[en] The author emphasizes the importance of energy efficiency, technology development, market forces and politics as issues that need to be addressed in North America for solving global warming problems. He suggests several ways technology can be used to maintain the level of consumption society wants without unacceptable increases in CO₂ emissions to the atmosphere

[en] Nuclear fusion is the energy source that powers the sun. For more than four decades man has sought to develop this essentially inexhaustible, clean power source for use on earth. Unfortunately the conditions needed to initiate fusion are daunting; the nuclear fuel, consisting of isotopes of hydrogen, must be heated to temperatures in excess of 100,000,000 C and maintained at that temperature long enough for the nuclear fuel to ignite and burn. Lasers are being used as one of the tools to achieve these conditions. The best lasers for this work are those that derive their energy from a unique set of optical glasses called laser glasses. The work to develop, manufacture and test these glasses has involved a partnership between university and industry that has spanned more than 25 years. During this time lasers used in fusion development have grown from small systems that could fit on the top of a table to systems currently under construction that are approximately the size of a municipal sports stadium. A brief historical and anecdotal account of the development of laser glasses for fusion energy research applications is the subject of the presentation

[en] The method allows pressurized filling with inert gas of thinwalled fuel cans after previous evacuation. The can charged with fuel is brought into a filling device connected to a pressure tank and a vacuum pump. The can is closed on the upper and lower end by seemingly equal welded caps. The upper cap, however, has a central though bore and an annular tee-slot in the covering surface. After putting on and screwing of a pressure resistant cover on the pressure chamber, this cover and the can are evacuated. Then the valve to the inert gas cylinder is opened until the desired filling pressure is reached in the device and in the can. Then a welding electrode passed through is moved downward coaxially to the can. Its conical point hits the still open bore of the upper cap of the can. The inner collar of the annular tee-slot mentioned above is melted off and closes the upper cap pressure-tight. The cap also prevents transfer of the welding heat into the can. Internal fuel rod pressures from 70 to 133 at have successfully been applied; evacuation goes down to 0.1 Torr. (HP)

[en] Method of filling a fuel rod, which may e.g. be inserted in a PWR, with inert gas at a pressure of at least 30 at. One of the front surfaces of the thin-walled cladding tube is provided with a central filling bore enclosed by a collar. The filling is performed in a pressure vessel in which the fuel rod is standing with the filling bore showing upwards. Above it there is placed an arc-welding facility. After filling the collar around the filling bore is melted off by means of the arc and forms a gas-tight closure. (RW)

No abstract available

No abstract available

[en] A nuclear-fuel assembly is described which has an end plug and is sealed except for a small diameter axial bore in the plug. A welding electrode of the same material as the plug has an end ground to a point. The tapered end is then inserted into the bore. Before the bore is sealed the assembly is filled with an inert-gas at high pressure. An electric welding current is then directed through the electrode and the plug to seal the bore. 1 Claim, 5 Drawing Figures

[en] A procedure for sealing the end plug of a fuel pin of a zirconium alloy or stainless steel within a pressure container, which contains an inert gas (preferably helium) atmosphere at a pressure of 35-133 kp/cm², is described. The internal pressure in the fuel pin allows detection of leakages by means of a helium spectrometer and reduces the compressive stresses to which the fuel is subjected in the reactor. (JIW)

[en] Small- to medium-scale densification experiments were conducted on Synroc D using graphite dies and metal canisters. Pressures at elevated temperatures were applied both isostatically (HIP) and unidirectionally (HUP). Spray-dried/calcined powders formulated for composite or average sludge compositions exhibited initial packing densities of about 25% theoretical. Final densities were in the range of 95 to 99% theoretical, depending on applied pressure and temperature. In final-stage HUP densification, we have found that porosity varies exponentially with time acording to the well-known expression P + P⁰ exp(-K⁰t). The rate constant (K⁰) has the Arrhenius form K⁰ = Asigma exp(-E/RT) which includes a stress or pressure term. Rate constants are calculated from approximately 20 densification experiments conducted under a wide range of conditions; activation energies in the range of 20 to 35 kcal/mole were calculated for the densification process. HIP densification and leaching results are reported for experiments with a wide range of variables: pressure (3 to 30 ksi), temperature (900 to 1200₀C), redox calcination method, powder fill density and metal canister material. The results support the conclusion that HUP and HIP densification parameters are very similar and that Synroc-D leaching behavior is essentially independent of density in the range of 90 to 100% theoretical.The densification of Synroc D in a collapsible metal-bellows canister has been simulated by means of modeling calculations. Radial buckling tendencies were also evaluated. Results from large-scale HIP experiments are also reported. Up to 50 kg of Synroc D was densified to greater than 99% theoretical density in a metal-bellows canister 36 cm diameter by 24 cm in height. These data were used as a guide to make recommendations for the full-scale HIP densification of Synroc D using metal-bellows canisters

[en] There is a wide spectrum of controls which are required to be in place to ensure the maintenance of quality in castings. Most of these are well known, and are not therefore considered in this paper. The parameters which are often overlooked, and thus not controlled, are (i) the rate of flow of liquid metal in the mould to avoid surface turbulence and the generation of macroscopic crack-like defects as a result of folded-in surface films; and (ii) the rate of quench following solution heat treatment. As a result of failure to control these critical parameters castings traditionally exhibit random failure from leakage, and mechanical failure, especially fatigue. Mechanical failure is enhanced by internal stress which is superimposed on service stress to promote premature failure. It is considered that these are the main reasons why in the past castings have been found to be unreliable, compared to other production techniques such as forging. Techniques to control both surface turbulence and internal stresses include respectively (i) the limiting of flow velocities in moulds to less than 0.5 m/s, and (ii) eliminating the water quench from casting heat treatments. These actions are expected to revolutionise the concept of castings as totally reliable products. (orig.)