December 1998

Some notes on nuclear weapons

Introduction into nuclear weapons

Nuclear weapons belong to the group of weapons of mass destruction. Nuclear weapons can be divided into two groups: atomic devices or thermo-nuclear devices. There are more variants like the neutron bomb, but they are essentially derivatives of the first two groups. Some qualities of the nuclear device, like radiation in the neutron bomb, are enhanced. You also can improve the blast or heat to cause more destruction. But all devices have a core of the same raw material or combination of them, 239 Pu, 235U and/or 233U.

Some technological details

An atomic device is relativily easy to build but the thermo-nuclear device demands better and advanced technical skills. The first device works on the principle of fission which creates a chain reaction which leads to an explosion. There are two ways to start the chain reaction, in general and simplified manner they function like this. The fission device can be of the gun type model or the more complicated implosion model. The gun type is easier to build but less effective. With the gun type a small load is blown into a ball of nuclear material. This will create a critical mass and the initiator with one neutron will set off the chain reaction. The implosion device is more complicated but more used and common. A ball of nuclear material is pushed together, the implosion, to create a critical mass. A initiator is fed into the ball from outside to set off the chain reaction. The fission implosive device can be improved through the use of a boostergas. This is a mix of deutrium and tritium. The result of a boostergas is that it will not significantly increase the yield of the device but it increases the fissionable efficiency of the used plutonium. The number of released neutrons will be multiplied by the use of a booster and these neutrons will create a higher efficiency because you have more fissions of atoms.

A thermo-nuclear device is much more complicated to construct. This device works on the principle of fusion. A thermo-nuclear device is in fact two nuclear devices. One small normal fission bomb, the socalled primary, and a bomb with the fusion material like lithiumdeuteride and tritium. The fission bomb will initiate the fusion in the second bomb through the radiation of the first bomb. This fusion will lead to a much higher yield than with a fission device. Where fission devices talk about KiloTonne, KT, yield, thermo-nuclear talks about MegaTonne, MT, of yield.

The problem of both principles is the timing. All components have to come together on the right moment to achieve the wanted reaction. The use of timing is also the basic of the creation of low yield nuclear devices. It will create a guided chain reaction to limit the yield of the weapon. The fission device is through the application of advanced initiators and suboptimal timing more useable and modern than the fusion device which are only usefull to create yield.

Development and consequences of nuclear devices

It is possible to develop and build a nuclear device, especially an fission device, in a laboratory without any testing. All testing can be done by computer simulations. It might be however difficult to build a save thermo-nuclear device without proper testing. Computer simulations might not be enough and the simulation technology not advanced enough. Test explosions could prove to be necessary if new thermo-nuclear devices are developed. Testing is however forbidden for the participants of the CTBT treaty. The CTBT treaty is a test ban on explosions of nuclear devices with a higher yield of 1KT. This will most probably limit or better end the development of new thermo-nuclear devices. But this treaty is in the case of thermo-nuclear devices irrelevant because the need or wantedness of thermo-nuclear devices has been diminished. The main reason for the CTBT treaty is that it eliminates all possibilities for other than the possessing countries to have thermo-nuclear devices.

The limitation of especially thermo-nuclear mega destruction devices and nuclear devices in general is thereby, for two reasons, in accordance with the policy of the possessing nations. Firstly, the possessing nations want to limit the proliferation of nuclear devices because they already have them and have no interest that some other countries also acquire nuclear devices. An end to nuclear explosions complicates the development of fission devices. If there is no possibility to acquire the right computer simulation programmes it will become very difficult to construct a save and reliable fission device. Secondly, the possessing nations have therby changed the objective of research and are developing low yield nuclear devices which could eventually be used and they can be developed by simulations.

Contrary to popular believe the real thing are not thermo-nuclear devices but boosted fission devices. Thermo-nuclear devices are only useable as weapons of last resort or at best as defence. To threat and keep off opposite forces to use nuclear weapons or a conventional superiority. Thermo-nuclear weapons are the ultimate threat, it will even keep a superpower at bay. But the use of thermo-nuclear devices is a kind of suicide. The negative consequences of the explosion of a number of MT devices will be disastrous for the whole planet, it will cause widespread radioactive contamination and a nuclear winter. Life on this planet would be in big trouble. The possession of thermo-nuclear devices is nice for the ego, it is nice to have. The political and military value is non existent, you cannot use them and will in the end limit your space to move. Every move will be viewed with suspiscion and will invite a countermove. The majority of foreign policy have to be dealt with through proxies just as in the cold war.

A boosted fission device is a better option. It is much more controllable, they are small and the yield can be limited to just a couple of KT. They can be eventually even be used against some kind of targets, like chemical or biological production and storage sites. The intense heat of a nuclear explosion would destroy all traces of chemical and biological weapons. The boosted fission device can certainly be used, the effects like the fall out is manageable from a low yielded device. The boosted fission device is the weapon of choice for the military. All development is aimed at those devices. The low yield, small size and the superficiality of test explosions make them very attractive.

But the implications could be in the end as difficult and worrisome as with thermo-nuclear devices. Militarily it is just another device/weapon with good and bad sites. If necessary and usefull it even can and will be used. Politically however it could prove to be disastrous if one leading nation would use a weapon of mass destruction. They would survive the natural consequences of the explosion and even win the conflict but the political fall out would prove to be deadly on the long term.

Finally the weaponization. A nuclear device must become a weapon if it is be viewed as dangerous and a threat. The capability to develop and build a fission or even thermo-nuclear device is not enough. It has to be delivered to the enemy. This is just as important as the device itself. For an example, what would be the use of a squadron of advanced jetfighters like the F22 in the defence of a countries airspace if you do not have the pilots to operate them.

This process of weaponization is just as difficult as the development of the device itself. The best and most attractive solution is the missile as way of transportation. To achieve that goal a missile has to be acquired which is strong, large, reliable and accurate enough to deliver the device. The accuracy, CEP, must be better the lower the yield of the device. The nuclear device has to be constructed according several spefications to fit in a missile and it must be that sturdy to withstand the natural forces which exist in the lanching and flying of a missile.

Nuclear weapons and the development N-weapons in the world

There are just a handfull of countries which are known and accepted owners of nuclear weapons. All five are members of the security council with a permanent veto right. The U.S.A., the U.K., France, Russia and China. There are three other groups of countries, first, the countries who possess the technological capabilities and the means to build a nuclear device. Second, the countries who also have actually builded a nuclear device or a very close to do so. Those countries do not want their ability to be officially known. They consider the possession of nuclear wepons as necessary item in their national defence. Third the group of countries, sometimes called rogue states, who are very activily busy in developing a nuclear device. Estimates forecast that they will be able to do so in approximately 4 to 6 years.

The first group of countries are most of the developed nations in the world. All countries who have mastered the skill of building and operating nuclear energy installations have in theory the ability and as important have the materials to put together a nuclear device, at least a fission device. Japan, Germany and the Netherlands belong to this large group. But they have no ambition to do so.

The other group of countries are the ones which are in the gray area of having already builded a nuclear device or are close to do so. They can construct fission devices with more or less advanced boosting technology. The possession of nuclear weapons is considered by those nations as a badly needed asset to protect the national interests of the country. The reason why they do not make their nuclear capability public is to circumvent the negative political international reaction and a possible arms race in the region. Officially they do not have them but everybody knows that they are around. To this group belongs Israel and belonged South Africa but they have destroyed their nuclear device. Israel is probably the strongest nuclear power outside the five acknowledged nuclear countries. The Israelis possess around 150 Jericho I and II missiles and they have an estimated 200 nuclear warheads. The Israeli Defence Force mastered the ability to build devices, build a missile and integrate both of them into a viable weapon system.

Two former countries who also belonged to the gray group are India and Pakistan. They were also suspected of the ability to build a nuclear device. India wanted to prove its capabilities because of strategic concerns and maybe out of frustrations over the CTBT treaty. India considered its strategic position versus China and Pakistan to be deteriorated. India has with both countries some old differences about territory and China as a nuclear power alledgedly supported Pakistan with their missile and nuclear programmes. The other grievance is the CTBT treaty which limits the not haves in their options and secures the position of the haves as dominating countries. The CTBT and the Non Proliferation Treaty does also not include a schedule to disarm, the Indians viewed that as an unfair treaty, with other words only advantageous to the haves. Mainly because those two reasons India decided it wanted to belong to the known and accepted nuclear powers and held a serie of five nuclear explosions to state that they possessed the capability to build nuclear devices. As a reaction to the Indian tests Pakistan felled compelled to show their capabilities and also held a serie of five nuclear explosions. There are however strong doubts with both series about the strength and number of the explosions. Both were most likely of the fission type and not that powerfull as stated. But simultaneous explosions and a certain soil structure can be the reason for the confusion about the number and strength.

India and Pakistan stated their ability with the explosions and gained enough information to run further testing through computer simulations. They do not have yet the capability to build a weapon but they will have it in the future. The minituriasation and hardening of a nuclear device is just a matter of time. Both countries already have reliable short range missiles. India the Prithvi and Pakistan the Hatf 1 and 2 and the Chinese M11. But both have a longer range missile under development, respectively the Agni and the Ghauri. In about three years both countries will have functioning nuclear weapons and in five years the longer range models will be available for introduction into the armed forces.

The third group of countries are the countries who do not have yet a nuclear device but who are very busy to build one. These countries, mostly all governed by one party regimes with a strong leadership, view themselve underpressure from the international community in general and the U.S.A. in particuliar. They want to limit the influence of the U.S.A. and want to remove the wrongly conceived threat from the U.S.A. They consider nuclear weapons very well suited for that job. Countries like Iraq, Iran and North Korea are very ambitious about their programmes to build a fission device. At the same time means of delivery, missiles, are under development in all those countries.

In reality ambition and the actual development are sometimes two different things. Iraq is because of the embargo and inspections of UNSCOM virtually out of the nuclear programmes development but this will last as long as the embargo and the inspections remain in place. North Korea has alledgedly shelved the development of nuclear weapon because of an agreement with South Korea, the U.S.A. and Japan. The missile programmes are however continuing at the same pace. Only in Iran both programmes, the missile and nuclear development programmes, remain on schedule. In two to three years a fission device could be developed and tested. Weaponization will at least take another two to three years before the device actually can be introduced into active service.