China
Africa
Explore chapters and articles related to this topic
Risk-taking: Submarine experience
Published in Guy André Boy, Edwige Quillerou, Risk-Taking, Prevention, and Design, 2023
Nevertheless, a submarine nuclear engine more and more follows the same rationale. A submarine is now designed to be safe independently from the nuclear propulsion which wasn't the case in the past. The assessment of the duality between Safety and Availability is no more an issue. Safety ‘won the game’ because designers integrated this in new nuclear programs by laws. France is the only one country that integrates in the law the precaution principle.
Other civil applications of nuclear energy
Published in Kenneth Jay, Nuclear Power, 2019
The technical feasibility of nuclear propulsion for ships was settled long ago by the Nautilus. This submarine demonstrated too that nuclear propulsion brings to naval operation a new order of strategic freedom and tactical flexibility; submarines or surface ships can stay at sea for a year or more, steaming at the highest speed if need be, on a few pounds of fuel; the fact that the fuel neither burns oxygen nor emits large volumes of noxious gases, means that submarines can stay under the water almost indefinitely and can operate at high speed and great depth—that they become true submarines instead of submersible boats. The naval superiority of nuclear-propelled ships is so great that economics hardly enter the picture. The costs of Nautilus’s nuclear propulsion system are said to have been some ten times those for an equivalent oil-burning boat. This is a small price to pay for the advantages and experience gained, but, even allowing for the fact that the installation was the first of its kind, the costs are far greater than those that could be considered in mercantile applications.
Fiscal Year 1967
Published in Irvin C. Bupp, Priorities in Nuclear Technology, 2019
The afternoon session began with consideration of the Plowshare program to develop non-weapons uses for nuclear explosives, one of the programs which the Controller had predicted would be a major issue with the Administration as the budget cycle progressed. Since we will later want to review this fascinating enterprise in considerable detail, it will suffice to note here that Plowshare in a sense was the “Rover” of the other weapons laboratory, Livermore. It respresented a major effort by Livermore to develop non-weapons applications for its considerable technical expertise. aircraft carrier. The Admiral thought there probably were such studies. A member of his staff commented that a recent internal Pentagon study of tactical air warfare was said to have convinced Secretary Me Ñamara that two additional attack carriers would be necessary in 1969–1971. Rickover observed that the Pentagon was “being subjected to industrial pressure to revive the Aircraft Nuclear Propulsion Program. “(Minutes of Commission Meeting 2139, September 3, 1965,)
Design of a Fast Molten Salt Reactor for Space Nuclear Electric Propulsion
Published in Nuclear Science and Engineering, 2023
F. Quinteros, P. Rubiolo, V. Ghetta, J. Giraud, N. Capellan
The first step in the design process of a nuclear space reactor is to determine the minimal core mass that is required to achieve criticality and sufficient reactivity margin for a given reactor layout and material composition. The approximate core layout used in our study is presented in Fig. 1. A spherical core geometry similar to one of the concepts proposed in the Aircraft Nuclear Propulsion (ANP) project (Ref. 2) has been chosen. This geometry allows minimizing neutron leaks and shielding requirements. It also helps to improve the fuel flow distribution inside the core cavity. Two particular differences with respect to the ANP design are that the pumps and heat exchangers (HXs) are placed outside the core and that the flow inlet and outlet pipes are located on one side of the core cavity. The molten fuel salt enters the core cavity through six inlet pipes that generate a jet directed toward the walls. The hot molten salt is extracted from six outlet pipes located in an inner ring. A thermal insulation layer based on a carbon foam is placed between the cavity cladding and the beryllium reflector to decrease the thermal coupling between them.
A Comprehensive Approach to Molten Salt Reactor Source Term Generation and Shielding Analyses
Published in Nuclear Technology, 2023
As M&S suites, SCALE included, rely on experimental data from which to validate their solutions, it is worth briefly describing the only demonstration-scale, molten salt–fueled reactor operated for any substantial amount of time, the Molten Salt Reactor Experiment (MSRE).[9] It is from this experiment that the most comprehensive body of molten salt reactor (MSR) operational characteristics can be found, which serve as the experimental basis for most molten salt–fueled reactor modeling validation. MSRE was born out of the Aircraft Nuclear Propulsion Program at ORNL during the 1960s. The 8-MW(thermal) MSRE reactor was operated successfully from 1965 to 1969 using both 235U and 233U as the fissile isotope dissolved in a 7LiF-BeF2-ZrF4-UF4 carrier salt.[10] The working temperature hovered around 600°C, and all generated heat was radiated to the atmosphere via a LiF-BeF2 secondary salt.[10] The MSRE diagram is shown in Fig. 1.
Numerical Investigations of Molten Salt Pump Journal Bearings Under Hydrodynamic Lubrication Conditions for FHRs
Published in Nuclear Science and Engineering, 2023
Yuqi Liu, Shuai Che, Adam Burak, Daniel L. Barth, Nicolas Zweibaum, Minghui Chen
Fluoride salt-cooled, High-temperature Reactors (FHRs), featuring particle fuel; graphite moderator; and low-pressure, high-temperature molten fluoride salt coolant, are used for electricity generation and process heat applications. Reliable high-temperature molten salt pumps are critical to the successful deployment of FHRs. Extensive development and testing of molten salt pumps were achieved during the Aircraft Nuclear Propulsion, Molten Salt Reactor Experiment, and Concentrated Solar Power programs. Various types of pumps have shown the potential to be used in the high-temperature molten salt environment. Canned-rotor, magnetic bearings pumps, without salt-bearing compatibility issues, are promising, but they are still in the early development phase.1 Short-shaft pumps, having a short shaft with an overhung impeller and bearings located above the shaft seal, are temperature limited and require adequate local shielding for radiation. However, the short-shaft pump would be attractive if the pump was provided with adequate local nuclear radiation shielding and if an ambient temperature below 93°C was maintained.2 Long-shaft cantilever pumps are the currently the leading candidate for large-scale FHR coolant pumps due to the sufficient distance for thermal and radioactive shielding.1