Explosives nuclear weapons

Plutonium has assumed the position of dominant importance among the trasuranium elements because of its successful use as an explosive ingredient in nuclear weapons and the place which it holds as a key material in the development of industrial use of nuclear power. One kilogram is equivalent to about 22 million kilowatt hours of heat energy. The complete detonation of a kilogram of plutonium produces an explosion equal to about 20,000 tons of chemical explosive. 

Linus Pauling is portrayed on this 1977 Volta stamp The chemical formulas depict the two resonance forms of ben zene and the explosion in the background symbolizes Pauling s efforts to limit the testing of nuclear weapons... 

Another safety issue to be considered which might be exacerbated in the reprocessing option is that the plutonium generated in power reactors, called reactor-grade plutonium because it is made up of a variety of plutonium isotopes, contains plutonium-241, which is subject to spontaneous fission (8). The mixture of isotopes makes it extremely difficult to build an effective nuclear weapon. However, an explosive device could be built using this mixture if control of detonation is sacrificed (48). 

Most modem projectiles and virtually all missiles contain explosives. The plasmas that result from explosives are intrinsic to operation of warheads, bombs, mines, and related devices. Nuclear weapons and plasmas are intimately related. Plasmas are an inevitable result of the detonation of fission and fusion devices and are fundamental to the operation of fusion devices. Compressed pellets, in which a thermonuclear reaction occurs, would be useful militarily for simulation of the effects of nuclear weapons on materials and devices. 

The earliest tables were compiled from data collected from nuclear weapon tests, in which very high yield devices produced sharp-peaked shock waves with long durations for the positive phase. However, these data are used for other types of blast waves as well. Caution should be exercised in application of these simple criteria to buildings or structures, especially for vapor cloud explosions, which can produce blast waves with totally different shapes. Application of criteria from nuclear tests can, in many cases, result in overestimation of structural damage. 

Denmark 1.5 days after the explosion. Air samples collected at Roskilde, Denmark on April 27-28, contained a mean air concentration of 241Am of 5.2 pBq/m3 (0.14 fCi/m3). In May 1986, the mean concentration was 11 pBq/m3 (0.30 fCi/m3) (Aarkrog 1988). Whereas debris from nuclear weapons testing is injected into the stratosphere, debris from Chernobyl was injected into the troposphere. As the mean residence time in the troposphere is 20-40 days, it would appear that the fallout would have decreased to very low levels by the end of 1986. However, from the levels of other radioactive elements, this was not the case. Sequential extraction studies were performed on aerosols collected in Lithuania after dust storms in September 1992 carried radioactive aerosols to the region from contaminated areas of the Ukraine and Belarus. The fraction distribution of241 Am in the aerosol samples was approximately (fraction, percent) organically-bound, 18% oxide-bound, 10% acid-soluble, 36% and residual, 32% (Lujaniene et al. 1999). Very little americium was found in the more readily extractable exchangeable and water soluble and specifically adsorbed fractions. 

Countries and groups that lack access to nuclear weapons may still have opportunities to obtain radioactive materials such as spent nuclear fuel. A bomb in which a conventional explosive charge causes dispersal of radioactive material is known as a dirty bomb. Such a device could result in psychological effects exceeding the physical damage it caused. Once again, new techniques are needed for detection (of both the explosive and radioactive material), and decontamination procedures would be essential if such a device were used. 

W. E. Baker, Explosions in Air (Austin University of Texas Press, 1973) S. Glasstone, The Effects of Nuclear Weapons (Washington, DC US Atomic Energy Commission, 1962). 

Design of petrochemical facilities for accidental explosions is similar in many ways to design of facilities Tor high explosive detonations, nuclear weapons effects and nuclear power accidents for which design guides arc available. However, blast design for petrochemical plants is different in that more structural damage may be tolerated, in accordance with a company s blast protection philosophy. 

Conventional explosive Explosive other than a nuclear weapon. Examples include nitroglycerine, picric acid, TNT, PETN, RDX, HMX, and TATB. 

If al-Qaida or another terrorist group gained control of one or more Russian suitcase nuclear weapons, they could be smuggled into the U.S. by small boat or overland from Mexico or Canada. The explosion of such a device in a crowded city could cause immediate deaths of tens of thousands and lead to cancer for many of the survivors. 

Primary explosives differ from secondary explosives in that they undergo a rapid transition from burning to detonation and have the ability to transmit the detonation to less sensitive (but more powerful) secondary explosives. Primary explosives have high degrees of sensitivity to initiation through shock, friction, electric spark, or high temperature, and explode whether confined or unconfined. Some widely used primary explosives include lead azide, silver azide, tetrazene, lead styphnate, mercury fulminate, and diazodinitrophenol. Nuclear weapon applications normally limit the use of primary explosives to lead azide and lead styphnate. 

The most extreme case of gamma radiation dose would arise from explosion of a nuclear weapon. Nuclear weapons release intense gamma radiation that can produce fatal doses miles from an explosion (see Chapter 5). A less extreme but more likely scenario involves radioactive materials dispersed via conventional explosives (dirty bombs), where only the immediate area is contaminated with gamma-emitting radionuclides. 

It is also unlikely that the doses associated with a dirty bomb will produce even the milder acute effects. Although the observation of acute radiation syndrome may be unlikely after a dirty bomb explosion, doses should be kept ALARA to limit the potential for acute and stochastic effects. The entire range of acute radiation syndrome effects will be observed after an attack with a nuclear weapon, as described in Chapter 5. 

A distance of 0.25 miles represents the radius of complete destruction for a 10-kiloton nuclear weapon (see Table 5.1). If an individual is just outside the 0.25-mile radius after a 10-kiloton explosion, the combined effects from all threats will likely... 

Figure 5.1 illustrates the primary threats based on the explosion of a 10-kiloton nuclear weapon. The distances are taken from Tables 5.1 and 5.2 and are intended to illustrate the impact such a weapon would have if detonated in a populated area. No specific fallout radius is provided because it depends on yield, location, and meteorological conditions and is very difficult to predict. 

Time and shielding can be merged into a single factor. The shelters described in Section 5.2.1 (walls, basements, etc.) really serve as shields from radiation, heat, fallout, and even from the air blast and flying debris. At the moment of explosion, radiation and heat travel at the speed of light and expose unshielded victims. At the instant of realization that a nuclear weapon has exploded, an individual should move as quickly as possible to a location behind a rugged shielding material. 

Humans are exposed to radiation from the testing and explosion of nuclear weapons and the wastes of nuclear reactors and power plants. Strontium-90 is a fission product from nuclear reactors. It is of particular concern because it has a long half-life of 38 years and becomes concentrated in the food chain, particularly plants-to-milk. The ban on atmospheric testing of nuclear weapons has reduced this hazard. Strontium-90 does have some industrial uses. Most people in developed countries receive minor exposure to radiation through medical procedures such as X-ray and various treatments for some diseases. 

Some compounds, such as strontium chromate and strontium fluoride, are carcinogens and toxic if ingested. Strontium-90 is particularly dangerous because it is a radioactive bone-seeker that replaces the calcium in bone tissue. Radiation poisoning and death may occur in people exposed to excessive doses of Sr-90. Strontium-90, as well as some other radioisotopes that are produced by explosions of nuclear weapons and then transported atmospherically, may be inhaled by plants and animals many miles from the source of the detonation. This and other factors led to the ban on atmospheric testing of nuclear and thermonuclear weapons. 

A single kilogram of radioactive metallic plutonium-238 produces as much as 22 million kilowatt-hours of heat energy. Larger amounts of Pu-238 produce more heat. However, Pu-238 is not fissionable, and thus it cannot sustain a chain reaction. However, plutonium-239 is fissionable, and a 10-pound ball can reach a critical mass sufficient to sustain a fission chain reaction, resulting in an explosion, releasing the equivalent of over 20,000 tons of TNT. This 10-pound ball of Pu-239 is only about one-third the size of fissionable uranium-235 required to reach a critical mass. This makes plutonium-239 the preferred fissionable material for nuclear weapons and some nuclear reactors that produce electricity. 

The most common use of plutonium is as a fuel in nuclear reactors to produce electricity or as a source for the critical mass required to sustain a fission chain reaction to produce nuclear weapons. Plutonium also is used to convert nonfissionable uranium-238 into the isotope capable of sustaining a controlled nuclear chain reaction in nuclear power plants. It takes only 10 pounds of plutonium-239 to reach a critical mass and cause a nuclear explosion, as compared with about 33 pounds of fissionable, but scarce, uranium-235. 

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