71 research outputs found


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    Inertial pressure of the KEWB (Reactor Safety Experiments) is calculated assuming that the inertial pressure rise is attributable to fission-nucleated bubbles. (C.J.G.

    Nuclear power for surface effect vehicle and aircraft propulsion

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    Economic and safety factors of nuclear powered surface vehicles and aircraft in transoceanic commerc

    Nuclear Thermal Rocket Engine Instrumentation Addressing Environmental Limitations on Temperature Measurements

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    The development of nuclear thermal rockets has received renewed interest in recent years due to the benefits that can attained from this method of propulsion. Currently, instrumentation work is focused on the evaluation of current and near-term technology for implementation within a nuclear thermal rocket engine. One aspect of this evaluation is focused on the various instrumentation requirements of the system regarding necessary measurement parameters and environmental conditions for survivability. Historical nuclear rocket programs that have been conducted in the United States provide the basis for this information and indicates a critical need for high temperature measurement technology that can survive extreme environmental conditions. Through a survey of the current state-of-the-art of temperature measurement technology indicates that are still several gaps between high technology readiness level instruments and their potential application in a nuclear rocket. Due to the need for in-situ re-calibration, Johnson noise thermometry provides the best path forward but requires an extreme temperature resistance temperature detector for operation. Currently, there is no such instrument available for use and requires investigation into the feasibility of such an instrument to be used within a Johnson noise thermometry system. The current work provides a conceptual design for a high temperature resistance temperature detector, an evaluation of the design, and experimental plans

    Final Report - Summary of Thermal Testing of the Furnace Characterization Unit (FCU) for the Coast Guard

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    Effect Of Neutron Radiation On The Mechanical Properties Of B4c

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    B4C is an important engineering ceramic used in a number of different applications. One of the promising applications of B4C is in the nuclear industry. B4C has a high neutron absorption cross-section (600 barns) and that is why it can absorb neutrons without forming long lived radio nuclides. As a result, B4C is extensively used as control rods, shielding material and as neutron detectors in nuclear reactors. During the reactor’s operation, the B4C undergoes severe neutron radiation and defects, such as vacancies and helium bubbles, are generated in the structure. These defects are responsible for the degradation of mechanical performance of B4C and can make this material unsuitable for further exploitation. Therefore, both crystal structure and mechanical properties of B4C were studied before and after radiation, as well as for the case when irradiated by neutrons B4C samples has been annealed in order to heal the defects introduced by the radiation. Fully dense B4C ceramics were produced by hot pressing at 2100ºC, 30MPa, and 45 minutes dwell time. 120 small bars of 2×2.5×25mm were machined according to the MOR bar standard. 40 bars after machining were tested as they were, 80 bars were irradiated with neutrons in neutron source for 3.5 months. 40 out of the 80 irradiated bars were annealed at 400ºC for 1 hour with an attempt to heal the defects possibly introduced by the irradiation. iv 4-point bending strength, SEVNB fracture toughness, and Vickers hardness have been measured on as received B4C, B4C after radiation, and B4C after radiation and annealing. The Weibull parameters were determined for each set of the conditions. The fracture surfaces of the B4C samples before and after radiation as well as after radiation and annealing have also been analyzed using SEM. X-ray diffractometer was used to collect diffraction pattern of the B4C, and Raman spectrometer was used to evaluate the vibrational response of B4C. Thus the effect of neutron radiation and annealing on the mechanical performance and structure of B4C has been analyzed

    Nuclear Energy and Environmental Protection: Responses of International Law

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    This article analyzes the international regulation of the protection of the environment from nuclear radiation that takes place largely through international institutions and fora. The discussion focuses on the regulation that is undertaken by the International Atomic Energy Agency and the European Atomic Energy Community. The article draws a distinction between the regulation of: a) radiation protection, which consists primarily of quantitative exposure standards, and b) nuclear safety, which consists of design and operating standards to prevent nuclear accidents. The article compares the degree of current harmonization/internationalization of the regulation in these areas and contrasts the advanced state of international radiation protection regulation with the nascent state of international nuclear safety regulation. The article also contains discussions of the strengths and weaknesses of existing international regulatory structures, the problems of enforcing international standards on sovereign states, and the potential for increased implementation and enforcement of existing structures. Finally, it offers recommendations for the future developments of the international regulation of environmental protection from nuclear radiation. The discussion takes an environmentalist approach to the problem of the regulation of nuclear energy. A distinction is drawn between the regulation to protect people from radiation and regulation to protect the environment from such hazards. It is argued in the article that the future body of international law in the area of nuclear energy should address both issues equally
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