[en] The computerized emergency response dose assessment codes (ERDACs) used in the nuclear industry commonly rely on Gaussian plume dispersion techniques. In coastal zones, particularly within 15 km of the shoreline, complex four-dimensional mesoscale meteorological regimes often violate some of the basic assumptions of Gaussian dispersion. For example a land breeze will initially advect materials offshore into unpopulated areas. Such effluents may pool over water only to return to land in the next morning's onshore flow, but in locations and concentrations unknown and undeterminable from on-site data and standard Gaussian modeling techniques. Improving the performance of ERDACs for a given coastal site requires a climatographic inventory of that site and its surroundings. This involves identifying the coastal mesoscale regimes (CMRs) that affect the site, including their annual frequencies of occurrence and the meteorological conditions that characterize them. Such a climatographic analysis has been performed for the Zion nuclear power station (NPS), which is located just north of Chicago, Illinois, on the western shore of southern Lake Michigan. The purpose of this papers is to summarize the results of this study and its implications for radiological emergency response activities. A conceptual framework for allocating resources in developing an adequate emergency response system includes three major factors: (1) frequency of the mesoscale regimes; (2) extent to which the regime can result in high concentrations/doses; (3) ease with which it can be modeled, with due consideration given for input data requirements

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[en] When human lymphocytes are exposed to tritiated thymidine ([³H]dThd), which acts as a source of chronic radiation, the cells become refractory to subsequent doses of x-rays. It is suspected that this adaptive response is related to a hitherto undiscovered radiation-induced repair mechanism. Earlier experiments had shown that the results were not an artifact caused by delays in the progression of irradiated cells to metaphase. The results of recent experiments are consistent with the idea that that chronic radiation from tritiated thymidine induces the formation of an enzyme that is necessary for the repair of those breaks in DNA that lead to chromatid aberrations, and that when poly(ADP-ribosyl)ation is inhibited, the repair does not occur

[en] Counting radionuclides on line has become very popular in recent years with many companies introducing nuclear flow detectors for chromatography applications. Many promises are made about the convenience and time saving involved in flow counting versus aliquot counting. While very true, pitfalls do exist in which accuracy may be sacrificed, unless care is taken. This paper identifies those pitfalls and offers solutions. Errors in the counts per minute can be introduced in each of these terms, counts, flow rate, and cell volume, that can be avoided by proper experimental planning. There are two techniques for detecting flowing radioisotopes; (a) heterogeneous, in which effluent is passed through a powder of solid scintillator and (b) homogeneous, in which liquid scintillator is mixed with the effluent. Each technique has pitfalls that are unique, which are discussed separately

[en] When calculating the energy deposition of fast charged particles in dense plasma by means of transport methods, it is frequently assumed that the ions as well as the electrons of the background plasma have a Maxwellian distribution. This paper presents a generalized transport method appropriate for taking into account the degeneracy of the electron component

[en] The benefits to the medical, pharmaceutical, semiconductor, computer, video, bioscience, laser, defense, and numerous high-tech industries from nuclear technology development fallout are indeed numerous and increase every day. Now those industries have made further progress and improvements that, in return, benefit the nuclear industry. The clean-air and particle-free devices and enclosures needed for protection and decontamination are excellent examples

[en] The first wall of a tokamak-type of fusion reactor separates the blanket/coolant from the plasma, provides for mechanical stability of the torus, and maintains a vacuum in the plasma chamber. Current tokamak designs require the first wall to withstand a neutron flux of 0.4 to 1.2 x 10¹⁹ neutron x m^-2 x s^-1, with 20% of the neutrons having an energy of 14.1 MeV. In addition to the high displacement damage, fusion neutrons will produce 20 to 30 times more helium and hydrogen in the wall than a reactor like Experimental Breeder Reactor II (EBR-II). Recently, the need for the first wall to demonstrate a low residual activity created a renewed interest in the refractory metal vanadium. Compared to the austenitic and ferritic stainless steels, vanadium and its alloys also provide lower thermal stresses for given flux, good strength at elevated temperatures, excellent compatibility with lithium (a proposed coolant/blanket material), and lower nuclear heating, helium generation, and void-swelling rates. Major concerns regarding the use of vanadium alloys for a first wall include: cost, reactivity with light elements (carbon, nitrogen, oxygen, and hydrogen) as well as various coolant/blanket materials, and resistance to radiation damage. These latter two areas will be reviewed in this paper

[en] This work provides a description of recent developments in the ICRF heating of tokamak plasmas. The use of the fast magnetosonic wave in the ion cyclotron range of frequencies (ICRF) has become one of the most important methods of auxiliary heating of tokamak plasmas. While present-day front line experiments, such as the Joint European Torus (JET), the Tokamak Fusion Test Reactor, and JT-60, are predominantly neutral-beam heated, future machines such as the ignition studies machine have been proposed as pure ICRF machines. Present-day experimental programs are being carried out on the Princeton Large Torus (PLT), TEXTOR, the Axially Symmetric Divertor Experiment (ASDEX), JET, and JFT-2M tokamaks while experiments on JT-60 will start shortly. These experiments are exploring a variety of issues of relevance to fusion research and the status of each will be discussed