Nuclear energy for the future?

[unixronin]

This is one of several articles I came across yesterday about thorium reactors.  A thorium-fueled reactor turns out to have several advantages over a uranium, plutonium or MOX-fueled one:

• Thorium is three to four times more abundant than uranium, much safer and easier to extract, and unlike uranium, doesn't require any enrichment — so, unlike uranium, it is all usable as fuel.  As a matter of fact, it's safer to mine thorium than to mine coal.
• Thorium is not of itself fissile, and requires a neutron "pump" of some sort to maintain a nuclear reaction, so a thorium reactor — particularly an accelerator-driven system — cannot go critical.
• The thorium fuel cycle produces far less and shorter-lived radioisotope byproducts than the uranium cycle, the major significant long-halflife isotope being protactinium-231.
• You can't build a nuclear weapon out of thorium, making it "safe" from the point of view of nuclear proliferation.
• A thorium reactor can "incinerate" plutonium, U235, and other transuranics, providing a safe means to dispose of existing transuranic fuels.
• Thorium reactors ideally operate at a higher burnup than uranium reactors, performing well at burnup levels over 150GWd/t, compared to 40GWd/t for a typical Generation II uranium reactor.  This presents some engineering design problems, but means less frequent refuelling (and consequently, lower downtime for refuelling) and better utilization of fuel.
• Thorium dioxide has better chemical and physical properties than uranium oxide; its melting point and thermal conductivity are higher, its coefficient of thermal expansion is smaller, and it is more chemically stable, including that it does not further oxidize.

Looks like an interesting technology that overcomes most of the arguments of both anti-proliferationists and the ZOMG-nukes-will-kill-us-all school of environmentalists.  (Of course, it still won't win over the AAAAAUUUGH-YOU-SAID-NUCLEAR set.)

Comments

[ithildae]

Do we have all the technology worked out to process Thorium at a reasonable cost? Last time I checked, the refining process was hideously expensive, and it was not ready for production quantities. We spent enormous sums of money to learn how to process Uranium, we stick with it mostly because the US government spent the money to develop the process to produce quantities at a reasonable price point.

It is kind of like GaAs being the next great thing in semiconductors, and it always will be. Silicon processing just keeps getting better, and all our equipment is developed for Silicon. Retooling is just not a reasonable, economic consideration.

[unixronin]

That seems to not currently be the case, plus as noted, thorium does not require subsequent enrichment.

[ithildae]

The linked article does not have any more details than we were talking about in the late 1970's about the Thorium cycle. Last year, India was talking about building three Thorium reactors, but backed away because the technology was not there for reactor design, or fuel acquisition. I do understand that we have some Thorium test reactor sites in the world, but AFAIK they are all attached to universities, and require significant putzing to make work.

The Thorium cycle is very promising, but until some significant money is devoted to commercialization, it will only be a promise. It is something that we should do, which means the politicians will always find more profitable places to put money.

[unixronin]

*sigh* Sad, innit.....