Future Energy Sources 1.9.1.3 Thorium Reactors

An excellent article, and the COSMOS article is particulaly good and more up to date than the others.

I am disappointed that I have not heard of the Thorium Accelerator Driven System before, in the recent UK report on energy. I would suggest we all contact out representatives to ensure some proper funding for this research so that the technique can be proved in full scale operation

Hi Hugh,

I first heard of the concept less than 12 months ago and like you was astounded that I had not heard of the technology beforehand. Recently the Australian Federal government commissioned a report into the prospect of developing nuclear power in Australia. I was astounded that the report only looked at existing technology and never even mentioned the concept of ²³²Th reactors.

I am not one to believe conspiracy theories, but it is quiet clear that the people that are pushing nuclear energy in Australia are woefully ill-informed and are not looking at all the possibilities. ²³²Th reactors are still being developed, however, it troubles me deeply when I see official reports that either gloss over or completely ignore technologies that show the sort of potential that this dose.

Masu,

I too was astounded that the recent UK government report into energy supplies, which did support the building of new nuclear stations, did not mention this technology.

Thus I have written to two of my local Members of Parliament, and to several of my friends so that they can start to ask the question and raise the profile of the issue.

The Q&A session at the end of the Cosmos report did imply that your Member for Flinders had asked a question of government, but probably nothing came of it. Is it time for Australians - you seem to have plentiful supplies of Thorium - to raise the issue with the press etc and get the ball rolling?

I particularly like the prospect that withing 5 - 10years we should have an option of fuelling some existing stations with a safer fuel which produces less waste and even that has the much shorter half life. In the longer term we can build all new designs.

Does anybody have any contacts with " Friends of the Earth" - it would be a good campaign for them worldwide.

Hi masu. Many years ago, 1972, I had been collecting minerals from nearby where I lived in Norway. Two of the minerals that I frequently came accross where Thorite and Monazite. both in extremely large crystals. I enquired about this and they told me that in Victorian times they mined these minerals for there content of Thorium oxide to be used in gas mantles. I knew that these minerals were radioactive and that 232Th could be used as a substitute for 235U. I also knew that if one used 232Th then the waste would be much less a hazzard. This information was obtained from the Norwegian research program into nuclear energy. So my question is, why has it taken so long for this information to be made public? Another question is, why has there been so little reaserch into this before now? I think I know what the answer is, while we have oil we have had relatively cheap energy up to now, but as the worlds oil supplies are dwindling we are in a panic to find the next generation of energy supply. Spencer.

Hi Scapolie,

"So my question is, why has it taken so long for this information to be made public? Another question is, why has there been so little reaserch into this before now?"

These are indeed good questions and I do not have the answers. I am not one to believe in conspiracy theories and this technology is still under development but the potential benefits are too great to simply ignore it.

Clearly the people advising the powers to be are not doing their job to the extent they should and that is where I will leave it.

Hi Masu and discussers,

the information on some thorium reactors were existent since the 60ties or earlyer.

There was a working thorium reactor in Germany - inherently safe - helium-cooled, if you google for thtr you will find the story.

The reasons for abandoning this concept are not clear, I heard from an interested side that the grafite balls that contained the oxidic fuel broke too easily thus making the whole concept questionable.

But the same person did tell me that this breaking of grafite balls occurred because the control rods were forced into the pile of balls from above and this force did breake the balls.

This was in the time when everybody important or "informed" person supported the ordinary uranium reactor with the hidden goal to get access to plutonium to build nuclear weapons.

So the information was and is existent, the discussion should be open again, naturally one company can develop only one type of reactor so they are biased to their own inventions.

Concerning the accelerator driven thorium reactor this was known but nobody believed that this type of accelerator can be built and I too I doubt about it.

I doubt also about the claimed 500years radiactive storage time of the thorium reactor waste. Is there any proof?

regards

RHABE

Hi RHABE. As far as I can remember the phyisist Edward Teller, one of the fathers of the atom bomb had discussed the probability of using 232Th in both a nuclear weapon and as a nuclear reactor way back in 1941. In the late 1960s through to the early 1970s when I was at college I was asked to write an essay on the history of the nuclear bomb as used against Japan at the end of the war. I read everything that I could come across about the subject. I can clearly remember that Teller stated that using 232Th for a nuclear reactor was a lot safer than using 235U. Of course, as it was they had developed the 235U bomb, and it worked,so all thoughts and development since then has been focused on this material to the detriment of 232Th as a nuclear fuel.

²³²Th is only fertile but it will become ²³³U in the presence of neutrons. This transmutation can occur with thermal neutrons while I believe that transmuting ²³⁸U to ^{239,240,241,&242}Pu required neutrons that have not been moderated so they a moving around at high speed.

The CANDU reactors have a particularly high neutron economy and this is what makes them candidates for ²³³U breeding.

The Fast Breeder Reactors FBR's use molten metal coolants to avoid the moderating effects of light water, heavy water, and graphite. They produce more plutonium than they use. It is important to realize that if the ²³⁸U remains in the reactor for a period long enough to make them economical power generators, the higher isotopes of Pu are produced rather than the bomb grade ²³⁹PU.

The IAEA, a UN body, keeps track of how much fuel is being passed through a reactor and they can tell if you are more interested in weapons program than a commercial power program

Whatever happened to lithium-plasma reactors?

The only thing I was able to find about lithium-plasma reactors was that they are a form of fusion reactor. Fusion is a whole different subject and I plan to cover that in a future discussion.

Do you have any links to data on lithium-plasma reactors, I would like to read up on them so I can introduce them in a future discussion?

www.jet.efda.org

www.iter.org

Hi Masu,

here are some links to recent thermonuclear experiments.

Any of the fusion experiments shall use some lithium blanket to avoid the most serious radioactive waste production by neutron capture of wall materials.

Lithium is a material that is much easyer to handle if compared to tritium and is converted into tritium if the fusionreactor is burning.

So I don't think there will be a "lithium-plasma-reactor" but any plasma reactor will have lithium as fuel. But some extra tritium to start with.

The JET experiment was the first and only on earth that had a controlled fusion burning - for 1 second only - it was not equipped with the wall liners of lithium and so the walls are now badly radioactive - activated by high neutron flux. So I don't believe that a fusion reactor will ever be clean!

There is no material (except silicon for semiconductors) with a purity of better than 1:1million (and this is very costly) so any high purity lithium will be contaminated with other elements that can be made radioactive by neutron capture.

May be the future experiments reveal some way to get a lithium suitable for lining the plasma reactor, or the necessary purity lithium can be supplied by a similar process that makes silicon pure enough for semiconductor purposes. So we shall try regardless the momentary cost.

And I would be glad if the European and US authorities would not have given way to the japanese pressures about location of the joint institutes. (Or finance it purely european!)

At the same time you will find data about the other type of fusion experiment at NIF (national ignition facility) in the US, may be also in France. Both experiments are said to be a major step towards fusion energy. But I don't believe this. Why on earth there is no question about international participation? money only? or manpower may be?

So I think that these experiments are designed to have a deeper look into the very first moments of ignition of a thermonuclear weapon. Nothing else would explain the speed and financing towards fast realisation.

RHABE

This topic is not new. The concept of a breeder reactor has been around for decades and experimental reactors have been built. However problems occur in the material used to get the neutron to the correct speed to react. Not to mention all the problems in constructing a new type of commercial reactor. Regardless separation of the end products must occur to use these activated products . Why not just reprocess the existing Uranium waste which will greatly reduce the amount of radioactive material (on the order of 10% of the uranium fuel is used up in a normal fuel cycle) and the unused byproducts have a greatly reduced half -life. Thus reducing the time the uranium waste must be stored (similar time frame to the 500 years you spoke of on the Thorium waste).

Reprocessing is a lot more complex than just taking the still unstable nuclei from the spent fuel rods. Everything the spend fuel comes in contact with, becomes contaminated and requires extensive cleaning and treating. When you reprocess spent fuel you end up with considerably more contaminated radioactive material than you started with.

Reprocessing is not the panacea that many believe it to be and you can end up with more radioactive material than you started with.

It all comes down to interested parties, the treasury want the cheapest solution, the government want a popular way out normally too afraid of rejection to decide on anything, the military of course want open access to plutonium. I did email T.Blair with the focus article no reply but then he is as good as dead. Brow will leave it until it is all too late. The majority of the people in the street could not care either way, they are all taken up with what to drink in witch pub. 45% of Brit's rate as alcoholics.

What hope is there when no one can be trusted to make any rescission at all.

The lights will begin to go out very soon. Just wait and see in five to ten years global warming will be a long forgotten thing and electrical generation will be the number one subject. I say go ahead now or it will be too late to be able to.

Here I go again, the CANDU already supports a thorium fuel cycle, a natural uranium fuel cycle, a MOX (mixed oxides) fuel cycle to destroy surplus weapons grade plutonium, and the DUPIC fuel cycle which will take the spent fuel from light water reactors which has a higher concentration of U235 than natural uranium and burn it.

The nonfissile but fertile thorium absorbs a neutron and becomes fissile U233, which then becomes the actual fuel. The CANDU can reach near breeder status while a true fast breeder could generate fuel for other reactors. In this case reprocessing raises its ugly head again.

As I understand it a CANDU would start with a partial load of thorium fuel bundles and as more U233 was bred and it became a contributing part of the fuel load more thorium bundles could be added. This is quite in keeping with the standard fueling procedures for a CANDU.

<>The CANDU may be refueld while on power unlike most commercial reactors. The reactor consist of about 480 pressure tubes running through a low pressure and temperature calandria vessel containing heavy water moderator. The high pressure high temperature coolant runs through the pressure tubes containing the fuel bundles. Each pressure tube contains 12 fuel bundles and every day 8 bundles are replaced in only one or two pressure tubes. If 16 bundles out of a total of 480x12=5760 are replaced every day then it will take 360 days to completely replace the entire fuel load. Sometimes bundles are also rearranged within the reactor in order even out the reactivity in the reactor. This fuel loading, dishcharging and shuffling is accompished by a pair of remotely controlled devices on each side of the calandria vessel

<>

<> Not bad for a reactor designed and built by a small country. It is a little known fact that we were also part of the Manhattan project but chose not to follow a weapons development path after the war.

<>Anyone wanting some more detailed information should contact AECL<> and ask for the ACR-1000 Technical summary. It describes the next generation of CANDU but also draws comparisons to other CANDU reactors. It is very well done 40 page document with lots of diagrams and tables. It is also free!

Hi curious_one

I just ordered my copy of the ACR-1000 Technical summary.

Is any CANDU reactor actually used in a Thorium fuel cycle or (even better) to denature Plutonium by 'burning'.

I too am curious.

I don't know if they have actually tested the thorium fuel cycle but I do believe that they have tested some MOX fuel bundles if not in a CANDU then in one of the test reactors at Chalk River that has a facility for testing CANDU fuel bundles. I know that there was some public opposition to transporting MOX in Canada from people who didn't really understand the truly minimal danger of transporting the stuff. They think that plutonium=Atomic bomb=explosion=fall out and contamination and death, if they only understood how difficult it is to make an atomic bomb. I would feel much safer if a truck carrying MOX fuel elements drove down my street than a tank truck containing propane or gasoline to the gas station a couple of blocks away. My neighbourhood was evacuated several years when a propane pipeline sprang a leak, the gas gradually seeped through the soil and was ignited by a passing truck. The driver was severely burned. Some of the propane made it into the sewer system and rumour has it that a woman who was smoking on the toilet decided to put her ciggarette butt in the toilet while she was still sitting on it. The resulting flash apparently resulted in some embarrasing burns.

The evacuation only lasted about 24 hours but all gas and electricity was shut off and when we were allowed back in the power was back and if you need help getting your gas back on you tied a white towel to your door knob and roving gas company trucks would stop, reset your gas pressure regulator, and help restarting pilot lites, etc. It was kind of an adventure and the government reimbursed us for living expenses according to current employee travel regulations. The claim submitted by one man who felt the safest thing for him to do was drive his family from Edmonton to Banff for two days was disallowed.

In the mean time we have had a SLOWPOKE reactor operating in the middle of the University of Alberta campus, on the same street as the major public transit centre on campus for over thirty years and most people are unaware of it.

Nuclear energy seems to so easy to attack, especially by those who don't have the least understanding of what is involved.

In addition to ordering the booklet have you visited the nuclear FAQ? Dr. Whitlock has done a real good job on it. I don't know whether to laugh or cry when I read some of his editorials, they are very well done and often done tongue in cheek. He is a man who loves his kids, the environment, and nuclear energy. I would love to be sitting beside him on a long airplane ride. I think that you can have confidence in what he says. If he got any sleep on the trip it wouldn't be my fault.

Sorry for babbling on, us grandfathers do that sort of thing. I will contact my source in AECL and do some research regarding the testing of thorium fuel cycles.

I recently recieved an e-mail form an employee of AECL. They have put test bundles of thorium fuel in some of their test reactors to measure their characteristics. The Indians, who have a lot of thorium and little uranium are apparently using thorium fuel bundles to balance the reactivity when using fresh fuel. It is government policy in India to pursue a thorium fuel route. They have a large fleet of CANDU and CANDU clones operating at this time.

AECL has also tested MOX fuel bundles but not all of the required international agreements are in place to facilitate using MOX on a production basis.

Thanks for info you gived ,indicating 'the nuclear FAQ' [created from Mr.Dr.Jer. Whilock].

Nic

I have watched the video,reviewed the specifications for the ACR-1000 & find it different than other reactors. If it truly can be as efficient using thorium & there is absolutely little chance of meltdown, pollution of any sort except when the reactor reaches the end of it's lifespan, then what needs to be done with the reactor & all associated plant equipment? Exactly how long is a reactor & associated equipment good for & what must we consider at the end of that time?

The CANDU reactors have an intended life of 60 years with a refurbishment at the 30 year point where parts subject to wear and tear are replaced. Primarily the Calandria tubes and pressure tubes. They also take this time to overhaul the steam turbines and posssibly the steam generators.

If you have any questions send me a personal message.

Grandpa Paul

India has done lot of work based on thorium as it has abundant thorium as raw material in the state of kerala. one has got to get USA out of its dog in the manger energy policies. in the mean time the nuclear energy technologist should begin to work with India on this as a start.

Hi to all,

everybody who is interested in the heavy water moderated and light water cooled CANDU reactor (India bought these and did further development work) and its next generation ACR1000 should read the brochure that is available for free at the below adress.

It is really a concept that has a lot of advantages.

Does anybody know the prices of uranium entichment to the typical 3.5% reactor grade?

This canadian reactor can burn the waste of other reactors (not all but a lot), can be operated with thorium (that is why India bought it),

can be operated with only 1.5% U235 as fuel,

has inherent safety because if loss of heavy water moderator shuts down immediately. Look at the brochur, I started being sceptical.e

More details will be discussed in june at:

www.icenes2007.org

where specialists will meet to discuss future reactor concepts.

RHABE

Leaflet describing CANDU and ACR1000 technology:

Pam Sprague

Marketing Services Coordinator
Atomic Energy of Canada Ltd.
tel: 905 823 9060 ext. 6574
fax: 905 403 7565
e-mail: spraguep@aecl.ca
URL: www.aecl.ca

Hi all,

Questions re thorium breeder reactor technology:

The short opinion I have cited below is too generalised for me to be able to figure out what it means. Does anyone out there have some insight into what may be being referred to here? For instance, some of my confusion arises from mention of contamination - but all radioactive substances have some 'contaminant' problems, surely? Then the mention of gamma emitters with very short half-lives - what does that suggest? Short half-lives are better than long ones; beyond this response I have none. The "similar problems" in recycling thorium... I thought we were looking at closed units for all cycles, except possibly for any boilers (which would need to be accessed for maintenance or replacement). Weapons proliferation risk of U233 ... anyone know any specifics on this?

"Developing a thorium-based fuel cycle

Problems include the high cost of fuel fabrication due partly to the high radioactivity of U-233 which is always contaminated with traces of U-232 (69 year half life but whose daughter products such as thallium-208 are strong gamma emitters with very short half lives); the similar problems in recycling thorium due to highly radioactive Th-228 (an alpha emitter with 2 year half life), some weapons proliferation risk of U-233 (if it could be separated on its own); and the technical problems (not yet satisfactorily solved) in reprocessing. Much development work is still required before the thorium fuel cycle can be commercialised, and the effort required seems unlikely while (or where) abundant uranium is available.

http://www.uic.com.au/nip67.htm

Why is it necessary to reprocess the irradiated Thorium. After it has been in the reactor long enough to generate a signifigant amount of U233, leave it there and burn the U233.

The previous post about the ACR-1000 brochure, under-states it, it is a proffessionally done 40 page booklet and well worth the e-mail..