Chemistry and Physics

Nuclear Weapons: Is North Korea a Threat?

Recently, no fewer than five nuclear testing reports have come out of North Korea, a state that seems to be detonating weapons of mass destruction unnervingly often. North Korea (or The Democratic People’s Republic of Korea) is possibly the most repressive state in the world, with a maddening system of totalitarian control, leader-hero worship and its secret service dedicated to punishing people for thought crime.

In light of the recent nuclear weapons testing, it is firstly important to ask what a nuclear weapon is, and what it means for this country to test them. One must understand which countries have confirmed nuclear arsenals and what this means for the international community.

Five states are formally accepted to have nuclear weapons and have also agreed to support an effort towards non-proliferation. They are: the USA, UK, Russian Federation, France and China.

Additionally, Israel is also believed to have nuclear weapons but has neither confirmed nor denied this. Pakistan and India are confirmed to have them, and although they have signed ‘peaceful use’ treaties, have not signed non-proliferation treaties.  A further five nations are confirmed to have at least partial control and responsibility in times of war: Germany, Belgium, Turkey, the Netherlands and Italy, with some fears that Saudi Arabia may make a similar deal with Pakistan.

North Korea is the next country believed to have nuclear weapons, with some ambiguity as to their nature.

There exist two types of nuclear weapon:

The first kind are fission atomic bombs, and they derive their destructive power from and operate exclusively through fission. These are the ones that were dropped on Hiroshima and Nagasaki. ‘Little boy’, the bomb that hit Hiroshima, caused 1.1 square miles of total annihilation, 4.4 miles of destruction, and killed 70,000–80,000 people, with the equivalent energy of 16 kilotons of TNT. Even so, by modern standards, such a weapon is tame.

The nuclear fallout generated by such a weapon poses a serious long term and possibly inter-generational risk to health, as demonstrated in Japan. The most dangerous isotope Iridium-131 persists in the environment, and takes roughly 80 days to decay to a ‘safe’ level.

Initially, nine weeks after the explosion saw most deaths from thermal injuries and radiation poisoning. Then there are the intermediate and late periods of 10-20 weeks, during which some deaths occur as a result of radiation. The delayed period was marked by damaged fertility and blood disorders. Hiroshima survivors also had a roughly 25% higher chance of dying from cancer than the average member of the Japanese population.

The other, more modern type is a hydrogen bomb. The hydrogen bomb derive its initial energy from fission, but the majority of the explosion comes from fusion of three isotopes of hydrogen. These are much more powerful, and thus the ones about which we are most concerned. The largest payload, tested by the USSR, generated an explosion of 50 megatons which is over 1000 times more powerful than the bomb dropped on Hiroshima. The only ‘plus’ to such a horrifying device is that it generates less nuclear fallout.

Currently, the best information available indicates that North Korea has never detonated a modern hydrogen bomb, but that they have managed to detonate an atomic bomb. Although it has been confirmed that North Korea has tested nuclear weapons, those with a payload greater than that of ‘Little Boy’; two questions need to be addressed if we are to determine whether North Korea has full nuclear capability. Do they realistically have the capacity to manufacture these weapons, and do they have the missiles to deliver them?

Siegfried Hecker, a nuclear scientist from the US, toured the North’s main Yongbyon nuclear facility in 2010 and has written a report on what he estimates North Korea to be capable of producing. His report on a Johns Hopkins University website states that he estimates there to be a large stockpile, sufficient to produce material for about 20 bombs by the end of 2016.  This estimate seems to be on the lower end when compared to other reports. Now that they actually have the technological capability and infrastructure to create the bombs themselves, this may be considered a serious international problem.

North Korea has been confirmed to have short-range missile capabilities which have a range of about 1000km, which easily puts Seoul and parts of Japan at risk. More seriously, the oppressive and antagonistic state is also very likely to have medium range ballistic missiles. Medium range extends as far as 3000km away from the launch site. Although for the last few years, North Korea’s capacity to launch medium range missiles has been limited, as of August 2016, North Korea managed to fire a Rodong missile that travelled 1000km and landed in Japanese economic zone waters, prompting strong condemnation from Japan. Fortunately the University of Nottingham is a nice and safe 5,330 miles from Pyongyang. North Korea seems to be a long way off developing long range missiles, which have a minimum upper range for 5500km and can potentially reach most places on earth; although the state is currently working on such technology and has published false evidence to give the impression of having it. However, a senior US military General, John Hyten, has expressed concerns that the arrival of such technology is closer than we think and should be a concern.

The issues that the regime are yet to overcome are: the effective miniaturisation and sufficient protection of warheads upon re-entry. Re-entry is a process at which the active part of the missile is propelled back into the atmosphere proper and drag suddenly becomes significant. Although there is some evidence that North Korea has managed to miniaturise nuclear weapons and sufficiently attach them to the warhead of a missile.

Although the current status of North Korea is very different from that of a nation like the US or Russia, which can realistically deliver a nuclear strike almost anywhere around the world within an hour, it is obviously a severe problem for the international community. In light of North Korea’s turbulent relationship with other nations, and the regime’s well documented capability for cruelty and disregard for human life, its testing of nuclear weapons may be a chilling portent of what is to come.

Dale Claridge

Image: Charles Levy via Creative Commons.

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