FIRST WALL LIFETIME OF THE NEAR TERM FUSION REACTORS
The first wall components of the near term fusion experimental reactors (NET, INTOR, FED) will be subjected to a complex loading situation characterized by multiaxial stresses, variable temperatures, interactions between cyclic effects (fatigue) and inelastic deformation (irradiation and thermal creep) and nucleation of surface cracks as a consequence of plasma disruption. An attempt to model this situation resulted in the development of the computer program SMILE(1), which allows us to evaluate the lifetime of a simplified first wall component as a function of the operating conditions and of the material properties. In this paper are given the results of a parametric study regarding the sensitivity of the different limiting failure mechanisms (thermal creep, swelling, ratchetting, fatigue and creep fatigue interaction, fatigue crack growth) to the variation of the operating condition. Results are represented by graphs in which a pair of independent variables, taken from sputtering rate, wall load, integrated wall load and burn time, covers a certain range on the axis. Each limit curve divides the graph into two fields: the lower of allowable conditions and the upper of structural failure. The figures below show as an example graphs regarding NET, INTOR and DEMO operating conditions. This parametric study indicates that the lifetime of the first wall will be mostly limited by the combined effects of plasma - wall interactions and of the cyclic operation of the machine, not only in the experimental reactors like INTOR and NET in which the integrated wall load is fairly low, but even for a DEMO reactor with an assumed burn time of 1000 s.
Bibliographic Reference: 13TH SYMPOSIUM ON FUSION TECHNOLOGY, VARESE (ITALY), SEPT. 24-28, 1984 WRITE TO CEC LUXEMBOURG, DG XIII/A2, POB 1907, MENTIONING PAPER E 31738 ORA
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Record Number: 1989123019900 / Last updated on: 1987-01-01
Available languages: en