Special nuclear material detection

Abstract A short history and treatment of the various aspects of nuclear forensic analysis is followed by a discussion of the most common chemical procedures, including applications of tracers, radioisotopic generators, and sample chronometry. Analytic methodology discussed includes sample preparation, radiation detection, various forms of microscopy, and mass-spectrometric techniques. The chapter concludes with methods for the production and treatment of special nuclear materials and with a description of several actual case studies conducted at Livermore. 

The technical aspects of fluorine detection by nuclear reactions as well as its applications to fluorine analysis in geological and archaeological objects are reviewed. Special attention is given to the determination of exposure ages of meteorites on the Antarctic ice shield and burial durations of archaeological bones and teeth. This information can be acquired by evaluation of the shape and penetration depth of the diffusion profile of fluorine that was incorporated by the sample from the environment. For a quantitative assessment of the data, several factors like ambient conditions and diagenetic state of the material have to be taken into account. 

Nuclear track detectors can also be used to indirectly detect fast neutrons. Fast neutrons interact with the base material of a special film and cause recoil protons to be released. These protons then cause damage tracks in the film which can be made visible and counted as described above. The number of tracks can be used to determine the neutron dose. 

Spent fuel is generally regarded as proliferation-resistant due to the high level of radioactivity and the low concentration of fissile material in the fuel removed from a reactor. High levels of radioactivity promote proliferation resistance because special, easily monitored facilities are required to process the fuel and the high level of radioactivity makes removal of fuel without detection extremely difficult. Spent fuel is also proliferation-resistant because the concentration of fissile material is below that required to achieve a nuclear detonation. 

Abstract The effects of interactions of the various kinds of nuclear radiation with matter are summarized with special emphasis on relations to nuclear chemistry and possible applications. The Bethe-Bloch theory describes the slowing down process of heavy charged particles via ionization, and it is modified for electrons and photons to include radiation effects like bremsstrahlung and pair production. Special emphasis is given to processes involved in particle detection, the Cherenkov effect and transition radiation. Useful formulae, numerical constants, and graphs are provided to help calculations of the stopping power of particles in simple and composite materials. 

The Type-J wipers are also used to take samples in a certain enrichment facility under safeguards in a nuclear weapons state. The wiper is inserted in a special metal fitting (a so-called Koshelev fitting) that is part of the pipe-work connected to the enrichment cascade. Therefore, this sample comes into contact with the UFe gas in the pipe-work and can be used to detect the presence of material with higher enrichment than declared. 

Monitoring the vital signs of those engaged in mission critical or hazardous activities such as pilots, miners, sailors, nuclear engineers, among others. Special-purpose sensors that can detect the presence of hazardous materials can be integrated into the GTWM and enhance the occupational safety of the individuals. 

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