologies that threaten existing and mature energy production technologies.

[MSimon]

Shipboard reactors (50 to 150 MWth) are not very large. It is all the other stuff that takes up the space.

True they are not extremely large, but larger than an MSR. And all the otherstuff in an MSR can also be compact by comparison to a PWR.
The other thing I didn't mention last time is they tend to be very LIGHT in comparison too. No massive pressure containment vessle.

MSRs also seem to harken back to the Physics rather than dally in technological issues. I like the concept whereby we can build a "black box" whereby Fertile material goes in, and extremely high quality Process heat and fission product comes out. In a Sub reactor, ultimately more fuel comes out than fission product. It's still a "once through" fuel cycle.

Now given the great physical potentialities of MSRs, how close, technologically can we get?

There seems to be a lot of political force that trends toward intransigence. The perspective: "Gotta protect the cash flows generated by existing systems" seems to be a strengthening American philosophy as existing energy Industries are now long maturing. This intransigence will have strong effect on any new energy technologies that threaten existing and mature energy production technologies.

How close can we get? The promise is much greater that the delivery. Fuel recycling is not easy. A high netron environment enhances the corrosiveness of the fluorine salts.

Start up is going to be tough. Sodium in the secondary heat exchanger is going to be tough. The tertiary water system adds complication. Preventing leaks in between the tertiary and secondary heat exchanger is not easy. It is hard enough in a PWR where water is the primary and secondary system.

No one has built one of these suckers.

And the ins always try to sabotage the outs.

The coal boys work: radiation danger and what do you do when it snows or the wind doesn't blow?
The nuke boys: AGW danger and it kills birds and what do you do after dark and did you know coal spews radiation
The solar wind guys: it aint renewable and it makes CO2 or radiation

Here is what Edison tried on Tesla/Westinghouse

http://powerandcontrol.blogspot.com/2007/12/roots.html

[kurt9]

According to the Wiki, the world known reserves of Boron is 10 million tons and of Thorium is 2.2 million tons. Each molecule of B11 in the fusion reaction produces 8.7 MeV of energy whereas each molecule of Thorium, converted to U233 produces 181 MeV. However, the energy from the Thorium reaction cannot be directly converted to electricity without a turbine, so assuming maximum Carnot efficiency of 40%, you still get around 80 MeV or so of electricity per reaction. Also, the waste heat from Thorium fission plants can be used to produce synthetic hydro carbon fuel for transportation, once the natural oil runs out or all of the remaining reserves are controlled by psychos we don't want to deal with. At least for energy on Earth's known reserves, Thorium fission is actually the better deal than B11-H fusion. Of course successful B11-H fusion offers other benefits that the Thorium fission does not.

Its a different deal for space-based (O'neill) civilization. Boron is a lot more common in the outer solar system than any of the heavy elements like Thorium. Mars and Mercury can be mined for Thorium. In terms of resource availability, D-D fusion represents the long-term solution. It would be nice to figure out how to do something useful with all of those neutrons other than to fission U238. Perhaps they can be used for industrial-scale transmutation.

[KitemanSA]

Start up is going to be tough.

Yup. The operators will have to learn the increadibly difficult art of melting salt.

Sodium in the secondary heat exchanger is going to be tough.

Sodium? Do you mean Sodium Chloride?

The tertiary water system adds complication.

Water? Do you mean Helium?

Preventing leaks in between the tertiary and secondary heat exchanger is not easy.

Yup. All that molten NaCl is just about impossible to keep out of the helium. No, wait, one is a gas. I guess you mean Helium into the NaCl. Unh, still not sure how that is a major issue.

No one has built one of these suckers.

Two built and run without significant issue.

And the ins always try to sabotage the outs.

May be the biggest hurdle of all.

Ya know, with all the weird statements you made, I am suspicious we may be talking about totally different systems. This is the one I am talking about.
http://en.wikipedia.org/wiki/Molten_salt_reactor

[MSimon]

Yeah. I may be confused. It wouldn't be the first time.

Tom Ligon was very patient teaching me Polywell.

[zbarlici]

"The People’s Republic recently ordered mineral refiners to reserve the thorium they produce so it can be used to generate nuclear power."

It seems that China, India, and France are looking at this fission tech seriously.

Suppose that the US govt. looks into it as well and figures out that "holy crap.. that really does work!", and thorium fission nukes get on the FAST-TRACK bandwagon to implement as the energy source of choice.

What will happen to polywell now that America`s energy problem, as it turns out, wasnt an energy problem at all because the problem was solved over 30 years ago!

Will it be forgoten too like Thorium???? You KNOW they`ll go for thorium if its been proven to work. Why fund any more research when we already got an answer to the energy issue.

[zbarlici]

perhaps this embargo on Mr. Nebel & team will end up being polywell`s downfall. Are the next wave of results going to be "nuanced " as well? Better step up to the plate before thorium does and puts the poly on the backburner.

[blaisepascal]

perhaps this embargo on Mr. Nebel & team will end up being polywell`s downfall. Are the next wave of results going to be "nuanced " as well? Better step up to the plate before thorium does and puts the poly on the backburner.

The amount of monies the Navy are investing in Polywell are still small, and will be small even in comparison with the amount of monies that would be dumped into building a Thorium plant.

It's not like Thorium is new, even in terms of discussion in this forum. The big deal is that Wired published an article about it, and thus a lot of immediate attention as been brought to it.

There are difficulties with thorium. One major one is the lifetime of Pa-233. The main desired reaction chain in a thorium reactor is Th-232 + n --> Th-233 --> Pa-233 + beta --> U-233 + 2beta, with U-233 being the main fissile fuel. Unfortunately, Pa-233 is both a neutron absorber and has a lifetime of 27d or so. I saw no mention of such problems in the Wired article.

It's going to still take a lot of research and money to figure out how to overcome these issues. While MSimon may have confused a Molten Salt Reactor with a Molten Sodium Reactor in his listing of engineering problems still to be solved, that doesn't mean he's wrong in highlighting that challenges remain.

[KitemanSA]

There are difficulties with thorium. One major one is the lifetime of Pa-233. The main desired reaction chain in a thorium reactor is Th-232 + n --> Th-233 --> Pa-233 + beta --> U-233 + 2beta, with U-233 being the main fissile fuel. Unfortunately, Pa-233 is both a neutron absorber and has a lifetime of 27d or so. I saw no mention of such problems in the Wired article.

Indeed, this is the main reason to have some type of hybrid system.
If you remove the Pa, the MSR can breed maybe 1.09 units per unit, not real rapid, but certainly enough to support the LONG tem growth rate. However, this requires reprocessing which opens the doors to other issues.
Without reprocessing, the neutron economy is just too low and the system can't acheive criticality. Enter the neutron source (Polywell?). If an external neutron source is added to the unprocessed reactor, it can be "driven" to operate. Current work has high energy accelerators providing protons to a spallation target which generates the neutrons. A DT or DD fusor may do in lieu of the accelerator. Thorium may be the continuation of the Polywell if Polywell can't stand on its own!

It's going to still take a lot of research and money to figure out how to overcome these issues. While MSimon may have confused a Molten Salt Reactor with a Molten Sodium Reactor in his listing of engineering problems still to be solved, that doesn't mean he's wrong in highlighting that challenges remain.

True, but most solutions have been demonstrated in lab level systems. From here on out, it is engineering, not physics. It WORKS!. Can it be made economical? I am pretty confident that the answer is yes, even if only as a breeder.

[Helius]

I like it. One pitfall that recurs is the concept that in a fission-fusion system, the 2 machines must be adjacent and operating in unison.

Not so. We could have a Fusion U233 / PU238 breeder separate from the big fissioning process heat generator. We could still average > 3 neutrons per fission, say 5-6 neutrons per fission; It would just be that some neutrons would be separated in space and time from the actual fissioning.