Based on reading the white papers on the LFTR design proposals (that I have been able to see) they all seem to incorporate a fail-safe (lower melting point) plug that will melt if the reactor begins to overheat (and well before it melts down) and the liquid salt/fuel mix will rapidly drain into a dispersed catchment area in which all reactions will come to a very rapid stop (by the liquid salt fuel mixture getting physically spread out and also potentially dampened down by neutron absorbing casing materials)
LFTR reactor designs have been tested (a long time ago at Oak Ridge) and these types have the potential to burn up over 99% of the fertile material (e.g. the Thorium) as it is transmuted into U233 and the decay products. Of all the GenIV breeder types LFTR seems to me to be the variant with the best safety profile and resource availability profile (lots of recoverable Thorium). However even if a big country like the US went all out to develop this electric energy generation technology -- the question remains how many years (decades more realistically) would it take to develop a reference design that has been engineered, tested etc. and has had all the kinks worked out (at the pilot plant level) and then to build out the LFTR infrastructure (from mining, refining, to re-refining, to the plants themselves and the waste processing and long term storage of the wastes that are not burned up in the breeder (medium term waste can still present half lives of a hundred years or so) I am not sure what the energy landscape of our world will be in twenty to thirty years -- but based on the peaking of all liquid fuels and of high grade coal as well it is going to have to be very different than the current fossil fuel based electric energy generation infrastructure we all depend on. Because the lead times are so long (at least 20-30 years) it is hard to predict how far the per unit cost of the market leader in solar PV will be at that point. If it continues to fall along the trend lines for decreasing unit costs that have prevailed for the last four or five decades then it may not even make sense to invest in them as Solar PV will become the low cost supply. Chris ________________________________ From: John Clark <johnkcl...@gmail.com> To: everything-list@googlegroups.com Sent: Friday, February 21, 2014 11:52 AM Subject: Re: The situation at Fukushima appears to be deteriorating On Tue, Feb 18, 2014 at 5:50 PM, LizR <lizj...@gmail.com> wrote: > Would this have happened if Japan had been using subcritical reactors with > thorium fuel? > If it were a Liquid Fluoride Thorium Reactor (LFTR) and the cowardly operators saw the Tsunami coming and ran for the hills and completely abandoned the plant then the liquid Thorium fuel (Thorium dissolved in un-corrosive molten Fluoride salts) would get hot, and that would expand the liquid, and that would cause the fuel to get less dense, and that would cause the nuclear reaction to slow down. Then a freeze plug at the bottom of the reactor would melt and the liquid fuel would drain out by gravity (no pumps would be needed) into a holding tank and the reaction would stop completely and the reactor would enter a safe mode. All this is assuming that the operators were completely incompetent and never lifted a finger to help the situation. And because the liquid Fluoride salt is not under pressure as water is in the Fukushima plant leaks would be far less likely and much less catastrophic even if they did occur. John K Clark -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.
