I leave my client closed and it doesn't have to catch up if I'm sending funds.  Otherwise I start it and leave it overnight about once every couple weeks.

I suggested to them the 410 shotgun, but then I realized that a reduced recoil 12 gauge has a lower peak chamber pressure than anything else on the market, which is the greatest problem with printing a barrel. Otherwise, a short section of 3/4 inch electrical conduit (EMT) surrounded by printed plastic for extra tension against expansion would work.

Our pleasure, to be sure.  I've been monitoring your blog at defensedistributed.com and was hoping to get an update on the progress.

It is for many, particularly in India.  That's beside the point. n_TOF has a research license under CERN.  None of these guys could do any such thing without the explicit support of CERN.  It is a highly regulated field of research, with good reasons.  India has been deep into research regarding the thorium fuel cycle for many years, but mixed fuel reactors are probably the best way to breed uranium from thorium in the near future, and any such breeder design can also transmutate nuke waste from LWR or BWR designs.  However, as I mentioned before, such designs are not safely efficient for power production as well, and work best as municipal heat.

No, a permit is required regardless of what you are doing.  In the case of small research reactors, the licensing process is often as expensive as the construction of the entire reactor.  One reason that no one makes small, neighborhood sized reactors even though they certainly could.  A town in Alaska has been asked by some manufactuer from Japan to field test a prototype reactor that supposedly needs no attention nor refuling for 30 years at a time.  I forget what that type was called but it resembled a pencil stuck eraser first into a concrete hole in the ground.  The eraser being the actual reactor and the shaft of the pencil being a set of molten salt lines to function as a heat transport loop to the surface where the generators would be housed.  Last I heard the town was all about it, considering that they were so remote that everything ran on deisal gensets, but the NRC wan't giving the idea the time of day.  That would have been ten years ago, I think.

There have been both nuclear powered commercial ship prototypes and aircraft.  Ocean ship are fine, but anything that can crash into a residential zone (as opposed to sink into a ocean of radioation shielding) is a bad idea.  That goes double for actual street vehicles.  I'd much rather see a hydrogen powered bus in a city with a nuke powered hydrogen plant than actual nuke busses no matter what kind of fuel cycle it uses.


Yes, easily.

Probably because for most anyone with any training in the field capable of doing it without killing themselves, the construction of a reactor without the consent of the NRC is a federal felony.

Excluding the "Nuclear Boy Scout" of course, but all he did was build a breader reactor in his mom's tool shed, and probably shorten his lifespan by about 20 years.


It's not accurate.


Negligible, a few grams per ton of fuel consumed, less after it's had more exposure to the neutrons and some has transmutated to other elements with shorter half lives.  The majority of them has half lives in the 4 and 12 year ranges, and can reasonablely be sequestered into leaded glass in a safe manner for 100 years or more.


I don't understand this question. I haven't seen the video, are the talking about medical radioisotopes?  They are valuable, but they are not created in any useful quantity unless the reactor is designed to do it deliberately.  Most such radioisotopes are created by one of a few tiny research reactors that produce negible amounts of electrical power, usually less than the facilty they are housed in consumes.  It's hard to have it both ways, wither the reactor is designed for research or it's designed for power production.


On a side note, there is more radioactive materals put into the atmostphere each year by coal plants, mostly due to the thorium in the coal in trace amounts, than that what was released by Three Mile Island.  Thorium is, literally, found everywhere on earth.

That's not quite true.  The transuratics are less involved in a thorium cycle, but there are more in a liquid reactor design, and since transuratics are a neutron 'poison' they would have to be delt with on an ongoing basis.  While the processing of a liquid core is technically easier than a spent solid core, it's still very real.

Oh, I see.  You're talking about a molten salt reactor.  While I agree that a 'meltdown' is meaningless in this context, I'm not sure that I would agree that a molten salt reactor is a good idea.  Deliberately keeping a neutron emmittor in a liquid state is just asking for problems, in my opinion.

Ah, therein lies the rub.  I haven't figured all that out, but I have to admit it's unlikely that I can get the costs comparable with a commercial product you can find at Wal-Mart, considering the additional costs of shipping involved.  The stuff is concentrated, as the sample size for one full load is only 2 tablespoons (one fluid ounce); but I haven't yet figured out the best way to ship it.

EDIT: I'm certainly willing to accept advice concerning the best method of shipping.

Correct, the greater issue with the spent fuel in uranium fueled civilian reactors is that the fuel isn't permitted to be concetrated greater than 20%, and the reactions are unsustainable once U235 drops below 3-5% depending upon the reactor design.  The rest of the core is mostly U238, and some is transmutted into plutonium.  It's the plutonium that has the long & hot half life, not the actinide wastes, and a thorium reactor doesn't produce plutonium.  A thorium reactor does produce U233, but it's 'burned' in the normal running process of the reactor so there is never much buildup there.  Also, since nearly 100% of the core is breedable fuel, a given core can stay in the reactor for much longer.  Therefore, not only are the actinide hazards reduced simply because of the time they spend safely sequestered in the reactor itself (and their much shorter half lives) but they also tend to be reduced due to ongoing neutron capture transmuttation.

Yes, that's a pebble bed reactor.  But his complaint about generation of consumer electricity is valid, the goal of making a inherently safe pebble bed core and one of efficiently producing power are at odds with each other.  However, a pebble bed style reactor, with each pebble encased into steel & corrosion resistant casings, would be ideal for lower level process heating or centralized apartment block heating.  Israel could make the desert bloom with a pebble bed reactor intended to de-salinate & pump seawater.  Russia & Canada could diverte many tons of natural gas and heat oil to other productive uses, even power generation.  This is the primary design use of the CANDU reactors that I mentioned, and the USSR had been using smaller (and notablely safer) reactors as downtown municipal heating systems in many of their more northern cities for a long time.

Where do you guys come up with this stuff?  Thorium fuel cycles are much more economical than a uranium fuel cycle, the only advantage that uranium had in the start was the desire of the DOD to create weapons fuel, and now because all of the nuclear industry is setup to process and handle uranium.  And yes, the tech has been known for decades, so it does "exist" even if it's not used.

Gamma rays do not 'induce' radioactivity, only neutron capture does that.  And no, you don't need uranium or plutonium.  One can make a primary neutron source with a spalation excelerator, such as in an energy amp reactor design; or from an Alpha emitter and a sheet of aluminum, as the 'nuclear boy scout' did in the 90's.

You can actually set the number of connections, but I don't know enough about it to tell you how to do it.  You could 'nice' the process, and that would slow it down somewhat.

An exaggerated claim, yes; but to say that there is no basis in reality is not quite true.  In a 'meltdown' (the kind that laymen think of, anyway) the core melts due to excessive heat buildup as a direct result of a runaway, super-critical reaction; thus a 'cascade'.  If the cascade is almost impossible, to say that they are temp limited is a fair claim for a basic understanding of the science, even if it's not technically true.

Okay, yes.  That's hyperbole.  Any reactor design can melt down, but some have inherently designed features that resist a cascading reaction that would lead to a 'meltdown' as in Chernobyl.  Those features make such an event very unlikely, but never impossible. 

There's plenty of research concerning thorium fuel cycle reactors, but I'm not willing to provide any for you because I'm not sure how much is still classified.  It shouldn't be because it's so old and not particularly useful for making a weapon, but I don't have the time or desire to check.  So no, not from me.  Google is all knowing, however, so use your google-fu and do some of your own research.  Just because it's publicly available information, doesn't necessarily mean it's not still classifed.  I know that doesn't make any sense, but in my experience there are few government rules that do not outlast their usefulness.

No, not necessarily.  There exist self-regulating reactor core designs that will tend towards a sub-critical reaction above a certain design tempeture, making a cascading reaction (i.e. meltdown) very unlikley.  A few such reactor designs have been around for some time.  I used to have a nuclear reactor training simulator around here somewhere, if I can find it I might post a link (can't remember if the simulator is classified).  One such reactor design, that does not claim that feature as a safety feature due to some other very bad effects, is the Candu reactor designed in Canada.  It's a great design that was stolen by the Chinese for their domestic designs after they bailed on Russian designs following Chernobyl.  That's actually probably for the best, but even they don't use it for their power reactors because it's not a presurized design, but an open top, deap pool design.  If it were to boil off about ten feet of it's water, the reduction in water pressure at the core would reduce the ability of the water to slow down the neutrons to capture range until after they had left the core, thus going subcritical.  Of course, those ten extra feet of water are also necessary for human safety as the water itself is the shielding.  Lose ten feet of cover water, and spectators start dying within a couple dozen feet of the pool's surface, so it's not exactly a good thing to advertise.

Not if you're willing to do it in your garage.  I'm not, because I'm not willing to die or kill my neighbors, but if you were willing, you could build a prototype energy-amp for about $50K.  Look up "thorium energy amp reactor" on Google, and then take that new knowledge here > http://www.unitednuclear.com/