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North Korean Nuclear Weapons, why enrichment?

  1. May 2, 2017 #1
    It is my understanding there are two alternative paths to a bomb, one which the North Koreans have possessed for over 30+ years which is a graphite moderated natural uranium fuel reactor.

    A 3rd path is the possibility of doping Thorium to produce short lived 233-protactinium and separate this product before it decays into 233-Uranium. Which maybe the bomb characteristics may be very different for a 233-U bomb, or even to be triggered by 233-U (even though I've read that there have been 233-U/239Pu bombs that weren't fizziles).

    So why all this focus on enriched 235-U like it's some holy grail?

    Is this just fluff to the masses that the media doles out? For instance a big part of shutting down Iran's bomb making ability was to control its plutonium pathways which arguably are now fully controlled (fuel is given, spent fuel is collected, reprocessing is validated to not have occurred).

    <Moderator's note: Political comment removed>
    Last edited by a moderator: May 3, 2017
  2. jcsd
  3. May 2, 2017 #2
    Instead of going into detail about your question, I recommend you study the history of the Manhattan project and the path they took towards the bomb. Two good books are the Smyth Report and Applied Nuclear Physics by Pollard and Davidson. I like these two sources because they explain the physics theory that was known at that time. Another good source is the now declassified tutorial that was given to new hires at Los Alamos who were working on the bomb. These sources help us understand why certain decisions were made. Of course thorium was studied. Decisions were based on technical and military considerations. Additional unclassified information about breeder reactors and the importance of plutonium are available online. Of course centrifuges play a vital role in the whole process.

    <Moderator's note: Political comment removed>
    Last edited by a moderator: May 3, 2017
  4. May 2, 2017 #3
    The second nation to develop nuclear weapons, the USSR, was not 'allowed' to do so by the US, it did so independently.
    In the case of the UK and France, their bombs could well have been intentional sharing of the technology with trusted allies.
  5. May 2, 2017 #4


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    So you would have recommended World War III to strip Russia of nuclear weapons?
  6. May 2, 2017 #5
    I do not want any kind of war with anyone. The idea was prevention. I should have just referred people to the Baruch Plan and then stayed on the technical side. There's lots of interesting topics there, including missile defense. The USA has now deployed THAAD in South Korea. Will it work? Hopefully we will not find out.

    Sorry, I need to stay away from this topic.
  7. May 2, 2017 #6
    The path they took to the bomb was constrained by the lack of understanding at the time that Boron was poisoning graphite moderation and preventing graphite moderated natural uranium fuel reactors. I recall seeing that the German Uranverein was prevented from producing sufficient quantities of plutonium because they couldn't get their graphite moderators to work for this reason, and with a starvation of Heavy water from Norway(?) when that facility was attacked, any pathway to plutonium without enrichment was shut-down.

    If I recall correctly the Manhattan project was overly complex including a program that collected 16,000 metric tons of Silver that inevitably got scrapped in favor of a gaseous diffusion process.

    They hadn't even invented the centrifuge enrichment process at that time, at least not into production quality.

    The goal of the Manhattan project was to get the bomb, period, and had numerous inefficiencies and glaring over-sights compared to with what is available today.

    So it's a great starting point but I think in the context of Iran vs. North Korea there's a bit more going on that weren't available to the scientists and engineers of the Manhattan project. I'd like to know more about the less mainstream methods, more about why they aren't chosen today after greater advances in the fuel cycles, moderation, and reactors to breed fissionable products.

    Mainly I don't see why centrifuges play a vital role when, as mentioned, graphite reactors can produce the 239Pu, and Thorium can produce the 233U fissionable triggers?

    Not sure about the solution to Nuclear Proliferation process. It seems the case of policy paralysis. "The entire world will be destroyed if you don't make the right decision, what's your decision?" typically leads to paralysis and no decision.

    It got out of control with a bomb-making arms race, early Nuclear reactor technology seemed more easy to control for peaceful purposes, and just seems to have spiraled out of control from there?
    Last edited by a moderator: May 3, 2017
  8. May 2, 2017 #7
    Can we get this down to a specific issue.please.
    Are we talking about the proliferation of nuclear weapons as a matter of global political concern,
    or are we talking about the most efficient methods of producing nuclear weapons?
  9. May 2, 2017 #8
    It's more along the lines of why does public discourse only seem to talk about the least efficient method to produce nuclear weapons. 235U enrichment?

    Is there reasons that a graphite moderated reactor producing 239Pu is not sufficient?

    Is there a reason that doping Thorium and extracting 233U is not sufficient?

    Or is the other reason something like, because those are less police-able we "ignore them"...out of sight out of mind kind of thing?
  10. May 2, 2017 #9
    According to many reports, North Korea is working on both uranium and plutonium bombs. It already has lots of uranium.

    This article addresses at least some of your questions.


    One good quote is "So a U-bomb is easier to make, but a Pu-bomb is better to have."

    Recall that Little Boy was a simple uranium bomb. Fat Man was a plutonium bomb. The history books say there was no need to test the uranium bomb because they were confident it would work. That is why the first atomic bomb test was the prototype plutonium bomb.
  11. May 2, 2017 #10
  12. May 2, 2017 #11
    Yeah, if fission bombs are possible, which they are,
    then Plutonium bombs can do more damage than Uranium bombs
    and ...
  13. May 2, 2017 #12
    Hey @IDNeon I see you are a new member. I hope you enjoy the forum. It really is very good. I am fairly new myself. We have had discussions in other threads about the nuclear issue. It's a very hot button issue, so to speak, for obvious reasons.

  14. May 3, 2017 #13


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    Staff: Mentor

    Indeed. I would like to remind everyone that discussing politics is no longer allowed at PF.
  15. May 3, 2017 #14

    jim mcnamara

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    Staff: Mentor

    @DrClaude - we've tried to clean up the thread a bit. Sorry if it confuses you.
  16. May 3, 2017 #15
    Good editing and from now on I think I will just discuss logic and mathematical equations. The world is so simple if I just stick with that. Besides, for me politics is like diet soda and Facebook. The longer I stay away, the better I feel.


    [EDIT] I deleted most of this post because I'm getting tired of my own opinions. I remember something I read in philosophy class about the view of the Greeks on knowledge vs. opinion. We need more knowledge and less opinion. Perhaps in place of opinion, we need logic alone.

    Did Mr. Spock even have opinions? Or would that be un-Vulcan?
    Last edited: May 3, 2017
  17. Jul 5, 2017 #16
    The problem with U-233 is the need for remote handling. Whether you attempt to remove proactinium from blanket material just out of the neutron flux, or if you take u-233 (and the accompanying u-232) from blanket material which has had a little time to get past the high intensity shott half life isotopes, this isn't something workers can be close to for long.
    Thus means chemical extraction through robots and cctv (which is more difficult than it sounds), or dealing with having to continually train workers to a high level of proficiency in a very technical field because they get sick and become unable to work after a relatively short period of useful work.
  18. Jul 7, 2017 #17
    Also, gamma rays from the U-232 and its daughters are energetic enough to damage electronics. A lot of extra shielding might be needed to protect the detonation circuitry. They also make it harder for people to steal U-233 material safely and without being easily detected.
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