Jeffrey LewisSetting Expectations for a DPRK Test

North Korea’s announcement of an impending nuclear test refers to a “a nuclear test of higher level which will be carried out by it in the upcoming all-out action…”  Most people seem to be focusing on the possibility of a device using highly enriched uranium — which is probably right but maybe not the whole story.

DPRK officials have been dropping some interesting hints lately.  In August, the DPRK indicated that it would be “modernizing and expanding its nuclear deterrent capability beyond the U.S. imagination.”  That would seem to suggest we should should broaden our realm of possibilities.

I’ve been thinking about the possibility of a North Korean thermonuclear weapons test since 2010, after North Korea started talking about Korean style thermo-nuclear reaction devices.  (Not quite as catchy as Gangnam Style, eh?) Apparently, I am no longer the only crank.  The Asahi Shimbun recently published an article entitled, “DPRK Likely To Use ‘Fusion-Boosted Fission Bomb’ in Third Nuclear Test.” Tony Namkung, who took Google’s Eric Schmidt to North Korea, has said that it “will this time be a thermonuclear test.”  He must have had some interesting conversations in Pyongyang.

Sounds crazy, I know.  But I think we have to at least consider an early DPRK effort at a thermonuclear weapon of one sort or another.  (I am still inclined to think a boosted design like the Alarm Clock is more likely than a staged device.)  We’ve systematically underestimated both North Korea’s capabilities and, even when those capabilities are found wanting, the leadership’s resolve to try anyway.

I’ve been thinking about this possibility again for at least three reasons:

First, the more I think about the film The Country I Saw (for a summary, reread the piece I wrote with Hanah Rhee for 38North), the more I think thermonuclear weapons are the obvious goal for North Korea.  It sounds strange, perhaps, but thermonuclear weapons were the Chinese goal as early as the late 1950s. In 2002, Kang Sok-ju told Jim Kelly responded to evidence that North Korea was pursuing uranium enrichment by stating that North Korea was “entitled to possess our own HEU, and we are bound to produce more powerful weapons than that.” Kang may have committed the canonical diplomatic gaffe — saying what he really thought. (Tong Kim certainly thought, in context, he was talking about thermonuclear weapons.) Also, if Kim Jong Il wanted to bequeath his son some technical accomplishments to make his first year or so in power an eventful one, putting a satellite in orbit, testing an ICBM and detonating a thermonuclear weapon seem like pretty solid ideas. We may wonder about North Korea’s technical capability, but I don’t think the North Korean leadership will simply settle for a small number of relatively crude fission-type devices.

Second, consider North Korea’s statement following its 2009 nuclear test:

The current nuclear test was safely conducted on a new higher level in terms of its explosive power and technology of its control and the results of the test helped satisfactorily settle the scientific and technological problems arising in further increasing the power of nuclear weapons and steadily developing nuclear technology.

“Higher level” explicitly refers to both yield and technology.  What is really interesting, though, is the statement of purpose: “the results of the test helped satisfactorily settle the scientific and technological problems arising in further increasing the power of nuclear weapons and steadily developing nuclear technology.” KCNA could not have been more clear that these tests were leading to something larger. Tom Schelling likes to point out that many first nuclear tests are better described as “demonstrations” than tests. He’s right, but the North Koreans are going out of their way to make it clear that their nuclear events are both.

Third, the North Koreans themselves have been talking more about thermonuclear weapons, and thermonuclear war, in recent months.  In addition to the August statement, North Korean Vice Foreign Minister Pak Kil-yon said in October  that:

Today, due to the continued U.S. hostile policy towards DPRK, the vicious cycle of confrontation and aggravation of tensions is an ongoing phenomenon on the Korean peninsula, which has become the world’s most dangerous hot spot where a spark of fire could set off a thermonuclear war.

I don’t think Pak is describing a war in which the DPRK are the only thermonuclear victims. I’ve gone back and forth over whether to mention that Kim Myong Chol, an “unofficial spokesman” for the DPRK, has been saying that the DPRK is developing thermonuclear weapons for years.  Kim isn’t privy to such details and uncritically repeats any claim he reads in Western media that suit his particular bromide of the moment.  (His source on North Korea’s thermonuclear weapons seems to be John Pike.) I am going to stick with state media and DPRK officials, while adding that KCNA repeated Kim’s assertion that “Unlike the past Korean War which was limited to the Korean Peninsula, the second Korean War will turn into a thermonuclear war and naturally spill over into the U.S. mainland.” Whether or not Kim is right about the particulars, the party line seems to be that North Korea won’t be the only victims in a thermonuclear war.

Given all this, we should at least consider the possibility that, in addition to testing an HEU-based device, the North Koreans may burn a fusion fuel like Lithium 6. China detonated a 250-kiloton thermonuclear device on its third test, after a design program that lasted little more than a year. India conducted one test in 1974. Then, on May 11, 1998, India conducted three simultaneous nuclear tests — one of which they claimed was a thermonuclear weapon. (India conducted two more tests on May 13.) There are lots of reasons to believe that India’s H-bomb was a disappointment, but North Korea has hardly been deterred from testing by the prospect of failure. Our friends in Israel seem to have a thermonuclear weapon of one sort or another with no known tests, plus whatever might have happened on September 22, 1979.

If the US intelligence community thinks this is even a possibility, the Obama Administration should be managing expectations with allies now as Bob Gates did with the KN-08.  It would help to emphasize that bigger nuclear weapons wouldn’t really change our commitment to the defense of Japan and South Korea and that it would be suicide for North Korea to use a nuclear weapons of any kind.

I don’t want to be alarmist.  North Korea might simply test an HEU device or maybe a more efficient missile warhead.  If they do try something fancier, it may not work — which means we might never know what it was. But it is important to understand that the range of North Korean possibilities may be much larger than we normally describe.  We are not likely to get more hints than we have now, unless the DPRK publishes a picture of Kim Jong Un holding a soccer ball with a Teller-Ulam device drawn on a blackboard or starts sending scientists to international conferences with papers on thermonuclear fusion.

Comments

  1. John Schilling (History)

    Fusion boosting was my first thought as well. If you have the sort of nuclear devices we believe North Korea already has, and a working breeder reactor, giving fusion boosting a try is the obvious next step. Done conservatively, it doesn’t compromise the ability of the device to function as a pure-fission weapon of (if they keep the 2009 design) 4-6 kiloton yield, and if it does work you get a substantial increase in yield at little cost.

    My second thought is the ugly one: “Higher level” is ambiguous in English, and I don’t trust my ability to translate Korean from a dictionary. But, “higher” as in altitude? One of the things that often seems beyond U.S. imagination, at least if you listen to the official pronouncements, is that Those Ignorant Norkian Peons could possibly have figured out how to put a nuclear warhead on a missile. Official pronouncements that sometime seem to read as a reverse-psychology version of “I double-dog dare you to demonstrate a for real warhead…”

    And nothing you can do underground can really address that, where outside observers are concerned. But a Nodong launch followed by a 5-kt (or boosted 50-kt) airburst over the Sea of Japan, that would about do it. For several unpleasant values of “it”.

    Hopefully the phrasing is less ambiguous in Korean, and fluent speakers here can confirm that we are hearing specifically “more powerful/sophisticated” or the like. Because while a live-fire atmospheric test would be completely insane, I am only mostly convinced the DPRK’s leadership is just pretending to be insane as a negotiating strategy.

    • mark (History)

      “Working breeder reactor?”

  2. Anon (History)

    And most of North Korean is immune to EMP effects.

  3. Cthippo (History)

    There is a lot to be said for an atmospheric test in terms of prestige and to shut up those who say you don’t really have it. It’s also not something another country is likely to start a war over. Sure they would be likely to throw a three cornered fit over the fallout, to which the North Koreans would reply “So what, how many did you set off in the Pacific?”.

    A thermonuclear weapon, or at least device, certainly seems within the realm of the possible.

    In real terms though, I don’t think that it would make any difference in the strategic balance. Nuclear weapons work in the mind far more than in war, and once the other side has them, the actual details of how many and how big don’t much matter except to wonks.

    • John Schilling (History)

      The actual detail of “how big”, in the sense of weight, matters to a lot of people. If it weighs half a ton (and if the KN-08 isn’t a hoax), it directly deters the United States, and if deterrence fails it kills a few hundred thousand residents of Seattle and maybe Los Angeles or San Francisco. If it weighs a ton, it directly deters Japan and South Korea, only indirectly deters the United States, and in the event of a deterrence failure kills people in Seoul and Tokyo. If it weighs five tons, it deters nobody and kills nobody except maybe North Koreans.

      If it weighs half a ton and the United States Government mistakenly belives it weighs five tons, well, that might matter quite a bit. Says the guy sitting literally across the street from the largest military target in Los Angeles…

    • Cthippo (History)

      I would say it already deters the US from a policy of forcible regime change in North Korea, which was, to my mind anyway, the whole point.

      Despite the fact that they may or may not be able to deliver a functioning weapon anywhere past their own doorstep, they have made our crossing of that doorstep too costly to contemplate.

      Depending on the size of the weapon and the capability of their delivery systems they may be able to threaten South Korea (almost certainly) or Japan (very likely), but that is not the same as deterrence, especially in the latter case as Japan has no real capability to project force into North Korea.

      Just out of curiosity, what is the “Largest military target in Los Angeles”?

    • SQ (History)

      North Korea ain’t party to the PTBT, but if what appears at 38north.org lately is any indication, it will be another underground test.

      The North Koreans are determined to do their own thing and are fond of telling us to get stuffed, but maybe they’re not quite as heedless of others’ concerns as it might seem at first. Consider the rocket launches to the south, declarations of drop zones, etc. Or at least, they try to arrange matters so someone else is the villain.

  4. Peter Hayes (History)

    If the North Koreans start testing above ground in tiny Korea, and if they escalate their testing to thermonuclear weapons, then they increase the risk of pre-emptive attack on their rocket and nuclear sites from tiny to substantial; and if prudent, they should move their leadership underground full time, assuming they have any situational awareness left after so many years of isolation and paranoia.
    What Kim Myong Chol in Japan writes is not signicant. BTW, he once told me that the North Koreans have a traditional medical cure for HIV-AIDS; and he asked if the US would withdraw its troops if they made it available? I told him nothing would make the US more likely to keep its troops in Korea than the DPRK holding hostage millions of HIV-AIDS victims around the world–if they have such a cure.
    Also, the DPRK has been referring to escalation to thermonuclear war in a second Korean war for yonks. Indeed, this was their indirect way during the Cold War of invoking nculear extended deterrence from China and the FSU, w/o the latter’s permission of course. In a sense it was true–US forward-deployed nuclear weapons in Korea at that time were partly aimed at FSU and China, and one could expect in a great power nuclear war, that they would have nuked everyhing in South Korea that might have hosted a US nuclear delivery system. In reality, no-one really knows what they mean. This is a guessing game that they will continue until…we figure out how to shape the environment, not behaviors, in ways that meet our and their fundamental strategic interests. That is not difficult to do in a military sense. It’s just hard to do politically!

    • Jeffrey (History)

      Just to be clear regarding “Kim Myong Chol,” as I noted in the post he tends to simply repeat whatever Western reporting he finds convenient. The case I cited is different, however. In this case, KCNA summarized his article, drawing attention to certain passages. It is the act of KCNA repeating that I find significant, not Kim’s original utterance.

  5. George William Herbert (History)

    We’ll have to see, but it appears that the test prep is for an underground shot.

    Certainly hope it’s an underground test…

    Attempting to figure out what they’re going to test, given the state of our knowledge of their program, is a bit of a stretch. We know a bunch of things it might be. Figuring out which one or ones (possibility of multiple nearby tests a la India or Pakistan) get tested is an interesting what-if game, but not able to answer the question reliably…

  6. Jeannick (History)

    .
    I’m not so sure ,
    an atmospheric test would not be seen as a good idea by the Chinese,
    playing around with a small (or fizzed )
    underground nuke is fine .
    having nuclear air burst in the neighborhood would certainly be frowned upon
    When all is said and done , the DPRK is the Rottweiler
    of Beijing ,aggression and a lot of barking are what it’s all about , they are on a leash .
    we’ll see how hard Pyongyang will get its chain yanked

    • ulan (History)

      “When all is said and done , the DPRK is the Rottweiler
      of Beijing ,aggression and a lot of barking are what it’s all about , they are on a leash .” —- Jeannick

      Maybe israel and britain are rottweiler of yankee, but DPRK is ally of PRC, not so-called “rottweiler”.

      “we’ll see how hard Pyongyang will get its chain yanked” —- Jeannick

      You will get disappointed

  7. SQ (History)

    The more interesting question is the one Jeffrey has teed up for us. What will the test consist of? If it’s much more advanced than the last one, will it work? Can the North Koreans pull off in 8 or 9 years what the Chinese managed in 2 or 3 years?

    Also, do the Norks really imagine that a TN weapon will let them tell Beijing to drop dead? Do they think it’s that simple?

    Not much to add there, I’m afraid, but the questions get you thinking. The contrast with the throwaway piece in this morning’s New York Times does not drape the newspaper in beams of glory.

    HEU or not HEU? That ain’t the question.

    • Cthippo (History)

      Assuming that it is another underground test and that it doesn’t vent, is there any way we would know what it was fueled with?

      For that matter, is there any really significant design differences between a Pu and HEU bomb? I’ve always kind of wondered about this one.

    • Jeffrey (History)

      I can’t imagine a technical way to infer design that doesn’t involve venting, but the intelligence community might have information about the yield of a plutonium design that would provide a hint. There are certainly some people who think 2009 might have been HEU fueled. I simply don’t know.

      At a basic level, one can implode either plutonium or HEU. Plutonium is said to be preferable for miniaturization, but I do not know the precise thresholds at which differences become significant.

    • John Schilling (History)

      Many of the early US implosion-assembly devices were set up to use a range of composite cores with whatever mix of fissile materials made most efficient use of the national stockpile that week. Unless you are going for a particularly lightweight design, even a pure-plutonium pit is going to be surrounded by a substantial mass of heavy tamper, very likely natural or depleted uranium. So you’ve got an implosion assembly that’s optimized for compressing maybe 50kg of mostly-uranium, and it makes relatively little difference whether that is (say) 35 kg of DU and 15 kg of HEU, or 45 kg of DU and 5 kg of Pu, or anything in between.

      I don’t have a copy of “Swords of Armageddon” on this computer, but I think the Mark 7 bomb/warhead, ~750 kg all-up weight and yields up to ~40 kt, could use composite pits, while the Mark 12 at ~450 kg and ~15 kt was a plutonium-only device. And sufficiently wasteful of plutonium that it was deployed only in limited numbers.

      At the other extreme, the very largest pure-fission weapons tend to use HEU because it reduces the required degree of supercriticality – HEU is as energetic a fuel as Pu, but has a substantially greater critical mass. But this really only becomes significant at ~100 kt or so, is wasteful of HEU even then, and would be tough to fit on any of North Korea’s missiles.

      If they test underground (and it does look like that’s the plan), then barring venting we aren’t likely to know what the material is. A high yield, anything much above 40 kt, would strongly suggest fusion boosting, but as far as we know you can boost HEU or Pu devices about equally well.

      40 kt or less, will just look like an upgraded or debugged version of the 2009 test. Consistent with Gadget/Fat Man/Mark III if you want to believe the Norks can’t build actual missile warheads, W-5 or W-7 if you consider that they can, and still no way to distinguish HEU from Pu. 10kt or less, will almost certainly indicate a lack of (successful) boosting and still won’t tell us what fissile material was used.

    • Cthippo (History)

      Thank you Jeffrey and John for filling in that gap in my knowledge. I had read about them using different cores in the basic mark 3/4 design, but I hadn’t put the implications of that together until now.

  8. Rob Goldston (History)

    An exam question: A new test might provide North Korea and Iran with a validated, deliverable nuclear weapon design, based on HEU. They each might soon have the capability to produce HEU in abundance. What are the pros and cons, short-term and long-term, of interdicting such a test? On balance, what should the U.S. do? Your answers will be collected in an uncertain number of days.

    • Cthippo (History)

      Pros: None that I can think of

      Cons: Damage to international reputation of US

      Probable violation of international law

      Reinforces view of US as a nation that unilaterally tries to impose it’s will on other countries through violence.

      Pisses off China (who are MUCH more worried about US bombers next to their borders than the North testing another bomb).

      Low probability of success

      Likely to provoke aggressive reactions from North Korea, including possible military acts

      This discussion has come up in one form or another with every breakout nuclear test since China’s, and in every case the conclusion has been the same, it’s not worth it. In the case of North Korea who already has a limited nuclear capability the return on investment is even more limited.

      As to what the US should do?

      I would argue that there isn’t much we can do. We could probably come up with somehow even more draconian sanctions, but it’s hard to see that accomplishing anything. The military option is, or should be anyway, off the table for the reasons I’ve mentioned above.

      Sooner or later we’re going to have to comes to terms with the reality that North Korea is not really a special case amongst nuclear weapons states and as such needs to be treated the same way we treat other NWS when they conduct tests, which is to say “we really wish you wouldn’t do that” and live with the reality that we can’t make them not do something just because we would prefer they didn’t.

    • mark (History)

      By “interdiction” you mean what, exactly? Trying to stop such a test by physical/military intervention/intel sabotage/bombing the test site? Getting the UNSC or the UNGA to say it’s illegal and immoral? Getting ROK, Japan, US, Russia, and China to warn DPRK that that test would have [X] as a consequence? Getting the same group of states to urge the Dalai Lama or the Pope to condemn such a test? Assuming that its withdrawl from the NPT is legally valid (and I know there are some who believe it isn’t) then to my knowledge DPRK has not eschewed the right to test nuclear weapons.

    • John Schilling (History)

      Pro: Successful interdiction means North Korea has an unvalidated design for a missile warhead that will almost certainly work, rather than a validated design that will certainly work.

      Con: Attempted interdiction, successful or otherwise, means that we are in an actual shooting war with an enemy that has nuclear weapons that will almost certainly work, and could possibly reach CONUS targets. Also, they may well have a validated design that will certainly work at ~5 kt yield, depending on what was tested in 2009.

      The part of the plan where North Korea quietly and rationally accepts defeat because we can nuke them worse than they can nuke us, I’m not real confident about that.

      Or were you imaging some form of effective interdiction that didn’t involve acts of war?

    • Jeannick (History)

      .
      the Mega buck question indeed.
      could North Korea serve as testing ground for an Iranian design ,
      It would have to be HEU ,
      machined and assembled in situ from locally supplied Uranium
      under Iranian supervision .

      Is Uranium easier to shape than Plutonium ?
      I read somewhere that plutonium is a difficult material to work with

  9. Jamie (History)

    “Largest military target in Los Angeles”?

    Seal Beach Naval Weapons Station???

    • John Schilling (History)

      Seal Beach is in Orange County, and wouldn’t actually make for a very good target – lots of very hard and widely spaced bunkers in a relatively isolated area.

      Los Angeles has the appropriately-named Los Angeles Air Force Base. No runways or airplanes, but headquarters for the USAF Space and Missile Systems Center and surrounded by the facilities of several major aerospace corporations involved in building and operating space and missile systems, all soft and tightly packed. Plus lots of completely uninvolved civilians because hey, in the nuclear missile age, what could go wrong with putting military installations inside large cities?

      I’m not actually all that concerned for my physical safety (well, except when bicycling in to work…), but I would rather prefer that neither the US nor DPRK leadership do anything stupid enough to result in an exchange of missiles.

  10. Jeannick (History)

    .
    Los Angeles central is probably one of the few city center which would be improved by a thermonuclear explosion
    pity about the railway station ,

  11. Homer Williams (History)

    Why has there been no discussion of the nuclear fallout that would result from an aerial test or military use against any site (Pyongyang or Seoul) on the Korean peninsula? Certainly, that should give any sane person on either side pause about using nuclear weapons of any size anywhere on the peninsula.

    Also, most of the analyses I have seen of the latest missile launch seem to have concluded that the current design has range, but not accuracy, and there is no indication of the technology required to bring a nuclear weapon back through the atmosphere. So, are we speaking of technology available now or sometime in the future?

  12. Chris V (History)

    My biggest questions about a third North Korean nuclear test: U235 or Pu239? If it is Uranium, what if any involvement does Iran have? The test of a Uranium-based device could also be thought of as Iran’s first nuclear test assuming they are involved enough to know all of the details.

    If there is fusion-boosting then where did the DPRK get the Tritium? I don’t believe they have a working reactor so it would have to be stored from years prior and the supply would be finite. Tritium has a relatively short half life.

    North Korea carried out its last two nuclear tests on a Monday. The 2006 test was at 0500-zulu and the 2009 at 0100-zulu. This would be 2pm and 10am, local time respectively. It would still be late Sunday evening for the US East Coast.

    Maybe it is a coincidence or maybe those calling the shots chose the timing with the idea that news media and politicians will spend Monday thru Friday talking about it. On the other hand there could be some internal reason for the timing.

    • krepon (History)

      Superbowl Sunday?!?
      MK

    • ChrisV (History)

      Superbowl Sunday seemed like a possibility. While not a holiday, it is a big event.

      The 2006 test occurred on Columbus Day and the 2009 test on Memorial Day. The next US holiday is President’s Day, February 18. A day or so before the State-of-the-Union address has been floated as another possibility but seems less likely to me.

      I remember it was the 4th of July, 2006 when the DPRK finally tested the TD-2 for the first time. I was disappointed that the missile didn’t work well enough for the North to show the video so we could finally get a look at this thing. For a decade the TD-2 had been almost mythical. There were drawings of what it might look like and then there were satellite images of it on the launch pad but unfortunately no launch video until the 2009 test flight.

  13. ulan (History)

    at first, sorry for my poor english

    my private guess/opinion is that the third nuclear test of DPRK is such a device:

    1. the device is a Teller-Ulam Device

    2. the primary is 6kg HEU as fissile materials with HMX as explosive lens

    3. the secondary use LiD-6 as fussion material, DU as tamper material

    4. the expected yield is 100kt

    5. the size and weight of the device fit into Nodong or Musudan

    as for the “actual” yield in coming third test, I guess it could be 60-80kt.

    • George William Herbert (History)

      Six kilos of HEU? Really?

  14. ulan (History)

    btw., the size and weight of the device fit also into MPV/SUV/Pickup likes Hyundai hexa space.

    for a third world country with limited resource and limited missile technology, if the goal is to destroy L.A. in case of needed, nuclear guerrila is also an important option.

    If the DPRK bomb could get 80kt yield, then only 3-4 such type of bombs should be enough to destroy L.A., of course, the pre-condition is that the north korea special force manage to smuggle them to L.A. successfully.

    • John Schilling (History)

      North Korea will never need to destroy Los Angeles. There is very little benefit to North Korea in destroying Los Angeles, and the cost would be enormous.

      North Korea would derive a substantial benefit from being able to threaten to destroy Los Angeles, but only if the threat is both credible and enduring. Threatening to destroy Los Angeles with an atomic bomb you have hidden in a pickup truck, does not accomplish that. Either the United States Government does not believe you, or it does believe you and proceeds to search every pickup truck in Los Angeles. And then to destroy North Korea.

      Threatening to destroy Los Angeles with a nuclear ICBM based in North Korea, provided both the nuke and the missile have been tested, that is a credible and enduring threat.

    • George William Herbert (History)

      As John indicated…

      ICBMs are weapons of geopolitical deterrence or menace. From a nation’s home territory, they are secure and not an act of war to posess.

      A preplanted nuclear device in US territory is an act of war; putting one in place is bad enough, but threatening to use one is worse. The US will end any foreign regime that does so, and the risk of discovery and interdiction is very high before and especially after the threat.

      They don’t even vaguely usefully match any nation’s ambitions.

      As a one time actual strike, maybe, but anyone initiating nuclear war against the US has to know what will happen in response.

  15. ulan (History)

    Even without D-T boosting, only with 6kg HEU and a HMX explosive lens, it is still possible to get at least 3kt yield, which is enough to make the secondary working.

    ICBM is only a utility to delivery warhead to target, for example, Moscow, Peking, Pyongyang or L.A.

    That is ICBM.

  16. ulan (History)

    nuclear weapon is a perfect weapon for threaten and deterrence, during the cold war, the only role of nuclear weapon is deterrence.

    what will happen, if B-2 drop smart bombs to Pyongyang, even US force captured or killed Kim Jong Un himself, likes Saddam or Osama?

    Yes, nuclear weapon could be used for deterrence. However, nuclear weapon is also a perfect weapon for revenge, even Boeing-767 could also be a weapon for revenge, likes 911.

  17. ulan (History)

    “North Korea will never need to destroy Los Angeles.” — John Schilling

    To be frankly, I do agree with you.

    “Six kilos of HEU? Really?” —George William Herbert

    Yes, it is my private guess/opinion.

    In the year of 1964, the first chinese nuclear test use device “596”, which is a implosion HEU bomb, without any DT boosting, with TNT&RDX as explosive lens. About 16kg HEU was used to build the device 596. At last the test at 1964-Oct-16 got about 22kt actual yield, and the weight of device “596” is only 1550kg.

    Even without DT boosting, but with proper neutron source and well designed HMX explosive lens, it is possible to get at least 3kt yield with 6kg HEU.

    So far as we know, in the year of 2009, DPRK got 2.98 kt actual yield with 2kg Pu.

    Some guys maybe thought that the technical goal of DPRK 2006/2009 is a primitive device, likes Gadget or РДС-1, however… maybe the technical goal of DPRK 2006/2009 is not Gadget at all, but something likes W44/W45

    • George William Herbert (History)

      ulan writes:
      “North Korea will never need to destroy Los Angeles.” — John Schilling

      To be frankly, I do agree with you.

      “Six kilos of HEU? Really?” —George William Herbert

      Yes, it is my private guess/opinion.

      In the year of 1964, the first chinese nuclear test use device “596″, which is a implosion HEU bomb, without any DT boosting, with TNT&RDX as explosive lens. About 16kg HEU was used to build the device 596. At last the test at 1964-Oct-16 got about 22kt actual yield, and the weight of device “596″ is only 1550kg.

      Even without DT boosting, but with proper neutron source and well designed HMX explosive lens, it is possible to get at least 3kt yield with 6kg HEU.

      So far as we know, in the year of 2009, DPRK got 2.98 kt actual yield with 2kg Pu.

      Some guys maybe thought that the technical goal of DPRK 2006/2009 is a primitive device, likes Gadget or РДС-1, however… maybe the technical goal of DPRK 2006/2009 is not Gadget at all, but something likes W44/W45

      You appear to be falling victim to the fallacy that nuclear weapon yields scale roughly linearly with fissile mass, in any manner (for a given implosion system, or implosion system to pit weight ratio, or anything else).

      That is not true.

      The yield is to a degree exponential with the achieved maximum criticality of the assembly.

      For six kilos of HEU to generate a high yield would take roughly achieving the explosive’s detonation pressure as the achieved internal energy of the fully collapsed HEU core, which as a rule seems rather tricky to achieve.

      Not to mention, efficiency: If you look at the Server equations, you see that the critical mass radius (r_crit in Carey Sublette’s online treatment at nuclearweaponarchive.org) is a r_crit^2 factor in efficiency.

      I haven’t gone and modeled a bunch, but this is not striking me as likely. I do have a hunch and have made the argument that their test devices were likely much more advanced than a multi-ton “starter bomb”, for a number of reasons. I don’t believe that they would achieve world-class bleeding edge demonstrated implosion system performance with a first tested design. Not totally impossible, but you would have to show me the plans and test results.

      There is taking them seriously, and ascribing to them magic powers. I take them seriously. You’re bordering on magic powers…

      Given where you appear to be I am not sure how safe it is for me to start throwing shock compression model results around (much less, who else reads the blog comments here), so I don’t intend to go do a bunch of models and post results, but if you are or aspire to be a weapon designer and think you have NK’s design, and it supports that critical mass and those warhead dimensions, we can talk offline.

    • Jeffrey (History)

      You’re a gem, GWH.

  18. ulan (History)

    If anyone talk about “bombing north korea” seriously, he should look at “Sino-North Korean Mutual Aid and Cooperation Friendship Treaty” at first. ( http://en.wikipedia.org/wiki/Sino-North_Korean_Mutual_Aid_and_Cooperation_Friendship_Treaty )

    According to the Article 2 of the treaty, China should use “ALL” military measures to protect north korea. The original treaty text in chinese is “缔约双方保证共同采取一切措施,防止任何国家对缔约双方的任何一方的侵略。一旦缔约一方受到任何一个国家的或者几个国家联合的武装进攻,因而处于战争状态时,缔约另一方应立即尽其全力给予军事及其他援助”.

    According to article 2, “ALL” chinese military measures should be used to protect north korea, of course, including chinese ICBMs likes DF-5 and DF-31/DF-31A.

    http://en.wikipedia.org/wiki/DF-5

    http://en.wikipedia.org/wiki/DF-31

    • Jeffrey (History)

      I doubt the DPRK is as confident as you are that that the Chinese would make good on this treaty, especially given the manner in which the DPRK secured the commitment.

      China was, and is, hardly an eager protector and domineering to boot.

  19. ulan (History)

    If DPRK is “REALLY” confident, then Kim needs/will not to spend lot of money on his own nuclear missile program.

    Yet the treaty is still there, so far neither Peking nor Pyongyang declears that the treaty is already invalid.

    As I know, there are also many discuss in Peking on DPRK nuclear test issue recently. Some chinese reviewers say that it is the time to give up the trouble, just let american “solve the problem” with B-2 and Tomahawk. Meanwhile many other chinese reviewers insist that Peking should not repeat the failure of N.S. Khrushchev and M.S. Gorbachev, and Peking should give clear message to White House and Pentagon that the treaty is still valid.

    Lets suppose that US fires Tomahawk to Nyongbong, then NK fires Nodong missile to Yokosuka (with chemical warhead, maybe). What will happen next? Will Peking declear that the treaty is invalid immediately? Or will Peking send SAMs and Airfoce to NK?

    Peking is not Moscow, and Pyongyang is also not Belgrad.

    My “private” opinion is, if US really attacks NK with B-2 and Tomahawk, it could be a “Sarajevo Incident” in 21th century.

    • George William Herbert (History)

      A NK conventional response against a US base after a hypothetical US Tomahawk attack on North Korea is one thing. A chemical warhead would likely lead to nuclear war.

      It is stated US policy that attacks on us or our allies with weapons of mass destruction will be responded to in kind; the US only has nuclear WMD left.

      Perhaps that would not be the outcome, but I would certainly hope that other countries are paying attention to our policy statements in this regard and avoid testing the matter.

  20. ulan (History)

    “I don’t believe that they would achieve world-class bleeding edge demonstrated implosion system performance with a first tested design.” — GWH

    1. the REAL world-class edge could get 10kt yield with 2kg Pu, but not only 2.98kt likes DPRK test in 2009. Of course, DPRK had also no Tritium supply, otherwise they could get higher actual yield.

    2. their first test in 2006 is not perfect indeed, only 0.55kt actual yield.

    In 2006, about only 20 minutes before the test, DPRK notified Peking that DPRK will launch the test, the expected yield is 4kt and fission materials is 2kg Pu.

    “It is stated US policy that attacks on us or our allies with weapons of mass destruction will be responded to in kind; the US only has nuclear WMD left.” — GWH

    the US has actual no real nuclear policy, to be frankly, China announced that China will not use nuclear weapon against a non-nuclear country and will not use nuclear weapon at first. Yet US never made such announcement.

    So at least in china, when analysts talk about US nuclear policy and Sino-US conflict even Nuclear exchange SERIOUSLY, they will assume that US will make a massive sudden strike at first, with more than 600 W-76 warheads and 100 W-88 warheads.

    That is the reason why General Zhu Chenghu once said that china is already to accept “the destruction of all of the cities east of Xi’an.” ( http://en.wikipedia.org/wiki/Zhu_Chenghu )

    However, according to the Sino-DPRK treaty and the chinese nuclear policy, if there is a second korea war and US uses nuclear weapon already, then China may also use nuclear weapons.

    Well, it seems the korea issue could be a second cuban crisis.

    • George William Herbert (History)

      I wrote:
      “I don’t believe that they would achieve world-class bleeding edge demonstrated implosion system performance with a first tested design.” — GWH

      Ulan responds:
      1. the REAL world-class edge could get 10kt yield with 2kg Pu, but not only 2.98kt likes DPRK test in 2009. Of course, DPRK had also no Tritium supply, otherwise they could get higher actual yield.

      2. their first test in 2006 is not perfect indeed, only 0.55kt actual yield.

      In 2006, about only 20 minutes before the test, DPRK notified Peking that DPRK will launch the test, the expected yield is 4kt and fission materials is 2kg Pu.

      You’re waving your hands without addressing a whole host of actual physics and engineering.

      Are you a nuclear weapons designer?

      Do you understand what a condensed matter equation of state is? Fermi gas? Shock and isentropic compression of materials? Can you run the spherical Gurney implosion formula, or computer codes for implosion systems? Do you understand Rayleigh-Taylor instability? How to model non-ideal effects in implosions and shock impingement?

    • ulan (History)

      “Are you a nuclear weapons designer?” — GWH

      No.

      “Do you understand what a condensed matter equation of state is? Fermi gas? Shock and isentropic compression of materials? Can you run the spherical Gurney implosion formula, or computer codes for implosion systems? Do you understand Rayleigh-Taylor instability? How to model non-ideal effects in implosions and shock impingement?” — GWH

      Only some basic concept of them. As I said, I am not a weapon designer.

      But I DO know such FACTS:

      1. the test of DRPK in 2006 used 2kg Pu and the expected yield was 4kt (assuming the notification of Pyongyang to Peking was right), the actual yield was 0.55kt

      2. the test of DPRK in 2009 got 2.98kt actual yield.

      3. with high technical capability, it is possible to get 10kt yield with 2kg Pu. With low technical capability (likes Gadget 1945), it is possible to get 10kt yield with 5kg Pu, or 20kt yield with 6kg Pu.

      There is also such information (I can not confirm the content): According to NKSIS (eng.nksis.com), after collapse of Soviet Union, some soviet scientists went to DPRK.

    • George William Herbert (History)

      Ulan wrote:
      Only some basic concept of them. As I said, I am not a weapon designer.

      But I DO know such FACTS:

      1. the test of DRPK in 2006 used 2kg Pu and the expected yield was 4kt (assuming the notification of Pyongyang to Peking was right), the actual yield was 0.55kt

      2. the test of DPRK in 2009 got 2.98kt actual yield.

      3. with high technical capability, it is possible to get 10kt yield with 2kg Pu. With low technical capability (likes Gadget 1945), it is possible to get 10kt yield with 5kg Pu, or 20kt yield with 6kg Pu.

      There is also such information (I can not confirm the content): According to NKSIS (eng.nksis.com), after collapse of Soviet Union, some soviet scientists went to DPRK.

      Let’s restate this.

      In 2006, DPRK conducted an underground explosion, of sub-kiloton yield (various claimed yields from 100 tons to as high as 12 kilotons, centered on 250-600 ton yield). They stated it was going to be a nuclear test. Initial reports did not detect radioactive materials in the air, though later ones did. Leaks from China indicated that DPRK may have told China that it would be a 4 KT target yield, and also that it would use 2 kilograms of Pu. Official DPRK media did not repeat those numbers, to my knowledge.

      It is unambiguously true that there was an earthquake, which is uniformly interpreted as an explosion.

      Given the announced nuclear test, earthquake, and radiation, there is pretty uniform acceptance that it was a nuclear test, but that is not factually proven.

      The alleged 4 KT target is entirely reasonable, lending credibility to the leaks from China.

      The 2 kg Pu is possible but very aggressive for a first weapons test. DPRK’s limited Pu supply would push them to try to conserve material, but that small a pit is very technically difficult. That leak, or that detail of that leak, raise questions as to credibility.

      You are asserting that we can take all of the above conclusions and rumors as true, without skepticism or detailed review and analysis. Without understanding how the engineering and science of nuclear weapons work, you are asserting that the 2 kg claim is reasonable and then wildly extrapolating from there.

      You do not know that the 2 kg is true. At best, we might accurately know that that’s what DPRK told China, though that is not proven either. That could well be an inaccurate report on what DPRK told China. DPRK also could have lied to China regarding the fissile content. DPRK also could have tried a 2 kg weapon and determined they didn’t have enough fissile material, so the second test might have required 3-5 kg to achieve the apparent and reasonable 4 KT yield target. Which the second test probably hit or came close to hitting.

      WE DO NOT KNOW – FOR A FACT – ANYTHING ABOUT THE TEST’S CORE BEYOND THAT THERE WAS A RUMOR OF 2 KG Pu.

      I understand how you may be fooled here. Understanding the quality of information sources, grading whether assertions are lies, myths, assertions, guesses, estimates, or known truth is hard. But you have to do that sort of analysis – and understand the technology – to extrapolate in a useful manner.

      If you start with something that is no better than an assertion, and do not understand the underlying technology and physics, you can’t extrapolate.

      If you try doing that, it is magic, not science or engineering. Magic is not useful in technical or policy discussions or debates. If you are fooling yourself with your magic, that is unfortunate. Please take this as an opportunity to learn more about how nuclear weapons work and how intelligence analysis works.

    • ulan (History)

      “In 2006, DPRK conducted an underground explosion, of sub-kiloton yield (various claimed yields from 100 tons to as high as 12 kilotons, centered on 250-600 ton yield). They stated it was going to be a nuclear test. Initial reports did not detect radioactive materials in the air, though later ones did. Leaks from China indicated that DPRK may have told China that it would be a 4 KT target yield, and also that it would use 2 kilograms of Pu. Official DPRK media did not repeat those numbers, to my knowledge.” — GWH

      according to the measurement and calculation of chinese national academy, the yield of 2006 event(I do not use the word “test” intendly) is 0.55kt, which is very high confident.

      “It is unambiguously true that there was an earthquake, which is uniformly interpreted as an explosion.” — GWH

      yes, the seismic wave is different between explosion and a real earthquake. It was an explosion without any doubt.

      “Given the announced nuclear test, earthquake, and radiation, there is pretty uniform acceptance that it was a nuclear test, but that is not factually proven.” — GWH

      There is even no radiation in 2009 event at all. However, most people accept that the 2006 even and the 2009 event are all nuclear test.

      “The alleged 4 KT target is entirely reasonable, lending credibility to the leaks from China.” — GWH

      yes

      “The 2 kg Pu is possible but very aggressive for a first weapons test. DPRK’s limited Pu supply would push them to try to conserve material, but that small a pit is very technically difficult. That leak, or that detail of that leak, raise questions as to credibility.”

      I think DPRK has their logic. Their goal is not a primitive likes gadget at all, but a working TN-Bomb trigger. DPRK knows clearly, they have not many chance to make nuclear test, every test will be (and is, indeed) a political bomb. Also, they have very limited Pu supply. So, why not choice a higher goal? There is much of technical difficulty indeed, yet such a higher goal is still not impossible. They could make subcritical test without any awareness, their computer is also far advanced than the computer once used by Teller and Ulam in 1950… Even with help from some “soviet scientist”, at least in china, rumor said many of them went to DPRK NOT only for money.

      The so-called “credibility” has not an important priority for them, they need a working Teller-Ulam weapon (I do not use the term “device but the term “weapon” here intendly) for themselves. As the first step, a 4kt yield trigger is very logical for them. The “credibility” issue should be solved by their Teller-Ulam weapon, but NOT by the trigger itself.

      “You are asserting that we can take all of the above conclusions and rumors as true, without skepticism or detailed review and analysis. Without understanding how the engineering and science of nuclear weapons work, you are asserting that the 2 kg claim is reasonable and then wildly extrapolating from there.” — GWH

      As you know, except seismic wave, nobody get any further information, even no radioactive gas leak.

      KH-12 can also not help to get further information.

      However, personaly I do believe that 2kg claim is reasonable.

      Just look at the fact, even no radioactive gas leak, which means that at least the underground nuclear test containment technology of DPRK is NOT a “beginner”. Yes, it is not a direct proof, but… you know what I mean, eh?

      “You do not know that the 2 kg is true. At best, we might accurately know that that’s what DPRK told China, though that is not proven either. That could well be an inaccurate report on what DPRK told China. DPRK also could have lied to China regarding the fissile content.” — GWH

      Its true. Lying to China is also possible, but personally I do think that this possibility is really not so big.

      “DPRK also could have tried a 2 kg weapon and determined they didn’t have enough fissile material, so the second test might have required 3-5 kg to achieve the apparent and reasonable 4 KT yield target. Which the second test probably hit or came close to hitting.” — GWH

      its possible, however I do think/believe that DPRK still uses 2 kg Pu in 2009. Because their work is for themselves, they are working for themselves.

      If you are the leader scientist of DPRK team, and your personal goal (also the goal of Kim) is to making a working Teller-Ulam weapon. After 2006 test with 0.55kt actual yield, which is far from expected 4kt result, what will you do? will you increase the usage of Pu to make the second test easier? Or will you still insist 2kg Pu and try to improve the explosive lens and neutron source to achieve a much better result later?

      Just tell me, which one will be your choice?

      I may tell you, If I were the guy, I would insist 2kg Pu and try to improve the explosive lens. Because my ultimate goal is a 100kt yield weapon with acceptable size and weight limit.

      “WE DO NOT KNOW – FOR A FACT – ANYTHING ABOUT THE TEST’S CORE BEYOND THAT THERE WAS A RUMOR OF 2 KG Pu.” — GWH

      You are right. However given the special relationship and the historical background between Peking and Pyongyang, personally I do think that DPRK did not lie to Peking in 2006.

      “I understand how you may be fooled here. Understanding the quality of information sources, grading whether assertions are lies, myths, assertions, guesses, estimates, or known truth is hard. But you have to do that sort of analysis – and understand the technology – to extrapolate in a useful manner.” — GWH

      Maybe we will never know the truth. Maybe we know it already, just without any so-called “proof”.

      “If you start with something that is no better than an assertion, and do not understand the underlying technology and physics, you can’t extrapolate.” — GWH

      given the fact that outsider has ONLY seismic wave record, even without any radioactive gas leak, we HAVE TO start it with some assertion.

      “If you try doing that, it is magic, not science or engineering. Magic is not useful in technical or policy discussions or debates. If you are fooling yourself with your magic, that is unfortunate. Please take this as an opportunity to learn more about how nuclear weapons work and how intelligence analysis works.” — GWH

      Thank you, LOL!

  21. ulan (History)

    Lets continue the suppose:

    1. US fires Tomahawk to Nyongbong

    2. DPRK fires Nodong to Yokosuka with Sarin warhead

    3. US B-2 drops a B-61 with 170kt yield to Hamhung, which is a “chemical industry city” in DPRK

    4. China fires a DF-21A with 90kt warhead to Guam

    …….

    Lets suppose that step 4 happened, after the step 4, what would be the reaction of US?

    • George William Herbert (History)

      Let’s not suppose. That’s supposing China’s new leadership are madmen.

      If that is true you all are doomed over there. I certainly hope it is not true. I see no signs it’s true.

    • ulan (History)

      “Let’s not suppose. That’s supposing China’s new leadership are madmen.” — GWH

      The topic is a mad topic.

      “If that is true you all are doomed over there. I certainly hope it is not true. I see no signs it’s true.” — GWH

      I will say the same thing to you.

      So whats the conclusion?

      The conclusion is: maybe US should get used to live with such a fact, DPRK has bombs, and they will build more of them. Soon or later, DPRK will also solve the reentry problem.

    • ulan (History)

      in the article of Mr. Xue Litai 薛理泰 (http://opinion.huanqiu.com/opinion_world/2013-01/3603107.html), his original text in chinese is:

      至于“增强型原子弹”,仍然属于原子弹,却在核装料中加入了高浓缩度的锂6(高浓缩度的锂6既可以用于核弹的装料,也可以用作核聚变动力堆的核燃料),爆炸当量小于氢弹,却大于原子弹,一般介乎五六万吨至二三十万吨高爆炸药。

      my english translation is:

      as for “boosted atomic bomb”, it is still an atomic bomb, however there is high enriched Li-6 in the nuclear materials (high enriched Li-6 could be materials for nukes, may also be nuclear fuel for nuclear fusion power reactor), the yield is smaller than hydrogen bomb, yet bigger than atomic bomb, usually between 50-60kt to 200-300kt HE.

      Geez, hard to believe how did this guy get his position at Stanford.

      GWH, why do you not write an email to Stanford (FSI-CISAC), just let Stanford fire this guy and do not waste money on his wage anymore?

  22. ulan (History)

    To be frankly, if a nuclear exchange with China/DPRK is an option for pentagon, they had better do it early, at best do it now.

    Nowadays China has still very limited JL-2 SLBM, only several dozen of DF-31/DF-31A and about 20 DF-5 ICBMs.
    Hence there is still chance for Pentagon to destroy most of chinese ICBMs and try a field test with GMD and rest DF-31.

    In worst case for China/DPRK (also the best case for US), Pentagon may try to launch massive sudden strike with roughly 1400 warheads to destroy all of chinese DF-31/DF-31A and DF-5, and C3I facilities and so on…

    At last, only very few DF-31A could survive such an attack. say, there are only 5 DF-31A could survive, then the task for GMD is only to intercept 5 DF-31A, each with 3 warheads.

    You see, its still a nice chance for Pentagon.

    The only risk is, if china fires almost all of DF-31/DF-31A and DF-5 before Trident D-5 SLBMs reaching their goals, after about 30 min. these DF ICBMs will delivery at least 80 warheads to at least 50 US cities, they are 20 5Mt yield warheads of DF-5, 15 1Mt yield warheads of DF-31 and 45 90kt yield warheads of DF-31A.

    If Pentagon does not launch such an attack now, after a few of years, China will build more DF-31A ICBMs and JL-2 SLBMs, the number could be much more than today, which will make first striking and intercepting being much more difficult.

    • Juuso (History)

      “At last, only very few DF-31A could survive such an attack. say, there are only 5 DF-31A could survive, then the task for GMD is only to intercept 5 DF-31A, each with 3 warheads.”

      DF-31 is a single warhead missile and there has been no evidence to show otherwise.

      This is claimed to be pic of the DF-31 RV and it’s clearly too large for DF-31 series to carry more than one.
      [IMG]http://i.imgur.com/ChUBHes.jpg[/IMG]

    • ulan (History)

      the chinese code for DF-31 is “东风-31”, and DF-31A is “东风-31甲”.

      Yes, DF-31 is a single warhead missile, the warhead has 1Mt yield.

      However, DF-31A DOES exist, and it CAN carry 3 MIRV warhead, every warhead has 90kt yield (similiar with W-76).

    • ulan (History)

      DF-31 is NOT DF-31A, likes Trident C-4 is NOT Trident D-5

      This photo is DF-31A (东风-31甲,3 MIRV, about 90kt yield for each one, 12000 km range):
      http://slide.mil.news.sina.com.cn/slide_8_457_1460.html

      This video is DF-31 (东风-31, single warhead about 1Mt yield, 8000 km range):
      http://news.ifeng.com/history/video/detail_2012_05/09/14419169_0.shtml?_from_ralated

    • Juuso (History)

      Where do you get information that DF-31 is armed with one 1MT warhead? I’m aware that wikipedia and few other sites claim that figure, but I have never seen their sources for it. Jeffrey put’s the yield at around 500kt and nuclearweaponarchive at 600-700kt.

      To my knowledge there has not been any pics of the DF-31A with it’s payload shroud removed, so how you know it carries three 90kt MIRVs?

    • ulan (History)

      “Where do you get information that DF-31 is armed with one 1MT warhead? I’m aware that wikipedia and few other sites claim that figure, but I have never seen their sources for it. Jeffrey put’s the yield at around 500kt and nuclearweaponarchive at 600-700kt. ” —Juuso

      Sorry, I can not tell you my information source on this topic, and I can not talk on this topic any further.

      “To my knowledge there has not been any pics of the DF-31A with it’s payload shroud removed, so how you know it carries three 90kt MIRVs?”

      I do have some proof, but I can not talk on this topic any further.

      Just take it as “rumor”, believe it or not, up to you.

    • Jeffrey (History)

      I am happy to have such rumors. I can be transparent. My 500 kt estimate is based on two bits of information.

      John Lewis, writing with Xue Litai and then Hua Di, claimed the goal was 500 kt or 600 kt.

      The yields of the last test series were around 90 kt. Under the 150 kt threshold test ban, the US assumed it could build new weapons up to about 500 KT through scaled tests.

      So, I figure around 500 KT, give or take. If someone told me it was a few hundred KT more or less, well okay.

      On mass (and girth), which would be necessary to MIRV, the US estimated the smallest PRC RV was 470 kg. I have no basis to object to this estimate.

    • Juuso (History)

      “Sorry, I can not tell you my information source on this topic, and I can not talk on this topic any further.”

      All your information seems to come from wikipedia and certainly not from some secret PRC vault.

    • ulan (History)

      “All your information seems to come from wikipedia and certainly not from some secret PRC vault.”

      my information does not comes from “secret PRC vault”, thats true, however, I have information source which are NOT wiki and I have also some proof indeed.

      For example, I can tell you, the surname of the leader chinese scientists who solve one of DF-31A reentry issues is “Pan”, the surname of another important chinese scientist who solve one of DF-31A rocket engine issues is “Cui”. You will not find such information on wiki.

      OK, I have talked too much on this topic, there will not be any conversation on this topic.

      Just take it as “rumor”, believe or not, up to you.

    • ulan (History)

      “Xue Litai and then Hua Di” —— Jeffrey

      Xue Litai, I think you refer to 薛理泰 at Stanford (FSI-CISAC), eh?

      If so, I may tell you, last week Mr. Xue wrote a text on third DRPK test issue in chinese, in this text, he wrote so: China used “high enriched lithium-6” to get boosting effect at May.9.1966 chinese test. Yes, his original words in the text is “high enriched lithium-6”. Maybe GWH will tell you how false it is.

      This web link is the text of Mr. Xue Litai in chinese:
      http://opinion.huanqiu.com/opinion_world/2013-01/3603107.html

      as for Mr. Hua Di, well, Mr. 华棣 is a rocket scientist, but not a nuclear weapon scientist. Maybe he can tell you the range of DF-5, but his words on specification of chinese nuclear warhead is also not so reliable.

    • ulan (History)

      in the article of Mr. Xue Litai 薛理泰 (http://opinion.huanqiu.com/opinion_world/2013-01/3603107.html), his original text in chinese is:

      至于“增强型原子弹”,仍然属于原子弹,却在核装料中加入了高浓缩度的锂6(高浓缩度的锂6既可以用于核弹的装料,也可以用作核聚变动力堆的核燃料),爆炸当量小于氢弹,却大于原子弹,一般介乎五六万吨至二三十万吨高爆炸药。

      my english translation is:

      as for “boosted atomic bomb”, it is still an atomic bomb, however there is high enriched Li-6 in the nuclear materials (high enriched Li-6 could be materials for nukes, may also be nuclear fuel for nuclear fusion power reactor), the yield is smaller than hydrogen bomb, yet bigger than atomic bomb, usually between 50-60kt to 200-300kt HE.

      Geez, hard to believe how did this guy get his position at Stanford.

      GWH, why do you not write an email to Stanford (FSI-CISAC), just let Stanford fire this guy and do not waste money on his wage anymore?

    • George William Herbert (History)

      Ulan wrote:
      in the article of Mr. Xue Litai 薛理泰 (http://opinion.huanqiu.com/opinion_world/2013-01/3603107.html), his original text in chinese is:

      至于“增强型原子弹”,仍然属于原子弹,却在核装料中加入了高浓缩度的锂6(高浓缩度的锂6既可以用于核弹的装料,也可以用作核聚变动力堆的核燃料),爆炸当量小于氢弹,却大于原子弹,一般介乎五六万吨至二三十万吨高爆炸药。

      my english translation is:

      as for “boosted atomic bomb”, it is still an atomic bomb, however there is high enriched Li-6 in the nuclear materials (high enriched Li-6 could be materials for nukes, may also be nuclear fuel for nuclear fusion power reactor), the yield is smaller than hydrogen bomb, yet bigger than atomic bomb, usually between 50-60kt to 200-300kt HE.

      Geez, hard to believe how did this guy get his position at Stanford.

      GWH, why do you not write an email to Stanford (FSI-CISAC), just let Stanford fire this guy and do not waste money on his wage anymore?

      I do not read Chinese and am unwilling to criticize without a more solid translation, but…

      The most common boosting is gas. Hoever, documentation of Li6-D solid boosting, also known as pill boosting, exists. Reportedly it is harder to make work compared to gas boosting.

      Also could be describing an Alarm Clock / Layer Cake design ( see http://www.nuclearweaponarchive.org/Nwfaq/Nfaq4-3.html#Nfaq4.3.3 ).

      Or he could be wrong.

      Without more insight into the Chinese I am not in a position to know more precisely what was said or whether that seems accurate. On this level of detail mechanical and non-expert translations are typically not precise enough.

    • Jeffrey (History)

      My best guess, based on not too much evidence, is that CHIC-3 was an Alarm Clock/Layer Cake type device.

    • George William Herbert (History)

      If that was referring to CHIC-3 then there are a lot of claims CHIC-3 was an Alarm Clock / Layer Cake type device, yes.

      I don’t know if anyone has gotten an official Chinese government statement to that effect, but it’s a widely shared belief. I don’t have any specific insight into CHIC-3 so only can go on what others have found and written.

    • Jeffrey (History)

      The Chinese historical description of that test is available here: http://www.dtic.mil/cgi-bin/GetTRDoc?Location=U2&doc=GetTRDoc.pdf&AD=ADA358815 At the time, they announced it “contained thermo-nuclear materials.” http://www.sinoperi.com/beijingreview/Articles-Details.aspx?id=24141&lang=EN# In other histories, CHIC-3 is omitted as though it is not a “real” test of a “hydrogen bomb.” Add the fact that it was airdropped, and I think it’s probably an Alarm Clock/Layer Cake.

      2. The first exploratory test

      Theoretical research concerning the hydrogen bomb had to be closely integrated with testing. In the process cf theoretical research during 1965, an atomic bomb test containing thermonuclear materials was carried out to derive measured data on thermonuclear materials fusion and examine the accuracy of theoretical calculations. After more than one-half of research, the Beijing Institute of Nuclear Weapons decided on a theoretical design program. During the development of the thermonuclear material components, manufacturing these very chemically active materials into components that met technical requirements required solutions for a whole series of technical and technological problems. To complete this task within the specified time period, engineer Song Jiashu and others undertook experimental research concerning finishing technologies, mechanical processing moisture-proof coatings and other aspects and also studied rather difficult finishing problems as well as several different technical measures. After less than a year of feverish work, they mastered the technical processes and manufactured thermonuclear material components that met specifications. At the same time, they decided on diagnostic measures for thermonuclear reactions in the area of testing technologies. This nuclear test was carried out on 9 May 1966. An “internal activation indicator agent” was used for the first time in this test and measured a total neutron count of 14 MeV. This provided data on equivalent amounts of thermonuclear material fusion and also permitted exploration of the remaining tritium in the gas samples used. The results of the experiments showed that the nuclear reaction process was basically identical to the theoretical predictions. This provided measured data for research on the principles of the hydrogen bomb that was being done at the time and provided the researchers with a better understanding of the laws of thermonuclear fusion.

    • ulan (History)

      1. Mr. Hua Di went to US in 1989, from 1989 to 1998 he stay in US, in 1998 he returned to China and get arrested immediately at airport. From 1998 to 2008 he stayed in Prison.

      Hence, Mr Hua Di has no idea what happened in China after 1989.

      Besides, Mr Hua Di is a rocket scientist, but not nuclear weapon scientist. He knows the size and weight of warhead of DF-5, but as for the yield, maybe his information is also not so reliable.

      As for Mr. Xue litai, the guy has actual no basic idea on nuclear weapon and nuclear science at all. Mr. Xue litai used to be a director of an important HK newspaper from 1979 to 1984. His higher education major was not science and engineering at all, but chinese literatur and chinese history.

      2. the first chinese nuclear test in 1964, used a design similiar with “air lense” for implosion lens component, likes US “Swan”-test, e.g., the design is more advanced than Gadget.

      3. the CHIC-3 test get actual yield 80-120kt, not so-called 200-300kt at all. The main purpose of CHIC-3 test is to get more information on the physic features of Li-6D. The design of CHIC-3 is similiar with Alarm Clock/Layer Cake.

      4. the first chinese nuclear test with beryllium is in 1969

      5. the first chinese TN-Bomb test in 1967 used a different configuration than Mike/Bravo. The primary is actually A2923, the secondary is 596L, the energy transfer is X-rays refractor contains cooper and aluminium. the actual yield of first chinese TN-bomb is about 3.3Mt

      6. the most advanced chinese nuclear warhead is similiar with W-87 and W-88, including size and weight of RV. The diameter of chinese primary is about 4cm larger than the primary of W-87. However, it does not mean that the Cox Report is correct.

      7. the first chinese neutron bomb test was in 1982, and in 1988 china mastered neutron bomb technology, at that time, Mr. Lee wenho had still not contact with china at all.

      8. in moment Peking get annoied for further nuclear test of DPRK indeed, but it does not mean that Peking will allow US to attack DPRK. Just like when you were still a child, sometimes your father would kick your ass if you did something wrong, however it did not mean that your father allowed some guy shot you with .44 at the moment. So please dont make any false decision.

  23. ulan (History)

    “China was, and is, hardly an eager protector and domineering to boot.” — Jeffrey

    As you know, my english is very poor, maybe I will get false understanding to your words. If my understanding is wrong, please correct me.

    My understanding is that you do NOT believe China will risk a nuclear exchange with US for DPRK, maybe you think that Peking will NOT do anything to protect DRPK free from any military attack.

    To be frankly, there are lot of facts which support your opinion.

    For instance, since 1990, China did not really help DPRK to improve its economy but bought billions US national debt, most of such US national debt will lose their value due to Inflation. In 1999 even a B-2 bombed chinese embassy in Belgrad “by mistake”, China had still not done anything. In 2010 US sold Taiwan lot of weapons, yet Peking still bought many Boeing-787. Nowadays there are also many public discussion in China and the topic is if China should just give up DPRK and let american “solve the trouble”. etc., etc…..

    However, “China was … hardly an eager protector”, well, please just go to DC and see the korean war veterans memorial. 54,246 US soldiers lost their life, 103,284 US soldiers wounded, 7,140 POW, 8,177 US soldiers “missing”.

    So, maybe you can say “China is hardly an eager protector”, but please do not use the word “was”.

    Whatever, so far the Sino-DPRK treaty is still there, neither Peking nor Pyongyang declares that the treaty is invalid officially.

  24. Jeannick (History)

    .
    The U.S. has no need to use nukes on NK
    even if WMD had been used
    conventional weapons could hammer the North with impunity
    leaving the U.S. of A. as the absolute good guy
    China would NOT respond and might even help

    Nukes are not weapons as such ,
    they are the end of the road.

    • ulan (History)

      “China would NOT respond and might even help ” — Jeannick

      General Douglas MacArthur used to also think so in 1950

  25. ulan (History)

    Ok, I have talked too much here, now I will leave here for a while.

    Nice to meet u guys.

    Last but not least, three video clips as my gift to u guys:

    http://v.youku.com/v_show/id_XNDk3NDQ3ODY4.html
    DPRK 2013 new year concert

    http://www.youtube.com/watch?v=gafGphvoh74
    Polyushko pole ( Полюшко поле ) – chinese version

    http://www.youtube.com/watch?v=6DTBvOfZi0Y
    12.12.2012 Unha 3/Kwangmyŏngsŏng-3 2 Ынха-3/Кванмёнсон-3 2

  26. George William Herbert (History)

    We have a winner:

    http://earthquake.usgs.gov/earthquakes/eventpage/usc000f5t0#summary

    Jeffrey has already been quoted by CNN:

    http://www.cnn.com/2013/02/11/world/asia/north-korea-seismic-disturbance/index.html

    Magnitude around 4.9, which works out to somewhat upwards of 10 kilotons, if the seismic data holds up.

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