The present studies of accelerators, which can produce nuclear fuel directly from electricity (without having initial inventory of fissile material) are reviewed.
Discussed are the following: the recent conceptual reactor designs using fertile fuels as target material, the calculation code of high energy nucleon-nucleus cascade reaction including fission, the nuclear fuel resource demands created by different combinations of light water, fast and accelerator reactors, the incineration of nuclear waste using neutrons produced by an accelerator and the problem of accelerator research.
The research plans being proposed in Canada and European countries, and the proposal for a μ^- meson catalyzed fusion reactor are also included.

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The Inter Ramp (Studsvik Inter Ramp-STIR) project is an international irradiation program for studying PCI/SCC failure behavior of BWR-fuel rods. The project has finished the activities in 1979 as 4 years program. The present materials describes outline of the results from the project.

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An out-of-reactor experiment was made to investigate the effect of distance between pellet ridges on the external-pressure creep of Zircaloy-2 tubes reinforced internally by pellets. The Zircaloy-2 tubes were packed with stainless steel pellets machined out at both ends simulating the hour-glass shape of UO₂ pellets. Distances between pellet ridges were selected to be 12, 22 and 38mm. The specimens thus formed were pressurized externally in an electric furnace, and the diameter changes of tubes were measured intermittently.
In our experimental conditions, the specimen packed with shorter pellets showed larger creep deformation than that packed with longer pellets.
An elastic-creep analysis was performed by using the finite element computer code MARCCDC. It was seen that large bending stresses would be induced in the vicinity of pellet ridges and these bending stresses were attributable to the large creep deformation observed in the specimens packed with the dummy pellets.
An empirical equation for external-pressure creep strain was derived from these data as a function of time, hoop stress, temperature and distance between pellet ridges.

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