Assembly, nuclear weapons

In 1950, the British government created the Atomic Weapons Establishment (AWE) to be responsible for designing and assembling nuclear weapons. On 3 October 1952, the United Kingdom became the third nation to conduct a successful detonation of a nuclear device. A defining characteristic of the British nuclear weapons program, however, has been its special relationship with the United States. This relationship was formalized on 3 July 1958 when the two countries... 

Nuclear Weapon Major Assemblies are packaged for shipment in accordance with the applicable service technical manuals viz, Army-TM s (Technical Manuals) (Ref 35), Navy-SWOP s (Special Weapons Operational Procedures), and Air Force-TO s (Technical Orders), etc. 

As to the dollar-value of the Arsenal, its facilities are valued at over 500,000,000. The nature of these facilities varies, from the conventional to the nuclear. Conventional ammunition production lines, control laboratories and inspection systems are maintained in stand-by and are occasionally used in experimental or pilot-lot production. Nuclear weapons ammunition, components and devices are developed and produced in the. necessarily special research laboratories, proof-testing facilities and production and pilot assembly lines... 

For the purpose of this discussion, radiological materials that could be used in a terrorist attack are divided into three categories (1) bomb-grade nuclear material, (2) nuclear reactor fuel and associated waste products, and (3) industrial sources. Bomb-grade nuclear material includes concentrated plutonium and/or highly enriched uranium (>20% U-235) that may be used to build a nuclear weapon, assuming a terrorist group cannot or has not already secured an assembled weapon. 

Implosion method Explosives are also used in nuclear weapons to generate the implosion required to bring the two halves of the radioactive device together. The implosion is achieved with the help of secondary explosives which surround the material and rapidly compress the mass to a supercritical state on their detonation. This encompasses two major assemblies (i) com-... 

Several technologies have been used for production of highly enriched uranium. A first priority should be detection of HEU production by the technologies with proven capability of producing HEU in quantities sufficient for the assembly of nuclear weapons. These technologies are ... 

Neutrons, emitted from nuclear detonations, particle accelerators and nuclear weapon assembly facilities and not found in fallout, can penetrate deeply, causing... 

A simple nuclear weapon derives its energy from nuclear fission. A mass of fissionable material is rapidly assembled into a critical mass, in which a chain reaction develops and releases tremendous amounts of energy. This is known as an atomic bomb. Nuclear fusion can be used to make a more powerful weapon. In such a weapon, the X-ray thermal radiation from a nuclear fission explosion is used to heat and compress a small amount of tritium, deuterium, or hthium, causing nuclear fusion, releasing even more energy. Such a weapon is called a hydrogen bomb and can be hundreds of times more powerful than an atomic bomb. 

A nuclear weapon is a fission assembly with a very short neutron cycle time t = 10 s. The criticality factor in a fission weapon is near k=2. From these parameters and Eq. (57.34) it can be easily estimated that the fission reaction in a bomb is over in less than 10 s. 

Most studies and reviews of nuclear weapons and their effects have focused almost exclusively on what would happen if they were used. Notably, though, this represents only one phase in the life cycle of nuclear weapons, which includes uranium mining, milling, conversion, and enrichment plutonium production and separation nuclear fuel transport other raw material production and weapon assembly, transport, storage, testing, maintenance and refurbishment, use, and disassembly and disposal, including recycling or disposal of aU component parts [7]. 

Adopting a thorium fuel cycle is an intrinsic measure that could hinder the possibility of misuse of nuclear materials for nuclear weapons. Within such cycle, U is produced with a noticeable admixture of a highly radioactive which essentially complicates reprocessing and assembly operations for nuclear weapons. The mixing of thorium with low enriched... 

In terms of amount, by far the most significant of the synthetic actinide elements is plutonium. Nuclear power production by fission in uranium produces as a byproduct approximately 50 tons per year world-wide of a mixture of plutonium isotopes. About 250 tons of plutonium is estimated to be in the world plutonium inventory, some still in unprocessed spent fuel assemblies from nuclear reactors. World inventory of plutonium by the year 2000 has been estimated at 2400 tons [57], Plutonium produced for nuclear weapons is mainly Pu, but plutonium produced as a by-product of energy production contains substantial amounts of °Pu, Pu, and Pu and small amounts of Pu [64]. The plutonium in the environment is due, in decreasing order of importance, to the testing of nuclear weapons in the atmosphere, the re-entry into the atmosphere and disintegration of satellites equipped with Pu power sources, and the processing of irradiated uranium fuel from nuclear reactors. 

Einstein s letter convinced Roosevelt, and in 1941 he assembled the resources to begin the costliest scientific project ever attempted. The top-secret endeavor was called the Manhattan Project and its main goal was to build an atomic bomb before the Germans did. The project was led by physicist J. R. Oppenheimer (1904-1967) at a high-security research facility in Los Alamos, New Mexico. Eour years later, on July 16,1945, the world s first nuclear weapon was successfully detonated at a test site in New Mexico. The first atomic bomb exploded with a force equivalent to 18,000 tons of dynamite. Ironically, the Germans—who had not made a successful nuclear bomb— had already been defeated by this time. Instead, the United States used the atomic bomb on Japan. One bomb was dropped on Hiroshima and a second bomb was dropped on Nagasaki. Together, the bombs killed approximately 200,000 people and led to Japan s surrender. 

EINSTEIN-RUSSELL MANIFESTO. On 9 July 1955, a manifesto was issued in London in the names of philosopher and mathematician Bertrand Russell (1872-1970) and physicist Albert Einstein, who had died three months earlier. It described the dangers posed by nuclear weapons to the future survival of mankind and urged that scientists should assemble in conference to appraise the perils that have arisen as a result of the development of weapons of mass destruction (WMD). This helped lead to the establishment of the Pugwash Conference on Science and World Affairs. 

PREINITIATION. The sequence and timing of events is critical to proper functioning of a nuclear weapon. Preinitiation occurs when the fissile material of a nuclear weapon initiates a chain reaction prior to attaining maximum compression or complete assembly. When preinitiation occurs, the result is either no nuclear explosion or... 

Z DIVISION. During the Manhattan Project, Site Y (the Los Alamos Laboratory, New Mexico) was the main facility for designing and producing nuclear weapons. As its work proceeded, the site became crowded with people and experiments. Laboratory space, family housing, and water were insufficient. By summer 1945, the situation was sufficiently critical that the newly designated Z Division, created to perform production engineering and final weapons assembly, was transferred physically from Los Alamos to Sandia Base, the former Oxnard Field, site of an airport outside Albuquerque, New Mexico. Earlier in 1945, this airfield had been transferred from the Army Air Corps to the Manhattan Project. Z Division became the predecessor to the present-day Sandia National Laboratory. 

Nuclear explosive device Assembly of nuclear and other materials and fuses that could be used in a test but generally cannot be delivered reliably as part of a weapon. 

If, instead, the group must assemble an improvised nuclear device, the group will need fissile materials, machining equipment, a simple weapon design, and a few technicians with the skills to work the nuclear material, fit the explosives, and assemble the device. As a result, a terrorist group will be most interested in nuclear materials. Type III technicians, and possibly weapons designers. 

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