More on why we need the Liquid Fluoride Thorium Reactor:
We discussed yesterday why the LFTR is a totally safe alternative not just for fossil fuels but also in relation to uranium-fueled Light-Water Pressurized Reactors. But let’s review:
- The LFTR is incredibly stable against nuclear reactivity accidents—the type of accident experienced at Chernobyl.
- Any increase in temperature results in a decrease in reactivity. Thus, as the liquid fuel temperature increases, reactivity decreases, thus reducing power and restoring the original condition. This is analogous to a weight on a spring. It is intrinsically safe and stable because of this.
- The LFTR is also totally safe against a cooling loss accident which is what happened at TMI.
- It is not possible because the liquid fuel can drain safely into specially designed cisterns. Once removed from the moderator, all fission reactions immediately cease.
Beyond safety there are two other areas that need to be address: nuclear weapons proliferation and overall efficiency, only a little of which I touched on in the last diary. While nuclear weapons resistant, I will address this in another diary if people are interested. For this diary, we should look at the overall contribution a LFTR can make to solving our energy crisis, and by 'our', I mean the planet’s.
I want to compare, using the following link to a Power Point presentation available here:
energyfromthroium.com
Uranium to Thorium, and this way we can all learn some essential facts about the wonders of the thorium (and uranium) fuel cycle. [Energyfromthorium.com is the central clearing house for all discussions, documentations and items related to both Thorium fuel and Liquid Fluoride Thorium Reactors. It is run by Kirk Sorensen]
Uranium:
- It takes 250 tons of natural uranium with 1.7 tons of U-235 for a gigawatt year of energy. We do this by turning this uranium into 35 tons of enriched uranium containing 1.15 tons of U-235. This is the actual fissionable fuel.
- This leaves about 215 tons of "depleted uranium", the stuff called "DU" used in weapons. It has very low radioactivity but is dangerous as a heavy metal. This 35 tons of enriched uranium creates 1 gigawatt year of power.
- It leaves after generation of this power with the current crop of Generation II reactors (all the commercial reactors now used in the US) about 35 tons of spent fuel or what people who oppose nuclear energy call "waste".
Thorium:
- For the same 1 GW year of energy, we use 1 ton of natural thorium. This Th is introduced into the liquid fluoride core of a LFTR and is turned into U-233 which is the actual fuel that is burned in this type of reactor. ONE ton folks, or about 7 lbs a day. That's it...equals 1 GW a year of electricity.
- This one ton of Th turns produces 1 ton, in a year, of waste. This waste can be isolated from the fuel salt and contains no uranium, plutonium or other long-lived actinides.
- Within 10 years, 83% of this waste can be sold to metal recyclers and used in other products. In only 10 years. The remaining fission products can be stored for 300 years after which it is less radioactive than natural uranium ore.
- There are 3200 metric tons of thorium nitrate, already processed, sitting buried in the Nevada desert. This Th can be used as is in a LFTR. It is enough to power 32 1 GW LFTRs for 100 years each. In other words, the fuel is already available to start the initial phase of converting our economy to a thorium energy economy.
- There are at least 160,000 metric tons of economically usable thorium in the US. This, however, are 'old' numbers, left over from when the last experimental thorium reactor was shutdown in the 1970s. Thorium Energy Corp owns, according to its own in-house geologists, reserves of up to 600,000 to 3 million tons. Are you all seeing the picture here? What this represents if exploited?
The LFTR represents a "Breeder" reactor even though it only produces little or no surplus. After an initial charge of U-233, U-235 or plutonium, you can add only 1 ton of Th a year for its 60 to 100 year life span. Every 10 years one has enough extra U-233 to charge a new LFTR. Every decommissioned LFTR can use its fuel as a starting charge for a new reactor. There is enough Th to completely convert and expand the US energy generation resources to LFTRs.
Because the LFTR runs at 1 atmosphere, the massive construction used to build containment in a standard uranium fuel PWR isn't necessary. Everything is smaller and thus much cheaper to build. About the only thing that remains the same is the generator, which can be a standard 5 MW generator up to a massive 1700 MW generator. LFTRs can be scaled up or down depending on the market need. The reactor is much smaller, the materials used can be standard industrial manufactured vessels and pipes. The turbine can be smaller since we will use inert helium or nitrogen instead of steam. It will run at much hotter temperatures and can be used to crack hydrogen from water or fresh water from seawater. Hydrogen, freshwater and electrical power can be produced from the same LFTR.
NNadir pointed out in my previous diary that the LFTR (or MSR as it's more popularly known) is the only non-commercial exploited nuclear technology around. Hopefully this will change.