Underground test

Finally, a study is underway to determine the suitability of the Nevada Test Site in southern Nevada which has been used in the past for both surface and underground testing of nuclear weapons, to see if it may possibly be suitable as a potential permanent radioactive waste repository site. 

The radiation - induced changes noted are in weight loss, gas evolution, mechanical sensitivity, thermal sensitivity and stability, and ex pi performance. The effects will be described with the type of nuclear radiation used. The format describes the radiation effects on expls, propints and pyrots with the sequence of radiations utilized (when applicable) as follows, a - particles, neutrons, fission products, reactor radiation (fast and slo w neutrons plus gammas), gammas (7), underground testing (UGT), X-rays, electrons, and other nuclear radiations... 

Underground Testing UGT ) of Pyrotechnics The earliest UGT ref to pyrotechnic ammo was reported by Willsey (Ref 22), in which 12 each M4S trip flares had been exposed at Test Able in Operations Crossroad. Also, Ml 11A2 fuzes... 

Most of the T from atmospheric tests is formed as HTO. Presumably, the heat of the fireball ensures oxidation. Ehhalt (1966) noted an increase in the atmospheric HT before the series of large thermonuclear tests in 1962 and 1963, but observed no increases correlated with individual tests. Mason Ostlund (1979) analysed samples of stratospheric air after the Chinese tests of November 1976 and observed a big increase in HTO but not in HT. HT may, however, be released following underground tests. 

An X-ray laser (powered by a thermonuclear explosion) was proposed in the 1980s as a military "death ray" its single underground test in 1983 was inconclusive, and its research was stopped. 

The number of nuclear tests conducted by all countries is shown in Fig. 10.1. The numbers of atmospheric tests each year are indicated by the scale above the horizontal axis and the number of underground test by the scale below the axis. Atmospheric tests were conducted primarily during the 1950s and in 1961 and 1962. In 1958, 1961 and 1962, there were 50 or more tests per year. Continued tests, but fewer in number, were conducted by China and France from 1960 until 1980. In all, there were 541 atmospheric tests. This compares with over 1800 underground tests—over three times as many as atmospheric tests. Underground testing began mainly after the limited... 

The records of the annual yields from nuclear tests show a predominance of atmospheric tests. The total annual explosive yields of atmospheric tests were particularly high during 1961 and 1962. The total yield of all atmospheric tests was 440 Mt. The total yield of all underground tests was 90 Mt, just 20% of atmospheric total. 

To describe underground testing in some detail, we shall follow the report of Bouchez and Lecomte (1996) which describes the French nuclear testing in the Atolls of Mururoa and Fangataufa (French Polynesia). The measurements relating to the operation of the device were made in the immediate proximity of the explosion point. All the measuring instruments were housed in a container, the lower part of which contains the nuclear device. 

The energy released from a nuclear explosion is measured in units of kilotonnes (kt) of trinitrotoluene (TNT) equivalent, defined to be lO cal, i.e. 4.184x10 joules of explosive energy. The explosive yield of all tests at the CEP site (atmospheric and underground) was equivalent to about 13 000 kt about 10 000 kt from atmospheric tests and about 3000 kt from underground tests. 

Fig. 10.18. Locations and yields of underground tests at Mururoa Atoll.

Mururoa has been the subject of three independent scientific missions during the 1980s. These studies were not allowed complete freedom to take samples and the information available to them was limited. The general conclusions were that there were low concentrations of radioisotopes in the environment consistent with the levels expected from global fallout from atmospheric tests in both the northern and southern hemispheres (which ceased in 1980). There was insufficient evidence available for the missions to form any firm conclusions about the likelihood and rates of leakage of radioisotopes from the underground tests. 

Thus Avrami [71] reviewed radiation effects on explosives, propellants and pyrotechnics. Here are some of the main conclusions taken from the work of Avrami and numerous authors initiating explosives are decomposed under irradiation with a-particles, neutrons, 7-radiation, electron irradiation and underground testing. Among the reviewed papers Avrami reported his own work on the influence of Co gamma radiation on the detonation velocity of explosives they all show a fall in velocity after irradiation. Cyclonite (EDX) appears to be particularly sensitive, less sensitive are PETN and HMX. Aromatic compounds such as TNT and Tetryl seem to be still less sensitive. 

A joint venture between the Fuel Cell Propulsion Institute (a nonprofit consortium of industry participants) and Vehicle Projects LLC (project management) provided the basis for the 2 phase project. In phase I, SandiaNational Laboratories was tasked with the design of the fuel cell powerplant and the metal-hydride storage, as well as system integration. Phase 2 includes system evaluation, safety and risk assessment, and underground testing in a production environment. 

The conceptual model in Figure 2, combined with a continuum model approach, is shown to be appropriate for the analysis of THM processes at the DST because the rock mass is highly fractured, forming a dense, wellfracture network for fluid flow. This differs from many other fractured rock sites in Canada, Europe, and Asia, where underground tests have been conducted in sparsely fractured crystalline rocks (Rutqvist and Stephansson, 2003). In those formations, fluid flow is dominated by a few widely spaced fractures, which means that a continuum approach may not apply on the drift scale. In relation to other fractured rock sites, the rock mass at Yucca Mountain is relatively homogenous (ubiquitously fractured), with much less variability in rock-mass mechanical and hydrological properties. 

On October 20,2006, the ninth World Congress of the World Federation of Nuclear Medicine and Biology was held in Seoul, Korea. On October 8,2006, North Korea had carried out a nuclear explosion in an underground test The United Nations Security Council denounced the Korean test China spoke for the first time of the need for appropriate punitive action. The contrast between the high degree of development over the past half century in South Korea compared to the mass starvation in North Korea illustrates the trade-off between the peaceful andmilitaiy uses of atomic energy, emphasized in the speech by President Eisenhower in 1953. 

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