Plasma and Fusion Research

Volume 3, S1051 (2008)

Regular Articles

Design and Optimization of Support Posts for Cryogenic Components in FFHR
Hitoshi TAMURA, Akio SAGARA and Shinsaku IMAGAWA
National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Japan
(Received 15 November 2007 / Accepted 23 February 2008 / Published 1 August 2008)

Abstract

FFHR is a concept design of a steady-state fusion reactor that has been studied to demonstrate a large helical device (LHD)-type fusion power plant. The weight and thermal contraction of cryogenic components are sustained by support posts. A folded multi-plate-type post adopted in the LHD could be feasible for the FFHR. The dimensions of the post were determined according to the buckling load estimation against a gravitational load. Using this fundamental design, the flexibility and stress distribution of the post were calculated by a finite element method. The flexibility against the radial displacement was 24 kN/mm, and the maximum stress for a carbon-fiber-reinforced plastic and stainless steel plate was 155 and 544 MPa, respectively, which were below their allowable levels. The heat loads were calculated as 10.5 kW at 80 K and 0.34 kW at 4 K; the results revealed that the heat load at 4 K was almost 1/20 compared with that on a post made entirely of stainless steel. Natural frequencies were analyzed to assess safety against external loads such as an earthquake. The results showed that the LHD-type support post was suitable for the FFHR from the mechanical and thermal viewpoints.

Keywords

FFHR, fusion reactor, superconducting coil, cryogenic component, support post, modal analysis

DOI: 10.1585/pfr.3.S1051

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This paper may be cited as follows:

Hitoshi TAMURA, Akio SAGARA and Shinsaku IMAGAWA, Plasma Fusion Res. 3, S1051 (2008).