Homepage Forums Innovative Confinement Concepts (ICC) and others BSF, a Contender that is Virtually Aneutronic

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  • #1398
    AvatarBSFusion
    Member

    Q: If fusion power plants produce neutrons, do they have to squirt them at people?

    BSF is an approach to fusion that uses directed energy (lasers) to ignite a bubble of fuel that is suspended deep inside a thick blanket of liquid (example: FLiBe). The matter surrounding the bubble confines the explosion and it also absorbs neutrons, which prevents them from escaping from inside the reactor. One possible fuel would be aneutronic decaborane, but hydrogen (50% deuterium, 50% tritium) is a better fuel because it has a much lower ignition temperature and it produces more energy. One disadvantage (or should I say property?) of DT fusion is that each fusion event produces one 14 MeV neutron. This would normally be a problem, causing activation of the unshielded structural material near the blast zone, but, since BSF has no internal structure, there will be no neutron induced activation. Perhaps mentioning this is overkill, but it is highly improbable that even one single neutron would be able to transit across a BSF blanket, which is the first step a neutron needs to take in order to escape from inside the thick metal sphere of a BSF reactor.

    Q: If neutrons can be used to make materials for the clean-up of nuclear waste, are they still bad?

    BSF will also produce large quantities of depleted lithium (Li-7), a material highly prized by the LFTR folks who want to build thorium reactors to digest our stockpile of nuclear waste. A 1 GW LFTR is expected to require 17.9 tonnes of highly enriched (+99.99%) lithium 7. This amount of Li-7 could be efficiently produced in a DT fusion power plant, as a side-product, taking about 80 GWe years.

    #12259
    AvatarKeithPickering
    Participant

    Robert Hargraves is fairly down on LiF as a salt for LFTRs in his recent book Thorium: Energy cheaper than coal because the Li produces radioactive tritium inside a LFTR, in quantities higher than can be legally released into the air (in the US, anyway). That means you need a chemical process to capture and sequester the tritium, hence more expense. Instead, Hargraves suggests another fluoride salt be subsituted for LiF, such as NaF for example. Not as good a neutron moderator, but that can be finessed by putting graphite into the core.

    #12260
    AvatarJoeviocoe
    Member

    Has any confirmed BSF experiment ever produced ANY neutrons and ANY energy level?

    Is there ANY peer-reviewed (non-discredited) research that suggests that ANY fusion (even DT) can be achieved using this approach?

    #12265
    AvatarBSFusion
    Member

    KeithPickering wrote: Robert Hargraves is fairly down on LiF as a salt for LFTRs in his recent book Thorium: Energy cheaper than coal because the Li produces radioactive tritium inside a LFTR, in quantities higher than can be legally released into the air (in the US, anyway). That means you need a chemical process to capture and sequester the tritium, hence more expense. Instead, Hargraves suggests another fluoride salt be subsituted for LiF, such as NaF for example. Not as good a neutron moderator, but that can be finessed by putting graphite into the core.

    Thanks Keith.

    I do not have access to Robert’s book, but here is a discussion about lithium-7 usage in LFTRs.

    AFAIK, Natural lithium is a mixture of two different isotopes, 7.5% Li-6 and 92.5% Li-7. Because it has a high thermal neutron capture cross section (see ENDF chart), Li-6 is classified as a neutron poison. If Li-6 were present in a LFTR’s LF salt, unwanted tritium would be produced via neutron capture: Li-6 + n -> T + alpha, but if the salt only contained Li-7 this would not be a problem. That is why the advocates of LFTR are suggesting such high levels of enrichment (+99.99% Li-7).

    When reading the chart below, it is important to realize that the spallation events on the right side are not expected to occur inside a LFTR because the average kinetic energy coming from prompt neutrons, released by fissioning one atom of U-233 (thorium reactors produce/consume this), is only 4.9 MeV.

    Attached files

    #12266
    AvatarKeithPickering
    Participant

    Quoting Hargraves p. 237:

    Although most Li-6 was previously removed from the fuel salt, more is continuously generated by n + Li-7 -> Li-6 + n + n. Tritium also comes from n + Li-7 -> He-4 + H-3 + n. A 100 MW LFTR would generate 25 mg of tritium per day, responsible for 240 curies of radiation. The US legal emissions limit is 10 curies per day (although 5200 curies per day is allowed in Canada), so the tritium should be removed and sequestered where it can decay harmlessly with a 12-year half life.

    #12267
    AvatarBSFusion
    Member

    Joeviocoe wrote: Has any confirmed BSF experiment ever produced ANY neutrons and ANY energy level?

    There has never been an experiment performed on a completed BSF device, because BSF is only an idea, having just recently been discovered; the necessary, interconnected parts, do not exist together, as a whole, in one place, but, nevertheless, each of BSF’s subsystems has been verified to work in isolation, at least conceptually, based upon examples of proven technology.

    Joeviocoe wrote: Is there ANY peer-reviewed (non-discredited) research that suggests that ANY fusion (even DT) can be achieved using this approach?

    BSF’s approach to ignition is similar to the concept of an “exploding pusher,” as explained in Phys. Plasmas, Vol. 2, No. 11, November 1995:

    “…Higher implosion velocities are possible in certain types of high-entropy implosions, in which the high-density shell is heated rapidly to high temperature and then explodes. In a so-called “exploding pusher target,” the center of mass of the shell or “pusher” is almost stationary as it explodes. The radius of the boundary between the inner edge of the shell and the fuel typically converges only a factor of 3 or 4. Such targets are quite insensitive to asymmetry. The direct-drive, electron-conduction-driven exploding pusher target was the most common early ICF target and was the first type of target to produce thermonuclear neutrons…”

    Joeviocoe wrote: …The BSF problems and limitations are not known because nobody in the scientific community has even looked at it yet. So to claim that a problem is “solved” is way too premature. A patent application cannot identify the shortcomings in the design or theory. You MUST write the paper…

    I agree, patent applications are not held to the same standards as professionally written journal articles, and I pity the unfortunate patent examiner who’s job it is to process mine. I also agree with you that it would be easier for an outsider to scrutinize the key concepts of BSF if a peer reviewed paper were published. But, it would be foolish for me to start writing that paper. There are certain requirements, unknown to me, that must be adhered to if one wishes to write a such a paper. Perhaps if I had had more exposure to reading scientific articles, I might consider attempting to write my own, but my knowledge is limited to a few “Scientific American” magazine articles that I read many years ago at a local public library, before they stopped carrying that subscription. That said, I would still like to continue improving my patent application, filling in missing details and making it easier to read. You could assist with that project, by pointing out the things about BSF that you find questionable. I expect some mistakes will be found in BSF’s patent disclosure, because it is so complex. Perhaps someone with a special expertise or willingness to look at it with fresh eyes can examine it, because an opportunity for improvement may be more obvious to them. Please, let me know if any flaws or potential weaknesses are identified.

    Thanks

    #12268
    AvatarJoeviocoe
    Member

    BSFusion wrote:

    I agree, patent applications are not held to the same standards as professionally written journal articles, and I pity the unfortunate patent examiner who’s job it is to process mine. I also agree with you that it would be easier for an outsider to scrutinize the key concepts of BSF if a peer reviewed paper were published. But, it would be foolish for me to start writing that paper. There are certain requirements, unknown to me, that must be adhered to if one wishes to write a such a paper. Perhaps if I had had more exposure to reading scientific articles, I might consider attempting to write my own, but my knowledge is limited to a few “Scientific American” magazine articles that I read many years ago at a local public library, before they stopped carrying that subscription. That said, I would still like to continue improving my patent application, filling in missing details and making it easier to read. You could assist with that project, by pointing out the things about BSF that you find questionable. I expect some mistakes will be found in BSF’s patent disclosure, because it is so complex. Perhaps someone with a special expertise or willingness to look at it with fresh eyes can examine it, because an opportunity for improvement may be more obvious to them. Please, let me know if any flaws or potential weaknesses are identified.

    Thanks

    The patents will do nothing for you except waste your money. The is probably no chance that it would be built by someone else and happen to built similarly enough to your patented description. Take LPP for example, their patents are based on things actually built, and are specific enough to real devices within their apparatus… and NOT conceptual design patents that have never been tested in reality.

    Like I said, you need to contact the folks who have actually put in the work previously. The approach may be new, but the concept has been experimented with before. They stopped for some reason, and you need to find out why exactly. It could very likely be a fundamental flaw or assumption that is flat out wrong… that makes it an impossible approach.

    Right now, BSF is no where near being a contender. It lacks any resemblance to a scientific process.

    #12271
    AvatarBSFusion
    Member

    A thread titled “Is lithium in FLiBe going to cause unsurmountable problems?” has been started at a LFTR site.

    Please stay on topic here, and use this link to redirect there.

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