Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

How big of a threat is North Korea?

  1. Feb 12, 2005 #1
    At CNN.com:
    Shortly after the U.S. response, the Pyongyang diplomat, Han Song Ryol, said six-nation talks were over and that the real issue is whether the United States intends to attack North Korea.

    North Korea has offically annouced that it has nuclear weapons for self defence.


    How big of a threat is this? tommarrow, I will be 17. I plan on working at a nuclear power plant (What fields would I have to know in colleage for this?), and/or NASA. I'm really paranoid that North Korea will nuke us or japan, I thought I'd post it here because .. well the subject is Nuclear Engineering and you people seem to know alot about nuclear power. If korea did bomb us, what would it do?

    Would the bomb have enough power to wipe out a big city such as LA, or the entire country? How powerful would this bomb be?

    I know the basics of how a atomic bomb works, but I'd like to know more information.
  2. jcsd
  3. Feb 12, 2005 #2
    If someone will attack the U.S (out of any country that could), you can bet that it will be Nth Korea, especially now that they have gone nuclear...

    You can blame your President for that, he's a filthy terrorist.

    Regardless of my views the only possible country that looks to have the ability against the all powerful U.S is Korea. Nothing you can really do at the moment - but try to get that idiot of a President out of there.

    The problem is that politics controls the armed forces...
    If only the Armed forces controlled all military applications, then some sense would prevail and war would only occur if a country tryed to attack another.
    But that's not the case, and this is a Nuclear Engineering Forum.

    So let's talk Nuclear - not Politics

    Not sure what type (or what Yield) nuclear weapons Nth Korea claim to have. Probably fission triggers, maybe thermonukes - but that is unlikley.
    It really depends how much nuclear weapons were detonated over land - to make any accurate predictions of what type of destruction would occur. Even after the hypocenter and blast zones - the most deadly is the radiation - and the wind will carry these partciles quiet a long way. These particles will probable cause adavanced leukemia. But that is if they detonate them. With a President like Bush, who needs enemies.
    Last edited: Feb 12, 2005
  4. Feb 13, 2005 #3
    Basic information regarding nukes and small-scale nuclear attacks

    Being nuked is not as big of a threat now as it was in the eighties. There are things you can do to prepare for a small-scale nuclear attack that can make life more pleasant than it might otherwise be for you after the fact.

    If you want to be a reactor operator, you will need a high-school diploma. If you want to be a nuclear engineer, you need to select a school that grants accredited degrees in that field. Here is a list:

    All nuclear engineering departments in the United States are jonesing for students. Call or write to any of those school's NE departments and they will send you free information packets. They will also offer free campus tours. You should take them up on those offers. At many schools, high-school students are invited to and able to sit down and talk with nuclear-engineering professors. You can ask them what their programs are like, what you need to do to achieve your particular goals, and what kinds of jobs are out there for nuclear engineers. Todd Palmer (of the Oregon State University department of nuclear engineering), for one, is a young nuclear engineering professor with a lot of energy and enthusiasm. He loves to talk to prospective NE students. Here is his academic web page with his office phone number:

    Don't be afraid to call him. He's a very nice guy.

    Here is a list of every class that you have to take to graduate from Oregon State University's four-year nuclear engineering program:

    Basically, like in any engineering field, you need to take a lot of calculus. You should study as much calculus as you can before entering college. It would also help for you to learn at least one computer math program such as Matlab, Mathematica, or Maple; learning all three of those would be excellent.

    I talked to professor Jack Higginbotham at the Oregon State University department of nuclear engineering about this and he told me it is highly likely the U.S. will be hit by a sole nuke sometime in the next few decades. One nuke (or two or three) won't be a big deal if we are prepared. It would have about the same effect or less as a Florida hurricane, and I don't know of anyone suggesting that Florida should be permanently evacuated simply because it is prone to hurricanes.

    North Korea is trying to keep details secret (in order to maximize its bargaining/diplomacy power), so we can't know that. For perspective, however, both India and Pakistan have been testing nukes that only yielded a few hundred tons of TNT equivalent. Hiroshima was about 15,000 tons of TNT equivalent, for comparison. I wouldn't expect North Korea to do any better than India, so we may be looking at very weak nukes here (if any exist at all; North Korea has never tested a nuclear device and may not have any devices at this time). It should also be considered that if North Korea tries to deliver a nuke in a ship, as opposed to an airplane or a missile, what will occur is a ground burst instead of an air burst, and ground bursts are much less effective than air bursts at destroying property.

    Megawatts and Megatons by Garwin and Charpak:

    Also, the number one best place on the web for all types of information concerning nuclear power and nuclear weapons is Jim Hoerner's Yahoo discussion group Know Nukes:
    Last edited by a moderator: May 1, 2017
  5. Feb 13, 2005 #4


    User Avatar

    Staff: Mentor

    To put hitssquad's numbers in perspective (I actually didn't know nukes could even be that small), Hiroshima and Nagasaki were small to medium-sized cities. A total of maybe 150,000 were killed. A similar-sized bomb in LA could kill a similar, if somewhat higher, number of people. A bomb that could "wipe out" LA would need to be hundreds of times larger and there is no chance that North Korea could make such a bomb for some decades. No single bomb exists that could wipe out our entire country - though the Russians have (if the bombs still work) enough bombs to do that.

    Another issue is delivery: North Korea's delivery systems are still relatively primative: think Scuds. There is some debate over the actual accuracy of such missiles, but certainly they won't have the range to even reach Hawaii for some time.

    Japan and South Korea have the most to fear from a North Korean nuke.
  6. Feb 13, 2005 #5


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    N. Korea's missiles can hit Alaska as well, although S. Korea and Japan would be my guess for targets as well...
  7. Feb 14, 2005 #6


    User Avatar
    Science Advisor

    Your professor Higginbotham doesn't know what he's talking about!

    A nuclear weapon - even a crude one that a rogue nuclear state or
    terrorist group could deliver is going to have a much greater impact
    than that of a Florida hurricane. Perhaps you misunderstood him.

    A typical hurricane has a total energy that would exceed many nuclear
    weapons - but it delivers that energy in an extended period of time.
    A nuclear weapons delivers its energy quickly - a sizeable fraction of
    which forms a blast wave that mows down everything in its path - to say
    nothing of the fireball that vaporizes everything within its radius.

    Although large hurricanes can cause tremendous damage - they don't
    level cities the way Little Boy leveled Hiroshima.

    It is foolish to underestimate the impact of a rogue nuclear weapon
    this way - and Prof. Higginbotham is doing a grave disservice.

    Dr. Gregory Greenman
  8. Feb 14, 2005 #7


    User Avatar
    Staff Emeritus
    Science Advisor

    from http://www.infoplease.com/spot/hiroshima1.html

    It's hard to know how much yield to expect from a North Korean warhead, but I would expect that they were trying for a bomb similar to Nagasaki.

    An air burst (like those of Hiroshima and Nagasaki) over a populated area like NY City or LA, would probably kill several hundred thousand or even in the millions very quickly, and many hundreds of thousands would die within years.

    The damage to the economy and infrastructure would be in the $100's billions. Immediately, there would be many more fires and no way to extinguish them, except in the peripheral areas not directly affected by the blast. Medical facilities within 60+ miles would be overwhelmed, and essentially unable to treat all the victims.

    As Morbius indicated, do not underestimate the severity of a nuclear attack.

    This thread is not of a technical nature and is more appropriate for the Politics and World Affairs forum.
    Last edited: Feb 14, 2005
  9. Feb 14, 2005 #8


    User Avatar
    Science Advisor


    Correct you are.

    Look what happened after 9/11; the FAA grounded commercial air
    traffic for fear that terrorists would repeat the type of attack on the
    World Trade Center and the Pentagon.

    Imagine that terrorists are able to smuggle a nuclear device into the
    USA via cargo container on a ship, or in the back of a truck, or....

    The response to such an attack would be to immediately close the ports
    to shipping, close the borders to ground shipments... - in other words to
    totally shutdown international commerce for fear that another one of
    those shipments contained another nuclear device!

    This is a very serious problem - and you can be sure that scientists are
    stepping up to answer the challenge:



    What we don't need are those that don't understand the problem and
    try to minimize those impacts.

    Dr. Gregory Greenman
  10. Feb 14, 2005 #9


    User Avatar
    Science Advisor


    If a crude nuclear device - like a Nagasaki bomb - were to be exploded in
    a city with the population density of New York City; then we're probably
    looking at something like 3 million casualties.

    [If memory serves, a report to that fact was released some time back.
    The makers of the movie "Peacemaker" must have read that report -
    in one scene, the 3 million casualties figure is cited if the nuclear bomb
    in the possession of the terrorist they are pusuing in Manhattan; is
    detonated. ]

    In other words, a nuke delivered on the island of Manhattan will be
    roughly a thousand times worse than the World Trade Center attack.

    Dr. Gregory Greenman
  11. Feb 14, 2005 #10
    Damn Big of a threat! I'm a army brat so at times I'm a little more at speed than the genrall public is about the army and the global commuinitte and in my honest opinion i belive we need troops on the boarder of south korea and in the waters surrounding n. korea as well as in other nabboring countries and then we need to attack them because one not only do they have tese weapons but there is evedence that they are selling them to terrorist groups like Al-Quida so I say we as a global commuinitty need to give them the choice of life or death (either they give up the wmd's or we attack them)
  12. Feb 14, 2005 #11
    Clarification of what Higginbotham has said regarding present nuclear attack danger

    http://ne.oregonstate.edu/people/faculty/higginb.html [Broken] (paraphrased by hitssquad) ----> ...it is highly likely the U.S. will be hit by a sole nuke sometime in the next few decades.

    Chris Allen (hitssquad) ----> One nuke (or two or three) won't be a big deal if we are prepared. It would have about the same effect or less as a Florida hurricane, and I don't know of anyone suggesting that Florida should be permanently evacuated simply because it is prone to hurricanes.
    Last edited by a moderator: May 1, 2017
  13. Feb 14, 2005 #12


    User Avatar
    Gold Member

    How big of a threat is this?

    It depends on (1) Does the bomb actually work (I'm not aware of much testing conducted by N. Korea, and without a test it is something of a hit and miss proposition to use a new military system even for U.S. defense contractors)? (2) Does N. Korea really want to use it (it has used its nuclear capabilities as a bargaining chip before and could easily be doing so again)? and (3) What delivery mechanism does it have?

    Assuming (1) and (2) are in the affirmative, Japan and S. Korea are most at risk from a N. Korean missile attack, although one could imagine a seaborne N. Korean missile brought into a U.S. port in e.g. a shipping container, or on a submarine. Seoul and Tokoyo are far more at risk than Anchorage or Oahu or L.A. or Seattle or Portland. New York City would likely be attack by North Korea only via a shipping container style attack. It is hard to imagine a N. Korean attack on an inland target like Phoenix or Denver even if it did have a working nuclear missile.

    A small nuclear bomb could level the core of a city and kill a like amount with radiation afterwords, it would not, however, destroy the entire country. It would take hundreds of state of the art sized nuclear bombs to "wipe out" the entire country. The deaths would be largely a product of population density because a bomb of a given size "wipes out" only a particular land area. An attack in San Francisco would kill far more people than an attack in Anchorage.

    Still the numbers would be in the hundreds of thousands, if not millions, in a high density urban area and would be far worse than any hurricane. By comparison, the worse peacetime disasters in the history of the world from man made sources like Bophal and Chernobyl have killed several thousand people, the Titanic killed 1,503 people, the deadliest sunk ships in history (in 1945) killed 7,000-9,000 people (the Wilhelm Gusloff and the Goya), the worst tornado in history killed 689 (March 18, 1925), and the "Perfect Storm" that formed the basis for the movie in 1900 killed about 8,000 people in Galveston (this and Hurricane Mitch which killed about 10,868 in 1998 were the highest death toll storms in North or South American history). There have been a number of Bangladesh cyclones, Chinese floods, major earthquakes and volcano erruptions that have killed numbers of people similar in death tolls comparable to a nuclear blast, but most have impacted intensely poor areas with residents who lived there and failed to take precautions simply because they had no other options.

    (1) and (2) are hardly sure things. Certainly, N. Korea could be annilated in retaliation, although it isn't clear that a U.S. President would want to kill millions of N. Koreans with nothing to do with the attack just out of spite. One would expect an effort to counter-attack first the vicinity of the launch site.

    Also, (2) doesn't serve much of a military purpose if directed at a major population center. Blow up Los Angeles or Tokoyo or Seoul, and you insure massive vengenece and no negotiations. The N. Korean government would be gone in a flash. An attack on even a less populated target, say Juneau or Maui or Nagasaki (cruel irony) would also produce a Pearl Harbor like reaction. The idea of a nuclear weapon is to threaten further action and convice the opposition you're crazy so as to bring them to the table. More plausible targets would be the Kuril Islands (Russia), Ryuku or Okinawa Islands (both Japan, the later with a large U.S. military presence), or some other small island in the East China Sea or Sea of Japan. Indeed, a nuclear test on N. Korean soil might be even more effective. Recent non-nuclear ballistic missile tests by N. Korea seem to be aimed at the same effect.

    I think a nuclear attack is also far less likely by the current regime, as the current leader has shown a strong desire to install his son as ruler, establishing a dynasty and indicating long term thinking which might see that the long term interests of the regime would not be served by a nuclear attack, than it would be, e.g. by a coup regime or provisional regime, installed after the assassination of the ruling family, which would be in a state of panic, not looking at the long term, and eager to establish their authority both at home and abroad.

    Also, the target of an attack could be influenced by a proposed missile defense system. An attack might actually be more likely if the U.S. has a missile defense system, and a N. Korean ruler might conclude that a defeated missile attack would provoke less of a response than a successful one, but over estimate the effectiveness of the defense system (which so far doesn't work: http://www.cbsnews.com/stories/2005/01/12/national/main666433.shtml). But, if there is actually a missile attack, you'd be glad we had a missile defense system, if it worked.

    Personally, a missile seems like a rather unlikely method of deliverying a nuclear attack by a N. Korea or terrorist group. Why invest in sophisticated missile technology that your opponent has invested billions in countering to deliver a nuclear attack, when a suicide bomber on a cargo freighter or fishing boat or yatch could do the same thing?
    Last edited: Feb 14, 2005
  14. Feb 14, 2005 #13


    User Avatar
    Science Advisor


    What if N. Korea got their weapon design from Pakistan's A.Q. Khan?

    Recall that one of the Pakistani weapons scientists, one A. Q. Khan;
    had been selling nuclear technology that the Pakistanis had developed.
    If Khan sold N. Korea a complete weapon design - then they have a
    tested weapon design - Pakistan tested it in the mid '90s.

    Nuclear weapons in the hands of N. Korea means that they can use it as
    a bargaining chip - perpetually.

    There's always "clandestine delivery" - you don't need a missile or a
    bomber; you just ship the weapon to your adversary.

    Courtesy of UCLA, consider the following from a speech by UCLA's
    Chancellor Albert Carnesale, a former professor of nuclear engineering:


    "We must also address the security of our borders. For example, the
    cargo containers that come into our country every day - by ship, by rail,
    and by truck - are large enough to hold many nuclear weapons. A nuclear
    weapon could fit in the trunk of your Toyota. You don't need a cargo
    container. Approximately 2% of cargo containers are inspected when
    they enter the United States. And what about all of the trucks, trawlers,
    and people that enter our country? The prospects for sealing our borders
    are not encouraging."

    You are, of course, ASSUMING you can attribute the nuclear destruction
    of New York to a given entity - the North Koreans. If a big chunk of
    New York city disappears in a mushroom cloud - what degree of
    assurance does the President need in order to retaliate against the
    proper perpetrator? The responsible party or parties may not
    claim responsibility.

    Which is why the missile defense is not being designed to mitigate attacks
    due to clandestine delivery. The missile defense system is for an entirely
    different scenario. There are multiple defenses for multiple scenarios
    and attack modalities - don't confuse them by running them together.

    Dr. Gregory Greenman
  15. Feb 14, 2005 #14


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    I haven't read any of the posts here but the OP's, so forgive me if this is redundant.

    As far as I know, the Taepodongs (I and II) are not capable of delivering a chemical, biological or nuclear payload. I believe only the short range Nodongs can take nuclear warheads.
  16. Feb 14, 2005 #15


    User Avatar

    Staff: Mentor

    Wait, did he used to be a Navy submarine officer? I learned differential equations from a LtCdr. Higginbotham (sp?) at the Naval Academy about 5 years ago. He was the weps officer on a sub that ran aground - not his fault, but it its still a career-ender. He is a nice guy though - and one of the best teachers I've ever had.
    It remains our stated policy to respond to a WMD attack with, essentially, total annihilation. However, I would like to think that any President actually faced with such a decision would show some restraint. And against a country like N. Korea, since they have, at most, only a handful, we would still be able to conduct a conventional war after they had done whatever they could do with their nukes.
    I'm willing to let this get a little political since nuclear weapons are, after all, strategic (political) weapons. An anti-tank missile isn't in play when its in a bunker somewhere, but a nuclear bomb most certainly is. And questions like "can one be smuggled in to NYC?" are both technical and political questions. That said, I have some purely technical questions:

    Morbius, what is your opinion of the odds that
    -a: North Korea has a nuclear weapon? and
    -b: That weapon would actually function without a successful test?
    (edit: ok, that's only half technical - you have to weigh how much you trust our friend Kim...)

    Next, regarding something said earlier, it was my understanding that to make a bomb with a yield of less than about 10kt requires some pretty sophisticated technology - meaning that most crude, 1st effort bombs will be in the 10-30kt range. Is that correct?
    Last edited: Feb 14, 2005
  17. Feb 14, 2005 #16
    How to make a wimpy nuke

    I don't know. He's been at OSU since 1987 and his picture is at his CV link which I posted:
    http://ne.oregonstate.edu/people/faculty/higginb.html [Broken]

    Higginbotham seems to be a popular name.

    If you walk down a hallway carrying three quarters of a critical mass and another person walks toward you carrying three quarters of a critical mass of the same isotope, a bomb will be assembled as you pass each other that will yield less than 10kt. It will not be a sophisticated bomb. The slower the assembly, the less the yield. The more premature the initiator neutron, the less the yield. If you want a sub-10kt yield, you could use even-numbered (from reactor-grade plutonium blends) plutonium isotopes since they give off neutrons more frequently. You could also set your neutron initiator to fire early. For an example of the last, Little Boy included a neutron initiator to make sure it fired. Setting that neutron initiator to fire just as a single critical mass was being assembled - as opposed to when it did fire which was after 1.5 to 2 critical masses had been assembled - would have caused the bomb to fizzle, and there would be our small yield.

    Using extremely small amounts of fissile material is another way to make a yield small, and I understand that that is difficult since the less the mass of fissile material, the more precise the bomb workings have to be in order to get it to assemble at all.
    Last edited by a moderator: May 1, 2017
  18. Feb 14, 2005 #17


    User Avatar
    Staff Emeritus
    Science Advisor

    Here is some background on Pakistan's program - assuming FAS is reliable.


    The question is then, what technology did Pakistan provide to North Korea - and what components. If Pakistan provided the package so that N. Korea need only assemble a pit, then in theory, they may have a 12-15 kT warhead, or if they got a boosted device, maybe up to 35 kT.

    Of course its all speculation at this point. Perhaps NNSA/NSA have specific intelligence, but that would not be in public domain.
  19. Feb 14, 2005 #18


    User Avatar
    Science Advisor
    Homework Helper

    Besides US and Russia,who else has functional thermonuclear device/intelligence??

  20. Feb 15, 2005 #19


    User Avatar
    Staff Emeritus
    Science Advisor

  21. Feb 15, 2005 #20


    User Avatar
    Science Advisor
    Homework Helper

    I have a crazy idea.Why don' the Americans do what the russians did in '62...?Get a couple of rockets+bombs oven into Okinawa,just in case...
    Would the Chinese & the Russians have something against it...?


    P.S.And if they do,why wouldn't the Americans allow the Japanese to develop nuclear capacities...?After all,60 years is a long while...
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook