Nuclear Structural Engineering最新文献

The construction of the vault and target rooms of the Harwell Variable Energy Cyclotron is described. The mechanical, heating, cooling, ventilation and electrical services for the building are discussed. Particular reference is made to the power operated shielding doors and to the safety circuitry associated with them.

This paper briefly discusses some dynamic problems in structural engineering as applied to the design of nuclear power stations. The following problems are analysed: seismic design, steam generator supports, design of fluid containers, the missile problem.

The MOSEL reactor concept concerns a fluid molten-salt reactor, in which operating conditions are influenced by salt freezing and boiling temperatures. The influence of temperature limitations on heat flux and power density is shown, and the importance of the thermal conductivity of the melt illustrated. A generalized diagram is developed relating various combinations of power densities and heat fluxes as a function of unit cell dimensions and flow conditions of the fuel stream. The temperature rise of the coolant through the core is shown to be a function of core size, flow condition, and heat flux.

High temperature thermoelectric materials show great promise for the direct conversion of nuclear energy to electricity. There are several basic reasons for this promise. An analytical technique is presented which may be used to predict and select high temperature thermoelectric materials, utilizing basic information on chemical compounds in their family groupings. This technique is demonstrated, and proposed materials are analytically evaluated for conversion efficiency and nuclear system compatibility. The predicted range of conversion efficiencies is competitive with or superior to present techniques of nuclear energy conversion. High temperature thermoelectric materials are expected to be superior to conventional thermoelectric materials because of radiation effects annealing as well as higher conversion efficiency.

Cycles of temperature up to 300°C were applied to concrete made with normal Portland cement and dolerite aggregate. Progressive loss of compressive and tensile strength was observed, combined with very large reductions of elastic modulus. Some of the effects are due to changes in the aggregate which affect aggregate stiffness and the bond with the cement paste. Conclusions are drawn in regard to suitable aggregates for operation at elevated temperature.

One of the mose important advantages of a natural salt formation as a repository for radioactive wastes is its essential impermeability due to its plastic properties. To prove the feasibility of disposal in salt mines a conceptual design has been developed and a demonstration of the storage concept is being prepared in a 1000 ft eep inactive mine in Lyons, Kansas. Economic studies show that costs for an actual disposal operation would fall well within the range allowable for competitive nuclear power. In the demonstration irradiated fuel assemblies from the Engineering Test Reactor with serve as a source of radiation in lieu of actual solidified wastes. Two radioactive arrays (one in the existing floor to check problems in the use of abandoned mines, and one in a specially excavated area) will each contain 14 assemblies in 7 cans. An electrically heated array will serve as a control. Mine renovations and additions are complete, and initiation of the two-year test is scheduled for late 1965.